TH400 Bushing & Part Questions
Cruising
Joined: Feb 2004
Posts: 14
Likes: 0
From: Denton Texas
Re: TH400 Bushing & Part Questions (gtr1999)
replace bushings as necessary.
Sun shaft bushings aren't usually necessary.
Ever hear of a professional shop using B&M stuff....?
Should tell you something.
I ALWAYS replace pump bushing, output bushing, and direct drum bushing.
On a Th400 for HP use a 34 element sprag and early direct drum is a good upgrade, as well as a spirolock retainer on the race, I rollerize the rear planetary to the case.
Sun shaft bushings aren't usually necessary.
Ever hear of a professional shop using B&M stuff....?
Should tell you something.
I ALWAYS replace pump bushing, output bushing, and direct drum bushing.
On a Th400 for HP use a 34 element sprag and early direct drum is a good upgrade, as well as a spirolock retainer on the race, I rollerize the rear planetary to the case.
Cruising
Joined: Feb 2004
Posts: 14
Likes: 0
From: Denton Texas
Re: TH400 Bushing & Part Questions (comp)
Yes,
Keeping it tight is a good idea, but the TH400 sun shaft doesn't see much side loading so the bushings don't wear and aren't as critical.
The direct drum is centered by the center support and the sun shaft splines into the center of the drum.
On a Th350 however the sun gear is attached to the sun shell, and it receives alot of side loading because the direct drum "*****" the shell and gear under high loads.
You double up the bushings on the TH350 sun gear as a fix.
I've replaced sun shaft bushings maybe twice in the 100+ Th400's I've done.
Even in 1500 HP monster truck applications the sun shaft holds up fine.
A testament to the pure engineering/mechanical feat that a TH400 is.
Keeping it tight is a good idea, but the TH400 sun shaft doesn't see much side loading so the bushings don't wear and aren't as critical.
The direct drum is centered by the center support and the sun shaft splines into the center of the drum.
On a Th350 however the sun gear is attached to the sun shell, and it receives alot of side loading because the direct drum "*****" the shell and gear under high loads.
You double up the bushings on the TH350 sun gear as a fix.
I've replaced sun shaft bushings maybe twice in the 100+ Th400's I've done.
Even in 1500 HP monster truck applications the sun shaft holds up fine.
A testament to the pure engineering/mechanical feat that a TH400 is.
