Chevrolet Suburban 3500 Questions

[Bigburb3500]

Yes, but only from tuners who don’t know the 6L80/90 as well as Justin does at blackbear. I’m at 251,000 right now on what I believe is the original 6L80 in my 2007. I’m not 100% sure, but I have no record of it being rebuilt in the Carfax, or in any of the other records that came with the car.

I figured as much. There was the same stigma with VW/Audi techs that tuned = no good but a quality tuner did a lot for the cars. I was just surprised to hear such a negative reaction when I said I had it tuned for longevity.

Plus, hearing that he built his business on the 6Ls I just surprised.

 

[Geotrash]

I figured as much. There was the same stigma with VW/Audi techs that tuned = no good but a quality tuner did a lot for the cars. I was just surprised to hear such a negative reaction when I said I had it tuned for longevity.

Plus, hearing that he built his business on the 6Ls I just surprised.

Yeah, that would've given me pause, too.

 

[Marky Dissod]

I was just surprised to hear such a negative reaction when I said 'I had it tuned for longevity'.

Yeah, that would've given me pause, too.

Would have given me ZERO pause. Clearly that mech has zero experience with properly written quality tunes that improve om what GM wrote.
That mech's reaction says more about him, than about anything else.

 

[Geotrash]

Would have given me ZERO pause. Clearly that mech has zero experience with properly written quality tunes that improve om what GM wrote.
That mech's reaction says more about him, than about anything else.

Gotcha. Then I would tend to agree. My sense is that most tuners tune for performance with a limited understanding of either the weaknesses of a given platform, or the implications of their tuning choices on durability/longevity. Justin has built his business on doing both by finding that sweet spot.

 

[Bigburb3500]

Would have given me ZERO pause. Clearly that mech has zero experience with properly written quality tunes that improve om what GM wrote.
That mech's reaction says more about him, than about anything else.

I will probably be going to him for review as he’s the only shop I have talked to that wanted to drive the truck first. All other shops want $$ upfront and this guy just seemed hesitant around “tuned” vehicles.
I really appreciate the feedback as I will likely go a different direction if he refuses to work on it because it’s tuned. Too much info out there about why GM trans NEED to be tuned.

Thanks gentlemen!

 

[Marky Dissod]

My sense is that most tuners tune for performance with a limited understanding of either the weaknesses of a given platform,
or the implications of their tuning choices on durability/longevity.

This is a somewhat excessive distillation of the truth that, once expanded upon, contains multitudes ... Well said.

I'll ad to this by saying that a thoroughly properly written pcm or ecm-&-tcm tune - even a 'blind' mail-order tune, believe it or not -
is always written in such a way as to improve on GM OE in as many ways as reasonably possible,
with at worst NO detriment to, at best improvements upon, longevity and durability.
If my mid 90s LT1 tunes were not good enough to supplant the GM OE tunes, I'd not have any right to call myself a mid 90s LT1 tuner.

... this guy just seemed hesitant around “tuned” vehicles.
I really appreciate the feedback as I will likely go a different direction if he refuses to work on it because it’s tuned.

Hey, I MAY be willing to concede (for this argument), that incomplete and/or bad tuners far outnumber thorough and good ones.
Based off of that concession, may I offer this advice: most mechs should never be told that a vehicle has been tuned,
because they will blame the tune (inferring with all their bad tuned experiences and lack of good tuned experience),
and maybe even use that as excuse to avoid doing their job as a mechanic in some cases.

 

[Bigburb3500]

This is a somewhat excessive distillation of the truth that, once expanded upon, contains multitudes ... Well said.

I'll ad to this by saying that a thoroughly properly written pcm or ecm-&-tcm tune - even a 'blind' mail-order tune, believe it or not -
is always written in such a way as to improve on GM OE in as many ways as reasonably possible,
with at worst NO detriment to, at best improvements upon, longevity and durability.
If my mid 90s LT1 tunes were not good enough to supplant the GM OE tunes, I'd not have any right to call myself a mid 90s LT1 tuner.

Hey, I MAY be willing to concede (for this argument), that incomplete and/or bad tuners far outnumber thorough and good ones.
Based off of that concession, may I offer this advice: most mechs should never be told that a vehicle has been tuned,
because they will blame the tune (inferring with all their bad tuned experiences and lack of good tuned experience),
and maybe even use that as excuse to avoid doing their job as a mechanic in some cases.

Couldn’t agree more. I think they have too much experience with bad tunes and VERY hard driven vehicles.

On thing about this forum I believe to be true: Active members here do not thrash/abuse/destroy their vehicles. They are here to maintenance and repair and are fairly reasonable ppl.

 

[Marky Dissod]

One thing about this forum I believe to be true: Active members here do not thrash/abuse/destroy their vehicles.

Unfortunately most of them share similar aversion to tuning as mechanics do.
As said before, a proper thorough tune has very few if any drawbacks and improves the vehicle's longevity / durability.

