I was running a little late one morning last week, I cranked the motor and as I got oil pressure on the gauge I put the shifter in reverse and pressed on the throttle more aggressively than normal. the rear wheels spun slightly and acceleration was good until a loud POP and then no more acceleration. No more reverse or forward gears. Even when I put the shifter in Park the tranny sounds like a ratchet at high speed thats slowing down. This is a 4L60E auto 4WD 95 Suburban with 155K miles. I've learned my lesson about hard accel on a cold motor or trans, much less in reverse. Does anyone have an idea on what I might have broken? And if a complete rebuild is the only way to fix it? Any sources on a good cheap 4L60E or 4L80E or rebuilder in North Texas?

thanks in advance for any help,

Tedd

 

It sounds like a broken hard part. Unfortunately, it really does not matter too much what exactly it is. It has to be torn down and inspected. These transmissions are common and most builders have a pile of spare hard parts under the bench. Sorry for the bad news and I wish you the best on the overhaul.

 

Put it in 4wd. If it moves than its not the tranny, but yet your rear differental. If it still doesnt move then yeah a hard part has broken, maybe the input or output shaft.

 

That's a good idea, trying 4 wheel drive, I'll try it and see what happens. But the weird noise in Park leads me to believe it's the tranny

What is the difference in a two wheel drive 4L60E and a 4 wheel drive 4L60E. The transfer case just bolts on to where the tail shaft housing is bolted? Correct? it seems used 4 wheel drive trans are a bit harder to find! What would I have to change if I used a 4L80E from a 1 ton two wheel drive truck?

Tedd

 

The output shafts on the 4wd transmissions are shorter, in addition to not having housings.

 

Can I buy good or rebuilt a 2WD trans, maybe a 4L80E, and use the output shaft from the 4WD 4L60E trans in the truck now? Assuming the output shaft is not the broken part?

Tedd

 

4L80 trannys are a whole new game. You would have to have a new driveshaift, computer proabaly wouldnt control it right, New transfer case. Just stick with a 4l60 from a 4wd.

 

A two wheel drive 4L60E with a swapped tail and output shaft from a 4WD isn't an option? used 4WD 4L60E's are to plentiful around here it seems.

Tedd

 

you would still have to tear down the 2wd tranny to use your output shaft.


on the 4x4 units, they still have a tail housing, it is just different from the 2wd type. the transfer case doesn't bolt straight to the tranny.

 

you may also check the slip yoke because i have had the splines come out of the driveshaft

 

reaction sun shell?

 

Maybe the shifter linkage broke? Have you got under the truck to check it out? I had a similar issue with the weird clunking sounds in park but that was with a TH350 tranny (parking pawl)

 

If the sun shell broke you should still have 1st and 3rd gears. So what was the outcome from this ????

 

Chevymec was the one who said try 4 wheel low, so I did, Hey-it worked!! So I tried 4 wheel high, Hey-it worked again? Two fer two so far. So why not try 2 wheel high I thought to my self? So I did. And miracle of miracles. it works fine now, all gears and reverse?? I had already priced a complete rebuild, right around $2,500.00. I was pretty set on pulling the tranny when I got a call from my Dad telling me he was at a Hundai(sp?) dealership and they offered him $4,500.00 for his '98 Tahoe 2 wd. Only $2K more than a tranny, for a whole vehicle. So I bought his Tahoe, this was before I tried 4 wheel low on the Suburban, now the '95 4wd Suburban is still a tuning project but not my daily driver. I did notice last week the ABS dash light was on in the '95?. So all is good, I'm very curious if the transmission gremlins took pity on me and fixed the problem as I slept or what the rational explanation is!!

What do you think happened to the '95's tranny in the first place? With Chevymec's suggestion it makes me think this may not be uncommon. Anyone in North Texas looking for a stump pulling suburban?

Thanks for all the posts

 

Could be shift forks in transfer case not holding in 2wd. Mike