Lifted_Avalanche_51

I agree didn't find out until I removed the transmission myself that it's the same one that i bought to put in it for the original rebuild.

RDF1

What gears?
Thats a pretty wide tire and 35" tall?
If you want to tow with it i would seriously consider cutting your losses and go ahead and do a 4l80 swap. And you mentioned possible future turbo? 4L80E swap for sure.
If you have 3.42 or 3.73 gears, i would look into gears also.

Modern Barbarian

I would tell the shop to stand by their product. A scrapyard 4l60 would have lasted longer than that. Don't let them off the hook and make them fix it until they get it right. It's the only way these shops will ever learn to stop doing crap work.

smokinlmm

I agree. I didn't give my shop much of a choice when my 6l80 did basically the same thing.

adriver

iTrader: (1)

Just because I have to say it every time for some:, I have no experience with your trans. Owning one or repairing any. I can tell you the 4L60 is a known weak point when stock towing or when more than bolt-on modified. Those are some big ol tires for stock gears. With your lift, cam, and headers, plus if you are in an avalanche you are in the heaviest body style out of this different 1/2 ton models (I want to say by a couple hundred more pounds). Then is that right, that you plan on towing with it too?? At the very least I think you should search and read up on the 4L80 swap. What it takes, but also those who have done it in the past, why, and how it worked out for them. You will read how some people have broken several 4L60s before swapping to the 4L80.

Not sure how much of the work you have done to this in the few months of ownership, or if you know the history, but with those mods, I wouldn't be surprised if it's already been replaced, maybe even a couple times or more, and they decided to get rid of it.

If you plan on going for the 4L60 again, I would suggest doing some ridiculous gears, and ask yourself right now how many times you are willing to keep trying to fix a known weak point. A $2200 paperweight IS tough, but having a collection of them will be tougher.

RDF1

I agree. I broke 17 4l60s in 13 months.
then I got a stock junkyard 4l80 with unknown miles. $100 shift kit and put over 300,000 miles on it with a turbo 6.0.
no regrets at all. I towed way more than the truck was rated for and bent the frame from using the airbags while towing 12,000#+.
it sucks to go thru that much money just to add more to the build. But with a good converter you won't regret it.

I suggest the 4l80 to all my customers since this turbo craze. Back in 2004 there wasn't many into the turbo trucks when I did mine so had to just give it a try and figure it out.

did 3 4l80 swaps last week, in a 2wd they are pretty easy to do.

Lifted_Avalanche_51

I replaced the TC and will be trying to make it work for now, I'm researching the 4l80 swap as we speak but need more time. If the trans has to come out again a 4l80 will be taking its place. I appreciate all the advice and POVs thank you all.

RedXray

Did the builder delete the lockups PWM? If so lockup should be a solid on/off. Also check if builder put on the wrong (short) filter with your deep pan starving the internals with fluid pickup. Not seeing much converter clutch in the pan but id replace anyway or do a cut/clean if it's an expensive stall converter.

This vid shows what lockup clutch looks like in the pan.

Lifted_Avalanche_51

I did replace with new TC, builder did no programing. Pulled the cooler from the radiator and put it on its own cooler and Temps are down around 171 168 ish. Trans reels good again but I'm not getting my hopes up.