2008 5.3/4l60e 3-2 downshift flare. Corvette servo? Extended servo pin?

[Dustin Jackson]

2008 5.3 4l60e 3.73 gears 180,000 miles lifted about 3 inches with 32 inch Ko2 tires

Hello gentlemen,

When I purchased the Blackbear tune for my motor and trans I was very unsatisfied with the transmission performance and I went back and forth with Justin and loaded a few different tunes he sent me but ultimately I was never happy with the trans but I didn't want to put it on blackbear, they said the trans is probably worn. The trans is old but still works great so I didn't want to push the issue.

Problems I had with the blackbear trans tune: harsh 1-2 shift until warmed up, very short 2-3 (happened very soon and didn't feel like it is in sync with engine speed), and 3-2 downshift flare (RPMs will raise high and then the gear engages and RPM drop back down as it goes into gear. almost like dumping the clutch, feels very concerning)

I will say that these problems probably existed before the trans tune but were amplified by the tune bringing them to my attention or were masked by factory trans tuning.

To solve the short 2nd gear problem I asked Justin to extend the duration of the 2nd gear but this basically got rid of 4th gear for me, my truck would go from 1st, 2nd, to 3rd to overdrive and only hit 4th gear under certain situations, I only ran it like this shortly before deciding this isn't a good solution and reverted back to stock trans tune in 2022.

This spring 2023 I reinstalled the first trans tune from Blackbear and have found parts of it enjoyable but the passing aspect when going uphill or passing on the freeway when I need that 3-2 downshift really is a problem.

This morning I came across this post that outlines someone else journey in solving this same problem: https://ls1tech.com/forums/automati...2-downshift-flare-any-4l60e-experts-here.html

Here is an album the poster made that includes the original problem, some servo testing and then another video explaining their fix and showing the results: https://photos.google.com/share/AF1...?key=MTh2MjR3bmQzY3o0RHlYRS1YSGUyallEQnAtZVB3

All this being said, it seems that the fix is to extend the length of the servo pin by welding a bead to the tip. This helps tighten the 2-4 band in turn eliminating the 3-2 dpwnshift flare.

Now my question is what do I do? I don't weld, is there a longer aftermarket servo pin I should use? Would a corvette server work? Do I get an extended servo pin AND a corvette servo? Can I run a corvette servo and trans tune at the same time?

- Signed by a man looking to milk every mile out of this transmission while drinking a lot of coffee this morning.

 

[Trey Hardy]

2008 5.3 4l60e 3.73 gears 180,000 miles lifted about 3 inches with 32 inch Ko2 tires

Hello gentlemen,

When I purchased the Blackbear tune for my motor and trans I was very unsatisfied with the transmission performance and I went back and forth with Justin and loaded a few different tunes he sent me but ultimately I was never happy with the trans but I didn't want to put it on blackbear, they said the trans is probably worn. The trans is old but still works great so I didn't want to push the issue.

Problems I had with the blackbear trans tune: harsh 1-2 shift until warmed up, very short 2-3 (happened very soon and didn't feel like it is in sync with engine speed), and 3-2 downshift flare (RPMs will raise high and then the gear engages and RPM drop back down as it goes into gear. almost like dumping the clutch, feels very concerning)

I will say that these problems probably existed before the trans tune but were amplified by the tune bringing them to my attention or were masked by factory trans tuning.

To solve the short 2nd gear problem I asked Justin to extend the duration of the 2nd gear but this basically got rid of 4th gear for me, my truck would go from 1st, 2nd, to 3rd to overdrive and only hit 4th gear under certain situations, I only ran it like this shortly before deciding this isn't a good solution and reverted back to stock trans tune in 2022.

This spring 2023 I reinstalled the first trans tune from Blackbear and have found parts of it enjoyable but the passing aspect when going uphill or passing on the freeway when I need that 3-2 downshift really is a problem.

This morning I came across this post that outlines someone else journey in solving this same problem: https://ls1tech.com/forums/automati...2-downshift-flare-any-4l60e-experts-here.html

Here is an album the poster made that includes the original problem, some servo testing and then another video explaining their fix and showing the results: https://photos.google.com/share/AF1...?key=MTh2MjR3bmQzY3o0RHlYRS1YSGUyallEQnAtZVB3

All this being said, it seems that the fix is to extend the length of the servo pin by welding a bead to the tip. This helps tighten the 2-4 band in turn eliminating the 3-2 dpwnshift flare.

