Help, I need a new t-case!!

[icenfire01]

So I just finished up a brake job, took "Old Red" for a test drive and heard a popping sound , did a little investigating. It only does it under load. If you hold the brake and give it some gas you can hear it, accelerate you here it. Pretty sure it is the chain slipping in the t-case. I havent pulled the plug yet to see if its dry, so I'm not 100%. My question is if I have to pull the t-case what should I replace it with. I have a few laying around how do I identfy what I have, and what will mate up to my 700r4?

 

[Big Ray]

rebuild it.....?

 

[Hogback Fabrication]

If the chain was slipping it would only happen in 4wd, probably the rear end

 

[sweetk30]

not all true.

i had a 208 tcase go bad. snap/bang/boom when on gas. only way to get it to move was 4wd low.

this all happened in 2wd just out drivin on the street.

found bad tcase by pullin drain plug and chunks of bearings come out with the oil.

 

[icenfire01]

Im sure its comming from trans/t-case, you can feel it under your feet and you can here it comming from right under the truck, not towards the rear. When my Dodge t-case went out you could hear it in two, or four.

As far as rebuilding it, it would be much cheaper replacing it with one I have. I have two laying in a storage building, and I have a 79 half ton and a 77 3/4 ton in the weeds in back. I just dont know if anything I have will mate up to a 700.

 

[diesel4me]

The 700r4 and a TH350 have the same splines (27 I think) and the same tail housing bolt pattern...if you use some other case besides the original one you may need to change the driveshafts too,the overall length of the T-cases vary by model and application..

 

[Carquest2424]

I have a tcase for 700r4 for 175

 

[Hogback Fabrication]

The 700r4 and a TH350 have the same splines (27 I think) and the same tail housing bolt pattern...if you use some other case besides the original one you may need to change the driveshafts too,the overall length of the T-cases vary by model and application..

The t-cases in your 77 and 79 trucks could be a 203 or 205.

The back side of the 700 and TH350 are the same except that the output shaft on the 700R4 is longer. In that case, you need to use a shorter output shaft (better way to go if you're rebuilding the trans) or a spacer, then the factory 350/203 or 350/205 parts work just fine.

 

[icenfire01]

Thanks for the all the info guys, the other thing I'm considering is just swapping the whole setup back to a th350/203. I never drive this on the road so and overdrive doesnt do anything for me, and I'm kind off unsure about the durabilty of the 700. If I do that will I still have to come up with a custom drive shaft?

 

[DizturbedOne]

It will probably come out shorter

Hard to say because a 203 is so much bigger than a 208... But a TH350 is a bit shorter than a 700R4 also.

I would guess you probably would, you only have an inch or two of difference either way if you want to use the same shaft depending on whether you have slip/fixed yoke, slip/CV/solid shaft, etc