'85 300sd won't go into gear - PeachParts Mercedes-Benz Forum

hickboyy · #1 08-21-2014, 08:44 PM

Last month I was driving to the store, and while cruising around the parking lot to find a place, I stopped and shifted into reverse to back up for a car to back out, but there was someone too close behind me, so I shifted it right back into drive. When I pressed the accelerator, the engine raced and then went into gear when I released the pedal. I thought this was an odd occurance, since it hadn't happened before, but I was able to still drive around the parking lot (This was at costco, so the lot is pretty big). Anyway, I found a spot (on the other side of the lot), went in and shopped, and when I got back out about an hour or so later, I started it up and it wouldn't go into forward or reverse. I tried shifting it in and out of all gears with the engine at idle and revved up a little, and absolutely nothing. I thought it might be the filter, so changed it there in the parking lot, and no change. After a tow home, I dug into it and completely rebuilt the trans, every o-ring, gasket, nylon, and seal (even the K1&2 support O-rings), this included a complete dis-assembly and reassembly of the valve body, replacing those nylons as I came across them as well. I have taken this thing apart twice now, and am absolutely positive everything is as it should be, but still no change in the situation. During this, I found absolutely nothing wrong, all the rubber was nice and supple (except the K1&2 o-rings were flat and a little hard, but not broken). No broken valve body springs, no metal in the oil, just a few reverse disks that had just worn to metal (due to the little check ball in the stator somehow getting behind the piston, maybe someone had it apart before me?). I also put a rebuilt TC in with the rebuild. If I raise one rear wheel off the ground while the engine is running, it will rotate forward slowly respectfully of what gear it is in, even reverse. I've been driving this car for about 5 years now and have never had any problems with the trans, the odo was busted at 188,000 mi. when I got it, so I know there are well over 200k on it, possible close to 300. Has anyone ever come across something like this? I have spent a LOT of time and money and not gotten anywhere with this one.....

PS....Trans is a 722.416

leathermang · #2 08-21-2014, 11:03 PM

Tell us how you filled the torque converter.....

Where did you get the information to do the rebuild ?

It would help in reading your posts if you hit the enter button every few sentences so you do not have one block of words...

hickboyy · #3 08-22-2014, 01:28 AM

I laid it face down and poured a quart into it. The rebuild kit w/ instructions came from Precision International. I got the TC through Dacco.

ROLLGUY · #4 08-22-2014, 10:18 AM

I had a 1984 300D with the exact same problem, except the trans is out and sitting on my garage floor. The car was working great, and then one day no movement whatsoever from the trans. No forward or reverse. I too changed the fluid and filter with no avail. The only thing I can think of is the pump went bad, but it did take all 6 qts of fluid after draining the pan and converter, and replacing the filter. I figured the pump must be working because it took all the fluid, and also there was fluid flowing to and from the cooler. Your trans still has a problem after it was "rebuilt", so the problem must be with a part you did not replace/rebuild. When you finally find the problem with yours, I will probably find the problem with mine, as it sounds like the exact same problem. My trans was working perfectly before this happened, so I am sure something inside just broke to cause it to work great, and then all of a sudden not work at all.....Rich

chasinthesun · #5 08-22-2014, 11:27 AM

In my case it was an 83 300cd,no reverse or forward as I was ready to head home for work ,trailered it home and it sat in my yard for 6 months , I decided to sell it "as is" and was cleaning up the old car for a possible buyer to come look at it,as I started up the motor that day I decided I would give it just one more try and sure enough it went in gear and reverse .The CL caller didnt show and I was glad to later find out my only problem was the linkage bushings were shot so the car could not realize it was in gear ,my last attempt found the gear .After 2 years of driving Ive had no problems with the trans.You can take the shifter rod off the car but before you do look how it is attached.You can then make a quick fix with some hose cut to sleeve onto were the bushing was located ,this piece youll have to cut just right to have no play ,its maybe 1/3 inch long ,youll sleeve this onto the shifter rod itself ,it then is held in place with the clip when you have the linkage for the shifter and the gear lever on the trans assembled , giving the shifter a solid feel again.The right way is of coarse new bushings.2 bushings to clips ,thats it ,pretty straight forward diy.

