I am wondering the proper way to get the stock 1956 Laurentian speedometer working on my TH400 transmission. It looks like it would screw in ok (I'm guessing, I have not trid but the threads and size look similar). Are there some sort of modifications I would have to do? Any information on getting the stock speedometer to work correctly using a TH400 trans would be greatly appreciated.
67Poncho said
Aug 4, 2011
I know in my '53 Bel-Air when I installed the 4-gear Saginaw, it virtually fit perfectly! I am sure it will go but you may have to change the drive or driven gears to be accurate with the tirse and wheels that you will be using!
dualquadpete said
Aug 4, 2011
67Poncho wrote:
I know in my '53 Bel-Air when I installed the 4-gear Saginaw, it virtually fit perfectly! I am sure it will go but you may have to change the drive or driven gears to be accurate with the tirse and wheels that you will be using!
Had to do that on my 64 Catalina when I pit in the turbo 350. I went to local trans shop, told him what gear ratio I had in rear end & what the tire dia. was, & he ordered the 2 gears for inside trans. & it's so close to my GPS speed [only off by maybe 2 mph]
seventy2plus2 said
Aug 4, 2011
I can't see this as being a big problem, just connect the speedo cable into the TH400. Once done, do a speed check (or better yet an odometer check over about 10 miles) . If odometer is reading high, change the gear in the TH400 to one with more teeth. If reading low, change the gear to one with less teeth. The gears are all color coded.
I am wondering the proper way to get the stock 1956 Laurentian speedometer working on my TH400 transmission. It looks like it would screw in ok (I'm guessing, I have not trid but the threads and size look similar). Are there some sort of modifications I would have to do? Any information on getting the stock speedometer to work correctly using a TH400 trans would be greatly appreciated.
I know in my '53 Bel-Air when I installed the 4-gear Saginaw, it virtually fit perfectly! I am sure it will go but you may have to change the drive or driven gears to be accurate with the tirse and wheels that you will be using!
Had to do that on my 64 Catalina when I pit in the turbo 350. I went to local trans shop, told him what gear ratio I had in rear end & what the tire dia. was, & he ordered the 2 gears for inside trans. & it's so close to my GPS speed [only off by maybe 2 mph]
I can't see this as being a big problem, just connect the speedo cable into the TH400. Once done, do a speed check (or better yet an odometer check over about 10 miles) . If odometer is reading high, change the gear in the TH400 to one with more teeth. If reading low, change the gear to one with less teeth. The gears are all color coded.