Now my question is what do I do? I don't weld, is there a longer aftermarket servo pin I should use? Would a corvette server work? Do I get an extended servo pin AND a corvette servo? Can I run a corvette servo and trans tune at the same time?

- Signed by a man looking to milk every mile out of this transmission while drinking a lot of coffee this morning.

Try either a corvette servo or the slightly better sonnex servo that may help.
I had to go back and fourth with my tuner when I done the Tahoe it was super sluggish then would shift too hard whenever stabilitrac would go off we tuned that out tweaked it some more and she’s perfect now I ended up not using the vette servo in it and ended up throwing it in my Silverado

 

[Dustin Jackson]

@Trey Hardy Does installing a corvette servo solve the same problem of the servo pin not being long enough?

 

[Dustin Jackson]

Update: I found some more information that would suggest my harsh shift from 1-2 would also be caused by the 2-4 band... It seems that I can kill multiple birds with one stone of solving this servo/short servo pin situation.

"The harsh 1-2 occurs by allowing the 2-4 band apply oil pressure to be re-routed to the 4th gear servo apply piston"

4L60E Harsh 1-2 Shift - Transmission Digest

Let us have a look at the systems and potential problems in a 4L60E that can cause a harsh 1-2 shift.

www.transmissiondigest.com

 

[iamdub]

2008 5.3 4l60e 3.73 gears 180,000 miles lifted about 3 inches with 32 inch Ko2 tires

Hello gentlemen,

When I purchased the Blackbear tune for my motor and trans I was very unsatisfied with the transmission performance and I went back and forth with Justin and loaded a few different tunes he sent me but ultimately I was never happy with the trans but I didn't want to put it on blackbear, they said the trans is probably worn. The trans is old but still works great so I didn't want to push the issue.

Problems I had with the blackbear trans tune: harsh 1-2 shift until warmed up, very short 2-3 (happened very soon and didn't feel like it is in sync with engine speed), and 3-2 downshift flare (RPMs will raise high and then the gear engages and RPM drop back down as it goes into gear. almost like dumping the clutch, feels very concerning)

I will say that these problems probably existed before the trans tune but were amplified by the tune bringing them to my attention or were masked by factory trans tuning.

To solve the short 2nd gear problem I asked Justin to extend the duration of the 2nd gear but this basically got rid of 4th gear for me, my truck would go from 1st, 2nd, to 3rd to overdrive and only hit 4th gear under certain situations, I only ran it like this shortly before deciding this isn't a good solution and reverted back to stock trans tune in 2022.

This spring 2023 I reinstalled the first trans tune from Blackbear and have found parts of it enjoyable but the passing aspect when going uphill or passing on the freeway when I need that 3-2 downshift really is a problem.

This morning I came across this post that outlines someone else journey in solving this same problem: https://ls1tech.com/forums/automati...2-downshift-flare-any-4l60e-experts-here.html

Here is an album the poster made that includes the original problem, some servo testing and then another video explaining their fix and showing the results: https://photos.google.com/share/AF1...?key=MTh2MjR3bmQzY3o0RHlYRS1YSGUyallEQnAtZVB3

All this being said, it seems that the fix is to extend the length of the servo pin by welding a bead to the tip. This helps tighten the 2-4 band in turn eliminating the 3-2 dpwnshift flare.

Now my question is what do I do? I don't weld, is there a longer aftermarket servo pin I should use? Would a corvette server work? Do I get an extended servo pin AND a corvette servo? Can I run a corvette servo and trans tune at the same time?

- Signed by a man looking to milk every mile out of this transmission while drinking a lot of coffee this morning.

If the problem is wear, there's nothing you can do to reverse it. It's worn and, as they do from new, continue to get worse. Just wanted to get that out there first. It's like the mentality of people doing all kinds of tricks cuz they want their abused and clapped-out 300K-mile engine to have all teh oil pressures on the gauge to make them feel like it's not worn.

Anyway, what you CAN do is adjust for the wear to help restore some of the original operation to make the most out of the clutch material, etc. that's left and possibly slow down the wear a little since the loosed tolerances contribute to slip, which contributes to wear. I used a Corvette servo, Sonnax Super 4th servo and a GM "Long Pin". I measured the travel in the apply piston and it was at the maximum (loosest) limit. The pin, installed as it came outta the package, put the travel at the minimum (tightest) spec. My heap has 222K miles and I've owned it since 147K. I have no idea if the trans is original, but I treat it as if it has all 222K miles on it. It seems to be doing fine. I've noticed no adverse characteristics hinting of failure. Since the engine work and tune, I almost always manually downshift with a throttle blip (rev-matching, yo!) to get it in the lower gear but not under hard throttle. It just makes me feel like l'm doing all I can to keep it alive.

