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The picture shows 85w-140, but under the details there is an 80-90. It says limited slip on the bottle and from the PDF:
The inclusion of Limited Slip Friction Modifier in this product makes it unnecessary to add additional friction modifier (Ford M2C118A, Chrysler MS5630, or GM1052358) in most vehicles.
But yeah, I remember seeing the 6oz thing, too, so I think I'll put in the 4oz additive and hopefully between the two that will be enough
I didn't think to hit that additional link. OK, maybe that Valvoline doesn't need any additional friction modifier. You could always call Valvoline or Auburn and ask them the same questions. In any case Daily Driver has a good solution. If it were me I'd take advantage of the opportunity to pick the brains of those guys just to see what they say and why.
The '98 Auburn rear should have non-synthetic, 80w90 lube with the GM LSD additive. This is the only combo I would personally use, and it's all I've ever put in my '98. This is what the first edition 1998 owner's manual calls for, as posted earlier in this thread.
Having said that, there was an odd discrepancy with the second edition '98 owner's manual that can be read about here:
Apparently, at some point they released a second edition that called for the 75w90 synthetic. If you read the link above, you'll notice that the member who had this manual didn't buy his car until 6/98, although it was built before mine, so there is a possibility that the dealership gave him the wrong manual with the car. I say this because my car is a March build, his is a February, so if mine came with a first edition manual his *should* have as well. However, mine was also purchased two months before his, so there was no chance of mine getting the manual from June of '98. The dealer may have somehow lost the original manual that came with this February car, since it sat on the lot for a bit, and then just got a new one prior to delivering the car, which was the later edition.
I wonder if GM started shipping some of the very late '98 cars with the new Torsen rear? Perhaps this was the reason for the change? I have not done any sort of research on that, but it's just one possible reason.
If you review the linked thread above, you'll find that the member with a confirmed Auburn had poor results from using other brands of synthetics, but somehow the GM synthetic didn't cause him any issues. In any event, it's not a thread that would be easily found because it didn't initially have anything to do with the specific '98 fluid requirements, but it might explain why the data in that shop manual groups the '98s in with the '99+ cars, apparently so did the owner's manual by the very end. BUT, what the second edition owner's manual doesn't disclose is if any of the very late '98s received Torsen rears.
To be safe, I would stick with 80w90 conventional and the GM LSD additive, if it were mine.
Thanks, I didn't see that post. It explains some of the discrepancies. It would have been nice if they listed the differential type instead of just the year.
I called up Valvoline - they said each quart has 4oz of limited slip additive. Should I just go with that and skip the gm additive? Will have a lot otherwise, not sure if that's bad. Otherwise can use cheapie stuff like supertech.
Last edited by Jason Novak; 06-27-2015 at 12:31 PM.
Thanks, I didn't see that post. It explains some of the discrepancies. It would have been nice if they listed the differential type instead of just the year.
I called up Valvoline - they said each quart has 4oz of limited slip additive. Should I just go with that and skip the gm additive? Will have a lot otherwise, not sure if that's bad. Otherwise can use cheapie stuff like supertech.
Then I would just put the two quarts of Valvoline in, and skip the GM additive initially.
Then do the procedure I described in the post above, and IF you get the negative symptoms (chatter, moaning/groaning, knocking, etc.), THEN add the l.s additive.
The 4 ounces overfill, if you need to do this is NOT going to hurt anything!
Well, switched fluids tonight. Got about 1.75 quarts out and refilled. Neither oil smelled too bad, must be different than the GM stuff.
Can't say if it's better or not yet - I know I still have other parts making noise, but it's not worse and it's nice to have the right stuff in it, especially since I plan to keep this car for a long time.
One last question - I did torque the plug to 26lb, there are still some threads visible - should have paid better attention before I took it out. I think this is normal?
06-26-2015, 08:36 PM
