jlagarde

OK, OK this is not for my vette but I value the vast knowledge I have always found here and would like opinions.

I have a 67 396 chevelle with a 454, 700R trans with posi tract

I purchased a set of 342 gears for the 12 bolt rear end from Randy's ring, yukon product. I was diligent in breaking them in for the first 100+ miles. Replaced bearings etc.

The problem I'm having is a terrible whine between 50 and 60 mph. This car is a daily driver and it's driving me crazy. We reopened the casing and checked the install, pinion depth and lash. all was perfect.

I spoke with the yukon tech and they said they don't warrant against noise in the gears. The tech guy said they can't make the gears to match OEM so I'm stuck with these gears. They won't help at all. Really bad attitude. So I'm out the gears, the install and the reopening to check everything.

So I ask, do these guys at yukon know what they're talking about or can I find gears that won't make noise?

Video here is not too great but gives an idea of the whine.

http://s1015.photobucket.com/user/zu...26257.mp4.html


If I only used the car for shows or something I could put up with it but it's my company car and being in it all the time makes it unacceptable and I just have a hard time believing Randy's Ring saying that they can't make rings that don't whine.

As usual, I will appreciate any thoughts, ideas and input.

Thanks
Joe

DansYellow66

If this is Randy's Ring and Pinion, I always understood they were a pretty reputable business. I'm surprised they would handle someones parts who seem to have such indifference to their quality or performance. Did that line of BS come from Yukon or from Randy's? It shouldn't take any great level of skill in this day and age to make a set of properly functioning 3.42 gears.

When you opened the case did the gear contact pattern look right?

67vetteal

If you are willing to: Open the Case again and clean the Oil off the Gears. Coat the Teeth on the Ring with Machinist Blue and rotate a few revolutions. This should show the alignment of the Ring and Pinion. Generally a Whining Gear Set is due to misalignment. The noise may just be the signature of the design but you really needs to see the alignment to understand where the noise is originating. Have you searched for the noise in Reverse? Drop the Gear Lube and spread some out on a piece of glass and look for sparkles in the sunlight. Listening to your video makes me think the Lube is a very light Weight. Is it? How old were the Bearings? Al W.

jlagarde

New bearings, 90 wt lube as recommended by Randys.

Here's a photo after opening the second time and about 200 miles.

Everything was checked and found to be within specs.

http://i1015.photobucket.com/albums/...psc44ee6d9.jpg


To be honest I thought Randy's Ring and Yukon were the same people. Got that info from a rear end guy who restores older models in California and I believe he is correct.

Thanks
Joe

midyearvette

Joe, looks like a lot of abrasion on those teeth to me, is it a "soft" gear set?
also seems the pinion shim is a tad too thick
does the pattern resemble a mirror image from in between the teeth.....jmo.....good luck

jlagarde

Not sure about the "soft teeth" Frank. It is whatever they sell as the Yukon product. How would "abrasion" occur iyho?

Thanks
Joe

midyearvette

just sayin' i agree with Dans Yellow 66 where a 342 gear is not that hard to set up ....should not whine as much as yours if at all.
they used to make softer gearsets for drag racing with a different heat treat process
with the rough texture on your gear teeth it could be a bad set and with the looks of the "file like" wear pattern, it will probably get worse with more mileage....the pattern should be smoother in finish than your pic shows....jmo...

jlagarde

I guess I'm more confused as ever. I'm either going to buy a new set from someone else or an aftermarket rear axle assembly. I'd like to save the money from a whole new unit however, I'd like to ask these 2 questions:

Which brand of gears should I consider to replace the yukons

and

What are the recommendations for aftermarket engineered rear axle assemblies?


Thanks Frank and all others for your help

Joe

kwkenuf

Have you considered that the setup may be incorrect even though your installer "verified" it was not?

4 Speed Dave

I've set up many gears and the pinion is too far out as in you need a thicker pinion shim to get the gear pattern more centered on the ring gear. The ring gear looks fine I don't think they even make a "Pro Gear" i.e. soft 9310 3.42 gear only 8620.

