tompumped

iTrader: (3)

I read that the eaton locking differential isn't very good, compared to the cone style clutch gm sure grip (auburn) unit. Which one should I buy? Supposably the clutches wear out fast.

11seccamaro

i think there both junk i had auburn scatered spiders get a moser 12 bolt

sofakingdom

iTrader: (1)

Yes the Eaton "Gov-Lock" is very weak. It uses the little governor weights to lock it up, such that it acts like an open, until the difference between the axle shafts exceeds some preset value (like 150 RPM or something). Then it locks up hard. In other words, no "posi" action occurs, until AFTER the wheels have already started spinning. It's designed for use in low-traction situations, like on mud; they can't withstand wheel spin on pavement. If they try to lock up with alot of traction, they WILL grenade. And they're not known for terrific reliability even off-road, as the S truck people can tell you.

The stock Auburn units are better for pavement, but are no longer serviceable, if the Auburn Gear Co. can be believed. (not that they would be likely to know anything about their product or anything like that) Last time I called them looking for service parts, they told me they were no longer available. GM and a few other suppliers still may have a few parts, and there might be aftermarket sources, but I don't know about any of that. And frankly I can't be bothered researching it.

The one to get, today, is the Eaton "high-perf" type. It is far superior to either. Or, the newer Zexel-Torsen that came in the LS1 4th gens, is a decent choice; especially the HD one. The one that SLP used to sell for $99 was the stock light-duty one. SLP of course has long since run out of their stock take-outs that they used to sell for cheap. Either the Eaton or the better Zexel will set you back about $400.

Everybody talks about "get a 12-bolt" or "get a 9"". That's maybe a permanent and effective solution for some people; but it's a MAJOR chunk of change, and not exactly practical for most, especially for somebody that doesn't race their car and doesn't have huge power and sticky tires. The 7.5" 10-bolt can be made quite a bit stronger than it came, not "bulletproof" or anything like that of course, but it can be significantly improved, easily and cheaply. Weld the tubes, use a girdle type cover (no chrome BS), a solid pinion spacer, good axles like from Superior Gear, a good posi, and NOT the Richmond Pro Gear, and it will hold up to nearly anything you dish out to it with street tires on it. The general idea is to hold all the parts in alignment internally as much as possible given the small amount of metal and the small size of everything, because they mostly tear up as a result of the gears and other things being able to force themselves out of correct mesh.

tompumped

iTrader: (3)

thanks, I think i'm going to go with the gm auburn unit I think. If you use a solid pinion spacer, do you still measure the turning preload with that inch pound wrench? The eaton units that i've seen are expensive. I just bought gm 4.11 gears, do you think they will hold up to a modded 355? thanks

tompumped

iTrader: (3)

I was just looking on ebay,and there is a zexel posi unit for sale maybe I will bid on it. Do you just have to get 28 spline axles, or do you have to switch anything else over. thanks

sofakingdom

iTrader: (1)

Yes, with the spacer, you measure the bearing preload the same way. You just have to keep assembling it, checking the preload, and disassembling it and re-assembling it with different shims, to set it where you want it.

4.11 gears are a problem with that carrier. The way it goes together, there's a little wedge thing that goes in and holds the axles in and all. The 4.11 ring gear is too thick to let it go in. There's a special wedge or something that you need in order to run that combo.

Other than that, 28 spline axles are all you need. I'd suggest Superior EV10-4 http://store.summitracing.com/partde...SAG%2DEV10%2D4

tompumped

iTrader: (3)

I'm new to setting up rears, but doesn't the pinion depth gauge tell you how much to shim it? I thought you just keep tightening it, till you get your turning preload. Which carrier is the 4.11 gears a problem with? thanks

sofakingdom

iTrader: (1)

You control pinion depth with the shim under the head bearing. What the spacer does, is set the preload on the head & tail bearings when you tighten down the yoke nut. It has its own shims that set how thick it is, which corresponds to how thick a crush sleeve would crush to. It has nothing to do with the pinion depth.

I was referring to the Zexel. Look through the 4th gen message boards; or maybe look for some of the people that used to come here that knew what they were doing if they haven't all left, seems like some of them had that carrier and knew what the problem is and what to do about it. I don't know the details, myself, other than to know that there is a problem. I've never had one of them and tried to do that.