1993 MX6 MTX Pennzoil Synchromesh 25.7k mi

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6,171
Location
Santa Barbara, CA
Oil Guard analysis Sample Date 9.7.06 Mileage 198,787 Miles on Oil 25,700 “ALUMINUM LEVEL HIGHER THAN NORMAL. MODERATE DEGREE OF OXIDATION INDICATED. SUSPECT HIGH OPERATING TEMPERATURE OR OVER EXTENDED OIL DRAIN. DRAIN OIL FROM UNIT IF NOT ALREADY DONE. RESAMPLE AT NEXT SERVICE INTERVAL TO MONITOR..” Viscosity 100C 13.1 H2O 0 Soot 0 Fuel 0 Glycol 0.5 Nit 0 Oxi 19.8 TBN 0 FE 34 CR 0 PB 8 CU 6 SN 0 AL 26 NI 0 MN 0 SI 34 B 0 NA 3 MG 0 CA 0 BA 0 P 0 ZN 0 MO 0 TI 0 K 0 Oxidation and Al flagged. I have a magnet on my fill plug, so FE may be higher than tested (it only had a little debris stuck to it, though). Pennzoil Synchromesh is 9.08 @ 100*C, so it thickened quite a bit due to the oxidation. Car is spec'd for a 75w90 GL4 MT oil - ran Synchromesh for better shifting (it did elimate all grinding I was having with old redline fluid). Refilled with Redline MT-90 (correct spec fluid). I was always worried about the thin synchromesh fluid for protection and it seems like I had a reason to be.
 

surfstar

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6,171
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Santa Barbara, CA
And its amazing how many people blindly recommended it along with GM Synchromesh, BG Syncroshift, etc. All those Synchromesh fluids - they sure shift nice, but at what expense? Despite the "bad" report, the wear numbers don't seem too high, although I couldn't find any other reports on this tranny to compare to. This is my second UOA from Oil Guard and this one also does not list AW additives like Ca, Zn, P? Not sure why. Don't worry Johnny, the Penz Plat UOA was quite good in my car. Works good when you use the right product. [Duh!]
 

MolaKule

Staff member
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21,838
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Iowegia - USA
How much paste on the mag plug. A thin film or thick and clustered? Check your shifter boot for crakcs, etc. since the silicon seems rather high. Z and P should be around 1500ppm+ for a synchromesh type fluid with Mg. for Synchromesh at 3500+ ppm.
 

surfstar

Thread starter
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6,171
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Santa Barbara, CA
Mola, just happened upon your reply. It was a very thin film. I think the shifter boots are okay, and this OCI was after I replaced the CVs, so there shouldn't have been external contamination. I have one UOA left, that I may end up using on the redline fluid after about 20k miles to see how its holding up. I don't think UOAs on my engine tell me anything new anymore.
 
Messages
43
Location
Miami, FL
I'm not sure what fluid was tested by Oil Guard. But it definitely was not Pennzoil Synchromesh. PSM would be loaded with P, Zn, and Mg, as MolaKule notes. This looks more like their 80w90 GL-1 product, which has no EP or FM additives. In that case, it would actually have sheared by about 20% from 16.8 cSt to the 13.1, which sounds about right. Old thread, I know. But I wanted to set the record straight for those researching GM/P SM in the future. Also worth noting is that very few manual transmissions run hot enough that oxidation thickening should be an issue. They are typically *well* under 100C. Also, the lack of EP additives in whatever this fluid was easily explains the high Al. There is every reason to believe that real Synchromesh fluid would have done just fine.
 
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5,069
Location
Saratoga, NY
Spockian, the report lists "zero" for all oil additives and surfstar says this was the second time in a row that the lab did this in a UOA ... so it appears they were intentionally omitted. Also, even an oil with no adds would have a few PPMs leftover from prior fills.
 
Messages
43
Location
Miami, FL
Originally Posted By: Bror Jace
Also, even an oil with no adds would have a few PPMs leftover from prior fills.
Right. That's why I'm saying that there is about a 0% probability that these test results are really from a sample of Synchromesh. If I had to guess, I'd say that the original poster mistook a bottle of Pennzoil GL-1 for the synchromesh fluid.
 
Messages
43
Location
Miami, FL
Originally Posted By: Bror Jace
Spockian1, surfstar said this lab omits oil additive particle counts.
No. He says he sent in samples of two oils and got back numbers with 0's for additive elements he was expecting to see >0 numbers for. He does not specify what the other sample was supposed to be. Based upon that, he speculates that the lab must not test for additive elements, and puts 0 in the report instead. And even he thinks that's very odd. But in this case, the KV100 of 13.1 cSt alone clearly identifies this as something that was never Synchromesh. If it were, that would be a whopping 45% thickening "due to oxidation" as surfstar speculates. That would be *very* notable even for engine oil, which sees temps of over 300F. But transmissions typically run *well* under 200F. Previous UOA's of Synchromesh show significant *thinning*. And Blackstone's universal average gives a range of 6% - 24% thinning over a 26k mile run. No oil is going to thicken due to oxidation at the moderate temperatures that a manual transmission sees. There is absolutely nothing in this UOA to suggest it was ever Pennzoil Synchromesh Fluid. At any rate, the analyzer in question is OilGuard... AKA Terry Dyson. Do you really think that Terry omits testing of those pesky and inconsequential additive elements, and then just lazily puts down a 0 for the value, instead?
 
Messages
43
Location
Miami, FL
Originally Posted By: Spockian1
At any rate, the analyzer in question is OilGuard... AKA Terry Dyson. Do you really think that Terry omits testing of those pesky and inconsequential additive elements, and then just lazily puts down a 0 for the value, instead?
BTW, you can completely disregard the above quoted sentence. It's totally bogus, and based upon a post I misread in the wee hours of the morning after nursing a car with a broken throttle cable about 100 miles on I-40 to get it back home. (Yes, it was stressful. Replace your throttle cable every 350,000 miles whether it looks like it needs it or not.) I do, however, stand behind the rest of the post.
 
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