Off Roading Forums banner

5 speed for a 700R4 project

1950 Views 7 Replies 2 Participants Last post by  CodyLee19
Hey , I have a 91 L.D. 3/4 ton 4x4. It has a 350 and a 5 speed. The 5 speed is the problem. Its too weak, I keep on going through tranny's about every 20k miles.. At 2k a pop that game gets old. I am going to be putting in a mildly built 454 or a nice 383 in there in the next 3-6 months, so I want to get rid of this transmission first. I plan on doing a 700R4 built to the hilt with a manual valvebody.I have access to a core for it now. It came out of a 2wd truck. What will I need to swap out or buy when I build this transmission. What changes will I have to make to make it work. I know a stand alone computer, what else? What will I need to do with my crossmember, or driveshafts? any other ideas? Will the transfer case bolt up, will I need to buy adapters for it? Mainly, what will I have to change with the transmission coming out of the 2wd? Thanks Cody Lee
1 - 3 of 8 Posts
Well, the output shaft will have to be changed in the 700R4 at a bare minimum. Some cases you couldn't even convert to 4wd. You're better off finding a smoked 4x4 700R4.

What do you need a standalone computer for?

I'd put a NV5600 in it if you keep smoking NV4500s. Especially since you don't seem to mind plunking down the $2k every other year.
Some 700R4's cases can't be converted from 2wd to 4wd (the way the tailhousing bolts up). Most can. I'm not aware of any 2wd transmission that has an output shaft that'll work in a 4wd (I don't know how they'd do it anyway).

You don't need a computer to tell a 700R4 to lock up. You can do it via pushbutton (since you're going to a manual valvebody you might as well) or do it the old fashioned way--vacuum switches.

It's going to cost around $900 to get a 700R4 beefed up and rebuilt plus you have to find an output shaft. A manual valvebody with compression braking will cost around $250.

I thought your truck was the beginning of the NV4500s, apparently not, eh? You can find one for around $1500-$2500 at a junkyard that is ready to go.
The 4L60e didn't get stronger internals until 1999 at which time it got new planetaries. Other than the valve body, it is essentially the same as the 89-91 700R4. The 86-88 700R4 is weaker, followed by the 81-85 being the girliest.

To my knowledge, there is no benefit to having the computer shift the transmission. This is especially true if you can adjust your throttle valve yourself.

4L60e and the 4L60 both suffer from the same problems a 700R4 does. So, technically, 98 and older 4L60es are outdated pieces of [bleep] too, only they need a brainbox to shift them. To me, that means they're even ****tier because that's one more thing to go wrong and leave you stranded.
1 - 3 of 8 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.