IMO, it's worth a shot. Supposedly, there are different length pins. At my mileage, I decided to get the longest and trim it if necessary. I read somewhere that the inside of a common washer has the correct radius for the tip. I don't recall what size washer, but we can research that if necessary. Anyway, you cut the washer in half and shave the tip of the pin down a hair at a time, maintaining its contour by comparing it to the halved washer as a guide.

I thought I took pics and posted them and details in my thread, but I'm not finding them.

The Corvette servo is, IMO, a standard item. The Sonnax Super Hold 4th servo might've been a splurge. But, it a good "while I'm in there" thing.

I believe I got my pin and stuff from Oregon Performance. Here's the pin and Corvette servo as a package and here's the pin by itself. I got my Sonnax Super 4th servo from Amazon (This). Also, this looks interesting. I'd like to summon the expertise of @NickTransmissions.

 

[Trey Hardy]

@Trey Hardy Does installing a corvette servo solve the same problem of the servo pin not being long enough?

I’m not sure it’s supposed to have a stronger hold on the 2-4 band that’s about all I know lol

 

[Fless]

@NickTransmissions might be a good one to weigh in here.

 

[NickTransmissions]

2008 5.3 4l60e 3.73 gears 180,000 miles lifted about 3 inches with 32 inch Ko2 tires

I'm at a family barbeque ATM but will review and provide a more in-depth response sometime tomorrow morning.

Only thing I'll mention now is I generally advise against messing too much with the factory tune on these transmissions. If you want the transmission to shift a certain way, you do it mechanically (spacer plate feed hole sizing, 2-4 servo band clearance, 2nd and 4th gear servo selection, 3-4 clutch clearance adjustment, clutch and band friction material selection (stock, high energy, red/blue plate etc), forward dr clutch piston return spring selection and accumulator mods/adjustments.

@Trey Hardy Does installing a corvette servo solve the same problem of the servo pin not being long enough?

No - a longer servo pin or shim does that.

Will explain more in the AM.

 

[Dustin Jackson]

@iamdub Thank you for the response, I think the information you provided validates that I am heading in the right direction.

Here is the guide that references the 3/8" washer being the right size for grinding the pin tip, for your future reference: https://www.jegs.com/installationinstructions/500/555/555-603300.pdf

I don't race or drive fast in my Tahoe so I don't think the Sonnax Super 4th Hold is my style but I agree that the Corvette server and longer pin kit are calling my name. Most of my driving is daily and low RPM action, merging and passing on the freeway is the most action this thing sees.

How do you recommend a shade tree mechanic measure the servo travel distance? I plan on using a drill and angle grinder to shave the pin if I need to.


Thank you Nick, enjoy the BBQ we can pick up on this tomorrow. For the tune I didn't get anything crazy, just requested recommend quality of life changes from Black Bear, if you think I should tune back to stock let me know.

I think the reason I re-installed the trans tune was because the shifts are super soft and I understand that the soft shifts come at the cost of clutch material and I thought that having the trans shift more firm would extend the life of it.

 

[iamdub]

Here is the guide that references the 3/8" washer being the right size for grinding the pin tip, for your future reference: https://www.jegs.com/installationinstructions/500/555/555-603300.pdf

Funny thing is I originally wrote 3/8" washer but then thought that was way too big so I edited it. Good job finding the specifics.

https://www.jegs.com/installationinstructions/500/555/555-603300.pdf

How do you recommend a shade tree mechanic measure the servo travel distance? I plan on using a drill and angle grinder to shave the pin if I need to.

I put a socket on the center of the cover and stuck a large prybar up in the trans tunnel with the curve of the bar against the socket. This gave me lots of leverage to easily and smoothly depress the cover just until it bottomed out. I used the depth gauge part of my digital caliper to measure how far the cover pressed in. It's just a cheap Harbor Freight caliper but does what I need. >THIS<

 

[dkad260]

Something that happened to my 4L60E in my Envoy around 160K, was a 2-3 flare on acceleration.

One of the check balls was pretty much pounded through the seperator plate and this is one major reason why 4L60's bite the dust. Once that ball can no longer seal, you get a pressure loss then a smoked clutch or band, or both. Ford uses Torlon balls in their panther chassis if iirc and that's one reason they go the distance.

