I know anything to do with fluids is apt to spark a heated debate, but there is a mildly unique set of circumstances regarding the 722.6 transmission in my XJR.

First of all, it shifts like butter. Could not ask for it to operate much better. Smooth and sure.

History of transmission. Previous owner bought car at 34,000 miles and had the transmission fluid changed at 41,000 miles. I talked to the shop he used and they said they changed the filter and gasket, and used the Valvoline Maxlife fluid. They are an import car specialist and say they use that in all 722.6 transmissions.

At 88,000 miles he took it to the same shop and they replaced conductor plate, electrical sleeve, filter, gasket and fluid again. Again with the Valvoline product. He gave me a Valvoline part number but I can find NOTHING online for that part number (001989080311).

The car now has 99,400 miles and the fluid level is perfect. Common sense says it does not need to be touched for many more miles. But, in all of my thread reading on this transmission over the past year I read a report claiming the hot viscosity of the Maxlife product did not meet, or even come close to, MB Spec. I am wondering if that's why he needed a new conductor plate about 47,000 miles after they put the Maxlife in? My inclination would be to put in the MB fluid or the Febi fluid (seem to be exactly the same) but I hesitate to start messing with what seems to be a good working transmission. My method is usually about 5 drain and fills about 400 to 500 miles apart until the fluid looks brand new. If I start doing drain and fills with the Febi fluid will the mixture of the two be detrimental in any way?

Any feedback?

 

If you are concerned about fluid compatibility then go to a Chrysler dealer for fluid. They use the gearbox because they were Daimler-Chrysler for years.

I used the Chrysler fluid a few times. It looks and smells a little different but it is for the 722.6 gearbox.

bob

 

I was hoping you'd be the one to respond, haha.

So, in your opinion motorcarman (Bob), should I even BE concerned about the fluid?

 

I have not heard that the 722.6 box is 'picky' about the fluid used. I just use the MB fluid or the Chrysler fluid. I did buy some FEBI fluid that was in the same bottles as the MB fluid and it seemed to work just fine.

bob

 

The 236.14 specification does allow for a range of viscosity and Maxlife is in the range, but towards the thinner end. It has a hot viscosity of 5.91. The Shell ATF has a slightly higher one. Mobil ATF is a bit higher still at 6.5. So if you are having shifting problems due to wear in the valves, Maxlife would not be the best choice. But if the box is working fine, I would stick with it.

My box does have shifting problems when hot, so I actually went with a 236.10 fluid, which is what the box shipped with back in 2001. It has a hot viscosity of 7.6, or almost 30% thicker.

So if you have hot shifting problems, I would suggest going for a 236.10 fluid, and forget 236.14 altogether. That means Redline D4, the only one that's easy to find.

The problem is, as I see it, is that the fluid spec has been getting thinner, through 236.10, then 236.12, then 236.14, while the box has been getting more worn. Now 236.14 is too thin to work well when hot, with my worn valves.

 

+1

Have used the Mobil 134 for many miles (more then 120Kmiles) without any issues. As mark says the Valvoline is only slightly thinner, so I see no reason to change it. However personally I wouldn't have used it and will stick to an oil meeting the specs.

Valvoline Maxlife doesn't have any Mercedes certification (ie like 236.10 or .14), that is probably why they use the NAG1 as reference on one of their spec sheets, a bit misleading imho, though after re-reading their sheet it says "Suitable for use in" not that it has been certified:

http://content.valvoline.com/pdf/maxlife_atf.pdf
https://bevo.mercedes-benz.com/bevol...236.10_en.html
https://bevo.mercedes-benz.com/bevol...236.14_en.html

 

The full name is Valvoline MaxLife Dex/Merc

That's what I use, and I have an old Mercedes issued
training document that lists it as compatible with the
722.6.

The fluid is very populer on the Sprinter van and Chrysler LX
forums. Both use the 722.6

Can't find it .... try Walmart or NAPA.

 

Mobil 134 has the highest viscosity I could find in a 236.14, 6.5, but is unfortunately very hard to find here in the US.

 

I've been running the MaxLife Dexron/Mercon fluid in my XKR for about 10k and I have no issues whatsoever. However, if I were to do it again, I'd probably just get the FEBI, Pentosin or Mercedes-Benz fluid. It's really not a big difference in price, and I change my transmission fluid between 30 and 60k (5 to 8 years and LOTS of city driving and less than 20mph driving).

If I were to change the fluid, I absolutely would recommend doing the little connector thing. Mercedes 0015409981 - LINK

I did not change the connector, despite knowing I probably should have, so when it leaks I'll do it and go back to the MB fluid. I bet I'm probably going to be changing the transmission fluid more based on leaks or stuff like solenoids or connector plate than mileage; so nbd.

 

I have a questions on the topic of this thread. Yes, the thread is over a year old but I started it so I'm going to use it again...lol

Does anyone know (motorcarman maybe?) how much you really have to drive an XJR between drain and fills? I want to do about 4 drain & fills replacing the filter and gasket on the last fill. I did the first one today draining out a little over 3 liters. I don't drive the car that much. Does it really have to go 200 miles in order to sufficiently mix the old fluid with the new? Could I theoretically drive it about 20 miles and drain & fill again with the same results?

Just curious. I would like to cycle through all the fluid but don't want to drive 800 to 1,000 miles to do it.