Just how strong is a 700R4?

mjp1080 · Dec 17, 2009

I just rediscovered that I have a 700R4 trans buried in the shop. It came out of an 84 chevy 3/4 ton with a 6.2 diesel motor and it looks like its been rebuilt. I want to install it in my truck to replace the sm465 I've been running, but I dont know if it will survive. What has been your experiences with this transmission. My truck has 550-600 hp at the flywheel and the rig weighs 5226 lbs. Will this thing work or do I need a th400? thanks

Torrance · Dec 18, 2009

try it. its already paid for.

NotSoPC · Dec 18, 2009

Torrance said:
try it. its already paid for.

X2 if you dont mind the work. It may hold for a while or forever but I would not think it to last really all that long with that power. I had one go out with only 300hp and about 30k miles on it. I would just go with the 400 and skip what could be just more work in swapping it in and out.:awesomework:

Fordzuki · Dec 18, 2009

I burnt up two with a 6.2 w/ Banks kit, and yes the TV cable was adjusted properly. Keep the manual. :awesomework:

NotSoPC · Dec 18, 2009

Why are you pullin the sm465?

unclestripey · Dec 18, 2009

700R4's have a reputation for dying when subjected to high horsepower and/or lots of towing in stock form. They can be built to take whatever you through at them however.

zukkev · Dec 18, 2009

Even freshly 'rebuilt' can **** parts with less HP than you claim to have---you can spend some bucks to build it up, but still not going to be bulletproof....stick with the manual, or go TH400...

Ed Bister · Dec 18, 2009

What X case are are you trying to run? the 700r4 has a longer output shaftso if your going to want to put a NP 205 or 203 you will have to replace the outputshaft with a shorter one from advance adapters. There cheep but you have to disasemble the entire trans to get to the shaft to swap it out.

i hope this helps

O ya I went throught 3 of these trans in my K5 in 2 years.

Eric · Dec 18, 2009

mjp1080 said:
My truck has 550-600 hp and the flywheel and weighs 5226 lbs.

:eeek:

WHITE TRASH1 · Dec 18, 2009

Of all the 700's to have you have the best chance for survival in stock form but you'll want to do a lot of work to that trans first. Keep in mind it is programmed to shift at low rpm so you'll want a good shift kit and higher stall converter. Then you'll want to upgrade the shift servo and put in a manual converter lockup switch.

At the end of the day I'd just put a good solid th400 in it and now mess with the 700 at all.

Boonie Buster · Dec 18, 2009

Marshall, I have one in my truck currently, i KNOW i'm not as hard on stuff as you, and I KNOW i dont have as much power, and I KNOW i dont have as big of tires, you'll bepulling it out every weekend.

Mine DID last 5 years before i ran it low on oil and torched the clutchs and bands, but I cant see you enjoying it or making it last. :booo:

Hey, maybe we can work out a trade!? 700r4 for a SM465! :redneck::haha: TRade for a few weeks!

frankybeans · Dec 18, 2009

Go with the th400. This is a dyno for an OEM 700r4 vs. a modified one.

PUO-BANNED · Dec 18, 2009

it's not holding up to that kind of power unless you sink some $$$ into it and if it's the early model before they upgraded the internals (89) forget about it because it's even more $$$

Don't listen to these dipshits who tell you to run it because it's new. they aren't the ones who have to pull it when the front drum explodes or if you ****ed up the TV adjustment and burn the tranny down.

Get a TH400 and I have a tech thread on here to make it shift hard and hold any gear manually with basic tools.

mjp1080 · Dec 18, 2009

Thanks for the input, I think I'll just get a th400 that mates to my 205. By the way, I'm getting rid of the manual because it shifts like a dump truck, too damn slow, "I wanna go Fast". Anybody wanna buy a sm465? I have two of them.

Freeride · Dec 18, 2009

I'd be interested in the 700R4 for a good deal.

mjp1080 · Dec 18, 2009

Not gonna sell the 700r4 just yet, I am trying to work a sponsorship with a trans shop and have them build it for me, if this falls through and I do end up getting rid of It I will post it on here.

Corey Y · Dec 18, 2009

mjp1080 said:
Thanks for the input, I think I'll just get a th400 that mates to my 205.

You willl need a 32 spline female input that uses a bigger bearing so your t-case will need to be bored out.

mjp1080 · Dec 18, 2009

Crazy Daze said:
You willl need a 32 spline female input that uses a bigger bearing so your t-case will need to be bored out.

I knew it! Nothings is cheap or easy, I wish a np208 was a little stronger. That would make this all real easy since I also have one of those.

Digger 5 · Dec 19, 2009

We went through 2 fully built TCI 700R4s in a 518 HP LS2 buggy (2,600 lbs) in probably less than 12 hours of run time. Yes, we beat the crap out of it but they seized up. Unfortunately I don't remember what TCI found as a cause (it was a trans problem, not install). The 3rd trans is in now but the rig isn't being used much and when it is it's babied.