Here's the scoop, a '91 Z28 305 with a 700R4. I was driving on the highway in OD @ about 100 km/h. all of a sudden the RPM climbs up and I'm trying to figure out what is going on. The tranny is slipping in 3rd and OD. I'll list the fact and symtoms, any advise would be appreciated. I'm a t-5 expert, and haven't really researched the autos much. Thanks...

- tranny fluid full
- 1st and 2nd gear work perfect, shifts hard into 2nd
- when in D or OD the car will start in 1st and shift to 2nd
- as soon as it gets to 3rd, the slippage begins, though I believe 3rd gear is engaging, it just slips.

Next question, will it hurt if I engage the lock-up torque after I start moving to stop the slip in 3rd and OD, then turn it off when stopping? This would just be for a couple of days. If more info is required let me know. Thanks again.

Arthur

 

Mine is doing the same thing. As far as I can tell, my problem is a smoked 3-4 clutch pack. (really common on 700r4/4L60e). Burned fluid is a dead giveaway. I was also reading about failed torque converters, stuck valve train in the valve body (namely 2-3 valve) etc. I was trying to find a quick fix for mine, doesn't look good. If you have any ?? I have the Gm book for the 700r4.
Hope this helps..

 

Thanks for the info. I'm doing more research but I want to just get this thing working because I'll be putting a 5 spd in soon. Maybe sooner than I wanted...

Any more info is welcome...

 

Hey, I'm having the same problems, but, when I shift manually from 2nd gear on through od there is no change in rpms or anything. Is that the same problem your having, I mean I'm pretty sure it might be shifting into 3rd but can't really tell, and i'm getting tired of driving around at 30 mph so I dont blow my engine. Any idea how much that'll run to get that fixed? I dont know anything about transmissions. so help would be appreciated.

 

If third and fourth gears are slipping, then the 3-4 clutches are burnt (see how that works...) Third and fourth gear share a set of clutches called the "3-4 clutch pack assembly" and is a very common problem w/ the 700R-4. The only way to fix is to remove the transmission and overhaul. While your in there, don't just replace the clutches like most shops would do, try to actually fix the problem by air testing the input housing and look for leaks around the input shaft, check or just flat out replace the 3rd clutch capsule, and install a transgo reprogramming kit. I've seen properly built 700's go 200,000 miles or more, and I have seen not so well built trannys burn those clutches up at 20,000 miles (from the factory) and 5,000 miles from podunk local shops

 

Wow - My 700-R4 just had the same thing happen to it.

Messed up 3 and 4 clutch packs, and an F-ed up torque converter.

My guy is rebuilding the tranny up with a custom machined torque converter (2k stall) all new clutch packs 1 thru 4 heavy duty, and a corvette servo assembly. It sucks hardcore, I feel for you man!

 

Is there any danger associated with this problem??

Mine does the same thing, BUT I have a T56 swap scheduled for early June......I really don't want to move it up, so i was wondering if it was OK to drive it like this for now???

Thanks

 

Drive it for now without 3/4 clutch packs? Well, if you don't mind wasting alot of gas and zoom around town in 2nd gear (keeping uniform speeds takes about 3-4k rpm... gas goes bye bye)

 

Not only will the gas mileage suffer, but the planetaries will over heat after awhile, then you will not have any gears.

 

A very valid point as well. That would suck. Don't put it off.

 

mine did that for about a year when cold and got better as it warmed up. problem got worse and worse to where i was finally having to use 1 2 and D when cold and i still got slip. i just went to a t56

 

I just took mine apart 3-4 clutch pack Fried, steels are screwed too. I was hoping that the other 700 I have could be rebuilt, but oops broken hard parts. I now have 1 cooked, and one fragged. bummer....