black_771

New to the forum! Looked around for this but didn't find exactly the same issue.

I have a 94 Corvette with the 4L60E transmission. I'm told this is the 700R4 but electronically controlled. My problem is at partial throttle, the trans shifts perfectly, but at wide open throttle is successfully kicks down into first, but when it hits redline it doesn't shift, it just bounces off the rev limiter.

I know in the 700R4, there is a governor spring that can cause this problem. Would the 4L60E have the same issue or has electronics replaced this governor?

Thanks in advance.

toptechx6

No governor as you suspected. Since it is electronic you may want to pull any codes. With any luck Pete K. will check in and have an answer, he is the resident trans guru, good luck.

black_771

"Pete K, please report to the front of the forum."

Funny, I spend about 10 years getting to know the 700R4 inside and out, never have a problem. As a matter of fact, I have a brand new on sitting on my garage floor right now. Then I buy a car with the same trans but with a computer on it and it's like I've never seen a car before. Funniest of all is I work on/with computers for a living. Gotta love irony!

black_771

The only code that pops up (and excuse me if I don't say this correctly), was from module one and listed "H72".

Is that even a transmission code?

SocalChvy

I had the Same exact problem in my C5, under normal driving the car works fine but as soon as I punch it, it red lines and stays there until I get off the the gas. I willing to bet that one of your clutch packs are burnt up..change the fluid and inspect the transmission pan for debris..

black_771

It's not clear from your post, but I'm guessing you are saying that because that's what was wrong with yours correct?

Pete K

I have never had that problem, but I will look into it to see what I can figure out.

black_771

Awesome! Thanks!

black_771

PeteK or anyone else, has anything come to mind what would cause this? I changed the fluid and the VSS sensor yesterday but haven't have a chance to road test it yet.

Boob

It's probably just slipping. Try this....run the car from first WOT until 500 rpm before redline then completely let off the gas and see if it upshifts. If it does, it's likely slipping under high pressure of WOT high rpm shifts.

How many miles on this transmission? Any modifications or rebuilds to it? Is there a tranny cooler on it?

black_771

It does shift if you lift off the throttle slightly. I shifts perfectly fine and strong at anything other then WOT. Is there something I can "measure" to verify if its slipping?

black_771

Well it's official, it's just worn out. I changed the fluid and filter and now if I give it even half throttle it slips so bad it as if I'm holding in the clutch (if there was one).

And to quote a line from the ad I bought it from "While the this car can be nit picked for flaws, you will find no surprises here."

I've driven the car three times.

Pete K

That sux
Sorry for the bad news.

Pete K

There are many available upgrades for this trans that are well worth the few extra dollars they cost. I would find a shop that will not only rebuild it, but make some of these upgrades as well. Every builder has his own "recipe" for success.
The good news is the time is right for a performance converter.

black_771

So Pete K, the general consensus is that you are the corvette trans God! What would you recommend?

If only the new 700R4 still sitting the crate on my garage floor were a 4L60E I'd know that my luck was turning around. As it is, no such luck yet. I guess I'll just have to pray harder tonight.

Pete K

Sometimes I am given too much credit. I am a construction worker that rebuilds and modifies these things for a hobby.Strange hobby I guess, but I enjoy doing it.
Assuming stock or mild performance, I would do the following upgrades without exception:
Beast reaction shell
Teflon pump and tailhousing bushings
Wide rear sungear bushing
Raybestos Z-Pack 3-4 clutch pack with the correct length apply ring
Hardened pump rings
29 element sprag(it is a double cage design to replace the garbage stocker)
Borg warner lo roller clutch
Reverse piston orifice mod
Alto red or kevlar band (standard width)

I was not a fan of the z-pack when it first came out. I did not like the single sided clutch/steel arrangement. I have had the ability to see how they have held up behind some serious power, and I like what I see.
The parts I have listed above should add less than $250 to the bill.

I also recommend buying the best converter you can afford. Quality converter= long life. Alot of the converters I sell are to solve a problem caused by $100 rebuilt converters.

black_771

Thanks Pete. With as much cussing and screaming as I've done lately when I'm working on my cars, my wife thinks cars in general are a "strange hobby".

Pete K

Do you have the confidence to rebuild it yourself?
If a dummy like me can do it, everyone on the forum can as well. Myself and others can assist with guidance, parts and suppliers.

sothpaw2

My wife is not so nice about the cussing.

How many miles were on the trans? I thought these went for well over 100k. mi.

black_771

Well,...I have the desire to learn. I actually ordered a trans rebuild DVD almost 2 weeks ago just in case, but the stupid thing has been on backorder since then. Once I see the video 50 or so times, I'll decide what level of confidence I have.

I can't seem to find it again, but to tell you the truth, one of the first threads I read here was about you helping a fellow member rebuild his transmission. It was probably the most informative thread I've ever read on any forum. That really gave me the idea that I could possibly do it myself. Like I said though, I'd have to see someone else do it first just to know what it should look like along the way.

My entire career is based on stuff I learned myself so I'm pretty sure I could learn how, but to actually turn that into a working transmission is a completely different thing. Trust me, you will be involved in some form if I do.

Thanks again!