Right now I'm working on installing a Richmond 3.73 ring n pinion gear set along with a POSI into my rear-end that was originally equipped with an open 2.73 setup.

I changed all bearings and races, pinion is in and depth is set exact to the marking on the pinion head.

When I place the carrier w/ the ring gear in, the teeth don't mesh with the pinion, not completely at least. I'm getting over 1/8" backlash.

All the parts match up correctly. I'm at a total loss on what to do.

Anyone ever encounter something like this?

Any advice is appreciated.

 

Which posi did you use? How are you measuring the 1/8" backlash?

 

posi is out of an early 4th gen, backlash was measured with a magnetic base dial inticator.

 

have you tried re-shimming the carrier bearing? thats how you adjust backlash

 

i've shimmed the carrier as far toward the pinion side as possible, and it still has too much backlash.

 

Sounds like you have 3 series gears, and a 2 series carrier.

Which makes the ring gear flange on the carrier, end up about .300" or .350" or some such, too far away from the pinion gear.

You need either the "special" thick gears (too late for that now); or a ring gear spacer; or the right carrier.

 

I tend to agree with Sofa's line of thought.

I have seen multiple mismarked gear sets also, nut I dont think thats the case as you prolly would have figured that out if your actually setting it up the right way(sounds like it).

Also tends not to be an 1/8 inch either lol

Double check the original carriers app and work from there.

later
Jeremy

 

no, i'm putting the 3.73's in with a POSI carrier from a 4th gen, which should be 3 series. What's the possibility of this posi carrier being 2 series?

 

ok, problem solved, I'm 95% sure that this carrier is actually 2-series, rather than the 3-series I was so sure that it was when i ordered the gears. I got the carrier and gears back in 2004 and am just now getting around to putting them in. Thanks for the help everyone.

 

Arbitrarily close to 100%

Well, this is a good lesson in why we tell people working on rear ends to stay away from the idea of "assume". Bad things happen when you do that. Like, you end up with parts that don't work together.

Since the normal shim thickness is about .240" - .260", and the difference in the flange location is near 3/8", then 1/8" sounds about right for how far the whole thing will still be off, even if you move ALL the shim to one side of the carrier.

The difference in carriers:



The one on the left is the 2 series. Note the relative location of the ring gear flange on the carrier. On the 2 series that whole part of it is almost flat; on the 3 series it's more of a cone.

 

Yeah, you'd be surprised how many 4th gens got the 2 series posi units. My buddy has a 95 LT1 Formula with a posi rear, and I was kinda shocked when we looked up his axle code and it turned out to be measly 2.73 gears! A lot of the automatic equipped 4th gens got these lousy gears, even though they're posi. The Trans-Ams and V8 cars with the 6 speed manual trans are the best ones to find a 3 series posi unit from. These cars usually have 3.23 with an auto, or 3.42 with a standard trans. Oh yeah, you might want to check with Richmond, Ratech, or some other gear company to see if they offer a ring gear spacer kit to convert a 2 series to a 3 series. This would be a lot cheaper than having to buy the thicker gearset or a 3 series carrier.

 

Well, I got the gear set from Summit back in dec. of 2004 and I still have the receipt, I'm just gonna take them back and exchange for the correct set.