 

[Geotrash]

Been a while since this thread has been updated. How is yours doing for you, @Bigburb3500? Did you get your transmission sorted?

I think I finally have the ride on mine dialed in when towing. The Bilstein 4600's made a HUGE difference, and after playing with tire pressures and weight distribution bars on the Equalizer hitch, I think I found the Goldilocks combo. It's so good now that my wife thinks it's as smooth as our Denalis with the rear air ride suspension are when towing. I wouldn't go that far, but it's night and day difference from where it started. I no longer worry about losing teeth driving over bridge transitions.

Here's the formula for our unique setup:

1/ Bilstein 4600s front and rear.
2/ Front tires on the Suburban set to 50 psi, rears set to 60. I'll take the fronts to 45 next and see if that helps even more.
3/ Tires on the Airstream set to 60 psi. They're load range E Michelin Agilis LT tires with a max psi of 90, but most Airstreamers run them between 55 & 60. The load carrying capacity only drops by a few percent at 60, and there is plenty of margin on them to begin with.
4/ Weight distribution bars on the hitch set very light, transferring only 150-200 lbs to the front axle. This allows for lots of flex between the Airstream and the Suburban, and will also reduce the risk of a common Airstream malady known as front end separation (FES).
5/ About 300 lbs of gear in the back of the Suburban.
6/ 90 lb dog in the 3rd row

 

[TripleFJeff]

In October a 3500 LT popped up, but sold almost instantly. I've been waiting to see if the owner of it would show up here...

 

[Bigburb3500]

Been a while since this thread has been updated. How is yours doing for you, @Bigburb3500? Did you get your transmission sorted?

I think I finally have the ride on mine dialed in when towing. The Bilstein 4600's made a HUGE difference, and after playing with tire pressures and weight distribution bars on the Equalizer hitch, I think I found the Goldilocks combo. It's so good now that my wife thinks it's as smooth as our Denalis with the rear air ride suspension are when towing. I wouldn't go that far, but it's night and day difference from where it started. I no longer worry about losing teeth driving over bridge transitions.

Here's the formula for our unique setup:

1/ Bilstein 4600s front and rear.
2/ Front tires on the Suburban set to 50 psi, rears set to 60. I'll take the fronts to 45 next and see if that helps even more.
3/ Tires on the Airstream set to 60 psi. They're load range E Michelin Agilis LT tires with a max psi of 90, but most Airstreamers run them between 55 & 60. The load carrying capacity only drops by a few percent at 60, and there is plenty of margin on them to begin with.
4/ Weight distribution bars on the hitch set very light, transferring only 150-200 lbs to the front axle. This allows for lots of flex between the Airstream and the Suburban, and will also reduce the risk of a common Airstream malady known as front end separation (FES).
5/ About 300 lbs of gear in the back of the Suburban.
6/ 90 lb dog in the 3rd row

View attachment 473215

I have been active on my Cadillac interior thread recently! I have the Platty front seats and working on the pin-out of the seats to get them to work. I’m not super happy with the seats in the Sub and just like the Cadillac seats more. Getting massage would be the bees-knees too!
The truck is doing well and I’m just about at 85k miles.
Some things I have learned: Transmission issue I mentioned a bit ago was self inflicted. When I did the trans fluid change I did not fill it up enough. I topped it off and the trans now runs around 120°-140° in the highway in ambient 30-50° weather outside!
My auto-wiper issue I mentioned about a year ago was fixed with rainex and a new set of wiper blades. I guess the passenger blade was streaking specifically on the sensor causing my weird experience. They were brand new wipers so that’s why I didn’t think they were the culprit.

We are regularly loaded pretty heavy for a “regular” vehicle. We went to the beach and had the full back of the truck loaded, 3 adults, one child, 150lb dog and a trailer hitch platform with 4 large crates packed with stuff. The amount of weight in the truck was great! Rode so smooth lol.

I also did the lower airdam trim to make it look like a PPV and did some repair on it. My ends had cracked and were not holding so I had to fix the tabs so the screws would hold it on. Turns out a solder iron melts this plastic PERFECTLY.

I’m rocking the Rancho 9000 adjustable shocks and they are fine. For the price you can’t beat them. I haven’t touched them since I set them last year.

Finally, these trucks are just great. I don’t regret the purchase at all and the BlackBear tune makes it so much more lively and better to drive. Thanks for touching base and your towing setup! Mine skews towards the daily driver and it’s just so much better than the light-duty versions.

 

[Bigburb3500]

In October a 3500 LT popped up, but sold almost instantly. I've been waiting to see if the owner of it would show up here...

Kinda crazy that we are a majority of the privately owned 3500 Suburbans and are active online!

 

[Walkerfever]

Glad you got the transmission sorted out. I can say without a doubt that a tune is fantastic for these things. I've spent the last few seeks reading up on what all the tables do, when they do it, how they do it, etc. I think I finally have mine where I want it. Do you know what all was done? IE when he disabled lock up, shift points, pressures, etc.? I'm curious.

