Jinxie

Just got this car going again since sitting for a couple of years.
Its an 85 with an auto.
I just put on 60 flawless miles when I pulled away from a light and it would not upshift into drive. Gear selector was in OD. When I dropped it into D, it also seemed to freewheel like I was in neutral. 1 and 2 and reverse work fine. I can start off from a stand still in D or OD and it gets the car up and going fine, but it just maxes out around 3500+ and wont upshift.
Is my trans shot, or could it be a band adjustment?
Thanks

Pete K

It's shot. Classic 3-4 clutchpack failure, more than likely.

856SPEED

silly question perhaps but what is the fluid level like? if OK, does the fluid look old (brown in color)?

Jinxie

Actually, fluid looks good and red still. Doesnt smell burnt. But it just happened 1 mile from home. I guess I could drop the pan and filter and see whats in there.
Now, Id like to tackle a transmission overhaul myself. I know its a specialty, but given time, Ill figure it out!
In the meantime, I dont want to be down for summer. Is ther another vehicle that I can get a "good" used from from and bolt in for the time being? Is this Corvette specific? Are there different tailshaft lengths? Speedo drives? Lockup connectors? Shifter locations??
My vette is an 85

Thanks for the help!!

856SPEED

not sure if the 700R changed during the course of the C4 run......I know there are other changes that happened along the way from 85-until the L460 went in......not sure there.....auto trannys are above me on the technical aspect of things.....I'd be taking my 85 to a trusted mechanic who is very familiar w/Corvettes and 700R4 auto transmissions....could be something minor.....

Wadew

Jinxie,
I have rebuilt many 700R4 transmissions. They are not an easy tranny to overhaul and there are a couple specialty tools that are necessary. I am not sure but I think just about any 700R4 from a 2 whl drive car should fit but there might be some shifting issues with some models.

Cruisinfanatic

I agree. There are relays and things that make it shift at certain RPM's. Get it checked out.

rodj

Pete K will confirm but any V8 T700 will work.Obviously it's shift calibrations will be different but for getting you back on the road....
Be aware if you get a late model T700 ('88+? ) you will also need the convertor because spline count changed from 27 to 30 splines on the input shaft
Vette tailshaft housing to direct swap BUT you may have to cut the output shaft to get the driveshaft yoke to fit because Vette housing is 1" shorter .Some have had to ; I didn't when I used a non-Vette T700 core for my perf rebuild

Flame Red

Take my advice, just get your original one rebuilt. I am not happy with the non-vette one that I put in my 90. Vettes have some different internals. It just does not behave the same at all. Ask Pete K, our resident expert. I should have listened to him and now I wish I did!

drjimmy

I agree. The tailhousing is different from others. The gear ratios could also be different. The cost of a rebuild is not that much. Mine was $500 with me doing the removal. Had them use heavy duty clutches and such from a Suburban. Had it rebuilt 10 years ago and I am not nice to my tranny!

kimmer

Same thing happen to me a couple of weeks ago, D and OD started to slip until they were no more, had my trans rebuilt and also had a stage 2 shift kit installed, very nice.

85vegasvette

replacing mine with a used 700r out of an 85 easy breezy

Cruisinfanatic

A 5 yr old thread