I'm wondering if any of you guys (or gals) out there that have (or had) a 300E, have any idea on the normal life expectancy of the automatic transmission in this car.

Mine is a '86 300E with 107K miles on it. I had this car without any AT problems for about 7 months now (purchased it with 103K Miles), but have recently started noticing some subtle changes in the way the shifts feel. Sometimes when starting up (in D) from a complete stop, the first shift feels a little "loose", and just this morning when I was overtaking another car I noticed a slight slip (revs went up) just prior to gear shift. Also (when parked) the "bump" when going from P (or N) to D (or to R) is somewhat more pronounced that what it used to be, and there seems to be some kind of short (barely noticeable) howling noise coming from the transmission when I move the stick from P to N, or D to N.

BTW. I just checked the AT Fluid level, and I found that it's about 1 inch bellow the MIN mark on the dipstick (level used to be OK). Oil looks clean and does not smell burnt. I'm going to top it off in a while and hope that (at least some of the) symptoms will improve or maybe (hopefully) correct themselves. I'm also going to check for ATF leaks, but as far as I can tell, my parking space floor looks clean (I'll check again after toping off the missing ATF).

In any case, since the car passed the 100K milestone I'm wondering if I've reached the end of the transmission's normal life expectancy, and if this the case, how soon should I expect that a rebuild will be needed.

Also wondering what other items on the car will call for attention in the next few months, or should be checked.

I'm aware most answers will depend on car maintenance and usage, but since I only have had this car for such a short period (only 7 months of everyday city driving), I don't really have much information on it's past history. I figure if anybody could give me at least something like an "average life span", or "at best" figures on this type of AT, than I would have some point of reference.

Thanks in advance.

Alex

You should not be anywhere near the average lifespan. I've had friends drive their Chevy for 300 000 miles on the original transmission with no problems. I have nearly 100k on mine and it works fine. I'm guessing
here, but I see no reason why you shouldn't get well over 200k miles.

Transmission failures at 100k are not normal if the car was not abused.

a transmission failure at 100000 mi, or more importantly, 18 years is not out of the ordinary if the unit has not recieved proper maintenence. if you cannot verify the flushes have been performed at the proper intervals, you may have a trans on its way out. please don't take offense at this, but you do know that the trans fluid must be checked with the vehicle at normal operating temp while running? sorry if that's a little elementary, but you'd be surprised. if there is an adjustment to the fluid level necessary, make it, and 90% of the time you will seriously reduce the symptoms and extend the life of your trans. i currently have a client that has close to (if not over by now) 700000 mi on his '86 560, which is a nearly identical trans to that in your 300. so longevity is more than possible with proper maintenence of the unit.

While on the subject of proper automatic transmission maintenance, my mechanic (independant shop) told me that the automatic transmission in my '98 E320 wagon is considered a "non-servicable" transmission. There's no dipstick and no way to flush the fluid other than dropping the pan. They suggested taking it to a transmission shop, but I'm a bit hesitant.

My question - and I apologise if this has been posted previously (my search of the forum showed nothing on this subject) - is it recommended to "service" this "non-servicable" transmission, or would dropping the pan on such a "sealed" system cause problems down the road? If the fluid should be changed, at what mileage intervals should it be done? Is there another way to remove the fluid, other than dropping the pan?

I'm currently not having any problems with the transmission, but that is my greatest fear with this car.

TPh.

I would recommend getting it serviced if you plan on going over 100000 miles with the vehicle. I know they are considered to be a "sealed" unit, and MB does not recommend it, but it is good piece of mind (I put a new 722.6 trans in my car @ 50000 miles due to catostrophic failure). Make sure if you do service it that ONLY MB ATF IS USED. It is a synthetic trans fluid specifically designed for that trans and the introdtion of a foreign fluid into the system WILL DESTROY IT. Your trans takes about nine quarts, and it is expensive. You will need a special dipstick that MB offers to measure the fluid. There is nothing that will happen if the trans pan is dropped, as we replace valve bodies with some frequency (as well as leaking trans pan gaskets). This could be an issue of some debate with other MB service professionals, but I do recommend this to my clients that are strting to get along in the mileage.

a transmission failure at 100000 mi, or more importantly, 18 years is not out of the ordinary if the unit has not recieved proper maintenence. if you cannot verify the flushes have been performed at the proper intervals, you may have a trans on its way out.

Hi PHAEDRUS242,

Thanks for the reply. Unfortunately I'm not sure of the service record of the car, but the ATF seems to be ok, it's bright red, no particles, and doesn't have any burnt smell.


please don't take offense at this, but you do know that the trans fluid must be checked with the vehicle at normal operating temp while running? sorry if that's a little elementary, but you'd be surprised. if there is an adjustment to the fluid level necessary, make it, and 90% of the time you will seriously reduce the symptoms and extend the life of your trans.


No problem, I rather get too much info than no info at all. Besides, this post might benefit someone else with perhaps somewhat less technical expertise. Fortunately I do own a set of CD's with the W124 service manual and a couple of books. In any case the ATF was checked at 90 deg, lever in P, and with a idling engine. A little more than a liter (about 1.25) had to be added to bring the level just bellow the MAX mark. The service manual states that the level should be checked at 80 deg, but here in the tropics your engine will usually run at 90 so I took into consideration some additional heat expansion of the ATF so as to avoid overfilling it.

Since I topped off the ATF level, I haven't noticed any more RPM flare ups during shifting, but call me crazy, I still can't totally convince myself that the transmission is shifting right. It still feels somewhat "loose" when it shifts from 2-3 (specially when starting hard from a complete stop, lever in D), but maybe it's all in my head. I'm taking the car tomorrow to a friend of mine that is very experienced servicing MB's, so the final verdict hopefully should be in by then.



i currently have a client that has close to (if not over by now) 700000 mi on his '86 560, which is a nearly identical trans to that in your 300. so longevity is more than possible with proper maintenence of the unit.

:o That certainly examplifies the importance of proper maintenance. Bet he's the original [lucky] owner.

Alex