700R4 transmission in a HMMWV

[Dock Rocker]

We brought this one back from the dead


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[StackJ]

And because of that, I'm darned tempted....

 

[davykeith]

I just ordered an HD 700r for $1800.

 

[aceecaus]

I'm in the middle of doing this but my new 4sp shifter isn't aligning with the shift points in the 700R4. Any suggestions?

 

[dhaumann69166]

Thanks guys for all your help. I'm definitely gonna move forward with the 700R4. I'll do a write up for anyone looking to do the same.

Looking forward to following your build. I am getting ready to do a 700r4 with a 241C. Everyone keeps saying it won’t hold up but I have personally seen them handle 750hp rock crawlers and 1000hp drag cars. Most of them were only mildly built.

 

[Bocephus]

Agree with you there. I've seen several people say the 700r4 won't handle it.............which leaves me scratching my head because its a 165hp motor........... Like you, I've seen them in several built rigs, and they handle it just fine.

 

[Sharecropper]

C'mon man.

If built correctly, the 700R4 will handle as much as a TH400. I purchased a Level 2 K-case 700R4 from Bowtie Overdrives rated at 450 HP and 400 FPT. $1650.00. Added the special output shaft to mate with my NP208. The length of the 700R4 is the same as the TH400 so no crossmember or drive shaft modification is necessary.

https://www.bowtieoverdrives.com/catalog/catalog_inc/viewitem.php?ITEMID=503

 

[Dock Rocker]

Agree with you there. I've seen several people say the 700r4 won't handle it.............which leaves me scratching my head because its a 165hp motor........... Like you, I've seen them in several built rigs, and they handle it just fine.

Horsepower isn’t what kills transmissions typically, it’s heat. Get a well built 700r4 with a beast sun shell and upgraded clutches and the biggest cooler you can find. The cooler adds capacity (more fluid) and cools faster. If you do those things you will be fine.


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[davykeith]

Ran into a snag on my conversion. The flexplate on mine is a six bolt pattern and it's not lining up with the three bolt hole on the converter. Any suggestions? Thanks.

 

[86m1028]

Horsepower isn’t what kills transmissions typically, it’s heat. Get a well built 700r4 with a beast sun shell and upgraded clutches and the biggest cooler you can find. The cooler adds capacity (more fluid) and cools faster. If you do those things you will be fine.
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I’d say TORQUE & heat kill them.
Agreed, bigger the cooler the better.
I think ANY trans will stand up behind a 6.2 !
I guess if you putt around in an empty truck (mall crawler) it will do fine.
There is a reason Gm never put them in anything bigger than a underpowered HALF TON !

 

[86m1028]

Ran into a snag on my conversion. The flexplate on mine is a six bolt pattern and it's not lining up with the three bolt hole on the converter. Any suggestions? Thanks.

Replace your flex plate with the correct one for a 700r4.

 

[davykeith]

Replace your flex plate with the correct one for a 700r4.

I went to Napa and they gave me BK 600541. Based on the research I've done, I believe I need BK 600542. I hope that's right because my mechanic is going to kill me if it isn't. It's holding up his lift. I know this sounds silly but I printed both pic's out and lined them up in the light and the holes are in different places. Fingers crossed.

 

[dhaumann69166]

Good idea on printing them out and holding them together. If you are building a 700r4 that came from a gas burner you will also need to change out the governor gear.

 

[davykeith]

Update: The part number FRA143 flexwheel had the correct hole pattern for my 3 hole torque converter. And just for the record, it's a 6.2 diesel I'm not converting from gas to diesel or vice versa. Still same motor. Drive shaft had to be shorted a bit, 1.75" or so. Small bracket adapter fabricated for the drive shaft and so far that's been it. It's going in today. I need to figure out how to do a lock up on it next.

 

[mdes0]

The rear shaft had to be shortened? Thought the 700r4 was close to a bolt in. You using a 218 or 242 transfer case?

Matt

 

[Dock Rocker]

The rear shaft had to be shortened? Thought the 700r4 was close to a bolt in. You using a 218 or 242 transfer case?

Matt

The adapter used to mate the different spline count 218 to the 700r Necessitates the different driveshaft length.


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[86m1028]

700r4 is 27 spline, turbo 400 is 32 spline.
How are you addressing that issue ?

 

[Dock Rocker]

700r4 is 27 spline, turbo 400 is 32 spline.
How are you addressing that issue ?

Several companies make adaptors.


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[frank8003]

Both my cars run LT1 against 460LE. Is not that the same and/or better than 700R?
There is PDF attached. If you see just a black boxes just click on it and it will work.View attachment 4L60E_B&M.pdf

 

[davykeith]

Both my cars run LT1 against 460LE. Is not that the same and/or better than 700R?
There is PDF attached. If you see just a black boxes just click on it and it will work.

It depends on what your meaning of "better" is. Yes as far as a more robust trans but no as far as cost and if you want to stay away from electronics and have a dumb trans. I prefer dumb and I'm only looking for grocery getter not offroading really.