TH400 Speedometer gears
Thread Starter
Tech Contributor
Joined: Aug 1999
Posts: 15,130
Likes: 3,938
From: Connecticut, USA
TH400 Speedometer gears
Anyone have the gear color/tooth count for the driven and drive gears for a TH400 with 308 and 336's. I looked through my books and couldn't find anything for the Th400. Not sure if the drive gear is the same for both and just the driven gear needs to be changed.
Thanks
Thanks
The ORIGINAL and bestest
Joined: Oct 2000
Posts: 10,009
Likes: 240
From: Toronto Ontario
Toronto Events Coordinator
Thread Starter
Tech Contributor
Joined: Aug 1999
Posts: 15,130
Likes: 3,938
From: Connecticut, USA
Thanks guys,
The book I have lists up to '71 and for the TH400 with the 350(base?) and the Sp H/Per 454 it lists GM # 8623311 for the drive for both the 308 & 336. The 308 driven is listed as #1359271 which the book says is 37 tooth Red. The 336 driven is # 1362195 41 tooth yellow.
The driven in this 72 th400 is white and is the original. That would be a 36 tooth gear # 1359270
Can anyone confirm this? I believe I only need the driven gear to go up to 336's but the book also lists a H/Per 454 which has different part #'s.
Unless the system changed in 72?
The book I have lists up to '71 and for the TH400 with the 350(base?) and the Sp H/Per 454 it lists GM # 8623311 for the drive for both the 308 & 336. The 308 driven is listed as #1359271 which the book says is 37 tooth Red. The 336 driven is # 1362195 41 tooth yellow.
The driven in this 72 th400 is white and is the original. That would be a 36 tooth gear # 1359270
Can anyone confirm this? I believe I only need the driven gear to go up to 336's but the book also lists a H/Per 454 which has different part #'s.
Unless the system changed in 72?
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
Originally Posted by gtr1999
Thanks guys,
The book I have lists up to '71 and for the TH400 with the 350(base?) and the Sp H/Per 454 it lists GM # 8623311 for the drive for both the 308 & 336. The 308 driven is listed as #1359271 which the book says is 37 tooth Red. The 336 driven is # 1362195 41 tooth yellow.
The driven in this 72 th400 is white and is the original. That would be a 36 tooth gear # 1359270
Can anyone confirm this? I believe I only need the driven gear to go up to 336's but the book also lists a H/Per 454 which has different part #'s.
Unless the system changed in 72?
The book I have lists up to '71 and for the TH400 with the 350(base?) and the Sp H/Per 454 it lists GM # 8623311 for the drive for both the 308 & 336. The 308 driven is listed as #1359271 which the book says is 37 tooth Red. The 336 driven is # 1362195 41 tooth yellow.
The driven in this 72 th400 is white and is the original. That would be a 36 tooth gear # 1359270
Can anyone confirm this? I believe I only need the driven gear to go up to 336's but the book also lists a H/Per 454 which has different part #'s.
Unless the system changed in 72?
I show for a 72 with 3:08 #1362049(42T-green) and for the 3:36 #9774413(34T-Lt.green)both use the same drive gear#8623313--T.H. 400 (350,Sp.H/Per.454) and (T.H. 400 w/H.Per.)(454)
Thread Starter
Tech Contributor
Joined: Aug 1999
Posts: 15,130
Likes: 3,938
From: Connecticut, USA
ok now that makes it even more confusing! I asked this on the NCRS site too and they confirm my numbers! I'm not doubting you I just don't know which is the way to go until I get the 336 in and build the diff.
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
I got this from the Corvette parts and Illustration catalog and its not entirely clear.I was trying to compare diff years and see how many teeth needed to be changed to make up the diff (3:08 to 3:36),but its diff when you get to 72 for some reason.I'll keep checking and see if I can make sense of it.
gtr - I tried to scan and copy these pages but I cant seem to get them clear. I went back and compared diff. years for 3:08 to 3:36 and the diff. is 3 to 4 teeth depending on tire sizes.I think the tire size is what makes it confusing.I also think they did some number changing.The book shows that you should have 37 teeth for a 3:08 and for a 3:36 you should have 41.Hope this helps.
EDIT --OK hold on I just contridicted myself.Give me few min. and I will get you copys.
EDIT-sorry I cant get it-maybe somebody else that has the catalog can show you the speedo gear chart-there is about 6 pages for the turbo's
gtr - I tried to scan and copy these pages but I cant seem to get them clear. I went back and compared diff. years for 3:08 to 3:36 and the diff. is 3 to 4 teeth depending on tire sizes.I think the tire size is what makes it confusing.I also think they did some number changing.The book shows that you should have 37 teeth for a 3:08 and for a 3:36 you should have 41.Hope this helps.
EDIT --OK hold on I just contridicted myself.Give me few min. and I will get you copys.
EDIT-sorry I cant get it-maybe somebody else that has the catalog can show you the speedo gear chart-there is about 6 pages for the turbo's
Last edited by ...Roger...; Nov 8, 2006 at 09:37 AM.
