I've looked through as many forum postings as I can find, and there isn't a lot of info on the Mercedes transmission used in the early XKRs. Lots of ZF info, but not much on the 722.6.

Is there a thread somewhere that I am missing? My 2001 XKR has just over 100,000 kms (~65,000 miles) and I doubt it has ever had a fluid change. I found some Mercedes documentation that says that there is a dipstick tube but it's plugged and you need to buy a dipstick off Amazon or Ebay. Does a 2001 XKR have a dipstick tube? Can it be used to fill the transmission after the fluid is drained and the filter is replaced?

 

Do a google search of the 722.6 and you will find lots of info, including utube on changing.The dipstick tube is so small that I don't think you can pour fluid in. I use my Mitivac to remove and replace fluid with a small dia. rigid poly hose that will reach the bottom of the sump and still allow some air flow. You can probably rig the same with a ordinary hand pump. Hardware stores usually carry a selection of rigid and flex tubing that can sleeve to make what you need.

The ebay dipstick works fine, and you can also buy replacement caps and locks. After changing the filter plan on doing two or three additional drain and fill steps, since the torque converter does not drain when you drain the sump.

 

SOME early torque converters have a drain plug so you might spin it around and watch the access hole in the bell housing for it.

Also be aware that if you are using PDU, WDS, IDS etc. to read the fluid temp, the selector lever must be in a GEAR (R or D) to read the temp. Park or Neutral will default to ENGINE TEMP reading. (see TSB 307-06)

bob

bob

 

It is very easy to do. I had my r done at a mercedes dealer at 70k after I got it as my local Jag dealers said it is a lifetime fluid and they can't even get it plus advise against it. At 110k I did it myself and then drove around for a few days and drained it agained to get as much out as possible although it really looked pretty good but the fluid was cheap enough. Don't forget to order the pins for the dipstick cap! I got 5 via Amazon or maybe ebay.

 

Although l have not done the job yet, l did aquire the kit containing filter, conductor plate and connector. If l am dropping the pan might as well do the works. Dipstick is easily available online and dipstick tube while small diameter would be ok for fluid fill.

 

Awesome. Excellent info guys. Thanks!

 

The 722.6/NAG1 is probably the most common 5-speed auto ever built, there is info all over the net on it and any transmission shop can change the fluid and filter.

You will need to buy a dipstick ($20 or so) and either a scan tool or a thermometer to get the fluid temperature. If using a scan tool the trans needs to be in drive. It is also a good idea to get a new plastic lock for the dipstick cap as you will have to break the old one when you remove it (trans shop will likely have these).

Changing the fluid and filter itself is easy. Getting it to the proper temperature to top off is extremely difficult. It should be 185F to get a proper reading and that is far hotter than it will be during normal driving. In the dead of an Alabama summer I had to beat it like a drum driving around town for about 15 minutes to get it that hot, I don't think it will even be possible to get it to that temp this time of year. The best thing to do would probably be to heat the fluid on a stove to the right temp before you add it into a warm car.