Th400 rebuild needed

[Ridgerunner]

I have a 89 Th400 from a k2500 Diesel. I need to get this rebuilt. I have heard that they are farly easy to rebuild but I am not really into trying something new on somthing that I am going to commute to work in every day. I have also heard that you can replace the first gear with a lower gear. I would like to do this also.

Are there any Transmission guys on here?

I also might want to go through the NP241 and check it out

Another question.....
I have 2 of these trannys. The one I want to rebuild has a large "HD" in the casting on the bell housing, and the other one does not. I assume this means "Heavy Duty" But what exactly does that mean??? Since it is in the casting I would assume that there is some sort of added strenth built into it.

 

[Ron]

As far as auto trannies go they are easy to rebuild, not C4 easy but close.

Ive ever changed any of their gears though.

Sorry dont know anyone in your area.
The HD is a source of universal debate. My best conclusion is you are better with it, but no can say why...

 

[sha_ba_do_bang]

As far as putting a lower first in that is certainly possible. We swap in planets from other chevy transmissions to get different gear ratios.

There are many different versions of the 400. I actually have one sitting here that has striaght cut gears (read noisy and stronger than helical cut gears). Some have different sprags, hardened input shafts. Others have different spline output shafts and bolt on yokes.

If Wilmington isn't to far I offer 12 month/15,000 mile warrentee on transmission rebuilds