Ya..we started at 30lbs, then 20, then 10..then..well, didnt need more than a finger.

 

CV's were fully rebuilt and inspected just before Xmas..new boots, new everything.

Was about a $6000 week back there..everything touched, was replaced.

Rear wheel bearings felt peachy as well.

The rear end has the thunka-thunka-thunka crunching only when you start to turn from perfectly straight..go straight, no rear end noise...which is why I wondered how TIGHT the rear was.

Not how loose it may be.

 

Ha Ha. Sorry, didn't realize that you had installed the unit separately hence my prior (very) weak attempt at humor.

I've seen LSD's that will do that (not on a 928 though)- one tire spinners on the ground that will still light up both under throttle. Of course, I don't know what kind of reflection that is on their LSD's condition.

Sounds like you may need to back into a puddle, do a launch, and see if any of that force translates into a posi burnout. The noise is a little concerning though, not familiar with diff noise being common among 928's.

 

odd....it does sound like wheel bearings to me.....replacing mine fixed it....

here is my highly in-accurate test....get both wheels off the ground.....spin one wheel.....the other SHOULD spin at the same speed..... The widow had a week LSD and the other wheel wouldn't turn at all..... Of course having someone hold the other wheel gives you an idea how strong it is...

Even though the Estate is having LSD problems....I think the diff itself is normal....its the suspension thats messed up...

 

Jeff--

For grins, verify with torque wrench that all the bolts from inner CV joint to the drive flange are tight. IIRC the spec is something like 62 lbs/ft, and that's more than a casual amount of torque in the relatively tight space. Similarly, verify both rear axle nuts are properly at 326 lbs/ft. A loose rear axle nut will not be clamping the rear wheel bearing correctly, and it will be noisy and in fact will be trashed pretty quickly.

You can simulate the slow-speed turning by raisng the rear and supporting it on the suspension arms with the wheels removed to keep the axle alignment close to driving normal. With zero LSD action you should be able to stop one rear wheel at a time with the parking brake cables. Or, put a vise-grip style clamp around the rotor and let it wedge against the caliper. If the problem is in the differential, you'll find it quickly by localizing the noise with the car idling in gear.

Did you drop the whole rear suspension out when you did the trans? New trans mounts? Put the original alignment shims back where they came from? Is everything tight again? Particularly the two long pivot shafts through the shocks and control arm?

 

FWIW Jeff, your video spins like my open diff...looks like the same one-armer spin strength I recently did after changing pads (one wheel elevated).

Don't know, but is it possible that lack of oil change could leave the LSD "trying" to operate at slight turn causing the noise. Perhaps the unit is fine, sounds normal going straight, is hindered when turning and attempting to activate (light chatter), and new oil with friction additive will allow it to engage as normal.

 

The torque spec is only 4-14 ft lbs. Hard to check on the car with all the other potential drag.

 

Gotta wonder how 4-14 lbs feet translates to 40% limited slip.

 

Actually, here's the mid/late 80s diff test. 7-25 ft-lbs. [For PSD, it is adjusted to just below 20 Nm (15 ft-lbs) according to WSM 39-212q and 212r.]

 

Im in Macau..so catching up.

Bill met me at Sears Pt over lunch, and we re-checked it.


He noticed the whiiiiiiine from out back, and the crunch-crunch-crunch in tight slow turns.


But..Ive NEVER had a single wheel spin under any conditions so far..since this was installed.


Will change fluid for the fun of it in a few weeks...the LSD is likelt...good.

4-14lbs eh...geesh.

There's something I dont know...in how that torque figure works the way it does.

 

It doesn't.

Porsche continued to call the limited slips 40%, even after they dropped the break away torque, in more than half.

These are not "dry performance" limited slips, but designed for wet weather or snow only.

 

Since this thread came up..closing on the rear end growwwwl.

960 302 063 09

Warranty replacement.

 

Are those wheel bearings.....when they failed on the estate it would HOWL in some turns, much less in the others.....replaced both....FIXED

 

Mang, I even gave you the part number....

http://www.autoatlanta.com/porsche-p...-91/307-70.php

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