Noises from my rear end... Options

[Steve91T]

I think I misunderstood what you were saying.

Me rocking the wheels back and forth was the only way I could make a noise similar to what I heard when rolling down the driveway. Is it normal to make a healthy diff do that? I'm guessing mine has a little more slop than what's normal (just a guess, I've got no idea). Maybe the LSD was binding, or slipping or something causing the pinion to kind of load up then unload, causing the clunk?

[Steve91T]

Someone one ls1texh said synthetic gear oil with the addative already included can cause chatted with auburns. It's better to use regular gear oil then add the gm friction modifier.

Does this sound right?

This post has been edited by Steve91T: Mar 19 2016, 01:09 PM

[Steve91T]

Ok so I picked up some friction modifier from GM and some Mobile 1 synthetic gear oil. It's half the price of Royal Purple.

I'll dump it in the pumpkin sometime over the next few days and see what happens.


One question, will adding more friction modifier make the LSD less effective?

[Steve91T]

The guys on ls1tech say I need to use regular gear oil, not synthetic. I'll try that unless I hear otherwise.

[79T/A]

With a clutch LSD, always use non-synthetic. Many already have friction modifier - be sure to read the bottle to confirm. Some have no additive, then you would add the gm friction modifier. The more modifier you add, the less effective the LSD will be. The less friction modifier you use, the noisier the diff will be (more chatter). When I used the POS auburn racers diff, I used standard gear oil with no additive. It made horrible noise, but if you use friction modifier in those things the tiny clutches burn out quickly.

I'm a fan of Torsen style diffs for track use. They last longer before wearing out, but can't be rebuilt like a clutch pack. I kept burning through auburn diffs (cone clutch) and won't go back. Currently using a Detroit truetrac. Not the best, but aftermarket support for these tiny 10 bolts is slim. Don't blame them for not wanting to support these junk axles.

[Steve91T]

Oh I couldn't care less how much noise it makes, I just want it to perform as well as possible.

So are you saying I should find regular, non synthetic gear oil with no addative? It won't damage it? I know it'll be noisy, but will it actually perform better?

[Steve91T]

I've been searching the web for way too long now on whether to use friction modifier of not and what I have concluded is there is a lot of crap information out there's.


From what I gather, the best is to use 80w90 non synthetic.


And I'm not going to use the friction modifier. Some say it will wear the auburn quicker, some say it won't but it will make it have more lock up, which is what I want. I know it will be noisy.

Since eventually I'm going to put a better LSD in there anyway, I really don't care about longevity, so I figure I have nothing to loose.

I'll do this tomorrow.

[dailydriver]

Not the best, but aftermarket support for these tiny 10 bolts is slim. Don't blame them for not wanting to support these junk axles.

Probably why Torsen stopped the production of the T2Rs for our app, along with the axle not being used for ANYTHING anymore. and their case quality/metallurgy issues. (IMG:http://www.frrax.com/rrforum/style_emoticons/default/sad.gif)

They DO make the T2R for the Blue Oval 8.8s though, both for the independent set ups as well as the stick axles.

This post has been edited by dailydriver: Mar 20 2016, 08:53 PM

[ReEntryRacer]

I've been searching the web for way too long now on whether to use friction modifier of not and what I have concluded is there is a lot of crap information out there's.


From what I gather, the best is to use 80w90 non synthetic.


And I'm not going to use the friction modifier. Some say it will wear the auburn quicker, some say it won't but it will make it have more lock up, which is what I want. I know it will be noisy.

Since eventually I'm going to put a better LSD in there anyway, I really don't care about longevity, so I figure I have nothing to loose.

I'll do this tomorrow.

I run an Auburn Racers cone type diff in my roadracer and I run Red-Line Shockproof (the heaviest version) without any modifier. It will make noise when its coming off track if it has been really heated up. Once cooled down, turn a left and a right circle at low speed and it goes quiet again. They all do that. And they last a couple or three of season's worth of serious abuse and then slowly deteriorate. If you can afford a Racer's version (call Nancy at Auburn, it will not be sold anywhere else) it will be replaced for the same cost as the repair parts for an Eaton clutch, with a 4 year no questions warranty. The new one gets another 4 year warranty. I keep two circulating to never buy a whole diff again.

[Steve91T]

Update: I filled the diff with Lucas regular 80w90. I did mostly highway driving with a couple of parking lot maneuvers. I notice a little noise in tight turns but nothing bad. On the way home I made a hard right turn from a stop and got on the gas hard. The LSD locked up hard and sideways I went. The same LSD with the expensive grape flavored synthetic gear oil, I would have lit up the right tire.

I'll drive it more tomorrow, but so far the diff actually seems pretty happy with no friction modifier. Much happier than the synthetic stuff.

[CrashTestDummy]

Yep, a lot of the synthetic stuff is, well, pretty slippery. That's the feature the vendors are going for. Works great, unless you actually need some friction, then the synthetics usually fail miserably. I think that may have been a problem with my 9-bolt (yes, bolt), but it seemed it gradually-developed the one-wheel-peel, so hammering on it for 10 years in an autocross environment with slicks may have had something to do with it. (IMG:http://www.frrax.com/rrforum/style_emoticons/default/ph34r.gif) Red Line synthetic is my gear oil of choice, too. It seems to do well in our Tru-Trac in the 9" that's now under the car.

This post has been edited by CrashTestDummy: Mar 23 2016, 02:58 PM