4R100 UJOR build question

kcernest

Observer
I have a 2000 7.3 short bus with only 63k miles on it with a great shifting 4R100 in it now. I'm weighing my options with the transmission part of the swap and would appreciate anyone's experiences and input.

A. Swap output shaft and housing myself
B. Pay a shop to do it (cost?)
C. Buy a reman 4x4 trans and sell mine(end up spending ~$1500 probably on this option after selling mine)

I'm distrustful of shops and prefer to do things myself, although I've never messed with a transmission before. I'd probably end up getting something along the lines of a Suncoast rebuild kit($600) for it while I'm in there if I do it. I'm afraid if I take it to a shop while they have it apart they are going to hold me hostage for parts and labor that I don't really need. Can anyone provide cost experience with having a shop do this?

Thanks for any input.
 

Bbasso

Expedition Leader
Depending on your location, have you considered john woods or BTS for the transmission work. Those two places are top choices.
 

kcernest

Observer
Depending on your location, have you considered john woods or BTS for the transmission work. Those two places are top choices.
They are but for north of $4k. I'm not towing or racing, just doing exhaust and a tune so I think a stockish trans should do just fine.
 

Bbasso

Expedition Leader
So you have called both of them and inquired about the prices on your option B?
And they told you $4K + thats shocking.
Seems like you'll be DIYing.
 

fawndog

New member
I believe swapping the shaft requires rebuilding it.
I just had a shop rebuild me a 4x4 4r100 and the took the 2x4 4r100 as a core, that's the easiest way. (keep your sensors and make sure the hardline on the side matches)
 

kcernest

Observer
Doesn't UJOR handle this aspect or have a vendor they respect to do this work?
I'm sure they do if you take it there but I'm buying their 6" kit and doing it myself.

I believe swapping the shaft requires rebuilding it.
I just had a shop rebuild me a 4x4 4r100 and the took the 2x4 4r100 as a core, that's the easiest way. (keep your sensors and make sure the hardline on the side matches)
What did they charge you in this scenario, if I may ask? I'm leaning towards buying a reman 4x4 one and selling the one in it. I can let potential buyers come drive it before I pull it for them so that should make mine more attractive to buyers.

I'd like to get some input from someone that's done this work themselves if it's here. If there's no more input after a few days I'll let the thread die.
 

fawndog

New member
$1300 which is normal for rebuilds around here, they agreed to the core swap so there's no "hostage".
Factor in the shaft, tail-housing, and warranty and it's a no brainer unless you build transmissions.
 

Corneilius

Adventurer
If you get a 4x4 donor, make sure it has the same VSS locations as your existing tranny. There was a year break where they went from 1 sensor on the bell housing only---to one on the bell housing AND one on the tailshaft.
 

ujoint

Supporting Sponsor
I always recommend to have a pro re do the existing transmission. There are a lot of upgrades to be made while its apart and the last thing you want to do is go into it twice (or more) We don't roll the dice to save $$ here, we have them all built to the same specs with a new TC and the bill is usually ~3k with the 4x4 shaft and tail housing & upgrades.
 

Davidl13

Adventurer
I always recommend to have a pro re do the existing transmission. There are a lot of upgrades to be made while its apart and the last thing you want to do is go into it twice (or more) We don't roll the dice to save $$ here, we have them all built to the same specs with a new TC and the bill is usually ~3k with the 4x4 shaft and tail housing & upgrades.
Do you do this work? Or do you have a local shop do it? Can you discuss the tech specs of upgrades? Or do you sell a kit of parts I can bring to my local tranny shop? (I am across the country)

I would like to beef up my tranny (4r100) on my 6.8L...
 

ujoint

Supporting Sponsor
Do you do this work? Or do you have a local shop do it? Can you discuss the tech specs of upgrades? Or do you sell a kit of parts I can bring to my local tranny shop? (I am across the country)

I would like to beef up my tranny (4r100) on my 6.8L...
We don't do it in house, above our skill level. We used to sell the parts for the 4R100 but there are too many variables thru the years. The shop doing the work will need to source the correct 4x4 tail shaft and housing that has the VSS.
 

Davidl13

Adventurer
We don't do it in house, above our skill level. We used to sell the parts for the 4R100 but there are too many variables thru the years. The shop doing the work will need to source the correct 4x4 tail shaft and housing that has the VSS.
Thanks.. I will look into it locally...

What makes and upgrade and upgrade?

How does a different torque converter perform better? What specs do I need?

Can you give me an idea of what I would do to make my 4r100 for robust, and be more efficient.. for the many abuses I put it through..

I really have no good knowledge of the transmission with reagrds of how to spec it out...

I am installing an external tranny cooler now.. it has been running too hot..
 

ujoint

Supporting Sponsor
I'll have to get all of the internal geeky stuff from my builder, he looses me every time. And he's on vacation this week.

You need to find a good local builder with a good rep.
 

Mmm pie

Observer
I'm in the same situation, I have 2 2wd 4r100's and have been weighing the options. Still don't have a plan as to which rout I'm going to go. I purchased a 4wd tailshaft and a cast steel 4wd tailshaft adapter. After reading through this I hope I purchased the right parts.
 
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