Joe Kizzire

Gears.... You cannot buy a quality gear for a 12 bolt anymore.

I've had cars with 12 bolts since 1968 and have had good service from them until GM quit making the gears. At first it wasn't to bad but then the aftermarket gears became worse and worse and have gotten to the point you can set one up (and I'm including all of the manufacturers because I've use all of them) and they would be quite, drive them around for two or three hundred mile and then the first time you would go to the strip and let the clutch out on slicks you get a whine on the coast side. The reason for this is the teeth on the ring gear is bending. The gears are not hard enough hence the gear manufacturer want you to do a two to five hundred mile break-in period with the hope that the heat cycling will do the heat treating that they (the manufacturers) should have done.\

With the 8.8 and 9 inch Ford you can buy the Motorsports gears which are made buy ford to their specs and you do not have this problem.

Their is one thing you can do that will help on the 12 bolt. You can chamfer the teeth on the ring gear at the top of the coast side with a file at a 45 degree angle. This will make it better when it does bend. It won't be as noisy. We use to do this back in the sixtys and it works.

StevieZ

iTrader: (3)

I just recieved a new set of gears because the ones in my NEW Strange 12 bolt went south after 400 miles . ( they sounded like a chain saw!) The new ones I was sent are Strange Motives and the box said
"Made In Italy".
I don't have much faith in these either!

mjf454

Remember Zoom gears? Talk about crap, and they were still better than what you can get today.

Joe Kizzire

Yes I remember Zoom gears. I use to use Sheiffer's some. They were OK. When Richmomd first started they were good gears but as time went on quality went down. You would think with CNC machining somebody would use good heat treating and produce a quality gear.

mjf454

I think today it is all about getting the most money for the least amount of work.

jimmyblue

iTrader: (11)

All "race" gears are ductile so they won't break.
The 12-bolt aftermarket is almost exclusively race
oriented.

Maybe you could find some NOS (New Old Stock, not
nitrous) old GM gears if you rooted around long
enough. Failing that, maybe just getting them
from a junkyard '70s Chebby truck and redoing the
clearance setup is a way to go. After all, what
is wear on a gear that thick, but a lash problem?

StevieZ

iTrader: (3)

If pinion depth was off, then the wear pattern will be uneven and no amount of adjusting the lash will correct it. It will always be noisy and running on one side of the tooth.