So I was wondering is it a good idea to service my transmission or doe these cars Mercedes Benz transmissions fall into the old notion that when you change the fluid you are removing important metals from the fluid which aid in transmission operation. I always liked changing the fluid under the theory that clean fluid has better friction protection then worn fluid with metals, but many old car guys will tell you don't touch the transmission fluid. Figured I would ask since many of you have very high mileage XJRs.

Also, do these things have limited slip differentials? I've read yes and read no, my recent experiments in tire friction tell me no and also had it on the rack and spun the tires and they go opposite directions which also leads me to a no. But perhaps mine is worn to the point of 1 tire fire

Thanks all.

 

What's your mileage ? Many people (including me) change at 100K Km - mine's a ZF but equally valid for the MB box.
There's no LSD as standard.

 

It has 140K on it. Dunno if it has ever been changed thanks for the LSD answer. I have had good luck changing the fluid in my automatics and normally do.

 

OK, change it. If you look for the Rev Sam video in the XK8 stickies all will be explained.

 

Absolutely not on the limited slip. I autocrossed my XJR a while back and I was blazing the inside tire out of every corner. It was quite fast all things considered, but I would have been several seconds faster a lap if I would've had an LSD and wasn't putting up smoke screens at every corner.

 

I wonder what was Jaguars reasoning behind that, couldn't have been to save money on their 70K car they were selling. Haha

 

I have 193K miles on mine and I don't know if its ever been changed either. I was also considering taking it to a shop to have it changed but also in my mind I'm unsure as there is no way to check the fluid either?

 

@BMC Nut

A lot of european companies moved away from LSDs in that era, even on their big bruiser sedans. I think it's because they thought (for some stupid reason) that the traction control systems that were starting to become commonplace at the time would make a mechanical LSD unnecessary. They all pretty much realized the stupidity of that idea by the mid 2000's and started putting posi's back in, but from the late 90's to the mid 2000's pretty much nothing got a limited slip.

 

wow

i think at that point i would keep driving it with this fluid until it shows problems and then get a new gearbox, unless you drive it on really long trips.
it is awesome it held so long.

 

I mean I don't know it to be a fact. I bought it from the 2nd owner. It has sat for 2 years with a bad fuel pump. I got it and started working on it replacing and changing things from neglect from 2nd owner. It's like he drove it until it quit, never replacing or maintaining. So good indication same tranny fluid exists lol.

 

from experience i (painfully) obtained during my story is that if it is that old, i would not bother to do expensive change. You will most likely end in situation that new oil will not work properly and you have to get new gearbox earlier and some costs wasted. I would slowly start to look for good price on rebuilt gearbox and drive it until it breaks. As i understood it, it wears gradually so you will get lot of messages of it going to fail before it would leave you sitting in woods on street.
Gearboxes in our cats are really good. I actually drove mine 100km with extremely low level of oil (shop's mistake) and it is now already for 1000km good.

 

I dont even know how or where to check the level lol There's no stick!

 

@Coastaljag, no X308 has a trans dipstick.

 

Here's the video I mentioned earlier.
This is also how you check the level.
Jaguar XK8 Transmission Fluid/Pan Change - YouTube

 

Apparently Jag were under pressure from Ford to get the X308 onto the market & earning money from sales, so the same diff was used for all 3 models-with the 3.2L having a different ratio to suit the smaller engine-none of them were LSD units.

However, the 4.0L XJ8 & XJR both had the same diff & ratio-it was never available as an LSD unit & is known to be a weaker unit than Jag diffs from the X300 backwards. It's most at risk in the XJR, as the diff is not uprated to handle the extra power of the XJR & so only has a marginal overload capacity if you start tweaking the power output of the supercharged models-the diffs have been known to let go on the odd occasion...

My XJR has 150k on the clock & the transmission fluid has never been changed-the geabox still works fine so I might as well leave it now. I heard from a guy who used to work on the MB gearboxes that they had more problems with those 'boxes after an oil change at high mileage, so in the end they just left the old oil in high mileage units. This guy has an XJR with 217k on it & still on the original gearbox & fluid...

I had thought about maybe 'refreshing' the old fluid by draining off a couple of litres of the old stuff & adding a couple of litres of new fluid, but the jury's still out on that one...

 

I'm that 'guy'

And indeed, I was a mechanic for a Mercedes dealer for umpteen years and as those gearboxes would accumulate miles, we discovered that draining off the old, nasty fluid and refilling with fresh (including a new filter) would lead to problems. My own folks had a '99 ML320 Merc which they bought new and drove to 220K and never changed the fluid and it shifted perfectly right up to the day they sold it and it still performs beautifully for the current owner. As Alex said, my XJR with 217K on it hasn't ever had the gearbox serviced and shifts are imperceptible. If I do run into problems and happen to need to overhaul my 'box, it will be thereafter that I put it on a 50K fluid/filter change interval, which is what Mercedes eventually recommended on that 722.6 transmission.

 

Out of interest, what sort of problems were you encountering when you did the oil and filter change on the MB boxes.

I'm curious, as my 2001 XKR has 138K on the clock and I was wondering if I should be getting worried about the oil quality and level etc. She's parked up in my garage when not in use, so I would notice if there were any leaks, but...........I guess it just plays on the mind a bit.
Andy

 

Hi Aaron-small world, although I took my time to finally join this forum

As is often said-if it ain't broke, don't fix it-unless it's secondary timing chain tensioners! My XJR has 150k on it & the gearbox still works completely normally.

Alex