I will say sometimes you do get a set of gears that are loud no matter what you do however the patter should be more centered on the tooth in this case.

midyearvette

i stand corrected, after anther look at the pic, 4 Speed Dave is correct about the shim
in the 90's i bought a whole complete axle housing from currie enterprises for 1,250.00 for a chevelle i built
no problems....
it should not be that tough to set up a 3.40 gear to be quiet.....

mechron

Sorry, the photobucket pic tells it all. I have never seen a worse ring gear pattern EVER. The guy who set up the gears is a moron. Look in any old Chiltons or Motors manuals, they all show the coast and drive contact patterns between the ring and pinnion. They should be centered on the ring gear. 001 on the pinnion or 005 on the ring will effect the pattern. Yours is WAY off that.

DansYellow66

For what it's worth I'll add a fourth vote for bad set up. I've never personally set up a ring and pinion but that contact pattern is not centered the way it's supposed to be from all the manuals I've studied.

jlagarde

Thanks for all the input.

I'll go with the faulty setup as the reason for now.

So now another question.

I have somewhere between 800 and 1200 miles on the gears.

Is this too many miles to adjust the gears or am I asking for more trouble?

I appreciate all the info

Joe

4 Speed Dave

Based upon that one and only picture that you have showing the gear pattern if it were me I'd try to use the same gear set and just set it up with the correct gear pattern. I don't see any blueing or signs of high heat so give it a try. From the pattern I wouldn't be suprised it if was .006-.008" off in pinion depth. With it this far off the side shims will need to be adjusted to get the backlash right in line. Did you measure the backlash you have now?

mechron

Joe, please take my advice. DO NOT throw good money after bad. Those gears are toast! There is no way to adjust the ring and pinnion after that contact pattern. The contact pattern has to be right from the start. Even 5 or 50 miles those gears were toast. Hypoid gears don't get a second chance.

This is coming from a guy who had a shop and set up many rears, ring and pinnions, not just vettes, 12 bolts, ford 9" and those big dana 60s used in the mopars in the 60s.

jlagarde

I'm leaning that way. I'll just have to commit to a whole new assembly which will be nice but costly.

Thanks to all
Joe

tracdogg2

Hi guys,
I'm not well known over here in C2. I do many of the custom diff rebuilds in the C3 section. Mechron is totally correct. Those gears were set up way too shallow and now they are toast. But there is another issue. I have installed over 50 sets of Yukon gears and they worked great. Until the last set. Setup went well, pattern was good, and the gears were quiet. 200 mile break-in, everything was fine. Until the first time he stood on it. The gears started howling like crazy. I take pics of all my gear patterns for customers and when I compared the pattern to original setup the gears were worn out. Pattern had run off the heel. I got the same line of BS from Randys. Drove from Dallas to Vegas to talk to them in person at Sema. I was assured by their guy that they would take care of it. They fired the guy. It took 7 months to get a refund. Their tech guy sounded like he was 20 years old. I will never buy anything from Randys again and no more Yukon gears.
I started using only Richmond gears No problems at all except for one set that somehow didn't get honed. At first they didn't believe me until I showed them gears. Had a new set the next day. Now that Motive owns Richmond gear I have no idea if the quality will be the same or not. For the past year I've been using USGear from Toms. They are a little harder to set up. Very touchy on pinion depth. But once you get the pattern they work great and are quiet. They are 8620. I do around 80-100 corvette diffs each year, everything from resto rebuilds to 12 bolt conversions. Finding a good gearset is a major issue with me and at this time only the USGear sets are worth buying. I also do all the Dana diffs but I only use Dana gears in them.
Mike

DansYellow66

Great information - thanks for posting.

tracdogg2

Your welcome Dan.
I should mention that I was buying Yukon gears thru a local company. Randy's called me constantly for over a year to get my business. I gave in and purchased from them, as described above. I bought 2 gearsets, 1 Yukon and 1 Richmond. That was and will be my only transaction with them.
Mike