8 3/4 problem

[whitey]

I got a set of 3.31's put in my 741. Since then I have a noise. It sounds like a rattleing/rubbing, it kind of sounds like when you taped a playing card to your bike for the spokes to hit it. I have the limited slip addative in it. It doesn't sound like any bearing I've heard before.

Anyone have any idea what it could be?

 

[demon seed]

Are you sure they're 3.31 cuss I've never heard of that ratio, regardless there's obviously something wrong inside, preload, mesh, depth, hell could be almost anything. Take it back to the person/shop that did the setup/install and have them fix it.

 

[6pk2goDemon]

Is it the cone type SG ? Mine made a bit of this noise on decel when almost stopped (5-10 mph). I don't have many miles on it, but I think (hope) it's gone. It was "rebuilt" by a local machine shop.

 

[whitey]

Are you sure they're 3.31 cuss I've never heard of that ratio, regardless there's obviously something wrong inside, preload, mesh, depth, hell could be almost anything. Take it back to the person/shop that did the setup/install and have them fix it.

Here's from 'mymopar.com':

"Gear ratios available on the 8-3/4" axle through the years include: 2.76, 2.93, 3.23, 3.31, 3.55, 3.73, 3.91, 4.10, 4.56, 4.89, 5.17, 5.57. On OEM gear sets, the ratio is usually stamped on the ring gear edge."

I took the car to the guy who set up the rear, after hearing the noise he said it was a cracked tooth.

 

[daredevil]

Here's from 'mymopar.com':

"Gear ratios available on the 8-3/4" axle through the years include: 2.76, 2.93, 3.23, 3.31, 3.55, 3.73, 3.91, 4.10, 4.56, 4.89, 5.17, 5.57. On OEM gear sets, the ratio is usually stamped on the ring gear edge."

I took the car to the guy who set up the rear, after hearing the noise he said it was a cracked tooth.

cool he found it before it ruined a case

 

[demon seed]

Here's from 'mymopar.com':

"Gear ratios available on the 8-3/4" axle through the years include: 2.76, 2.93, 3.23, 3.31, 3.55, 3.73, 3.91, 4.10, 4.56, 4.89, 5.17, 5.57. On OEM gear sets, the ratio is usually stamped on the ring gear edge."

I took the car to the guy who set up the rear, after hearing the noise he said it was a cracked tooth.

Sorry, I guess I should have been more specific in saying for the last quite a few years that only "new" gear sets available for the 741 have been 3.55, 3.73 and 3.91. Most of the other selections have been phased out years ago for the 741. The 742 still has lots of new gear set selection. I'd be curious to know if that 3.31 gear set was brand new "out of the box" when your guy installed them.

 

[whitey]

No, those gears were used, I got them off ebay. Visually there was no defect in the gear set. BUT, I guess it can be just like a head or block, there could be a crack that fluxing could find that the eye can't.

True Daredevil, found before it ruined the case, but more importantly the sure grip unit, I do have another 741 case with a non SG unit that I could have used.