When I had my 2-3 flare at 160K, I changed the seperator plate with an OE plate from the dealer. Make sure you so this as it's spec'd to your VIN.

I also added the vette servo, and while I was in there, replaced a few accumulator pistons and the shift solenoids, also did the TCC PWM eliminator.

Trans still works at 335K miles.

 

[NickTransmissions]

2008 5.3 4l60e 3.73 gears 180,000 miles lifted about 3 inches with 32 inch Ko2 tires

Hello gentlemen,

When I purchased the Blackbear tune for my motor and trans I was very unsatisfied with the transmission performance and I went back and forth with Justin and loaded a few different tunes he sent me but ultimately I was never happy with the trans but I didn't want to put it on blackbear, they said the trans is probably worn. The trans is old but still works great so I didn't want to push the issue.

Problems I had with the blackbear trans tune: harsh 1-2 shift until warmed up, very short 2-3 (happened very soon and didn't feel like it is in sync with engine speed), and 3-2 downshift flare (RPMs will raise high and then the gear engages and RPM drop back down as it goes into gear. almost like dumping the clutch, feels very concerning)

I will say that these problems probably existed before the trans tune but were amplified by the tune bringing them to my attention or were masked by factory trans tuning.

To solve the short 2nd gear problem I asked Justin to extend the duration of the 2nd gear but this basically got rid of 4th gear for me, my truck would go from 1st, 2nd, to 3rd to overdrive and only hit 4th gear under certain situations, I only ran it like this shortly before deciding this isn't a good solution and reverted back to stock trans tune in 2022.

This spring 2023 I reinstalled the first trans tune from Blackbear and have found parts of it enjoyable but the passing aspect when going uphill or passing on the freeway when I need that 3-2 downshift really is a problem.

This morning I came across this post that outlines someone else journey in solving this same problem: https://ls1tech.com/forums/automati...2-downshift-flare-any-4l60e-experts-here.html

Here is an album the poster made that includes the original problem, some servo testing and then another video explaining their fix and showing the results: https://photos.google.com/share/AF1...?key=MTh2MjR3bmQzY3o0RHlYRS1YSGUyallEQnAtZVB3

All this being said, it seems that the fix is to extend the length of the servo pin by welding a bead to the tip. This helps tighten the 2-4 band in turn eliminating the 3-2 dpwnshift flare.

Now my question is what do I do? I don't weld, is there a longer aftermarket servo pin I should use? Would a corvette server work? Do I get an extended servo pin AND a corvette servo? Can I run a corvette servo and trans tune at the same time?

- Signed by a man looking to milk every mile out of this transmission while drinking a lot of coffee this morning.

Dustin,

Drop the pan and check your 2-4 band clearance by moving it back and forwards using a flat blade screwdriver. You should see no more than 1/8" travel. If it's more than that you'll need to remove the servo assembly and look at the end of the apply pin. GM produced four different apply pin lengths to my knowledge.

There should be either no grooves, one groove, two groves or three grooves. The more groves you see, the shorter the pin is.

Based on your band clearance and pin size (assuming you have too much travel, e.g. too much clearance) you can do one of two things:

1. Locate a longer pin and install it in place of your current pin
2. Install a Transgo shift kit that includes a gold-colored shim that will take up the excess travel by physically moving the 2nd gear assembly and pin appx .100 closer to the band anchor location, taking up the excess slack

Shift flares in these transmissions are usually caused by
> excessive band clearance
> worn servo sealing rings
> excessive 3-4 clutch pack clearance (as the 3-4 pack wears, the clearance increases and the timing of apply and release between the band and 3-4 pack becomes out of synch)
> check balls stuck in the separator plate (see @dkad260 's post above)
- The 1-2 check ball wears the plate and get's stuck much more so than the others
- Inbalance between hole sizes for the 2-3 shift feed port and 3-2 exhaust port in the separator plate (seen only after rebuilds and the builder drills one out but not the other)

Servo Info:

The 700R4 and 4L60E servo assembly consists of two different servo pistons: one for second gear and one for fourth gear.

