Transmission / Overdrive: speedometer

[bobkat820b]

hi all I am new to the world of Studebaker ... I recently purchased a 1960 red lark 6 cyl with od ... I have lots of questions but right now I would like to find out how I can correct the incorrect speedometer ... it is reading a constant 20% over the actual speed ... any suggestions? ... you can reply here or directly to my email ... bobkay820b@gmail.com ... thanks ... bob

[JohnM15]

Welcome to the world of Stude. I think what you need to do is find where the problem is (duh!). Is tire size different from standard? Has your differential ratio been changed? Getting you production order from the Studebaker Museum can tell you about the tires and axle ratio as shipped.

[bobkat820b]

thanks for the quick reply but whatever the cause is i need to reduce the speedo reading by 20% ... any suggestions?

[pdrnec]

Speedo drive gear at the transmission is available with different number of teeth - you need to know the tire size and differential ratio to find the right one in the parts book.

[Steve L]

Try PATC Transmissions., Bossier, La (888) 201-2066. They carry ratio adapters that you place between the trans housing & the cable. Screws right on. They have some standard units, but can make any ratio you want. They have a nice internet site, take a look. I just bought one & installed.
Wanted a 25 % reduction, but would had to have waited for the right gears to come in. Settled for a 26.3 % reduction (stock) $62+ 8 postage & it works great. If you are going to be into the trans, you can do it a lot cheaper by just changing the gear rings. Probably less than $30. I could only find one speedometer shop in the St Louis area & they wanted $150 to fix it.

I used our GPS system to calculate actual speed compared to speedo reading to get my ratio.
It can also be done by tire size, rear end ratio & other factors that I believe they also show on their site.

[GEEMAC]

I use Speedometer ServiceCompany, 5801W.Villard Avenue,Milwaukee,Wi 53218 Phone=414-463-6660. Have been in business since 1920, Have had very good luck with these folks at reasonable prices,ask for Rodger Luckow. Mac

[bobkat820b]

thanks for the info on PACT ... i see they should have the adapter to at least get my speedo to to be close to accurate ... i am wondering that if i did the caculations and found that i need a different pinion gear in the trans with a different number of teeth than the one that is in there now, if that can be replaced on its own without taking the trans apart to replace the ring gear that is inside the trans ... anyone know? ... once again thanks to all for such helpful info ... Bob