What's new
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

Hd Th400?????

K

K5dreamer

1/2 ton status
Joined
Mar 14, 2005
Posts
3,081
Reaction score
2
Location
Alexandria, Va
I noticed today that the bellhousing on my TH400 has HD cast into it. I was unaware that there was an HD version of the TH400.

what makes the HD TH400 different from the regular one?
 
K5dreamer said:
I noticed today that the bellhousing on my TH400 has HD cast into it. I was unaware that there was an HD version of the TH400.

what makes the HD TH400 different from the regular one?
Click to expand...




IIRC, 4X4 cases and HD cases have more webbing and are a little thicker than 2WD cases.
 
I have 2 TH400 trannys in my basement and the one that came out of my M1008 has an HD like you talked about. Don't know what it means but I hope its good. I think my other tranny says 39 or something.
 
a quick google search got me really excited for a minute or two. it said something about a HD TH400 being known as a TH475, with strait cut planetary gears, and a tailshaft mounted E-brake...... and then i found out they were only in big delivery trucks and RV's. :(

so i guess it just means that the case is stronger. i read something about an inspection port being held on with bolts instead of screws, and the flywheel cover was aluminum instead of plastic. or something along those lines.
 
Transmissions with "HD" / "K" / "39" cast on them are all heavy duty versions of the 400. The difference is in the actual case, as stated, having more webbing and a flywheel cover made from aluminum (instead of tin) held on by 3/8" bolts. Afaik, all cases after '78~'79 are HD versions.

I don't believe there are any differences in the guts based on the case being an HD. The differences in guts (sprag, tailshaft length, etc) has more to do with application.
 
K5dreamer said:
a quick google search got me really excited for a minute or two. it said something about a HD TH400 being known as a TH475, with strait cut planetary gears, and a tailshaft mounted E-brake...... and then i found out they were only in big delivery trucks and RV's. :(

so i guess it just means that the case is stronger. i read something about an inspection port being held on with bolts instead of screws, and the flywheel cover was aluminum instead of plastic. or something along those lines.
Click to expand...




I have a TH475 :D !

IIRC, they're rated for vehicles with a GVWR of 33,000LBS :eek1: !
 
You must log in or register to reply here.

Latest Posts

Top Bottom