There were three different 2nd gear servos that are commonly found in the 4L60E, they are typically identified by the last three digits of their respective part numbers. I put them in order of their respective apply surface areas (the more apply area, the stronger the hold on the band, all other things equal):
- "554" - installed in lighter duty applications w/v6 engines
- "553" - installed in the majority of v8 applications
- "093" - known as the 'corvette' servo, installed in vettes, f-bodies and some sub-models of Escalade, Yukons and pick ups

This picture shows the 553 servo on the left and the 093 servo on the right - the 093 servo has appx 10-13% more apply surface area and if substituted for the 553 servo will firm up the 1-2 shift slightly. A sonnax super hold 2nd gear servo will firm up shifts more than the GM vette servo. Note the grooves on the end of the pin. Two-groove pins are the most common and likely what you have.

The fourth gear servo piston is inside the cover and the same servo piston was installed in all models. Install a billet forth gear servo piston kit if you need more holding power in overdrive.

My recommendations
Put your truck up on all four jack stands (or at least the rear wheels), put it in neutral and then,

1. Drop the pan and check band clearance - this will also allow you to view the pan and determine if the trans needs to come out for a complete rebuild or if installing a shift kit and tightening up band clearance will suffice
2. If band clearance is too high, install the Transgo SK4L60E shift kit along with new valve body gaskets (use the orange stripe gaskets) - that should fix your clearance problem (and possibly others as well)
> follow the step by step instructions provided in the kit
> If your spacer plate has check ball locations that are excessively worn, install Fitzall's repair sleeve kit (this is a separate kit from the Transgo kit) - otherwise you should not have to replace it
> Install new shift solenoids and a new electronic pressure control solenoid (all of these are on the valve body which you will have on the bench to install the shift kit)
3. Reinstall the servo assembly after you have installed the shift kit parts but BEFORE you reinstall the valve body
> Air check the servo's operation by introducing compressed air into the two feed port locations (see pic below) - fourth gear port is on the pan rail and 2nd gear is between the worm tracks
4. Once you have validated the servo functions and applies the band upon air check, measure clearance again - should be 1/8" or so; spin your drive shaft to confirm it's not binding
5. Reinstall the valve body - tighten all bolts to 104 inch lbs - make sure the long 8mm bolts go back into the exact same holes that they came out of - if not, their added length will interfere with and lock up the sun shell (or not go all the way in depending on where you try to install them)
6. Install a new filter, pan gasket and pan (don't forget your magnet) - Torque all pan bolts to 98" lbs
7. Restore the factory transmission tune and take it for a test drive

If band clearance is acceptable upon initial inspection, follow steps 2-7 anyway as likely your servo sealing rings are worn and fluid is being allow to bypass - other components (acc springs, plate, solenoids, etc are also worn)

I have a few 4L60E videos you can refer to for guidance:
> Valve body reassembly (simply swap the shift kit parts in place of the factory parts, following the instructions in the kit)
> Servo Assembly (skip to 49:00 for the servo)
> Final assembly (skip to 5:00 for the air check procedure)

If i think of anything else, ill edit the post.

 

[Dustin Jackson]

@NickTransmissions Thank you for the response, I have been digesting it this morning and what you described is certainly a larger pill to swallow VS just a servo + pin.

And frankly, the installation of that shift kit looks outside my technical ability: https://res.cloudinary.com/transgo/wbiss/sk/SK4L60E.pdf

After spending last summer deleting AFM in my driveway during 100+ weather I am wanting to limit the time I spend laying under this thing if I can lol

Does the pan need to be dropped to measure the 2-4 band travel? Everyone else I've seen I think they have the pan on to do it.

At this rate I am thinking:

1.) Start with inspecting my current measurements with the harbor freight caliper, doing the corvette server and longer pin depending on the measurements.

2.) Evaluate the transmission behavior after that to see what outstanding complaints I have about it and if needed install the recommended shift kit in fall once the weather cools down.

3.) Continue to educate myself on the ol 4l60e, maybe watch a couple shift kit install videos to familiarize myself with the process and develop a disaster recovery plan for the day I need a new transmission. When my 5.3 had a lifter failure I was completely unprepared, I was fully aware of the AFM system and the common failures but I never thought it would happen to me, I was so caught off guard that I went and bought a 94 k1500 to drive until I could figure out what to do, that added $2,000 to my AFM delete project. DIY AFM delete + 94 k1500 was still cheaper than a new motor! But I would like to have a game plan ready for the transmission.

 

[NickTransmissions]

@NickTransmissions Thank you for the response, I have been digesting it this morning and what you described is certainly a larger pill to swallow VS just a servo + pin.

