Dave@KTS

O.K. Guys, Been in contact with several manufacturers on the axle issue.

Moser says all castings for the 12 bolts are Moser's own U.S. made, They claim that the only complaints are from the Torque arm suspended cars. The connection of the arm is at such a location that resonates the harmonics of the gears. This is then amplified thru the torque arm like a tuning fork.

I also have been in contact with GM on this issue. Attached is a GM service bulletin that was issued some time ago reflecting torque arm axle noise.

Moser claims that they sell 20 12 bolts everyday pretty much 5 days a weekwith very few complaints. The complaints they did investigate were the result of not breaking in the gear properly, also severe positive pinion angles
and after market installed parts such as lower control arms, torque arms and drive shafts.

As you guys know anything other than a stock rubber bushing will transmit harmonics and road feedback.

Moser says that they have no complaints with their 12 bolts for the A or G body vehicles, something else that they pointed out was the fact that no one has complained of breaking one of their 12 bolts.

I also talked with several gear companies and they also stand by this torque arm noise problem. Not only for the 12 bolts but the 10 bolts as well. The 9" housing has no noise problems because the torque arm bolts to a bracket that bolts to the housing.

Well that's the skinny on what the manufacturer's have to say. This is not my conclusion for I have not gone through one of these noisy units yet.
That story is yet to come.

Thanks,
Dave K.
KTS Race Cars

Dave@KTS

Here is the bulletin

cyphur

iTrader: (10)

cool. glad i have a moser 9"

1ScrudeDude

Dave, thanks for the info.

The claims by the 12 Bolt manufacturers make some sense, but what about when your rear goes from dead silent to a howling banshee after some track passes?

The torque arm didn't just appear at the timeslip booth!

LightweightZ28

iTrader: (2)

Sorry if I missed it in another post.....but have you talked to Strange about your 12-bolt getting louder and louder? If so, what did they say? My Strange got marginally louder after its first track visit. I had been told that some believe the crush collar gets crushed more than it should be on hard launches and throws settings off. However, guy at Strange told me that they don't use crush collars. Maybe when you get a free moment you can see what they tell you about that.

1ScrudeDude

I called Strange about it, and they were so-so helpful. They asked if I followed in the break in procedure, and I told them "religiously."

He then said to take the car to one of their authorized dealers here in FL, but that was 3 hours away. And if nothing was wrong, it appeared as though I was going to get stuck with the labor charges, so I said "screw it."

Dave@KTS

Yes I hear what you guys are saying.
When I asked why are they quite when
new and than get noisey they replied
with the break in issue. Did you guys honestly
go 500 miles under 50 mph?
I know I never ever did! Thats insane!
Like I stated at the end of the post,
This is not my conclusion and I will
try to help you guys out with some kind
of helpfull info. I am a Moser dealer but
I do put the customer first.

Dave K

Dave@KTS

Yes on the Strange 12 bolts.
Strange seems to have the same problems.
You dont hear as much because they dont
sell near as many. Moser does sell way more 12 bolts.

Dave K

JRick212

iTrader: (6)

What about currie? I have not seen any info regarding curries 12 bolt. I have done searches and can barely find anyone that has one.

Tally TransAm

iTrader: (17)

fyi on the 9" thing

broke mine in for 500 miles under 50 mph and my 9" made some noise, very bareable though. after 1 trip to the track (5 passes) the bitch screamed so damn loud i couldnt drown it out with my radio. swapped carriers and put the same gears back in and it barely makes any noise at all now. im convinved if i would have had it set up correctly to begin with it would be silent

im convinced its in the setup

Dave@KTS

What make is the 9" you have

Dave K

glennster

iTrader: (1)

I bought my moser 12 bolt used with over 8k on it and it was quieter then most stock 10 bolts I had heard.I even bragged about it on here after I did the swap.After 2-3 track jaunts it absolutely screamed on decel and clunked bad down to a stop,it was so unbearable I rebuilt it with new gears,solid pinion sleeve and yolk.I'm breaking it in now,slight audible whine at 45-55.Love it now.

Tally TransAm

iTrader: (17)

moser

Billingsley Racing

iTrader: (4)

In our testing, we have found the "after track noise" to be bent ring/pinion teeth. This seems to increase with lower ratios. As good as the 12 bolts are, there is only so much they can take. The available torque and weight that most of these cars have combined with a good suspension is a real test of drivetrain components.

pewterta

iTrader: (6)

so that means how much horse power are the 12 bolts really ok with???

Dave@KTS

Moser claims the 12 bolts are good for 1000-1200 hp

Dave K

Scalpel

iTrader: (4)

It's the weight of these cars that kills the rears, moreso than the HP.

Launching a 3600lb+ car w/slicks at revlimiter dumps will break nearly all race rear components.

Dave@KTS

Thats why you get the Pro cut gears.
The cut is designed for drag race use.
I hate the street/strip concept.
Never works trouble free.
And Never Ever will!

Dave K

Scalpel

iTrader: (4)

Exactly.

mzoomora

iTrader: (36)

The difference between the Pro gears and Street gears is more than just the cut. The material is softer and designed to give some and bend rather than break. So as far as noise goes, they will most likely generate more noise, and will deffinetly wear out sooner due to the softer material.