BOP TH350 speedometer gears (large diameter) - Third Generation F-Body Message Boards

99Hawk120 · 01-24-2003, 10:04 AM

Okay, I'm changing the speedometer gears in my TH350 to accomodate a 2.41 -> 3.42 gear change, and I'm running into a problem: I cannot seem to find the right speedometer gears. I need to use a 17 tooth red drive gear and 45 tooth light blue driven gear. These are all for a CABLE DRIVEN speedometer assembly.

I have head that the large diameter TH350 gears are the same as the gears on the 700R4; the drive gears certainly look identical. I have a 17 tooth red 700R4 gear, so if that will work, I'm set there.

The driven gear and sleeve is proving to be a problem though. I gave the GM dealer the part number (25513052) from the TGO FAQ, and he says the sleeve is 40 something dollars and discontinued, but he sent me the gear anyway. I got the gear, but it doesn't do me any good. The original gear is molded with a long shaft sticking out of it; this gear has no shaft, but rather a small "D" shaped hole in the center. It looks as though it is for an electronic sender (like on the later thirdgens).

Does anyone have the correct part numbers for the NON ELECTRONIC sleeve and driven gears for the 700R4? Or a source for them besides GM?

Apeiron · 01-24-2003, 11:30 AM

Yeah, you've got a gear for a VSS. I'd have to dig for the sleeve P/N, but you can get the gear P/Ns from <A HREF=http://members.shaw.ca/crussel/speedo.exe>this.</A>

99Hawk120 · 01-24-2003, 12:12 PM

I think I'm going to go with a 15/39 combo instead of 17/45, that way I don't need to spend $30 on a new sleeve.

I came up with 864260 for the 15T gray gear and 1359273 for the 39T brown gear.

Nordbert · 01-27-2003, 03:22 PM

Check out a 25512339 on www.gmpartsdirect.com. It is for
40-45 teeth. I found it at www.transmissioncenter.net if you
want to look at their gear chart. I put this stuff in "favorites"folder
so it is easy to look up.

99Hawk120 · 01-27-2003, 03:26 PM

Yeah, I did eventually find the sleeve #. I still don't want to pay $30 for it if I can avoid it.