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GMC TH700 Trans and transfer anyone got experience?

Posted: Wed Aug 15, 2012 9:12 pm
by Hilux_Ryan
Just wondering if anyone has had any experience with US sourced GMC trucks that run the turbo 700 4 speed auto mated to the matching NP (New Process or some such) transfer case?
If so whats the reliability, low range operation etc. like? are they any good or not worth the hassle? Also any chance fitting the complete unit into a Hilux?

Reason being I have an old Hilux with 253 and stock 4 speed, but I have just done a deal and got myself a 308 motor. Have thought about converting the old girl to auto for a while now, mainly because the stock gearbox is getting a little clunky, and I wouldnt mind having an overdrive for any longer drives.

Anyway during my research into fitting up a transfer case to an Aussie delivered TH700 to suit my application, I stumbled (trolling ebay) someone selling the Th700 and transfer from a Chev truck of some kind, it looked like the common Commy type trans but with a transfer on the back, with a centred rear output and an offset to the right front output, which appears to suit the Hilux with little more than a relocated transmission crossmember and a couple of custom tailshafts. And the extra length of the trans means my front shaft would become longer which is good as the old girl has a very front short shaft, and the rear shorter which it has plenty of length so is not a problem.


So as mentioned, anyone got any experience or knowledge? I'm guessing they are fairly strong due to being fitted behind 350s etc. in full size trucks, but are they compact enough they wont weight the Hilux down too much? and does the early TH700 have a non lockup converter that will be suitable for a carby engine without the need for a controller or more electrical connections?

Re: GMC TH700 Trans and transfer anyone got experience?

Posted: Wed Aug 15, 2012 9:47 pm
by GUtripper
Can't talk too much about the th700 other than as far as i know it's the non electronic forerunner to the 4l60 slusher.
I believe it's strong enough for the job you are after, but like most boxes probably has it's weaker points that can be improved.

NP transfers should easily handle your application. It should have a round tag on it designating the model number. Most are good, parts are readily available. They come in different variations and I've seen plenty behind 308's, 350's, 360's and bigger.

Re: GMC TH700 Trans and transfer anyone got experience?

Posted: Tue Aug 21, 2012 10:05 pm
by Hilux_Ryan
Thanks for the reply, yeah I know the TH700 is the mechanical version as found in early V6 commodores, but just wondering if anyone had experience with the US versions.

As it happens the bloke sold the 308 I was supposed to be buying to someone else with no warning *I had the money waiting for him to tell me it was ready to pick up) so this project is definitely on the back burner.

Thinking of selling the Hilux now, I decided by the time I do this driveline change, I could just buy another set of engine mounts (which would be the only bit left of the current setup) and sell this one as is for almost as much as it would cost to build again with what I want.