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We've learned the hard way that third-party fluid makers' & marketers' claims cannot always be trusted. We should be especially skeptical when a marketer claims that one fluid is a suitable replacement for dozens of other fluids. Here's a simple chemical comparison anyone can do. I'm attaching the Material Safety Data Sheets.
For Mobil ATF 134, a fluid approved by Mercedes-Benz for use in the 722.6, the kinematic viscosity at 40 degrees Centigrade is 29.6 cSt (mm2/sec).
The kinematic viscosity of BG 312 at 40C is 34.28 cSt, or 15.81% more viscous than Mobil ATF 134.
The kinematic viscosity of BG 315 at 40C is 28.7 cSt, or 3% less viscous than Mobil ATF 134.
To put these numbers into perspective, the difference in viscosity between 0W grade engine oil and 10W grade oil is less than 8%.
The base oil of both BG products is different from the base oil of Mobil ATF 134, and the disclosed additives are different. Viscosity at various temperatures is not the only criterion that matters (other factors include slippage characteristics/friction modifiers, anti-corrosion and anti-foaming additives, etc.), but it's the most critical characteristic, and comparing viscosities is a simple way to judge the similarity of two fluids.
BG claims that both of the above fluids are suitable for use in the 722.6, despite the fact that their chemical properties are very different from each other, and also different from a known approved fluid.
These fluids may, in fact, be "good enough" for use in your transmission. But with so many fluids approved by M-B to choose from, why take the risk?
Cheers,
Don
this is why i spent way too much time coming to the conclusion that since i can't find super 90 for my diff, I ended up using 75w110 that is 20.8@100c, when the super 90 was at 19.5. Not as thick as 140 and since nothing exactly matches Spirax Super TS90, it was better than 75w90. Which is too thin. That 90 110 SAE split sent me for a spin. Good read though.
All 722.6 transmissions are not built to the same specifications. The Chrysler cars using the 722.6 unit do not have the same specs as the 722.6’s used in the XKR’s.
I don't really think this is true. There are differences, but those are across the entire transmission line, not specific to the makee, yet the fluid recommendations don't follow with those changes or modifications, they go exclusively by nameplate. Dodge (who at the time was owned by Mercedes) recommended Dodge fluids regardless of transmission spec, while Mercedes recommended Mercedes spec fluid.
For example - Our 722.6 in the XKR has some differences in hard parts between it and the latter 722.6 V8 transmissions Dodge and Mercedes started using in 2005. But Mercedes cars got the same changes as Dodge did in 2005 and they continued to recommend Mercedes spec fluid even when their cars got those changes.
Also, the transmissions that are most different are the transmissions used in Mercedes V12, and they recommend the same fluid in them too.
I don't really think this is true. There are differences, but those are across the entire transmission line, not specific to the makee, yet the fluid recommendations don't follow with those changes or modifications, they go exclusively by nameplate. Dodge (who at the time was owned by Mercedes) recommended Dodge fluids regardless of transmission spec, while Mercedes recommended Mercedes spec fluid.
For example - Our 722.6 in the XKR has some differences in hard parts between it and the latter 722.6 V8 transmissions Dodge and Mercedes started using in 2005. But Mercedes cars got the same changes as Dodge did in 2005 and they continued to recommend Mercedes spec fluid even when their cars got those changes.
Also, the transmissions that are most different are the transmissions used in Mercedes V12, and they recommend the same fluid in them too.
The early Hemis and SRTs had off the shelf AMG boxes and they recommended ATF+4 in them and all other cars that followed. The Crossfire was an exception with the M112 V6 + 722.6 combo and they recommended 236.10, 236.12 OR “Synthetic Dexron III”.
236.12 is what MB introduced at the start of 722.9 production and rolled over to the 722.6. Fuchs describes it as an “Ultra High Performance DEXRON III-generation-ATF for automatic transmissions”. It is significantly thinner than conventional Dex IIIs of the time, much like Dexron VI that came out a couple years after.
ATF+ 3/4 was introduced after Dex II started turning into water in the old 46RE and all the other famously bad overdrive boxes. It’s usually slightly thicker than Dexron III and probably has some other friction modifiers.
In short the NAG-1 has had 4 different factory fills.
Need something close to the jag’s factory fill for a fraction of the price? Valvoline Dex/Merc blue bottle. Want a full synthetic? Mobil 1 Synthetic. Want something more like ATF-134? Valvoline MaxLife red bottle.
when shopping for a “kit” make certain that the conductor plate is a genuine Mercedes Benz part, or the Jaguar version.
I made the mistake of getting an eBay kit which was
suppose to have the genuine M-B parts,
it didn’t .
If I’ve been correctly informed, the trans temp sensor is built in to the conductor plate.
Now, with the non M-B branded part, I have to put up with intermittent false “high trans temp” warnings. Even got one of those when the car was stone cold after sitting overnight.
I do now have the correct M-B part, and am waiting for more motivation to pull the plate off.
I’ve been told there are many Chinese copies of Mercedes parts, they even have the M-B logo. So take care where you purchase parts.
for everything else. remember, forum members get 10% off of most parts when ordering from Barratt. I order by phone, just to be sure.
Z
PS. I had a transmission shop do a complete fluid exchange with new +4 fluid going in. My transmission didn’t like the +4, and shifted 100% better when I drained it all out and replaced it with Fuchs 134
YMMV
.
Can I interject a question here? Did the '03 XK8 like mine come with a 5-speed then the 6 s-speed trans? When buying the supplies for my trans fill Rockauto sent me the wrong filler. I may have ordered the wrong one but I degress. It's a Hastings TF177, would that be for the 5-speed??
If it fits a Jag trans it is free to a good garage for the postage. It's way too late to return it and I hate to waste it. Ping me if interested. TM
Thanks Don, then that doesn't explain why Rockauto has The TF177 listed for an '03, they also listed the right one which I used.
However, it's still up for grabs if it fits someones car.
TM
I did this change 20k miles ago in my 00 XKR. I used the Valvoline Maxlife Synthetic ATF, a new Mercedes coupling, and a Mercedes gasket. Shifts great at 110k now. I bought the generic 722.6 dipstick tool on ebay too. I basically assembled bits from eBay.
Thanks Don, then that doesn't explain why Rockauto has The TF177 listed for an '03, they also listed the right one which I used.
My experience with Rock Auto and all other parts sources is that their information comes from the manufacturers' catalogs, and if the manufacturer provides incorrect information, so does Rock Auto (or AutoZone, Parts Geek, O'Reilly, NAPA, etc.).
Just a comment from my recent experience,
Cheap *** 722.6 Conductor plate Kit with filter and feedthrough connector might lead to puddle of mb-transfluid on the floor.
The diameter of the chinese copy feedthrough AND its O-rings are total of 0,3mm smaller in my case leading to disappointment.
If I had noticed the difference I could have solved the issue it with thicker O-rings... (or would have just keept the old feedthough)
Conductor plate seems to work well.
I suspected speeds sensors on old conductor plate were bad, so replaced during oil change to eliminate the possible cause.
I purchased the set (plate, filter, gasket and feedthrough) for 70 euro's incl shipping....
