Need rearend advice BADLY!

Thanks ahead of time for anyone's input/$.02 worth.

I have had my 4.10:1 Richmond gears go south for the second time in 6 months. I had the first set installed by a friend because I didn't have the time to do it. He did a great job, and I certainly trust his work (ASE certified master tech). The second set I installed my self using all of the proper GM tools such as the pinion depth gauge, and dial indicator for setting backlash. I know they were installed within .002" of spec. on the pinion depth, and .001" on the average backlash. The housing is straight and good, the bearings are good with normal wear patterns. The first set of gears, one tooth broke off of the pinion gear. I was not under heavy load (doing only 25-30MPH) when it happened. The second set, TWO teeth right next to each other broke off of the pinion, also occurring under low load. On both occasions, the teeth have an interresting break in them. You can see the grain in the metal, like it was already weak. I DO NOT use slicks on my car, and I have been to the dragstrip a total of 3 times in the 6 months I had the 4.10's. It is a stick car with the normal bolt ons. Not that powerful.

So, now that I have written my life story, what is the best gear set made for the HORRIBLE 7.5" rearend? Brand/additional parts recomended/fluids/break-in procedure/etc.? I want to make sure that this set lasts a little longer. Strange gears were recomended, but I also see a lot about the Motive gears. What is your experience with any of these brands in a 4.10:1 ratio? I know any lower gear would be stronger, but I can deal without the performance of the 4.10's.

I WILL say that Sumit Racing has been GREAT through this whole ordeal. They exchanged the first set after 126 days of use , and the second set after 117 days of use. They carry a 90 day warranty, but honored it anyhow.

Thanks again,

Cole

From your description of the failures, I suspect improper heat treating on a batch of gears, and you got two sets from the same batch.

Usually rear end gears are "case hardened" which forms a hard, wear resistant layer maybe .05 inch deep all over, and also produces a tough core which is somewhat softer, maybe like a Grade 8 bolt, or slightly harder. You should be able to see this "case" or shell in the broken areas.

After the initial hardening at maybe 1650 F, the gears are quenched in oil or water, then "tempered" at a lower temperature, like 400-600F which greatly reduces the brittleness without decreasing the outside hardness very much. If the tempering temp. was wrong, or in the worst case, skipped altogether, you should break off the teeth like you describe.

Buy another major brand of gears. The problem is you don't know who made them; hypoid gear generating machines aren't in every gear shop. Some manufacturers make gears for many sellers. You might ask Richmond if they make their own, and also the next vendor. They may or may not tell you. At the very least, visually compare the new gears with the broken ones for tool marks, markings, color, etc. You'll be able to tell if they came from different sources.

My $.02

I don't know who manufactures the gears for Moser but I really like the set of 4"11's I just got from them.

http://www.moserengineering.com/products.htm

Moser Engineering has the right type and ratio gear to fit your needs. All of our gears are made in the USA by one of the best known and trusted gear companies in the business. Our gears are all CAD designed, CNC machined, and Computer Control Heat Treated to ensure you receive the highest quality and best performing gears on the market.


Give them a call, at least, and talk to one of their techs.

Good Luck
Guido

you sound like a moser salesman.... i've had bad moser experiences, i have 35 spline axles in my car, i backhalfed the car this summer and had the 12 bolt housing narrowed at Ed Quay's... i sent my axles back to Moser to have them shortened 8.968 inch.... the salesman asked me what that number meant, i told him that was how much i needed off each axle. He said they do it the old fashioned way, with a tape measure. yikes.. i told them 8 and 31/32 wouldn't you know that they shortened them both 8 and 5/16 over 5/8 of an inch off. i called them and they said that it was ok because there was 1 inch in the middle of the spool.... 5/8 and 5/8 is more than an inch i'd put one in and the other would pop out.... they said oh just chop saw them off myself... Hardened alloy axles that i paid 90 buck to get shortened.. i missed a weekend of racing because of that... about a month later i got new rims 5 on 4.5, i wanted another pattern drilled and tapped for 5/8 studs, they drilled the pattern wrong and forgot to tapl the 5 on 4 3/4 holed, the wheels wouldn't even fit on the axels, they said it was the weld wheels, i tried 4 different weld wheels and 2 different centerlines, same result... shipped them back and they had to replace both axles.... both time they declined to refund any money...

anyway, buy strange or another set of richmond from somewhere else....

Thanks everyone for the info. I am not a Moser salesman, just a disgusted PREVIOUS Richmond customer. I picked up a set of Strange 4.10:1 gears from Thunder Racing. I will be installing them this weekend, and I will let you know after two weeks and they're broken in how they work out.

Have a good weekend,

Cole

Originally posted by az1gplus
Thanks everyone for the info. I am not a Moser salesman, just a disgusted PREVIOUS Richmond customer.

I think Calculated Risk was referring to Guido67SS's comment.

I picked up a set of Strange 4.10:1 gears from Thunder Racing. I will be installing them this weekend, and I will let you know after two weeks and they're broken in how they work out.

Have a good weekend,

Cole

If you get a chance, visually compare the Strange gears to the Richmond. You should noltice subtle differences.

Good Luck!

I feel that know matter what gear you stick in there, they will blow. When the car was stock with bolt-ons, I poped the rearend four times(breaking teeth off), and It happened once to the wife. I wish I would have replaced the whole rearend after it broke the first time, but just my .03 cents

good luck

Neal