01 XJR, 139k miles, new to me this past August. Car runsnad drives great, I have zero issues with the trans shifting or engaging any of the gears in normal or sport mode. Shifts are very smooth at low throttle, firm but not abrupt at heavy throttle. I'm currently trying to assess the condition of the fluid and its level to make sure I know the baseline, figured I don't know when its been changed before so I'm plannig to do a drain, drop the pan and do the filter, gasket, etc and then top off with the proper fluid. I know this will leave quite a bit still in the torque converter, but unless the old fluid is truly nasty I'm presuming this is a good way to go. No plans for blue top solenoids or any upgrades, just maintenance.

OK, so I bought one of the generic Mercedes dipsticks on Amazon, says its for the 722.6 trans and it has the cap for the tube, which my car was (and still is) lacking when I bought it, only recently discovered that it should be there. Link below, this is the one that has the two sets of measures for cool and hot readings.

https://smile.amazon.com/dp/B07MCX9C...roduct_details

Folowed the procedure as best I could, seemed pretty clear. Drive it for awhile to get it good and hot, park it on a level surface and then run P-R-N-D-N-R-P for 5 seconds each, then sit running for 2 minutes, shove the dipstick down the tube till it stops and then pull it out to measure.

Problem I have is I got virtually nothing on the dipstick. It came up dry except for a tiny bit of what seemed like dirty grease, not a liquid. I repeated this a few times and got the same result consistently, pic attached below. I feel like I have to doing something incorrect here because I can't see how this thing could possible be so low on fluid that it doesn't register, yet it operates flawlessly. I marked the dipstick where it stopped in the trans, hoping someone can tell me that its just not going in far enough. I got about 513mm from the tip to the mark, give or take a couple mm I'd say. The plastic tip of the dipstick is not 100 true off the end of the flexy part, its a couple degrees off straight. I did try rotating it while pushing it down. It very much feels like its hitting the end of the tube...maybe I've got something in the tube that is obstructing it? I might be able to get a boroscope down there to look, assuming it'll fit.

So, any thoughts here? What is that goop on the end of the dipstick? I don't like the look of it at all, looks gritty. To my knowledge, the pan is undamaged, there were no dents or dings in it the last time I was under there and I've had no impacts into anything that would dent it. I'm more inclined to beleive that its me doing something wrong rather than an actual problem.

Thanks.

 

I see in another thread that M Stojanovic measured his and it was 706mm which is waaaaay longer than I'm getting, so likely my problem is not being persistent enough with wiggling it around.

 

You can verify the length of dipstick insertion using a length of bicycle, or motorcycle if not too thick, brake cable (the sleeve only). It will go fully in much easier. I measured 704 mm on the dipstick and got the same length when using a bicycle cable. And yes, it can be quite tricky to insert the dipstick fully in as it encounters quite a bit of resistance at the tube bends.

 

I measured it out and put a mark at the ~704mm point and fiddled again. Eventually got it to maneuver past the bend that I thought was the end of the sump and it went right in, came out with fluid all the way up to the end of the dipstick, but it was cold and not running so I'm not using it as a measurement, just know that it goes in now. I'll do another proper measurement later this week...got distracted by pulling the rear seat out in an effort to get at the subwoofer so I can recone it and maybe get some sound out of it...on the upside I picked up something like 53 cents in change under the rear seat.

Thank you sir!