1995 GMC transmission went south yesterday

[Jeepwm69]

Was driving home from the city yesterday with a new water heater, and noticed the truck started revving a little and didn't seem to pull as well. Progressively got worse and worse, and I knew the transmission was going out. Checked fluid and it was full but burned smelling and dark. Ended up having to get towed in the last 20 miles to the house.

So, I know the 95 is kind of a transition year between the 700R4 and the 460 transmissions, so will have this one rebuilt. One place has quoted me $1250, and waiting to hear back from the other. Not a lot of reputable places in the boonies where I live, but the places I've asked have been recommended by shop owners/racers.

Truck only shows 70K on the odo, hardly any towing since my grandfather bought it 20 years ago with 35K on the odo. Added a transmission cooler several years ago, but fluid hadn't been changed unless it was done prior to the truck coming into the family. I had a load of Mobil 1 ATF with plans to change it when the weather got nice this spring, but guess I waited too long.

If I have this bench built what is involved with getting it back in the truck? I'm a manual transmission guy so not much to screw up there other than getting the clutch play right. I assume I'd have to adjust the shift cable possibly, or will this thing bolt right back in?

[Accelo]

1993 and up are 4L60E's
Likely 3rd gear went out. This is the weakest point in this transmission.
$1250 would be a bargain where I live.

It takes a lot of special tooling to replace the bushings, specialized snap-ring pliers, etc.
I recommend getting it done as it will be weeks faster.
If you purchase a used one be careful as the many differences between years need to be considered.

[Myself]

Actually.....MOST of that trans can be rebuilt with only one special tool which you can build with threaded rod and c channel. I've built SEVERAL 700r4/4l60 trans. USUALLY when you lose drive but still have first, second, and reverse....the 3-4 clutch pack burned up. It's very common on those. https://transpartswarehouse.com/0577...xoC9PYQAvD_BwE
The special tool you need looks like this......https://www.amazon.com/Bonbo-T-0150-...CTCKPKTCA&th=1 I made mine with threaded rod so I could put the threads THROUGH the assembly and tighten a piece of flat steel on the back side to compress the springs. I can use mine for ALL the sprung assemblies that way. It's not that difficult to replace the 3-4 clutches. You have to drop the pan. Pull the 2-4 band servo/piston. Pull the front pump. Use a magnet to pull out the 2-4 band retaining pin. Pull out the band. Then grab the whole forward assembly and pull it out of the trans.
https://www.youtube.com/watch?v=gSXE-GvWXhA


All that being said.....$1250 is a BARGAIN if it's getting built right.

[D.B]

Have your converter gone through. It will need flushed out or better yet opened up and cleaned. What trash and debris that was in your transmission is now in your converter. Also, thoroughly clean your transmission lines and transmission coolers. Auto Parts stores sell aerosol cleaners just for this purpose that can be attached to the lines and fittings. I would use several cans, you can never be too clean.

[Jeepwm69]

Originally Posted by D.B

Have your converter gone through. It will need flushed out or better yet opened up and cleaned. What trash and debris that was in your transmission is now in your converter. Also, thoroughly clean your transmission lines and transmission coolers. Auto Parts stores sell aerosol cleaners just for this purpose that can be attached to the lines and fittings. I would use several cans, you can never be too clean.

Yep, I rebuild a lot of ATV engines. I learned early one that even if the bottom end is good, if you don't tear it all the way down and clean EVERYTHING out, the grit/dirt from the bottom end will ruin a new top end in short order. Gotta flush out the oil coolers too!

The $1250 price is about a 90 min drive from me. That shop/salvage yard was recommended to me by some drag racers who work at a local oil change shop.

I found another shop that is 20 miles from me, and called it. The guy is 82, and has run the shop since the early 70's. He said that transmission came out in the early 90's when I mentioned it as being 95 only. Said they were from 93-95 IIRC. Very sharp mentally, and the interesting thing is, his name is Jack, and his shop was "Jack's muffler and transmissions". When I was a kid we'd pass his shop and I'd tell my grandfather (also named Jack) "Hey, look! It's your shop!" My grandfather owned a Pontiac, Buick, GMC dealership from the late 40's to the late 80's, and would say "I know that guy, and he does great work" Never in a million years did I think the same guy would still be running that shop.

Jack quoted me $1950 plus tax, but said it would be 3-4 weeks, because he fell and broke a bone in his leg, and has minor surgery on it before he can go back to work. He has a "young big ol fella" to pull the transmissions and put them back in, but he does the actual work.

Dad (who is 86) says "Someone that old might miss something" and I said "but he's done so many he can probably do them in his sleep now".

So for now, I'm leaning towards taking it to Jack. My grandfather was pilot, and always had a very high standard when it came to mechanical work of any kind. I think if he was impressed with this guy that I'd be hard pressed to find a better place to have it done.