I had the transmission replaced about 55,000 miles ago and when the
car was in for its last service (355, 000 miles on car) I had them do
the transmmission service as well. When i first got on the freeway i
could feel something strage when under full acceleration it tried to
shift from 3rd to 4th. It was jumpy, like it didn't know if it wanted
to shift or not. I let off a little and it shifted fine. I figured it
was because the transmission was cold so i didn't think much abou tit.
A few weeks later, it started doing it between other gears as well. I
checked the fluid and there was too much. I drained some out to the
proper level but i am still having the trouble that, even if not under
full acceleration, the transmission does not want to go into the next
gear unless i let off a little bit.
In this first pic (i believe is the transmission control valve?), if
i take the bottom hose off, the transmission does not pull as hard and
i still have to lift off to get it to shift, but it does not have that
While looking for a vacuum leak, i came across another problem. Next
to the brake master cylinder is a large vacuum hose and there is a
branch off it (pic 2) that has been plugged. It looks as though the
top of the part in pic 1 haqs been plugged as weel. There are only 2
hoses attached but there are 3 ports. I do not know if these lines are
suppose to be connected to eachother or to other things or what they
even control. I can see no loose hoses that have been plugged that
would attach to either of these locations mentioned.
Any ideas where to look or what to test? Anyone have a vacuum diagram
for a 300SDL?
86 300sdl 357,000mi
80 450sl 220,000 mi
I would say it is probably a vacuum problem. First of all, get a vacuum
gauge and test how much vacuum you have. Test it at the vacuum pump first...
I can't see the picture as I think is a large file. Even with cable modem,
it didn't load up. You should consider posting it on a host... like Kodak
pictureshare or something similar...
Who serviced your transmission?
This isn't the first time that I've heard of folks having trouble
following having their transmissions serviced. Under normal operating
conditions, I would not do a fluid and filter change until 100,000
miles. IMO, it's just another opportunity for something to go wrong,
like accidentally introducing some dirt, etc in the process. Also,
many of the shops now do it via a power flushing process, which is
supposed to get all the fluid out, but I'd be a little leary about.
If it were me, when I found the tranny was behaving strangely upon
leaving, I would have checked the fluid level and then gone straight
back to the shop to document that you noticed the problem immediately.
It's very bad advice to not follow the recommended service schedule
for your transmission if you plan to keep the car for a long time. If
you drive on pavement, change the transmission fluid and filter every
30,000 miles. If you drive on gravel roads or under very dusty
conditions, service the transmission every 15,000 miles. At least
that is the recommended schedule for my Mercedes.
I have a 1982 300 TDT with 408,000 miles on it. I bought the car in
1993 with 144,000 miles on it. I bought it after the original owner
had just replaced the transmission for a 2nd time. I suspect they
were not servicing the transmission as per the recommended schedule.
I have followed the schedule above and have had no trouble with the
transmission that was in the car when I bought it and I have driven
over 250,000 miles with it. Not long a go I met a friend who is a
diesel mechanic in Las Vegas. I had left my Benz at an airport
parking lot and he flew in a couple of days before me and used my car
for a couple of days and he commented that the transmission shifted
I use Amsoil synthetic transmission fluid now, but I used Chevron
dinosaur tranny fluid for most of the time I have had the car. It
shifts with more authority and a bit smoother with the synthetic. I
did not notice an increase in fuel economy when I changed to Amsoil.
There is another "vacuum change over valve" ( what ever that is)
mounted behind the ABS box on the drivers side fender. This one has 3
lines attached to it, one of which comes from a round part attached to
the back of the injection pump. There are two lines coming off this
part and with the engine running there is only vacuum from one. The
other has a 3 way connector on it and one split goes to the change
over valve behind the ABS and the other goes to a round blue vacuum
contraption also mounted just behind the ABS box. The top of this blue
canister has 2 ports labeled TRANS andVAC. I have found that when the
transmission starts acting up, i can take the hoses loos from the
splitter (one to the blue canister and the other to the vacuum change
over valve) and the yellow hose connectors are wet with motor oil. If
i clean them off and re-attach everything, the transmission does
better for a few days.
How is oil getting into a vacuum line?
The entire splitter (about 1 inch rubber in ech direction) was
covered in oil and the outside of all the vacuum lines in this small
are are covered in oin, almost like it was leaking from somewhere else
and was blown onto the hoses, but the fender wall and ABS and
everything else nearby is bone dry, just the vacuum tubes and
connectors. So much so that even after wiping them off it is hard to
tell the color codes on them to match them up where they attach on
their other ends.
The vacuum change over valve from the first pic connects to the top of
the engine on the drivers side. This hose also has no vacuum with the
engine idling and when removed from the engine end or change over
valve end, it is slightly wet with oil. Before the service was done, i
never had any trouble with the transmission. They also did an
oilchange service when they did the transmission service. Is there any
way something they did could cause this or is it just coinsidence?
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