Trans choice questions.

bert powell · 04-09-2013, 09:58 AM

Ok, I am looking to upgrade my transmissions. I have a GT/DA Camaro with the 402/300 engine, car weighs 3210. I have two TH400 with alum drums, etc. These easily last a 100 runs without much more than a fluid/filter change. Would like to upgrade and hopefully pick up some. Protrans out of my league currently. Here are some options:

Redo TH400s with some lightening (I have access to a machine shop to gundrill, etc) alum reaction carrier (help?). Probably not much faster but still bullet proof.

Kilgore TH400. Should be faster (any idea how much?) and I hear they have alot of the issues fixed. Will they last?

Build TH350 with alum drums, lightening. Any idea how much faster? Will it hold up?

Rossler or Coan TH350, can maybe afford one to start with. How much faster do you think it would be?

As a side note, I have a GM 904 core and could get another. Would they be strong enough behind a low hp big block with alum drums, etc? How much faster?

Have some concerns about these smaller trans behind a big block. You can PM me if you don't want to reply here. Thanks for any help you can give me!

Jim Kaekel · 04-09-2013, 11:22 AM

I would go with the TH-350. Get the aluminum forward and direct drums (with HD sprag). If you can find a TH-250, they have a lightweight sun gear shell, gun drilled output shaft and front planetary that uses a roller bearing. TCI sells a low volume pump that is reasonably priced. If you have machine shop access, you can lighten up the output shaft and planetaries as well. Also, convert all thrust washers to needle thrust roller bearings. Another plus is installing clutch separators in low/reverse, second and high gear clutch packs, which cuts down on rotational drag. The higher you spin the motor, the more the lightweight stuff helps. Just my .02.

bert powell · 04-09-2013, 11:27 PM

Quote:

Originally Posted by Jim Kaekel

I would go with the TH-350. Get the aluminum forward and direct drums (with HD sprag). If you can find a TH-250, they have a lightweight sun gear shell, gun drilled output shaft and front planetary that uses a roller bearing. TCI sells a low volume pump that is reasonably priced. If you have machine shop access, you can lighten up the output shaft and planetaries as well. Also, convert all thrust washers to needle thrust roller bearings. Another plus is installing clutch separators in low/reverse, second and high gear clutch packs, which cuts down on rotational drag. The higher you spin the motor, the more the lightweight stuff helps. Just my .02.

Thanks for the reply Jim! What are clutch separators?

Mark Yacavone · 04-10-2013, 12:23 AM

Quote:

Originally Posted by bert powell

Thanks for the reply Jim! What are clutch separators?

Bert, Are you thinking about building the 350 yourself? If you are, PM me and I will answer your question for you.

Jim Kaekel · 04-10-2013, 08:05 AM

They are short, round strips of rubber, a bit thicker than the steels, and are used to separate the clutches from the steels to reduce rotational drag. Alto Products actually makes them for the Powerglide that can be used in a TH-350 or TH-400 as well.

04-09-2013, 09:58 AM	#1
bert powell Member Join Date: Jul 2002 Posts: 243 Likes: 36 Liked 34 Times in 12 Posts	Trans choice questions. Ok, I am looking to upgrade my transmissions. I have a GT/DA Camaro with the 402/300 engine, car weighs 3210. I have two TH400 with alum drums, etc. These easily last a 100 runs without much more than a fluid/filter change. Would like to upgrade and hopefully pick up some. Protrans out of my league currently. Here are some options: Redo TH400s with some lightening (I have access to a machine shop to gundrill, etc) alum reaction carrier (help?). Probably not much faster but still bullet proof. Kilgore TH400. Should be faster (any idea how much?) and I hear they have alot of the issues fixed. Will they last? Build TH350 with alum drums, lightening. Any idea how much faster? Will it hold up? Rossler or Coan TH350, can maybe afford one to start with. How much faster do you think it would be? As a side note, I have a GM 904 core and could get another. Would they be strong enough behind a low hp big block with alum drums, etc? How much faster? Have some concerns about these smaller trans behind a big block. You can PM me if you don't want to reply here. Thanks for any help you can give me!

04-09-2013, 11:22 AM	#2
Jim Kaekel VIP Member Join Date: Jul 2002 Location: Michigan Posts: 1,227 Likes: 133 Liked 531 Times in 108 Posts	Re: Trans choice questions. I would go with the TH-350. Get the aluminum forward and direct drums (with HD sprag). If you can find a TH-250, they have a lightweight sun gear shell, gun drilled output shaft and front planetary that uses a roller bearing. TCI sells a low volume pump that is reasonably priced. If you have machine shop access, you can lighten up the output shaft and planetaries as well. Also, convert all thrust washers to needle thrust roller bearings. Another plus is installing clutch separators in low/reverse, second and high gear clutch packs, which cuts down on rotational drag. The higher you spin the motor, the more the lightweight stuff helps. Just my .02. __________________ Jim Kaekel 3836 STK

04-10-2013, 08:05 AM	#5
Jim Kaekel VIP Member Join Date: Jul 2002 Location: Michigan Posts: 1,227 Likes: 133 Liked 531 Times in 108 Posts	Re: Trans choice questions. They are short, round strips of rubber, a bit thicker than the steels, and are used to separate the clutches from the steels to reduce rotational drag. Alto Products actually makes them for the Powerglide that can be used in a TH-350 or TH-400 as well. __________________ Jim Kaekel 3836 STK