And frankly, the installation of that shift kit looks outside my technical ability: https://res.cloudinary.com/transgo/wbiss/sk/SK4L60E.pdf

After spending last summer deleting AFM in my driveway during 100+ weather I am wanting to limit the time I spend laying under this thing if I can lol

Does the pan need to be dropped to measure the 2-4 band travel? Everyone else I've seen I think they have the pan on to do it.

At this rate I am thinking:

1.) Start with inspecting my current measurements with the harbor freight caliper, doing the corvette server and longer pin depending on the measurements.

2.) Evaluate the transmission behavior after that to see what outstanding complaints I have about it and if needed install the recommended shift kit in fall once the weather cools down.

3.) Continue to educate myself on the ol 4l60e, maybe watch a couple shift kit install videos to familiarize myself with the process and develop a disaster recovery plan for the day I need a new transmission. When my 5.3 had a lifter failure I was completely unprepared, I was fully aware of the AFM system and the common failures but I never thought it would happen to me, I was so caught off guard that I went and bought a 94 k1500 to drive until I could figure out what to do, that added $2,000 to my AFM delete project. DIY AFM delete + 94 k1500 was still cheaper than a new motor! But I would like to have a game plan ready for the transmission.

Youre welcome.

Pan has to come off to do it right. Servo travel itself is irrlevant unless you can see how much movement you have in the band.

Plus you need to see what's in the pan so that you can properly prepare for what to do next based on what you find. If the fluid is black and you have excessive clutch material showing, id put the pan back on and yank it out for a rebuild.

You can leave the valve body alone if you're not comfortable with pulling it down as its not the source of your problems from what i can tell atm.

Check band clearance to see what you need to do. If too high, install a longer pin and re-check. Once done, restore the factory tune and take it for a spin.

You're right on the edge of being undergeared relative to your tire size so your shifts wont be as crisp compared to if your axle ratio was numerically higher. I wouldnt say it's a problem that needs correction just to something to be aware of (4:11 ratio would be in the sweet spot for 32s).

 

[Dustin Jackson]

Put the factory trans tune back in and man this thing operates so smoothly, can hardly feel any shifts.

Any thoughts to why it operates well under factory tune but under modified tune it runs poorly?

 

[Marky Dissod]

Put the factory trans tune back in and man this thing operates so smoothly, can hardly feel any shifts.
Any thoughts to why it operates well under factory tune, but under modified tune it runs poorly?

The modified tune apparently was not properly programmed for that particular transmission.

Many details need adjusting for a proper tune.
Sometimes all it takes is one detail overlooked for a tune to 'run poorly'.

 

[NickTransmissions]

The modified tune apparently was not properly programmed for that particular transmission.

Many details need adjusting for a proper tune.
Sometimes all it takes is one detail overlooked for a tune to 'run poorly'.

That's exactly why i tell anyone who'd listen not to tune them at all as 99.99% of the time it's completely unnecessary. Anything you want to accomplish shfit quality-wise can be done internally via mechanical calibration.

Put the factory trans tune back in and man this thing operates so smoothly, can hardly feel any shifts.

Any thoughts to why it operates well under factory tune but under modified tune it runs poorly?

Glad its working normally again for you. You also now know what to do to make it shift more to your liking without having to mess with the factory trans programming.

 

[Dustin Jackson]

@NickTransmissions I trust you man, I am going to run with the servo and longer pin and leave the tune stock.

 

[Marky Dissod]

That's exactly why i tell anyone who'd listen not to tune them at all as 99.99% of the time it's completely unnecessary.
Anything you want to accomplish shift quality-wise can be done internally via mechanical calibration.

I do NOT disagree with this statement in the least.
Although I have some experience tuning the 4L60Es behind LT1s for improved durability and longevity, I prefer carefully chosen hardware upgrades over software upgrades.

Tuners have to know what kind of hardware they are working with.
They have to ALSO know how to tune for that hardware - even if that hardware is just conscientious mix'n'matching of OE.

 

[Dustin Jackson]

Update: I installed the corvette servo and longer servo pin from Oregon performance while I had Covid a few weeks ago.

Thoughts so far:
- Shifting is slightly more firm and quicker.
- Shifting into reverse and drive doesn’t bang as much as it used to.
- 2nd gear seems to last longer, before I had a very short 2nd gear unless I really buried my foot into the gas.
- Downshifting doesn’t flare anymore - when accelerating to pass my RPMs would flare up before it shifted from 4-3 or 4-2. Really happy about this.

Not going to lie it wasn’t a night and day change in all aspects of driving but transmission seems to perform a lil bit better in certain situations and I am happy with it, cheap little mod.