Planning to upgrade the 12 bolt rear end in my 1970

[diggerbob]

I'm going to have a buddy rebuild the rear end in my 1970 SB. I plan to upgrade the old open carrier with an Eaton limited slip differential and will get a new 3.73 ring and pinion gearset. I called Toms Differentials today and they said that they can't get the 3.73 US gear ring set anymore so it looks like I will go with Yukon on the ringset. Does anyone have any useful bits of wisdom to offer regarding what vendors to check with? As of now, it looks like Toms Differentials for the Eaton unit and installation kit and Randy's Ring and Pinion for the gear set.

[68Gold/white]

I read here, or somewhere... recently. An experienced drive train builder, preferred Motive Gear As his preferred brand of gear sets. Can’t remember the reasons. Not understanding why Tom’s couldn’t use another brand...

[jimijam00]

Some places are refusing to use offshore junk, because they don't want it coming back.

[gmc684x4]

I seen a few threads on dislike for Richmond gear ring and pinion as they provide zero support for there products yukon r&p i seen positive threads about them

[71meangreenc10]

I have a Motive set and it has been fine. If you can get a Richmond Gear set to work without some noise, good luck. Digging into that a few years ago it read they changed the metal process in India and had to be beyond perfect to run without noise. Lots of info on that subject on the web.

Smitty

[Mike C]

I set up a set of Elite gears in a 12 bolt last year with a Yukon LSD. I would certainly use both of those again and would choose the Yukon LSD over the Eaton because it's $100's cheaper.

[MikeB]

It's been several years since I bought from them, but Randy's pre- and post-sales support was excellent. And their YG-series gears are very quiet, but not the cheapest. I suspect their ZG-series would be just fine for a truck.

Here is the difference:

USA Standard gears are made by Yukon - same materials, process, plant, drawings, etc. When the Yukon gears are brought in house, they go through quality control. If the contact portion of the ring and pinion don't meet tolerances for a quiet gear (too rough), then the gear is downgraded to USA Standard (ZG) rather than tossing it in the trash. It's still a great gear strength wise and etc, but in some instances they can be noisy. I have several customers of mine that all they buy is USA Standard gears and I've yet to hear of any actually being noisy.