speedo driven gear keeps getting chewed up
 

The driven gear, 23 tooth one for my 3.73's, keeps getting chewed up. the drive gear looks fine. I only take a couple thousand miles and then it is junk. I have had this problem with the tranny in an 81 coupe and also in my 93 coupe. Same t-5, different cable, cluster and VSS .

94 cobra t-5 with a 93 cobra input shaft and input retainer conversion for the 93 car.

Any Ideas? Thanks

The 23 tooth driven gear for the 90 and up AOD's and T-5's are needed for 3.73 gears. The trans that year came with an 8 tooth drive gear. If you have a T-5, just go to a trans shop and have them remove the tailshaft and replace the 8 tooth with the 89 and older 7 tooth drive gear. With 3.73's I believe your driven gear goes to a 19 tooth,(red). Look at a 19 tooth gear vs. a 23 tooth gear and see how much thicker the gears are on the 19 are vs. the 23. There's your problem. The teeth are too thin on the 23 to last any length of time. AOD people are going to have it tougher as the whole trans must be disassembled to remove the tailshaft housing and install a 89 or older tailshaft housing. The drive gear is machined into the AOD housing making changing the housing the only alternative.

Thanks for the help. To bad I found this problem after I reinstalled my t-5 for a leaky top cover reseal job. Here is a link that covers all the gear combos. The 6 tooth drive gear is supposed to be better for numerically higher gears. http://www.geocities.com/mgnedell/n...ech/speedo.html

Or - you can have a speedometer shop install an inline mechanical gear-box to correct the ratio (for under $100 parts & labor). If you don't have any shops local, you can remove your speedometer cable and mail it to someone like www.powls.com (that is what I did to correct my 4.10's - and it works great).

Does the gear box depend on the origianl gear that keeps breaking, the 23 tooth, or does it replace the driven gear too?

You would put a 19 tooth gear back in - then get them to match the ratio for that. Basically, you are supposed to drive a known distance (like on the highway) of 10 miles, then tell them what your odometer says you went, then they make a correction box specific for your needs.

Solution
 

http://forums.stangnet.com/showthrea...er+Speedo+Gear


Try this link and read about a 23 tooth gear that is supposed to be stronger.