Since the 700r4/4L60E's are *very* questionable in a performance application (I just blew my 5th one) I was wondering if it would be possible to swap in a 4L80E? Has anyone done this, or considered it? Another question, would the 700r4 tailshaft fit on a 4L80E? I have a Vette, and the torque arm bolts to the tailshaft. That's why we have to use the more expensive ZF-6 over a T-56 in a manual swap...

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408cid 1985 Corvette
http://www.mojosgarage.com

 

The 4L80E is huge, heavy, take a lot of power to operate and are about as bullet proof as tin. They LOVE to break parts (due to a design flaw) and you will need a computer to control it. Oh yea, you will need a mortgage to buy one. Other than that it is great!

The 700/4L60 on the other hand is actually a pretty good tranny. The sunshell is a weak point but the newest ones from the dealer is better. I would install a TransGo Reprogramming Kit in your tranny. Try to avoid going for the slam bang 1-2 shift and you will find the tranny lasts longer too.

[This message has been edited by transfixleo (edited October 29, 2001).]

 

I have a TransGo kit in my current (tranny #5) blown 700r4. I'm looking for an alternative that will actually hold up. I had read in GMHTP that GM was considering a 4L80E for the SSR because the 4L60E was too weak, so I thought it may be an alternative. I guess not.


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408cid 1985 Corvette
http://www.mojosgarage.com

 

The TransGo kit is the primary piece you will need to keep it alive but certainly not the only piece. Even they will tell you that. How much power dp you have? How is the car used? What mods do you have? How does the tranny fail? Etc.

 

I'm putting out roughly 500 crankshaft HP. I have a Superrammed 408 with about every mod you can imagine. Once, I tore the input shaft out of the clutch drum. Once, I cracked the case. Another time it shot some component out through the case. Most of the time I drive like a granny, but when I get on it, I'd like it to hold together. It's not my daily driver, it's a fair weather weekend cruiser and occasional grocery getter. The 3/4 clutches in my current tranny started slipping when I was passing someone on the freeway at around 130mph... This last one lasted for a couple of years, much longer than the others.

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408cid 1985 Corvette
http://www.mojosgarage.com

 

Which torque converter are you using with this setup? What are the modifications you have done to the motor, etc? (1) The so-called secret on this trans is never to use a 12" torque converter under any circumstance in a high demand situation (450 horsepower & up). Its weight & diameter are a tremendous factor in determining how long this transmission will last. (2) The right modifications, including the Trans-Go Performance Shift kit are all a part of making this live/work correctly. (3) The type of driving you do, will determine the parts you need & the setup that is required to make your transmission last, along with the right torque converter. I have quite a few transmissions on this board (in similiar situations) working out well, and I may be able to help you out on this. If you have any questions on this please call me at 800 7763288 M-S 11-7 PST or e-mail me.

 

HMMM, I have a 350 with AFR heads which will produce 450 hp at the crank, and i have a supercharger to add to that power. Is it possible to build up my 700R4 to handle the power?