Help? Advice? 300E transmission prob... - PeachParts Mercedes-Benz Forum

KNanthrup · #1 09-17-2003, 05:16 PM

Ok, so my car ('86 300E) has had this transmission trouble for a while... in short it basically seems to disengage, or free wheel for a second when shifting up from 2nd to 3rd gear. Now, I had made a post about this a while back and I talked to one other guy on here who had the same trouble. Later he followed up and said he had it fixed and it was some sort of vacume module.

Anyways today I took my car in to this shop that advertises that they specialize in Mercedes... and so I talked to the guy and he asked me when it was last serviced, etc. He was kept saying that if the transmission filter wasn't replaced recently then it could be causing problems, and that it should be done anyways because it would be useless to do other stuff when that could be the base root problem. Anyways I told him that I had talked to someone else about the problem and that they had a similar situation and had a vacume module replaced. He didn't seem to be catching on or going in that direction at all and unfortunately I don't know what vacume module it was or if there is one for the transmission or anything so I couldn't specify. All he told me after that was that there is only one adjustment for the transmission and that it's for all gears (how firm it shifts I guess). He's backed up all this week until early next week so I told him I'd give him a call if I decided on it. He quoted me at about $120-130 to do the filter/fluid change.

What do you guys think? Personally I don't think it's the tranny filter, although replacing it may help it shift smoother in other gears, but why would the filter be the cause of only the 2-3 shift to be bad? All of my other gears shift just fine. Also, that's 120 bucks out the door just to get started.. and I have no idea where it could lead from there. I'd be afraid to have that work done and then be told my tranny is bad or something. Any advice or help is appreciated

-Kevin

joe p · #2 09-17-2003, 06:55 PM

Thats a 2-3 flare. There is a valve body accumulator kit for that.

Joe

KNanthrup · #3 09-17-2003, 09:02 PM

Quote:

Originally posted by joe p
Thats a 2-3 flare. There is a valve body accumulator kit for that.

Joe

Thanks for the response. Where can I get this valve body accumulator kit? And why does it take a kit when it doesn't do it from the factory... or does the kit fix it so it never does it again? Also, if I were to get this kit, would the vacume module or modulator or whatever have to be replaced as well to fix the problem?

Should I take it to the dealership to have this done or find another outside shop?

psfred · #4 09-17-2003, 09:07 PM

I'ts probably an early failure of a seal, and the kit has a better seal in it.

Any good tranny shop that deals with MB can do this, it's not a terribly difficult job, but the mechanic MUST be familiar with the transmission!

Filter and fluid change isn't a bad idea, either, as a plugged filter can also cause shifting problems.

Peter

KNanthrup · #5 09-17-2003, 09:10 PM

Yeah I figured I better go somewhere that the mechanic recognizes what I am describing and trying to explain. The last guy I talked to had the modulator replaced for less than $200. If I get could my problem fixed at that price I would be very happy.

Oh and isn't the modulator under the pan? If it's going to be pulled I'll have it all done anyways.

psfred · #6 09-17-2003, 09:20 PM

Modulator is on the side of the tranny, outside, has a vac line to it.

It is possible to adjust it for snappier shifts, but this will only hide the problem, not fix it.

Steve Brotherton has a long article about transmission adjustments. The link is in an old thread, but I don't remember which now. I'd read that before jumping around too much, then you will know what to tell the shop.

Peter

mbz1 · #7 09-17-2003, 09:39 PM

Are you sure it is the 2 to 3 shift that is flaring or the 3 to 4 shift, i am sure your trans takes off in 2nd. I just fixed an 260E that had a real bad slip shift into 4 it was a bad sealing ring in the very back drum in the trans, you have to take everything out of the tranny to get to it. there is 2 of the sealling rings back there one had blown out and looked like it had a big tear in it. now i know that the 260E has the smaller 190 transmission in it but it is built the same way for the drums and cluches.. as the 300E tranny..

Hope this helps

Rob...

KNanthrup · #8 09-18-2003, 04:01 AM

Thanks for the help guys,

I will definately search the site some more to gather info before going into another shop. I do realize that my tranny starts in 2nd, and yes it is the 2-3 upshift in which the flare occurs. from there it hits 3 to 4 without any flaring or delay. When I drop into 1st, it also upshifts into 2nd just fine. I guess it's sort of broken down to either a bad modulator or a blown seal inside. I'd like to hope for #1...

KNanthrup · #9 09-18-2003, 04:05 AM

Now if I were to take it into another shop and they give me a run-around, should I just specify to them to change the modulator if it's cheap enough to start out with? Apparently the part itself is like $70, and then with labor it wouldn't be too expensive. Probably a little cheaper than having the filter and fluid changed and I think the chances of it being the modulator over the filter are pretty high. If that doesn't work then they'll probably have to tear in and check the seals but I'd rather eliminate an external possibility that's cheaper than have internal seals checked with high expense to find out there's no problem. Is there perhaps a way to test this modulator?

300E24V · #10 09-18-2003, 08:09 PM

The kit is called the K1 accumulator kit and the part no. is 126 270 44 77, but this doesnt always solve the problem as I found out last month.I have the same problem and it still exists so it is time for a rebuild.
Good luck anyway.