Weirdest thing I've seen. Did a , nothing similar showed up.

Put the drive and driven gears in several years ago when I put in the 2.93 rear. A little less than 2 years ago, transferred them over to the fresh '83 TH700, which had what looked like a replacement tailshaft housing on it. Speedo has worked fine all this time, but when I pulled them out this past weekend to change the speedo gears for the 3.23 rear going in, the tops of the teeth of the driven gear (41T) look like they've been shaved off in a lathe - the tops of the teeth are squared off, not sheared like you would expect with a hard-to-drive speedo or cable. The teeth still engage the drive gear (just replaced the drive gear, 17T to 15T, for the 3.23's), speedo still works fine, how this happened is beyond me. Didn't find any plastic shavings in the pan (although I wasn't looking for them when I drained the tranny).

At first I thought it might be the drive gear clip loop coming around and clipping the driven gear, but the more I think about that, the less I think that's likely.

Oh, the driven gear housing is the correct one for 39-up tooth gears.

For the record, the speedo cable and cruise are from the '86 donor car, which didn't use the mechanical cruise governor. Cable goes directly from tranny to speedo.

 

The hole in the speedo cover where the gear goes in is probably elongated. When this happens, you get the results you see. Replace it with a good one.

 

I didn't feel any slop, and it was fine in the other transmission.

The speedo works fine. Really weird.

Suppose I can get a new housing if & when I decide to get a new driven gear. Still need to get a hold of TCI and let them know the 40T driven gear they sent me didn't have the right shaft, wouldn't fit in the housing. Perhaps take care of it then.

 

I had several shave off in many different 700`s...speedo always worked though

 

Which hole in the output shaft did you use to hold the drive gear in place? The front hole or the back? The correct one is the front. If you use the back hole, it can destroy the driven gear.

 

I don't recall which the old gear was in. When I put the new one on, I put the tailshaft housing on, eyeballed it and said, "That ain't right," and discovered it was in the rear hole. Moved it to the front hole for this install.

I very well may have had it in the rear hole before. I can't remember details from Aug '05 when I last put it together (thought I was trying to put it back together the way it was, though).

I'm still baffled why it shaved across the entire width of the gear. Not cupped or slanted or anything. And why the speedo still works, for that matter.

The 41T is a little too slow (I was showing 86 MPH going through the traps today, timeslip said 94), so I'll try to get a 40T and new housing to go with it, and make sure it's all together like it should be.