speedometer gear replacement

[canner78]

i was wondering how you replace the speedometer gear in a 904 tranny. i have a new gear and i was planning on putting it in but i was told you have to buy a gasket set before you do it. i have replaced chevy ones before and they just have a o ring seal. are mopar ones different. what do i do to change it. thanks for the help.

 

[canner78]

does anybody know? i would really like to get this done tonight.

 

[H22A4]

I would replace the seal only if it was leaking. When I put in my new speedo gear last month, it wasn't leaking past the shaft end so I didn't replace the seal that was in the speedo cable housing.

 

['64 Cuda]

If you have the style that came out in 66 & was used up until I-Don't-Know-When, the adapter has a special O-ring. It's red & made of a special material that is supposed to swell up once it's in contact with the trans lubricant to give a better seal. (This is the big O-ring, about 1 1/2" in diameter. I don't know about the smaller one insite the gear.). I needed one & was told by a Mopar dealer that I had to buy the whole adapter with the O-ring for almost $20. I tried using a regular O-ring but had trouble finding one the right size & it always leaked, even after I gooped it up with a bunch of heavy grease to help it seal. I ended up ordering the correct style one from a local Pronto Auto Parts. Don't remember the price but I think it was well under $2. I ordered a spare just to have around.

 

[fishy68]

How you replace it wasn't addressed so here goes. Unscrew the speedo cable from the adapter. Then it takes a 1/2" wrench or socket to remove the retainer holding the adapter in place. BTW: You should spray it down with brake cleaner or carb. cleaner before starting so you don't get anything in the trans. The adapter is clocked a certain way depending what speedo pinion is used. You'll see numbers on it with a line to align on the ext. housing according to what gear your using. I always install it using the highest number setting first then turn it to the correct location for your speedo gear. Install the hold down and screw the cable on and your done.