Transmission is slipping ? - PeachParts Mercedes-Benz Forum

meapoho · #1 10-20-2010, 03:08 PM

Hello All,
New to the forum as having purchased a 1987 300TD about a year ago.
Car has been driving GREAT all summer long after re-locating to RI from CA.
It is starting to get a little colder now in the mornings here in the East, and perhaps this is the problem? Last Sunday I went to go driving in the early morning, let her warm up as usual for about 3 min and put in reverse, backed out of the driveway and went off on my way. About a 1/2 mile later stopped at the bank, put in park and let idle as waiting at ATM. Went to put in D and engine revved but no forward movement. No grinding or noise just no movement. Put in 2 and drove off, put in 3 then D, no problems until I slowed down to corner, then it would rev and not go forward until dropped into 3 or 2. Went home. Took to a transmission shop about 5 miles down the road in Bristol RI and it drove fine doing the 3 to D shifting, but would do the rev no go when starting from a slow or stop. Mechanic has looked at it and says can't find any thing wrong with it and has only done that once the past 2 days he has been driving it, he does not no what seems to be the problem. SO...... any ideas ? Good Mechanic in the RI area ? Things to look for ? It has about 250K and has no symptoms leading up to this problem at all. Thanks for any leads or answers. cheers,

babymog · #2 10-20-2010, 04:12 PM

Start by changing the transmission fluid and filter, including the torque-converter fluid (via drain plug). If you have someone change the fluid using the "flush" method, you are probably finished with this transmission, or perhaps that has recently happened and has caused your problem.

If it is intermittant, best to start there.

muleears · #3 10-20-2010, 04:14 PM

I don't mean to be insulting but have you checked the fluid level? That's what mine do when they get low.

meapoho · #4 10-20-2010, 04:19 PM

no insult taken.... yes i did, was fine. I asked the mech. if it was low also, he said fine. And no, the "flush" method has not been done since I have owned the car and put approx 9K on her. Will ask him to do a fluids change and filter ?

latitude500 · #5 10-20-2010, 05:07 PM

Keep us up to date on the outcome. Sorry your having problems.

barry123400 · #6 10-20-2010, 07:23 PM

I might dump some transmission additive with a big name in there for a day or two before changing the fluid and filter. Being intermittent is the issue.

Just what I would do. It is perhaps risky depending what is going on but might free a sticking item in the valve body. A person does this at his own risk. What colour is the transmission fluid now? Still a nice red?

meapoho · #7 10-20-2010, 11:23 PM

yea, think maybe a fluid/filter change before additives. Don't know how keen I am on those kind of things being to oil/fuel/drivetrain, but not ruling it out either, Color ? don't know but like I said, the transmission mechanic that I took it to did not mention anything out of the ordinary, and it appeared red when I looked at the level before I took it in, but that was just off the dipstick, have not seen a larger quantity of it to gauge a difference. Still open to suggestions, but will mention a change of fluid/filter to the mech. tommorrow.

vstech · #8 10-20-2010, 11:25 PM

good way to test color is with a white lint free cloth, wipe the stick. red hurray. black/brown/pink... bad...

babymog · #9 10-21-2010, 10:41 AM

Someone here mentioned a filter in the valve body, I don't recall the thread nor do I know the significance (or difficulty) of this task.

vstech · #10 10-21-2010, 10:43 AM

I know there is a filter in the pan, bolted to the underside of the valve body... I'm unaware of a filter IN the valve body.
I've not had one of these open though, so it's possible.
or are you talking about the thread that discussed, the pan filter getting sucked into the valve body and jamming up things.
yeah, that would not be a good thing...

thayer · #11 10-21-2010, 12:08 PM

I have had luck with large name additives. brought a completely gone tranny back...only driven about 1000 miles on her so time will tell. Changing the fluid is absolutely key...do it twice if you have the time. once you KNOW the fluid is clean and you are still slipping, then maybe start adding additives.

tbomachines · #12 10-21-2010, 12:19 PM

Quote:

Originally Posted by vstech

I know there is a filter in the pan, bolted to the underside of the valve body... I'm unaware of a filter IN the valve body.
I've not had one of these open though, so it's possible.
or are you talking about the thread that discussed, the pan filter getting sucked into the valve body and jamming up things.
yeah, that would not be a good thing...

I believe there is a little screen in the valve body itself that can get gunked up, but not sure which transmission that pertains to. I have read a thread or two on it here.

babymog · #13 10-21-2010, 02:42 PM

Quote:

Originally Posted by thayer

I have had luck with large name additives.

Would that be good luck or bad luck?

Joe Marroso · #14 10-21-2010, 06:06 PM

Quote:

Originally Posted by babymog

Start by changing the transmission fluid and filter, including the torque-converter fluid (via drain plug). If you have someone change the fluid using the "flush" method, you are probably finished with this transmission, or perhaps that has recently happened and has caused your problem.

If it is intermittant, best to start there.

Babymog,

Am I to understand, by your reckoning, a flush for a MB automatic ruins the transmission? This is your experience of all automatics or just Benzs?

Thank You
Joe Marroso

babymog · #15 10-21-2010, 06:59 PM

I'll put it this way:

I know two people who own/have owned transmission rebuilding shops. They both tell me that the flush machines are the best thing that ever happened to the transmission rebuilding business; Many customers come in with transmission problems when their cars worked fine before a recent flush. The story usually includes the customer going back to the flush/change shop and being told that the trans was likely about to fail, and the clean fluid was just too much for the transmission (or some version of the same excuse). Neither of these guys will use a fllush machine nor allow one near their vehicles.

I believe that it can be done properly, but if not flushed properly then catastrophe will result.

Also, the flush does not address the filter. If you have the pan dropped to change the filter, you can assess the type and amount of sediment in the pan for some diagnostics, plus then half of the fluid is already drained. Mercedes equipped the torque converter with a plug also so that you can drain almost all of the fluid in the system (even a fair amount from the cooler should drain back), so there's no reason in my mind that one should short-cut the change by using a flush machine.

Further, many of the shifting problems in these 722 transmissions seem to be a result of a plugged filter, ...

At this point, seems kind of silly clicking the "Post Quick Reply" button.