I purchased this car awhile back and the guy said it had different gears in it. I'm not sure which ones if any. The 10 bolt 7.625 housing for my car says its suppose to have 2.73 gears but idk, I'm not familiar with rearends. Also it looks like they have some wear on it in the middle, anybody know how that's happening and if it's a problem?

 

The gear ratio will be stamped on the ring gear. Something like 45:11 or so. Divide the numbers to get your ratio. From those markings in the carrier, I'd say your pinion isn't set right and is rubbing the carrier. Not a good thing.

 

Wow...I've never seen that before. So that's got to be pinion depth, right? Too many shims between the pinion and bearing?

 

No, those marks are from a pinion that has been loose. If the pinion nut backs off or a pinion bearing goes bad it will allow the pinion to make contact with the differential case. If you tried to set the pinion deep enough that it made contact with the differential it would be way too deep to actually run that way.

You already have the cover off, so just count teeth. Divide the number on the ring gear by the number on the pinion gear and that is the ratio. 41/11=3.73

 

That makes sense. Thanks.

 

It does make a wining noise when I'm decelerating. I spoke with a shop around the house and they said what you said, that's it's not shimmed properly. I'm sure it's the same people that I bought the car from that messed with the rearend, they did a 305 tpi to 350 carb engine swap and wired the fan and fuel pump with speaker wire. Almost caught the car on fire.

 

I'm offshore right now working but as soon as I'm home I'll be playing around with it again, thanks fellas

 

Check the pinion nut. This is a very common problem with these rear ends. The pinion nut backs off. If it's loose then torque it to about 125 to 150 foot pounds. It's best to take the nut off and clean the threads and use red Locktite on it.

 

Ok I'll try that when u get back home, thanks

 

I didn't think it would actually run that way. Never thought of a loose pinion nut, but that makes sense.

I thought I could see a stamping mark on the ring gear in the pic, which is why I suggested using that instead of counting the teeth on both. I didn't se jack stands, so assumed it was in the ground, which would make it hard to turn things to count the teeth.

 

It's unmistakably 2 series; the pinion flange is flat on the side away from the gear.

I see 5 teeth on 1/3 of the pinion. That means the pinion has 15 teeth. Since 2.73 is 41 & 15, and is AFAIK the only common gear in this model of rear w 15 teeth, I'd be inclined to suspect that's what it is.

It's an Auburn carrier... probably no good.

The tooth marks on the carrier are indeed from the pinion bearings being wore out; when in forward gears, the pinion tries to push itself outwards, but in reverse, it tries to pull into the case. Could be just the nut is loose, but if it is, it's because the bearings are wore out.

Looks to me like there's not much in that pic worth saving.

If it has 26 spline axles besides, probably time to throw it in the trash and start over with a better core.

 

Yup I think I will upgrade to a 28 spline Eaton and some 28 spline axles and maybe some 3.42 gears