Cheap Fix (was rear end juddering...)

You're the second person to recommend Redline.

But, so far so good with the mineral oil and the GM LSD...it runs smooth as glass.

NOW he tells me!!! ;)

I just thought since it was LS rated that it would work with the LSD with no modification. Since it was $9 a quart, at 1.5 quarts, I didn't want to have it *NOT* work and dump $24 out...

Some how that just doesn't seem right. If a limited-slip differential needs a different lube from a standard differential then a gear lube rated for limited-slip should already have in it all the additives needed. There really is no other major difference between the two types of gear lube.

What do you do if you replace a seal and loose a cup of gear lube? Do you have to drain the rest of the lube out and replace it with new in order to ensure that you have the right amount of additive? Why rate if for service in a limited-slip differential if it really isn't ready for limited-slip service?

Jack

There's a reason it's called a 'skilled trade.'

AHHHH, I see now. You guys go to school so that you know when a supplier is pumping out BS. In other words, you know what to believe and what not to believe.

BS

Jack

Well, that is an important part of it... ;-)

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I doubt it.

And they even manage to find time to teach proper service procedures.

hachiroku was told a number of times to add the friction modifier to the M1 gear oil he had installed. It has been explained to YOU why gear oils do not automatically contain the friction modifier to begin with. I guess your schooling taught you that it would be easier to -remove- the additive if it were already in the gear oil versus simply dumping a bottle in as part of the refill.

RTFM

Actually my schooling taught me that it is best not to make claims that aren't true. That habit leads to law suits and lost money.

As for using gear lube in more than just rear end assemblies, that's why you put labels on things. Truth in labeling tends to give you the information you need to ensure that you use the right product for your needs without having to sort through the BS. If you need gear lube for a transmission, use standard gear lube (non-LS) but if you need gear lube for a limited-slip rear end, use LS gear lube. But, according to you, LS gear lube isn't any different than non-LS gear lube.

And you approve of this practice.

Jack

Well, since Mobil 1 did not make any claims that aren't true, I'm not sure what your point is.

Mobil 1 gear lube is properly labeled. Exxon Mobil also make available product data and specification sheets for all of their products. Had hachiroku bothered to read them, he'd have avoided wasting his money by dumping the M1 gear lube out.

And somehow you think that the label on a bottle of gear lube is instructions on how to service a drive axle.

Yup, whatever the FSM specifies.

Use gear lube and the proper friction modifier additive just like it says in the factory service manual.

No it isn't. The service requirements however, are.

You have to add sugar and water to Kool-Aid. Been that way since I was a kid. Of course, if you skip the instructions, it tastes like shit...

Ahhhh, I understand now. Thank you for clearing that up for me.

Jack

I did read them.

I also read the Toyota recommendation for mineral oil, which they still advocate for vehicles that are LSD-equipped.

It does seem that way. But that's not the way the world works.

TWO types of gear lube??? There are many types, and there are HUGE differences! Just as an example, gear lube suitable for hypoid gears has to have additives that are definitely NOT needed for helical and straight-cut gears found in manual transmissions, and the hypoid lubricant can actually impair the function of the synchronizers. Ditto for limited-slip additive. Conversely, running a non-hypoid lube in a hypoid differential can shred the ring and pinion in no time.

Its not nearly that picky. Haven't you ever owned a limited-slip?

Because its important to know that its compatible (read that as "not harmful to...") limited-slip diffs. And there may be some out there that don't need extra additives, too. Certainly Torsen limited-slips don't because they don't have clutch packs or cones at all.

No, you just have to NOT be ignorant.

Which you would, if you took the time to read the car's owner's manual.