Hello everyone! I have a 1990 K5, picked it up from a buddy of mine. While driving in second gear it will rev out as if its in neutral and not shift. The fluid was low so I topped it off and also adjusted the TV cable, no change. I've read that the C3/4 clutches may be toast. Tomorrow I'm going to change the fluid and filter and see what I find in the pan. Any ideas? Also any recommendations of what rebuild kit or reman trans to look into if the trans is shot? Im very familiar with the Duramax/Allison side of chevy but not so much here. Located in VA Beach if that helps. Thanks

 

I personally don't know much about the 700r4, however I imagine a rebuilt one should be fairly cheap!! I do know around here u can find 4l60e ( the electronic version of the 700r4) for right around 650-750 rebuilt....there is a fellow member here that rebuilds transmissions, perhaps he will respond? It does sound though that the 3-4 clutch pack is toast ....is the fluid burnt? Or dis colored? If it is I would try a filter and fluid change, however I'm sure there is some internal damage.....

 

When my astrovan did that same thing , the band was burnt..might as well change all required parts while your in there. My was the 4l60E and I can't rebuild that myself so big bucks at the shop it was....I had 2 astro's had to do the tranny in both overtime....I made sure my Jimmy was a manual...I can deal with a clutch ..lol.

 

Yes 3&4 clutches are gone. If you have not driven it much and the fluid is clean you can drop the trans and fix it for about $15 plus fluids. That is if you don't drive it much and are willing to roll the dice. I did this in my car when I set the TV wrong first time out after a fresh rebuild.
1. Drain fluid.
2. Drop transmission.
3. Remove torque converter.
4. Remove valvebody.
5. Remove oil pump from front of transmission housing.
6. Remove 2&4 servo piston and 2/4 band retaining pin. (Unfortunately that is the only reason you need to remove the valvebody but I have never tried doing it otherwise)
7. Pull input shaft/drum assembly out. The first set of clutches when you look at the end are the 3&4 clutch pack. Pick up some new ones along with 2&4 servo cover oring and valvebody gaskets. Put it back together and mak sure fluid is full and TV is set correctly.

Otherwise you can look for a used or rebuilt one.

 

Thanks a lot guys. I'm going to check some places out for a rebuild, or locate a 4L60 or 80 for a swap.

 

A 4l60 is a 700r4 but a 4l60e is newer and requires a controller to run with a 90s engine. Same with a 4l80e unless you go with a th400.

 

Yea thanks, I did some searching and found that out. Not going to go electronic, trying to keep this cheap as possible "if that's a thing" I'm only $846 deep and that's including the vehicle price. Any recommendations for a reman trans, or kit with convertor?

 

A mis adjusted TV cable on these transmissions can be fatal to them. It is extremely important to be sure that it is adjusted properly and maintained.
I have had good luck with kits from a place called Oregon Performance Transmission.
i was able to get a complete kit for a TH400 with Koleen Steels, good heavy duty Kevlar Blue clutches and Kevlar bands both reverse and secondary for just under 300.00 bucks. My guy who builds high performance tranny's could not believe what i paid . It had everything he would use in the kit plus the extra heavy duty bands and even wanted to know where i got the kit. It was less than what he could get the parts for.

 

Thanks I'll check them out.