Jonathan@Tick

iTrader: (5)

Just pulled the gear out of my car again today. The gear that came in the moser 12 bolt lasted about 4 trips to the dragstrip before it became unbearable to ride in due to all the whine. It done fine for about two weeks of highway driveing, but every trip to the strip it became worse instantly. Then I put a new Motive gear in the car and it too has done the same story. I set the pinion dept exactly as it said too using the new ratech 12 bolt depth tool. Now you can hardly even hear the radio at highway speeds! It roars more when it is pulling than when it is coasting. Can a gear set flex? The noise starts instantly after a pass or two at the strip. The car has turned a best 60 ft. last week of a 1.46, am I just going to have to live with the noise if I plan on leaving the line at 6,000 plus rpmS?

pewterta

iTrader: (6)

that realy sucks..i wasa all excited about changing my gears cause they whine like hell...now it looks like it cant go away...god i should of jus kept my 10bolt

mzoomora

iTrader: (36)

You can bend teeth on a pinion. Usualy though you can run a 1.4 60 ft no problem. A 12 bolt just isnt the ideal rear if you are trying to leave at 6000 rpm. The 9" has 3 bearings supporting the pinion, and takes hard launches better. First thing to do would be to recheck the pinion preload and then the backlash in 4 places on the ring. If you used a crush sleeve they will collapse slightly usually after 1 hard launch.

flexybronc

How do you break them in?

Jonathan@Tick

iTrader: (5)

Talked to the guys at Richmond and Mark Williams today about the problem. They both said that there was no street gear that can take the abuse of a 6,000 rpm clutch dump of a stick car. Mark williams can cryo treat the gear for added stregnth, but they said it still wouldn't last very long. They suggested to run a pro gear and take the car off the street, or to back the launch rpms down. The problem they said was that the teeth on a hard launch would actually bend or fold under the pressure, thus creating the terible whine. They also said that the same thing would occur in a 9". I guess I'll just put a posi back in it with another new gear and start launching it at around 4,000. The spool sucks for the street anyway.

Scott@DrivelineSolutions

iTrader: (22)

B.S. I leave off a trans brake at 4500 on a NOSed 3320lb Camaro and go 1.31 60' on a street gear. It can be done you just gotta get the rear set up right. Gear noise is a sign someone didn't do the job right.

P.S. I use 80w-90 wolf'shead oil and I have yet to hear a peep out of my axle.

mzoomora

iTrader: (36)

Is this a 9"? That wouldnt suprise me. A 12 bolt, I would be impressed. As far as set-up, it it was quiet before, I dont think set-up is the problem. I have heard from guys installing gears that were quiet for a couple of months, until they took it to the track. The shock can hurt them pretty quick. I agree with you though, a 9" street gear can withstand that kind of abuse w/o problems for a good while.

tump

Yep thats what 12 bolts do after a good beating, Try a louder Stereo system,thats what I did.

Steve Burger

iTrader: (33)

Call Jay Billingsly and ask how he fixed this on my Moser 12 bolt. It had to do with the pocket the pinion race sits in not being machined right. They could not get pinion depth right without a little machine work. I launch hard all the time and have had a quiet Moser for a year now.

Still owe Jay and Brian a steak dinner for that one.

1ScrudeDude

Or you can get a Harlan Two Step and launch ~3500 to 4000 rpm on an M6.

Any 12 bolt that you take to the strip will whine shortly thereafter.

Mine howls because of a horrid misshift and ongoing wheelhop issues.

Loud on the gas, quiet on coast. 60-73 mph in5th or 6th rings my ears.

Tranzor

That's exactly what mine is like... in that exact mph range in those gears too. 6th is the worst for me. But, the upside to it is my gear still look fine after a whole season of drag racing and leaving at high rpms... unlike my 10 bolt gears which were destroyed after a few hard launches on Nittos.