 

[Bigburb3500]

Glad you got the transmission sorted out. I can say without a doubt that a tune is fantastic for these things. I've spent the last few seeks reading up on what all the tables do, when they do it, how they do it, etc. I think I finally have mine where I want it. Do you know what all was done? IE when he disabled lock up, shift points, pressures, etc.? I'm curious.

I’m sorry, I do not. I asked for a generic tune for longevity. He gave me way more than that lol.

 

[Geotrash]

In October a 3500 LT popped up, but sold almost instantly. I've been waiting to see if the owner of it would show up here...

Yeah, the word is out there on them now so there are multiple buyers for a meager supply.

I'm waiting for the Duramax Specialties guys to figure out there's a market for gassers, too. Not everyone wants a Duramax in an HD rig. It would be a challenging conversion given the switch to IRS on the '21+ Suburbans, but GM themselves has an HD version out there in government service with a solid rear axle. I can see a conversion with the L8T doing very well for a shop like that. None of the big 3 automakers will make an HD SUV for the consumer market because the regs have made it unattractive for them. But a small shop operating under different rules could make a killing.

 

[Bigburb3500]

Yeah, the word is out there on them now so there are multiple buyers for a meager supply.

I'm waiting for the Duramax Specialties guys to figure out there's a market for gassers, too. Not everyone wants a Duramax in an HD rig. It would be a challenging conversion given the switch to IRS on the '21+ Suburbans, but GM themselves has an HD version out there in government service with a solid rear axle. I can see a conversion with the L8T doing very well for a shop like that. None of the big 3 automakers will make an HD SUV for the consumer market because the regs have made it unattractive for them. But a small shop operating under different rules could make a killing.

The T1 gen HD Subs will be a VERY interesting vehicle in the future because I think they only come armored. They are not like the K2 HDs that are designed for retrofit. They come spec-ed for military/police use.

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Not saying it won’t happen but I don’t think they will be the tow rigs ours have the ability to be.

 

[Geotrash]

The T1 gen HD Subs will be a VERY interesting vehicle in the future because I think they only come armored. They are not like the K2 HDs that are designed for retrofit. They come spec-ed for military/police use.

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Not saying it won’t happen but I don’t think they will be the tow rigs ours have the ability to be.

Understood and I agree, but it comes down to whether or not the stock 1500 T1 body can be made to work safely on a modified version of the older 3500/2500 frames. The wheelbase is longer so some frame mods will be needed, but for a shop like Duramax Specialties, frame mods are a likely a walk in the park once the engineering is done. And they have the electronics/coding know-how to integrate those components together as well. They're selling well-integrated frame+diesel-swapped K2 Suburbans for $120K sitting on new 2500/3500 frames from GM, so there is a market there willing to pay the big bucks to a shop that can/will do it in ways that eliminate compromises.

 

[Bigburb3500]

Understood and I agree, but it comes down to whether or not the stock 1500 T1 body can be made to work safely on a modified version of the older 3500/2500 frames. The wheelbase is longer so some frame mods will be needed, but for a shop like Duramax Specialties, frame mods are a likely a walk in the park once the engineering is done. And they have the electronics/coding know-how to integrate those components together as well. They're selling well-integrated frame+diesel-swapped K2 Suburbans for $120K sitting on new 2500/3500 frames from GM, so there is a market there willing to pay the big bucks to a shop that can/will do it in ways that eliminate compromises.

Let me go grab that extra $120k in my checking account and buy one hahaha

 

[Bigburb3500]

@Geotrash - I had my truck dump all its power steering fluid at a gas station today. No warning or change in driving which is odd but I’m thinking a bushing went bad (see second picture) you can see the gear inside.

Just wondering if you can take a picture of the bottom of the power steering pump to make sure I’m not crazy.

 

[fasteddy]

I was just reading this thread and was wondering what the enchantment is (besides novelty) with a 3500 sub. I've been towing for a long time, primarily enclosed trailers loaded with a race car, spares and tools, sometimes tipping 7000-8000lbs. While the diesel trucks are the best with 3/4 ton suspension and 900lbs of TQ, I found my Escalade ESV with an LT6.2 engine can handle the job fine....less a few MPGs. I think tow rating for the ESV is rated the same (8300lbs) as the 3500 Sub but the LT6.2 engines have a boatload more TQ than the 6.0L....460lbs vs. 380lbs.....its a big difference. And its TQ that pulls weight. I got rid of my diesel trucks, because the cost to maintain is so much more than the gassers. So I like 6.2s, DOD deleted! Have 2 LOL. And ESV's are so cheap, sub $20K tow vehicle....and comfortable with a rockin sound system. That being said, if GM made a 2500 Sub with a 6.6 L8T, I'd buy one Today! LOL