JNorris

iTrader: (4)

Judging from the pictures does it look like I have the pinion shimmed correctly?


Thanks

John

mzoomora

iTrader: (36)

Take a little shim off your pinion and double check you back lash. It should be more ceneterd on the tooth. Also, make sure to check it in 3 places around the ring gear. You could probably run it like that, but it would probably have some drive side noise.

JNorris

iTrader: (4)

The back lash is set at .007. The pinion has a .024 shim. The gear set is a used Richmond 3.73 in a 10-bolt.

mzoomora

iTrader: (36)

.007 is too tight for a street gear. You should shoot for .010-.012, they say .008-.012, but I like .010-.012.

JNorris

iTrader: (4)

How will changing the BL to .010 affect the pattern?

Currently the gears whine. Will changing the BL reduce the whine?

Thanks

nick_s

iTrader: (11)

you need to set the pinion deeper in the case - get that wear on the middle of the gear as stated. That will be most effective in making it quieter- but you also have richmond gears, and i have found them to be a tad louder than other mfgrs. changing the backlash to .010 wont really effect the pattern. and backlash measurements are kind of personal preference, rule of thumb is .001 per inch of ring gear. but normally set my cars up with no less than .008" Good luck with your project!

mzoomora

iTrader: (36)

If you look at the pics, he is too deep in the case, he needs to remove some shim and bring it out some.
The backlash wont effect noise or patters that much, but on a street car they build up a lot of continuos heat, so the gears expand more. You need more backlash to allow for oil to get in there when they get hot and expand. If you are a .007 and each expands .0015, now all the sudden you are down to .004, which isnt much for thick gear lube to work well enough. I know it sound like small BS, but by adding .004 you are doubling the space for gear lube.
What kind of noise are you getting now? You may want to double check that your crush sleeve is seated properly also.

JNorris

iTrader: (4)

Well I put the new gears in about a year ago (1000 miles and ~60 ¼ mile passes ago) and had some whine above 60mph mainly on coast. There was a little whine under throttle. As time went on and with 2000 miles and ~60 ¼ passes with sub 1.6 60’ times the gears got louder and louder and started to whine all the time. This past weekend on the way home from the track they were louder than usual so I broke the rear down to inspect it. The carrier looks fine and the rear specs are right where I set them a year ago.

Pinion preload is around 25 - 30 in/lb
I just checked the backlash and it is .008 - .009
And I used a .024 pinion shim.

FWIW the guy at Richmond told me that these gears (49 series) usually take a .030 - .038 in a GM 10-bolt. He thought it unusual that all I had in there was .024.

I think I am going to have to buy a new set of gears if I want to get rid of the whine.

CHIEFMB2

iTrader: (3)

Are you using a pinion depth setting kit? I always go from center of carrier bearing to pinion face and match the numbers using pinion shims I've never got the numbers dead on, but close, then shim the carrier if needed to get my recommended backlash. I use a housing spreader to slide shims in and out of the carrier. Almost all of them have turned out perfect. Richmonds are sometimes off on the 3pt backlash check. It might be the pinion bearings compressed more after getting on it and threw the depth setting off. Just my .02

mzoomora

iTrader: (36)

That pinion pre-load seems high for gears that have been run. If you re-use old bearings it should be set at about 15, if you use new ones you set at 25 and it will loosen to about 15. That wouldnt really account for any noise though.
I would say a new set of gears is in order, you will probably never get those quiet after they have been run in.

JNorris

iTrader: (4)

No I am not using a pinion depth setting kit. Where can you get one? On this install I just guessed.
The next time will use a loose pinion bearing that will slide on and off the pinion and do a mock-up installation and check the pattern until it is correct.

JNorris

iTrader: (4)

With the exception of the whining, is there any reason (dangerous?) I should not continue to use these gears for the next few months?

What gear set brand do you recommend?

mzoomora

iTrader: (36)

You should be fine if you continue using it. If it is a 4.10 or 3.73 or similar, then just use a OEM GM gear. You can buy them pretty cheap.

JNorris

iTrader: (4)

mzoomora - Thanks for your help.

GuitsBoy

iTrader: (4)

I installed my 4.10s with .0065 backlash and my gears are silent. The pattern was more centered than that in the pictures, however.

S_J_H

Richmonds can be a real PITA to setup. I had a real nice centered pattern and they still made plenty of noise. And changing backlash DID make a large difference in noise. I tried .008 and .014. .014 was much quieter. A bit loose for some but I never had a problem with it.
Steve

nick_s

iTrader: (11)

It's all how you look at it When I measure pinion depth I refer to it as being deeper since, in this case, he has to take shim out and the measurement will be larger. I know were both on the same page though!