Does any body have any knowlege of the "paper" spacers used in the early M6 transmissions? I plan on using the Amsoil Fluid but a nagging doubt keeps coming up regarding the Spacers and Synthetic Fluid.
Is this an issue???
Barrier

 

might be a good idea to send an email to www.rpmtransmissions.com , they suggest oem spec Dexron III

 

Or PM Subdriver; he's an Amsoil guy. He'll probably pipe in when the sun comes up on the West coast.

DBD

 

I do not believe there is any one best product.
The challenge is that all lubricants start with a basestock ( natural or synthetic) to which additives are dosed to meet or exceed certain specifications. Manufacturers decided how much they want to exceed the minimum requirements.
BUT...
Additive companies improve their packages continuously and as a result oil companies regularly change their formulations. What was best last year may not be the best now. Since the landscape is constantly changing you will not find many our oil is better than their oil changes... There is just too high a probability of litigation.
That being said lubrication fanatics are jsut aout as zealous as wax fanatics. The users all tout what they bought as the best.

Stick to a major brand that meets the spec and you will be fine.

 

Dexron VI

 

Perhaps I wasn't clear. I plan on changing the fluid to Synthetic. My question is not which is best, but which Synthetic is compatable with the
"Paper" spacers in my '99 M6 transmission.
I have been using Synthetic Lubricants in all my Vehicles since the '80s. I have found them to be far superior to the Dino Lubes. I have lived thru the old engine will leak MYTH, changing to a Syn product at very high mileage with no ill effects, only postive results from a mileage, heat and RPM at idle test.
I usually use the brand thats easiest for me to find and stock up on, with price as a factor.
Does anybody know about this?
Is Dexron VI full synthetic? Who actually produces it for GM?
Barrier

 

Calling SubDriver!!!!

Divine intervention requested....

Bob

 

Or goes down...

The C5 transmission takes a fluid meeting GM Dexron III specification. I've been using AMSOIL ATF, which meets Dexron III specs, in my 02 Z06 for several years now and have not had any problems. I've also got many customers from the forum using this fluid in older C5s and no one has reported any problems.

One thing not mentioned above by rws.1 is how the basestock used in the fluid can impact its performance. For example, I've read that ester, a Group V basestock used by Redline, causes seals and other porous material to swell. On the other hand, I've also read that PAO, the Group IV basestock used by AMSOIL and Mobil 1, causes seals and other porous material to shrink. Finally, Group III synthetics, which are highly refined petroleum oils, won't have much different impact on seals and other porous materials than a typical dino fluid.

To counter the PAO seal shrinkage, I've read that AMSOIL blends in a small percentage of ester which results in a slight overall seal expansion.

I believe, but don't know for sure, that is for these reasons that some synthetics have been reported to have problems with the paper blocker rings in older C5 tranny's, and others haven't.

In answer to your question on Dexron VI, I've read reports that indicate that this spec can not be met with petroleum based fluids, but that it also doesn't require a full synthetic. I take this to imply that a synthetic blend, or maybe a Group III synthetic basestock will be able to meet the spec. That said, I am aware of no aftermarket company, AMSOIL included, that has a fluid meeting this new standard on the market yet.

 

Thanks for the help! I guess I'm not going to wait for the Dexron VI Spec Fluid.
I was planning on a Amsoil change with the exception of Mobil 1 for the engine ( I think I have about a 2 years supply of that, thanks to Walmart).
Barrier

 

I would sell the mobil oil to a neighbor or ebay it. Look at the independent test results between Amsoil and the rest of the comp. I cant believe I used Mobil 1 in my baby....never again!

 

After yanking the valve cover on my 1997 LS1 with 110,000 mi (for a header install), I couldn't believe how clean it was. Prior owner used Mobil 1 from day 1. Maybe on paper Amsoil is better...but the price and availability, plus actual real world results of Mobil 1 are good enough for me.

There is a point which something is nominally better than a comparable product, and under NORMAL driving conditions you won't see a difference. I bought Amsoil to test out but the price isn't great...even at dealer cost.

 

Dexron VI has been available for a while now, I've been using it in my trans for almost two months now. It seems to be working fine. As far as who makes it, I think it is made by Mobil.

 

Mobil 1 is a good oil, no doubt. But used oil analysis reports consistently show there are better oils on the market, AMSOIL included. How much that matters is clearly subject to debate.

As for price and availability, that depends somewhat on your perspective. For those whose preferred method of shopping is to run to the nearest Walmart, Mobil 1 is clearly the most available. For others such as myself, I prefer to buy online anytime of day (usually late at night after my daughters have gone to bed) saving myself the time and money associated with a trip to Walmart.

AMSOIL pricing, especially for AMSOIL Preferred Customers who buy at dealer cost, the shipped price is essentially the same as Mobil 1 Extended Performance. The tranny fluid may be slightly more than Mobil 1 (I haven't priced the Mobil 1 ATF recently), but it is less than other top line synthetic transmission fluids such as Redline.

 

Ditto

 

Chuck at FLT does not recomment synthetics for his built A4 transmissions.

He is recommending Dextron VI instead of Dextron III now.


DH

 

I am using GMs Synchromesh. As far as I know its synthetic. I have probably 3k miles on it since the change in my MN6 and I have been pleased. Smooth shifts.