oamhmad

iTrader: (1)

My vibration problems persist. I've narrowed it down to either the drive shaft or rear end.

With the rear axle on jack stands and the axle shafts pulled is it OK to run up the motor in gear turning the drive shaft and diff carrier for about 10 seconds?

I'm trying to eliminate the axle shafts as the vibration source.

8Mike9

Should be fine, carrier/pinion bearings will still get oil.

Bob88GTA

iTrader: (2)

Not my issue but what keeps the oil in the tubes with the axles pulled?

8Mike9

very little oil wicks down the axles..the rear isn't filled above the tube holes, but what does wick down, the seals keep it in.

sofakingdom

iTrader: (1)

Make sure you either take all the small parts (gears etc.) out of the carrier, or put the pinion shaft back in.

Restrorob

iTrader: (7)

For some reason me see's axle gears-spiders and possibly carrier being all tore up......

oamhmad

iTrader: (1)

If the center pin shaft is reinstalled into the carrier two of the spider gears will be held in place.

What would hold the other 2 spider gear that normally turn the axles in place? will they fly out of the diff-carrier when it spins up?

MoJoe

iTrader: (5)

Side gears will be trapped in place by the spider gears, which are held in by the shaft, held in by the bolt.

oamhmad

iTrader: (1)

I think the diff is done. I pulled the cover off and some of the spider gears are chewed up bad. It still locks but the chewed gears explain the occasional clunk I hear.

What are my options? Replace spiders, buy new/used LSD carrier or buy entire new rear end?

Would anyone recommend replacing with another G80 locker or does everyone hate these things?

I currently have 3.23 gears.

sofakingdom

iTrader: (1)

Of all the choices there are, I would put installing a Gov-Lock at the VERY BOTTOM of the list of preferences.

I would put an open in my car before I would use one of those steaming buckets of monkey plop.

Next worst choice would be an Auburn; especially a stock one, but an aftermarket one as well.

oamhmad

iTrader: (1)

What would be a good choice then?

The car is never going to see more than 350 hp . street driving only.

sofakingdom

iTrader: (1)

Eaton is what I use.

Others have used the Yukon with good results; some people like the Truetrac, or the Detroit locker.

Not really a question of "horsepower", as such; more, how you want the rear to behave.

Damon

I just wanted to jump in to say I've NEVER had a problem with Auburn posis. I've used 4 of them over the years and every one has worked flawlessly right out of the box. Even the little 7.5" rear in the back of my mild supercharged Malibu has one (pushing about 475 HP). While I'm slowly killing that rear from years of medium-hard lanches, the parts that are going downhill are NOT in the posi. It's been bulletproof.

Would I use an Auburn posi in manual trans car or a car launching off a transbrake? No. You're better of with an Eaton in that case. But for a typical automatic launching off the footbrake, you'll never have a problem with it. And the price is right.

oamhmad

iTrader: (1)

So I have a T56 and I'm prbly going to be barely pushing 300 rwhp once I'm done with the motor. I'm not going to drag it. Street only with the occasional burnout or donut. Would you still recommend an auburn?

sofakingdom

iTrader: (1)

I would NOT.

Every Auburn I've ever had, seen, or heard about, wore out quickly. Worked somewhat OK while it worked; which in general, wasn't long. In addition, one Auburn I had (a "high-perf" aftermarket one for LT1 cars, with the 3-ch ABS tone ring installed) had other problems as well: the whole end of it , where the bearing presses on, on the side opposite the ring gear (pass side), sort of screws into the main body of the carrier and is pinned in place, and the threads had so much play I could wobble the end piece around in it by hand. The car was absolutely UNBEARABLE to drive, with all the vibes. Of course the clutches were already wore out too, so I ended up throwing it away after calling Auburn and them telling me that they couldn't/wouldn't supply parts to rebuild it, and their highly-touted "exchange program" only covered products less than 3 years old (my unit would have been maybe 7 - 8 yrs old at the time). What a crappy outfit. I will NEVER do business with those rectal orifices again, even if they are the LAST MFR OF DIFFERENTIALS IN THE WORLD and it means I have to WALK.

oamhmad

iTrader: (1)

OK that does it. Eaton Posi it is then

oamhmad

iTrader: (1)

Ok back to why I started this thread.

I pulled the axles, replaced the center pin and bolt in the differential and ran it up to 80 mph to check for vibrations.

The good news: Nothing bad happened to the diff. Even though I didn't fill it back up with oil. I guess the residual oil is enough to keep thinks lubricated for a little bit.

The bad news, the vibration at 70-80 is still there. This rules out the axles from being bent. Next I'm either going to try to remove the diff carrier or try to adjust the pinion angle to see if the vibration is affected.

8Mike9

If you haven't change the factory setting on your rear, most you could lose is a degree or so due to the torque arm bushing....now cit could be well worn, you'll have to look...but a degree here and there (assuming nothing is jumping around) won't cause a vibration...would probably take 3-5 degrees off, to start abnormal wear on the needle bearings.

Ya kinda have me thinking you lost a driveshaft weight..or possibly be bent.

Checking/balancing should not be to spendy.

paulo57509

I would think it would be much easier at this point to remove the drive shaft and take it to a drive line shop that can check/re-balance the shaft. Might be a good idea to have them install new u-joints before balancing.

oamhmad

iTrader: (1)

This car has a t56 swap so the tail housing angle could be off. The drive shaft is an aluminum LS1 shaft. It was recently balanced at a drive shaft shaft. Made zero difference. It was pretty well balanced when I got it.

The vibration was present with the original 700R4 transmission and steel shaft as well. It didn't change when I swapped in the t56. I then switched to the aluminum shaft and it improved but is still present.

I've eliminated the axle half shafts. Maybe I have a bent torque arm that is throwing off the drive line angles.