What is a TH-475...?

:Smarty: What is a TH-475 Transmission? I heard that they are TH-400 trans,used in motorhomes,they have straight-cut gears,low gear set(2.75 vs.2.48,extra clutch pack,etc.) Advantage,Disadvantage...I don't hear of anyone using a TH-475....I'm just asking. Jay B.Britt,Jr.

 

Everything I can dig up pretty much indicates that the TH475 has straight-cut gears, a heavier case, and provisions for a tailshaft mounted parking brake, sometimes has a bolt-on rear yoke, and deep pan. They were used in heavy duty trucks and motorhomes.

I think the reason you don't hear about any of us Buick guys using them is that they were a Chevy bellhousing pattern only. The TH475=3L80HD

 

Would it be possible to take the guts out of a TH475 and install them in a BOP TH-400 case? Or does the "heavier case" of the TH475 make this impossible? Just a thought.

 

They were also used in FWD Eldorado's behind the 500.

 

The FWD Eldo/Toro/GMC motorhome trans is a TH-425. I haven't worked on a TH475, but likely most all the parts & case interchange between a TH400. The heavy duty transmissions had more clutch plates, and some had extra bracing molded into the case, same internal dimensions. Bruce Roe

 

the c50 c60s had them

 

Id expect that set up to be loud in a passenger car.

 

My question is, "Who's breaking TH400's so much that they need one?"

 

Now the can of worms is open, anything can be broken. Can you overload the 400 we know the answer is yes, weight, traction, gears, drive shaft, lets say we double all that strength wise, Whats gonna give next assuming we have enough power.

Then there's a question of the extra clutch's, do we have a slower shift, or is there any way to improve on shift speed.
Just a thought.
Wil