i just installed a rebuilt eaton 10bolt posi and first test drive it (1mile) it was whining but it would cutout when i let off the accelerator. should i worry about this sound or is it just breaking in? i put posi additive in.

thanks

 

No it is not the "posi" whining.

Sounds like you didn't get the backlash right.

Get yourself a set of shims, and select suitable ones to get the backlash to about .006-.010".



When you say "rebuilt Eaton posi", I hope it isn't one like this; the infamous Eaton "Gov-Lock", aka Grenade-Lock. If it is, don't worry too much about the backlash, because it probably won't survive long enough for the backlash to ever matter.

 

GM Eaton Locker Series 3

i hope its not... doesnt look like it to me.
i just put the old shims on it i figured they would work.

when you say "won't survive" would that mean the posi will quit and it will be open or it plainly wont go anywhere?

 

That is the much maligned gov lock... sorry...

He means the little pieces in side will fly apart and destroy everything else. Sorry about that, too.

 

Yup, that's the Grenade-Lock, all right. Not really a posi... it acts like an open, until the RPM difference between the 2 axles reaches about 150 RPM (that's what the 2 little weights on the little pins are all about, they make a "governor"); at which point it locks up with a bang. It was originally designed for military trucks for use strictly off-road. So what happens in a "performance" application is, you nail the gas, and the right tire spins, like it always does; and when the "one wheel squeeel" gets up enough speed, it suddenly locks. BAD BAD BAD for maintaining stable vehicle control. And on pavement, with some power and any degree of traction at all, its overall weakness results in the whole thing exploding when it locks up, and sending shrapnel through the cover and into the gas tank. It is garbage. Totally the wrong thing for a car to go fast with.

I hope you didn't spend any actual money on it; although looking at the little "bug" down in the bottom right corner of the pic, I'm inclined to suspect you did. Big mistake.

Sorry you didn't ask about it BEFORE you got it.

 

well dang... $180...
so recomendations anyone? i guess im going to take it back out, install the stock open carrier and try to return it.

 

That is why everyone should not try gear changes and repacing other parts in the rear axle. It is NOT your nornal DIY job. As you are finding out.

 

It is not a bad do-it-yourself job, as long as you know what parts to use, that is!

I used to work on those in military trucks and they broke just as often in them as they do in street cars.
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I would suggest looking for a used 4th gen zexel torsen posi unit now. Put that one back on ebay and start it out at 99 cents. Let it go to the high bidder...

 

Ouch!!

That's a HIGH installment of the "dumbass tax" (aka the sofakingdom tax... yeah, BTDT, how do you think we found out about stuff like that before Al Gore invented the Internet so we could have message boards?)

Oh well, we live and we learn, or we don't live long. Right?

I agree, put it back where you got it, and try to reel in the next "greater fool". Don't worry, there's one out there. Hopefully, more than one. ALOT more.

A hint on how to find them: DO NOT put it in the car section, and DO NOTadvertise it as an "Eaton" diff!!! Instead, put it in the truck section; write it up as a "freshly remanufactured Original Equipment" part for whichever year group of trucks it is (26 spline is 88-back, 28 spline is 90-up, MAKE SURE you get that right. Count it.). DO NOT mention it as being for S trucks; say it's for an Olds Bravada in your description. Put S-10, "Blazer", S-15, etc. in your keywords, so that people who exploded theirs, will find it; just not in the decription, so it looks to the casual reader like something a cut above "regular".

Just like the guy you bought it from.... he didn't lie (I'm assuming), he just made it seem like something better than the dung actually is.

 

thanks you guys are alot of help. and i should have probably used that help to begin with...

bygones...

well back to ebay.

my whole car is DIY... thats what makes it "mine"