May have blown transmission or TC today- suggestions on rebuilds

[bigfootchiro]

So, like the title says, I have have blown the trans. Reason why I don't think I did is the trans still shifts firmly; however, on downshifts it's stuttering, plus is worse with TC lockup. Most problems are happening once TC locks up, plus it's not locking up on a consistent basis. Any advice on what to look for? Also, don't want to spend an arm and a leg on this. I've had to spend enough on vehicle repairs lately. Will possibly do the rebuild myself and/or with a friend. I was looking at PATC, Oregon Performance, and Monster for rebuild kits (but hearing iffy results about Monster). Any input is greatly appreciated!

 

[TigerEyz3]

Personally, would suggest going to a local, reputable transmission shop and have them examine it and/or work on it. Could be the TC, could be other things... a reputable shop will be able to accurately assess the situation.

 

[bigfootchiro]

TC is definitely shot (we think the original major engine misfire may have caused this), but won't know if the clutch packs are contaminated until it's pulled. At this point in time, I'm probably going to have the whole thing rebuilt or do 4L80E swap. Which would be better/easier/less money?

 

[Martinjmpr]

TC is definitely shot (we think the original major engine misfire may have caused this), but won't know if the clutch packs are contaminated until it's pulled. At this point in time, I'm probably going to have the whole thing rebuilt or do 4L80E swap. Which would be better/easier/less money?

From what I've read the 4L80 swap is pretty major surgery. The 4l80 is longer than the 4l60 so you may end up having to fabricate transmission mounts, adjust driveshaft lengths, move transfer case if you have a 4x4, etc. It's do-able, but not cheap and not easy.

FWIW my trans went out last year (lost gears 3 and 4 while coming home from a camping trip, was able to limp home in 2nd) and the rebuild was about $2000 OTD with a 12 month/12k mile warranty from a pretty reputable shop here in Denver.

I can't remember if that included a new TC or not, though.

EDIT: Just noticed yours is a 1999 so what I said may or may not apply. I know it applies to the GMT800 trucks but I don't know if it applies to the GMT400's.

 

[bigfootchiro]

From what I've read the 4L80 swap is pretty major surgery. The 4l80 is longer than the 4l60 so you may end up having to fabricate transmission mounts, adjust driveshaft lengths, move transfer case if you have a 4x4, etc. It's do-able, but not cheap and not easy.

FWIW my trans went out last year (lost gears 3 and 4 while coming home from a camping trip, was able to limp home in 2nd) and the rebuild was about $2000 OTD with a 12 month/12k mile warranty from a pretty reputable shop here in Denver.

I can't remember if that included a new TC or not, though.

EDIT: Just noticed yours is a 1999 so what I said may or may not apply. I know it applies to the GMT800 trucks but I don't know if it applies to the GMT400's.

I appreciate the input! I think you're right about the length and having to shorten the driveshaft.

 

[TigerEyz3]

All things being equal, having the 4L60E rebuilt (with beefier internals) is going to be much cheaper than converting to a 4L80E. The 4L80E is a heavier duty transmission than the 4L60E. However, the conversion requires a tailshaft speed sensor, plus new: output yoke (different spline setup), drive shaft, computer reprogramming, harness repinning, and ideally you'd replace the 10b axle with a 14b (next weak link in the drivetrain)

I've had my factory transmission rebuilt a few times since I've owned it. The last rebuild was done by a great local shop (I would NEVER recommend the shop that did the first two rebuilds... ). Regardless of who does your trans rebuild, I'd suggest going with beefier internals. There's a lot of room for improvement in the 4L60E when it comes to being in our trucks to say the least -they were designed for cars, not heavy trucks.

To your point about going through the entire trans, I'd highly recommend it if ANY component has failed (clutches, planetaries, TC, etc.). As Martinjmpr stated, you're looking at the $2k+/- ballpark. The transmission internals aren't significantly different between the GMT400 (4L60E has 4 planetaries) and GMT800 (4L65E has 5 planetaries).

As an aside, It's a good idea to get to know your transmission folks. Even if you do the work yourself, they can be a valuable resource.

 

[willxfs]

The 4L80E swap will likely be more expensive. Its about 1.5 inches longer so the rear drive shaft has to be shortened and the front has to be made longer (new probably). The tranny cross member can slide back easily so thats no big deal. 4L80e output shaft to the transfer case is bigger so the input coupler on the transfer case has to be swapped out. There's an extra speed sensor on the 4l80 that has to be wired in to one of the four connectors for the computer under the hood. Also, a couple of the wires on the transmission connector have to be repinned. Or you can buy an adapter. Also your computer will need to be reflashed.

There's a guy on you tube, user name is transmission bench, that has excellent videos on rebuilds. He also sells rebuild kits. I'm certainly no transmission expert but this guy seems to know what he is talking about. Worth a look, in my opinion. Good luck. About 5 years ago, I bought a level 2 from PATC and its been a good transmission. Not cheap though... Wish I would have attempted the rebuild myself.

 

[willxfs]

Sorry for the duplicate info. TigerEyz3 has the 4l80e conversion covered pretty good.

 

[bigfootchiro]

The 4L80E swap will likely be more expensive. Its about 1.5 inches longer so the rear drive shaft has to be shortened and the front has to be made longer (new probably). The tranny cross member can slide back easily so thats no big deal. 4L80e output shaft to the transfer case is bigger so the input coupler on the transfer case has to be swapped out. There's an extra speed sensor on the 4l80 that has to be wired in to one of the four connectors for the computer under the hood. Also, a couple of the wires on the transmission connector have to be repinned. Or you can buy an adapter. Also your computer will need to be reflashed.

There's a guy on you tube, user name is transmission bench, that has excellent videos on rebuilds. He also sells rebuild kits. I'm certainly no transmission expert but this guy seems to know what he is talking about. Worth a look, in my opinion. Good luck. About 5 years ago, I bought a level 2 from PATC and its been a good transmission. Not cheap though... Wish I would have attempted the rebuild myself.

I will definitely check into his page. I've been looking at getting the PATC level 3 master rebuild kit. Problem is, I have no idea if I need the SUPER master rebuild, or just the master rebuild. Both come with clutches and whatnot.

 

[bigfootchiro]

Are the S10 4L60E the same as all the others, with the exception of the higher stall? Also, I'm constantly seeing "93-97" 4L60E, but I think that is designating the change of the Camaro prior to the LS1. Would the 99 Tahoe fall into that category or 93-97?