1995 E300D Transmission (722.435)
 

I'm currently having some transmission issues and I wanted to start getting some background information on this particular model. My current thinking is that I might have some problems with the linkage or the vacuum, but I haven't yet had the time to determine what/where the problem is. Nevertheless, I already have some questions and I thought it would be good to start a thread about this transmission. My current questions (with more to come as I investigate) are:

1.Are there any know problems with this transmission (722.435)?

2. Are the B2 piston and K1 spring problems, which have been discussed on earlier models, also a problem with this transmission?

3. Does anyone have any vacuum diagrams for this model?

Thanks!

AFAIK, the 722.4 first showed up in 1985 on the last of the W123s (722.416 in my 300D-T). It was also used in the W124 series and made its last appearance on the 1996 E300D, which had the new W210 chassis. I have not read here of any serious design or build issues that surfaced during this 11+ year run. When the 722.438 in my '96 was rebuilt (at 248,000 miles, due to leaking seals), the mechanic said the wear parts looked to have another 50,000 miles on them and the "hard" parts were all good.

What problems are you having?

Seemingly some erratic shift patterns. This is one of those situations where I bought used and don't really know what is normal and what to expect. Plus, being the NA diesel, i expect it to be a little on the sluggish side. Anyway, performance has always been poor when climbing hills - I could floor it and not get any response - just maintaining speed and if the grade was steep enough (like climbing up the Rockies) actually lose speed.

Recently I started experiencing some slipping (I think?) when accelerating from a dead stop. This has only happend a few times. Almost as if it is having trouble catching. I have to back off and ease into it to get some momentum. Higher gears give no problems after this.

Looking over the throttle linkage and cable I found a couple of broken plastic pieces on the cables, but not sure if this is a problem. I can post some pics of these. I messed around a little, but didn't alter anything. Nevertheless, the next day the shift pattern seemed a little different.

Now there seems to be a little flaring from 2nd-3rd. I have to back off to get it shift around 3000 PRMs. Also, when traveling at highway speeds, if I floor it, it will kickdown (even on hills now), but after it does it makes a rattling sound and seems to have to fight to accelerate.

As an aside, sitting idle and shifting between the following gears goes as follows:

Park - Drive = immediate engagement
Park - Reverse = 1-2 second delay
Reverese - Drive = immediate engagement
Drive - Reverse = 1-2 seconds

Sorry for vague and long-winded overview of the symptoms here. It is a lot to ponder right now, so I would appreciate any suggestions anyone might have.

The fluid is not low, actually high and a little dirty - as soon as my parts come in I will be changing the fluid and filter.

Thanks in advance for any help.

I have never had a fluid change solve transmission problems.

That having been said, it sounds like it is repairable, but probably not externally.

Give it a new filter and new fluid, maybe it'll help, easier and cheaper than the alternative.

It sounds like your pressure is low, can be checked with the correct pressure gauge per the M-B transmission manual. Some will try adjusting the modulator, which will give you more firm shifts, but probably won't affect the reverse issue because it isn't likely creating enough pressure at idle, which indicates either a worn reverse band, or low pressure from a worn pump or leaky internal seals. Either one of which will require transmission removal to cure. It might be worth having a competent shop test pressures (one is done while driving or on a dyno).

Look for friction material in the pan, if there is a lot, might be too late. If not, could be that a new pump or new seals will cure it. Seals are cheaper but while it's apart, ...

Here's some more info:

http://www.peachparts.com/shopforum/tech-help/99833-info-722-3-722-5-transmissions.html

Thanks, I appreciate the advice here. I agree that the fluid and filter change probably isn't going to amount to much, but at least it will get me a look in the pan. It seems like I have couple of seperate issues going on here, but not really sure of anyting yet. I will let you know what I find as I go, but I will definately be looing for advice on this one. Thanks.

Jeff - thanks a million man, this is great. I have only skimmed over this and have already found answers to a couple questions I had. At the very least this will help me diagnose my problems. Here a couple of other questions I have right now:

1. How do I know the throttle linkage is properly adjusted - or how do I properly adjust it if it is not?

2. Where can I find a set of pressure gauges to run a hydraulic pressure test on the transmission? Are these specific gauges for Mercedes, or can I pick up a set at a parts store and it will have the necessary fittings?

If the throttle linkage (search Bowden cable here) is too loose, the car will shift too soon. If too tight, it will shift too late (upshifts that is). It does not affect the shift harshness.

I'm not sure, I have a gauge from long ago, ... just the fittings that are important.