Limited Slip Posi?

[Unofficial]

I have a friend who is into the whole Chevy thing like I am, and we're always comparing our trucks and talking about parts/upgrades. He's completely rebuilding a 350 that will be pushing 500 hp and he's getting rid of his limited slip posi. He said I can have it for $150, but I'm not sure how hard it will be to install and if it will even fit. We have the same gears (I think) and he got the posi from a corvette or something. Is it worth it? And how hard is installing a posi on your own?

[VileZambonie]

It most likely won't fit. Find out exactly what it came out of.

[Captkaos]

If it came out of a Corvette I can assure you it won't fit.

[JJSZABO]

How hard are they to install?

Normaly I wouldn't change my own rear end - "looks" to complicated to get the shims and pre-loads set correctly.

[Captkaos]

With the right tools it isn't "hard" at all.

[ccz145a]

So, what tools required? Is it just a dial indicator and heavy duty torque wrenches to set pre-load on the pinion bearing crush sleave that is out of the oridinary for the diy crowd?

[JJSZABO]

So, what tools required? Is it just a dial indicator and heavy duty torque wrenches to set pre-load on the pinion bearing crush sleave that is out of the oridinary for the diy crowd?

yes, yes, good questions.

I've heard that setting up a rear correctly is more of an art than mechanics - that is, to get it right.

[SUX2BU99]

^ True dat. It requires a 'feel' for it, which is best learned by experience. That's how I see it anyways. Kinda like tuning a carb or body work. It's all about the guy who is doing the work, not always about the specs and tools he has in his hand.

[VileZambonie]

I am the king of rear ends lol.... I can set up any final drive or differential with ease even without the proper pinion depth mock up. I taught myself when I was working at a Jeep dealer and there was an influx of dana 35C's with the driveline vibrations. We had field service engineers coming in with EVA's and coming up with cockamamie ways of elimintaing the driveline issues when I did a few simple tricks to pinpoint the source of the driveline vibrations. I figured out that even though Dana was really good with providing us with the special tools and etching the pinion depth variance on the pinion face their measurements VS installations were way off. A simple gear tooth contact pattern analysis revealed incorrect pinion depth on nearly ever single Dana 35c I worked on. From there I set myself up with an extra set of shims, pinion bearings, races and large race shims. By correct the pinion depth and setting the backlas I nailed down every single final drive with a near perfect contact pattern. This eliminated so many driveline vibrations I was king. I was getting 4.4 hours warranty time and banging them out in less than 2 hours. I've never met someone who can set up a rear end half way decent and it is a specialty due to the fact that so many don't take the time to learn how to do it correctly. Preloads are critical also.

As far as special tools, a depth gauge, a dial indicator, inch pound dial type torque wrench are all you really need aside from some basic tools and a jig to hold the companion flange when crushing the sleeve. If you take the time to do it yourself you'll appreciate the results. I built the rear end in my 74 13 years ago. Sorry for the ramble.

[JJSZABO]

Good job as always Vile  

Great explanation!  Thanks