So, I yanked my TH400 out and dropped it off at the local tranny shop to have them go through it and seal it up since it was leaking horribly. They called me and told me I needed to come down and look and it wasn't good... The tranny is wiped. Bearings are shot, case is shot, etc. They told me whoever put it together had big clearancing issues and it was a matter of time before it just imploded. So, here I am at a crossroads..

They are going to give me a price on a new rebuild tomorrow, but are estimating $1500-$2000 to put it back together with hardened parts and the necessary replacement parts that aren't wiped in the current tranny.

Here's some pics that were taken of a few internals...

I am looking for suggestions on getting a new th400. The car is an LT1, weighs 3800 with me in it, and you can figure close to 1000 HP at the wheels. Car is getting a big turbo and is mostly drag raced with a little street time for fun.

A buddy told me at that price, I might as well get a powerglide and move forward from there. He said I can use my current TH400 converter, but will need a new driveshaft.

Any thoughts on getting the TH400 rebuilt? Get a new one? Go with a glide?

Thanks!

 

This is the first time I've ever heard someone talk
about a TH400 case being "shot". It's not a wear part.
I think I would collect my basket of parts and mosey
on down the road.

Seems like for that money you could get one on a
pallet delivered, with a lot less suspicious story.

 

If this is true, as Jimmy stated buy a new one. I run a Hughs with TB and it has many 10.0s or faster passes and many street miles. Still going strong!

 

I'd buy another core and find a different builder.

 

Which model Hughes are you running?

 

the cases do go bad-broken lugs in the case-some of the larger trans places have the ability to repair some of the case problems, but way to many 400 rebuilable cores for $100 or less out there
i prob have 15- 400's and 4l80e's, i see a deal and pick it up-even a BOP can be used, they sell an adapter, or cut the bellhousing off and use an ultra bell
and no, i dont sell the cores, lol-now and then a trans shop will call and i throw them a core, and they take care of me
i have seen large bins of trans cases sent out for scrap, just to damaged

 

Th400 cases do go bad. In your case it looks like the rear case washes spun do to a bearing failure if I had to guess. I have also seen the snap ring for the intermediate clutch break the lugs as well. Personally I always install a bearing in the back of the case and make sure to get the endplay set up with performance spec's in mind. Look up Jakes Performance for a TH400. I know he specializes in these units and his prices seem reasonable for what you get. Best of luck with your project. Vince

 

Not sure exactly which model number but when it was purchased this is what was said " I want the strongest th400 you make under a turbo glide" and that is what I got. Sorry so vague but that's what i got.

 

I'd get a used core and find another builder - or learn to rebuild it yourself!

 

I have pulled apart TH400's in the past. Not my cup of tea. I know what I am good at and what I am not. Trannys are on the NOT list.

 

Turbo spline converter won't work in a glide unless you put a turbo spline'd input shaft in it, there are quite a few on the market. A glide will run about 3k bucks though to last at the 1000+ hp level, but I'd run the glide for consistency over a TH400. Otherwise... I run a coan TH400 and it's a great trans. you might want to do a 300m input...

here's mine...
http://www.coanracing.com/Catalog.as...uctDetail=1556

 

A good th400 for that power should have a bearing in the back instead of that 3 tab washer to start with. I would get in touch with Jakeshoe on here. He makes some great pieces. You will be suprised how much the TH400 can take.

 

Whistling z, We have 400's rated from any where between 800 hp and 200hp. Visit our website and look at them , We also have glide from 900 hp to 3000 hp. Our 900 hp 400 with a brake is less than they want to rebuild them and we do not need a core.

Greg
FTI
1-866-726-8358