Advice on new trans
 

Found out i need to replace my messed up 700r4. Shop suggested using a 400. the frame is a 84 k10 4x4 and has a new 350 SB. No computer anymore. Not doing much long distance travel over 60 mph any more. Any advice appreciated.

Re: Advice on new trans
 

Swapping to a TH400 will require a different converter, trans mount relocation and most likely the driveshaft will need to be shortened. I think the shop is steering you in the wrong direction...

Re: Advice on new trans
 

I agree with Black Sheep. 700r4 is a good trans and a good option for a 350 sbc. Perhaps they just have a 400 laying around and want to sell it to you.

Re: Advice on new trans
 

If the truck is 4x4 you may have a few more issues including whether or not the 400 will bolt straight up to the transfer.

It also depends on if you plan some serious off road work. That may be the shops line of thinking in that the 400 may have less issues for hard core off road work than the 700R4 might.

The main issue with the 700R4 has always been getting the TV cable dialed in. It has to be adjusted right on the money or you have problems. Some guys have a real issue with getting it adjusted right.

Re: Advice on new trans
 

Actually they have nothing to sell. My trans just sat for 15 years right after it was rebuilt as is now slipping. they recommended sending it out to Trans shop for flush and stuff but the Trans shop says it probably a waste of $$. Theres no computer any more and i have a manual OD lock switch. Afraid i will forget the switch on or off and cause damage. II have no plans of any real offroad use. MAy be for occaisional snow/sand use. Replacing with a summit th400 (0r 350) is the option i'm asking advice about. See attached build link for lurid details.

Re: Advice on new trans
 

This exactly the info i need to hear Thanks!!

Re: Advice on new trans
 

You might ask around about who is the go to shop to have 700R4 transmissions worked on in the area. If those guys don't like them it may be that they have had problems working on them in the past. Or reliability problems with transmissions in trucks guys wheel.

Re: Advice on new trans
 

I would say never swap back to a 3 speed, non OD trans. There are shops now that will change the valve body and eliminate the TV cable adjustment. Get the 700 built correctly and be happy. Had the same problems with an AOD(ford version) and it took three tries in a street rod but I finally got it right and having that OD gear is great!, even though, like you, I don't need it that often.

Re: Advice on new trans
 

Found a shop that seems ok about 70 miles north. They recommended a full rebuild of the 700r4 with a Transgo kit added to eliminate the dash od switch. Will cost $1400 i haven't got and may look for a sponsor from VFW or Vietnam Veterans.

Anyone had any experience with the Transgo kit?

Re: Advice on new trans
 

I know it would be a long drive but there's a guy that's been selling transmissions on Craigslist for years in Portland. I haven't bought from him myself but it might be worth checking.
https://portland.craigslist.org/clc/...335135698.html

Or this one in Eugene
https://eugene.craigslist.org/pts/d/...334720493.html