Rear and Speedo problem.

[gotmonte]

Hi everyone. I have an 85 monte and we subplanted (well the previous owner did) a 355 into the car and a th350 with a 12 bolt and 4.56 gears.

heres my problem. My speedo doesnt work. Doesnt register. I brought it to the mechanic and he said the gear is missing? Some gear for the rear or something like that. Anyone know what he was talking about? And if you do know what is he talking about, how do I go about getting that gear and what would it entail to get it working? What exactly do i need?

I am tired of every friggin car I have not having a speedo.

 

[beermonkey9417]

its prob. eather the driven gear or the drive gear in the trans. theres a cable that goes from the speedo to the trans. its held on with one nut or screw and if taken off trans fluid will pour out and there will be a gear attached(driven gear) and if you look inside the hole there will be shaft with a spiraly gear on it(drive gear). to get the speedo to read right you need to know how many teeth the drive gear has the rear end gearing and the size of the tire. then go here http://www.bgsoflex.com/speedo1.html this should help. you prolly only need the driven gear but just to make sure call them or email to get yer questions about it and if you dont want to do the work take it to a trans shop. the only reason i know all this is because i have a th350 and the speedo on my elky doenst work and i have to do this here gear swaping. good luck!

 

[85 Cutlass Brougham]

I would tend to think the drive gear is missing and not the driven gear. This is because a missing driven gear would cause a massive fluid leak. However, since you have a TH-350 it is easy to install a driven gear. You will have to remove the tailshaft to get to it, but that is not a hard task.

 

[leftrightother]

If you don't know your tire Diameter and want an easy way to fig it out go here:

http://www.tciauto.com/Products/TechInf ... _gears.asp

 

[beermonkey9417]

i didnt have to remove the tail shaft to do mine. thats odd i guess...

 

[leftrightother]

i didnt have to remove the tail shaft to do mine. thats odd i guess...

I am guessing that you just changed the driven gear then on the side of the trans.