Is the the Speedometer assembly?
if so, will I have to drain the tranny in order to change the o-ring?
Thanks.

 

Yes and yes.

While you're there, the leak can be coming from two places. There's the large o-ring on the circumference of the speedometer drive itself, and then there's also an oil-seal on the shaft inside the cavity the cable end fits into.

 

Thank you.

To be sure i understand you correctly, if i change the o-ring i will first drain the tranny? Got it.

I also have an assortment of o-rings: Is the replacement o-ring a general enough size where a suitable sub can be installed, or do I need to go ahead and order an exact replacement?

I'm going to try the o-ring first before I begin having nightmares about dropping the tranny.

 

Yes, drain the transmission first. I tried to swap the o-ring without draining the transmission once; big mistake. You wouldn't believe just now much fluid came out of the speedo drive opening.

I just picked one from an assortment I had. I might have a spare speedo drive on the shelf still that I can measure for you later today.

 

I measured 24mm ID, 29mm OD, and 2.5mm thickness for the o-ring.

 

Thanks to all of you for your wisdom and suggestions. I gave it a (maybe) 1/2 turn twist. So far, dry as some good *** gin!