TH 400 Cases Which one

Cole · Dec 1, 2011

Which TH-400 Case is the Strongest and Why? I have heard so many different stories I don't know what to believe. I know some of you knowledgable people on here have the answer.

86tank · Dec 2, 2011

I had always thought that there was only one type of case for the 400. I know there is a k case th350, but never knew any difference in the 400. I may be wrong though. The one in my buggy is a 2 wheel drive and it is identical to the ones we run in the mud trucks.

KyTrash · Dec 2, 2011

Cole, If you want a bullet proof Th 400 case, J&W just came out with 1 and it's bad ass,just like their powerglide cases. I though the 4 wd cases have heavier webbing around the back? I will check the other case that I have in the morning.

johnnyrude · Dec 2, 2011

If you can find a th400 out of cucv with diesel those were the hd series and have Ed at ptc to build it it will be bulletproof that just my 2 cents

Cole · Dec 2, 2011

KyTrash said:
That's what I thought but I'm not sure. A few people I have talked to said there all the same then some say there different. That's why I'm trying to find out.

johnnyrude said:

If you can find a th400 out of cucv with diesel those were the hd series and have Ed at ptc to build it it will be bulletproof that just my 2 cents

Click to expand...

Yeah I will have PTC swap over the internals because that's who built it originally.

Here is my transmission I just pulled out. It has HD stamped on the bell housing

Draco · Dec 2, 2011

I wonder if you did that on BS3 when you crashed? I'm sure the latest didn't help....that would take a hell of a lick to do that. :dunno:

Either way....Hope you're back rolling soon. :dblthumb:

payne97 · Dec 2, 2011

How is your motor trans and tcase mounted ive looked at your buggy but cant remember

I would say some thing is movin

U may have some chassis flex

mrdrinksalil · Dec 2, 2011

From what I've been told by my local trans builder is that the strongest case used the 6 bolt aluminum dust cover with the two struts that ran up to the engine. Also, other than cases breaking because the Tcase isn't supported/ frame flex/ broken driveshaft is that under big power the helical cut planetaries push against the back of the case and can crack in that area (just like that pictue someone posted). All there is in those cases is a bronze bushing between the case and that output shaft. I believe TCI has a bearing to replace the bronze bushing but im not positive.

This is why in big cab and chassis stuff they started running straight cut planetaries and called them TH425 or TH475 or something like that.

This is the best case though is the new J&W but I dont even know if you can get one yet.

Cole · Dec 2, 2011

All my stuff is hard mounted. My case broke because the mid shaft wedged into the transmission when the yoke on the atlas broke.
I was just curious about the different cases. I'm not worried about the way it is mounted because its been that way since it was built and I've thrashed on it and not had problems.

mrdrinksalil · Dec 2, 2011

Cole said:
All my stuff is hard mounted. My case broke because the mid shaft wedged into the transmission when the yoke on the atlas broke.
I was just curious about the different cases. I'm not worried about the way it is mounted because its been that way since it was built and I've thrashed on it and not had problems.

Call your local transtar. Mine sells cases for $150. They sell the "HD 4x4" case for $260 but there wasn't one in the entire country when I called.

Cole · Dec 2, 2011

mrdrinksalil said:
Call your local transtar. Mine sells cases for $150. They sell the "HD 4x4" case for $260 but there wasn't one in the entire country when I called.

I found a couple of regular 400 cases and one that is the 4x4 HD. That's why I was wondering about the differences. Either way I'm headed to take it to PTC this afternoon, so hope to have it fixed pretty soon.

payne97 · Dec 2, 2011

If i ever get mine back ill post a pic of the way i welded the back right where yours broke

KyTrash · Dec 2, 2011

Th475 is straight cut gears and Th425 is FWD,direct drum sprag is reverse rotation. Cole, all three of my cases look the same in rear.

Wes in TN · Dec 2, 2011

I dont know anything about the TH400 but i can say J & W is awesome to deal with. Eric there knows his stuff and responds to calls and emails immediately. I ordered a custom built torque converter from him on Tuesday morning and had it on Thursday. Give them a call.