ROLLGUY · #6 08-22-2014, 12:06 PM

Quote:

Originally Posted by chasinthesun

In my case it was an 83 300cd,no reverse or forward as I was ready to head home for work ,trailered it home and it sat in my yard for 6 months , I decided to sell it "as is" and was cleaning up the old car for a possible buyer to come look at it,as I started up the motor that day I decided I would give it just one more try and sure enough it went in gear and reverse .The CL caller didnt show and I was glad to later find out my only problem was the linkage bushings were shot so the car could not realize it was in gear ,my last attempt found the gear .After 2 years of driving Ive had no problems with the trans.You can take the shifter rod off the car but before you do look how it is attached.You can then make a quick fix with some hose cut to sleeve onto were the bushing was located ,this piece youll have to cut just right to have no play ,its maybe 1/3 inch long ,youll sleeve this onto the shifter rod itself ,it then is held in place with the clip when you have the linkage for the shifter and the gear lever on the trans assembled , giving the shifter a solid feel again.The right way is of coarse new bushings.2 bushings to clips ,thats it ,pretty straight forward diy.

Definitely not a shift rod or bushing problem with my car, but for the OP I can't say.

hickboyy · #7 08-22-2014, 04:48 PM

Glad to hear I don't have a unique problem, bummer neither of us have found a fix, though...... I, too have ruled out the linkage being the problem, I can feel and have verified that each detent is where it is supposed to be. I also made sure the valve on the valve body moves with it as well. And yep, my pump is definitely moving oil, I have the stain in my driveway to prove it

hickboyy · #8 08-23-2014, 04:08 AM

The thing that is so odd about this situation is that it happened by merely shutting off the engine and restarting it later. It would make a whole lot more sense if it went out while I was driving it.

ROLLGUY · #9 08-23-2014, 10:28 AM

Quote:

Originally Posted by hickboyy

The thing that is so odd about this situation is that it happened by merely shutting off the engine and restarting it later. It would make a whole lot more sense if it went out while I was driving it.

That is exactly what happened to my car (it was a friends car until I bought it with the bad trans). It was driven on a couple errands, and then went to drive home after being parked for 5 minutes, and nothing. I still have the trans sitting in my garage awaiting some miracle fix that I might find. I know there has to be something simple that can be easily fixed. For it to work great for a hundred thousand miles and then just quit is just weird.....Rich

EDIT:

I found the old thread about this car:
Something broken? No power from engine to wheels

hickboyy · #10 08-24-2014, 10:22 PM

OK,so I've sent most of the day now scouring the internet looking at anything I can find to try and figger this this out......

So far, I've come up empty handed, everything I have checked and re-checked seems to be within spec.

Here is a question: what is the first thing to energize when the engine is started?

It seems to me that my problem may lie with something that is simply not energizing, since the trans. was working before I shut the engine off, and then stopped working after that....

hickboyy · #11 08-24-2014, 10:23 PM

Also, does anybody know of a hydraulic schematic, if there even IS such a thing?

ROLLGUY · #12 08-25-2014, 12:35 AM

I know a gauge can be used to check the pressures in a couple different places on the trans. Mine is out of the car, but I am sure you can check yours easily. It may have enough power in the pump to pump fluid, but not enough to make enough pressure to operate the trans. I should have checked the pressure before pulling the trans, but I did not have the proper gauge. I used the engine in another car anyway, so the trans was not needed. However, I would like us to find out exactly what the problem is with our transmissions- you so you can continue to use your car, and me so I have a good spare trans....Rich

hickboyy · #13 08-30-2014, 04:25 AM

OK, so out of frustration/desperation, I pulled the trans back out and took it apart again, and found that the rubber lip on the K1 piston had flipped when I originally installed it, I also went ahead and changed the K1 and K2 support O-rings. I also put the B3 piston check ball where I thought it belonged. No luck....

After buying a "parts" transmission, I found out where the check ball was supposed to go, as that trans still had it intact and properly placed, so out my trans came for the 3rd time.

After getting the check ball right, and using the valve body from the parts trans, I now have a driving vehicle........

Not sure what the determining factor was in all of this, but I suspect it was the valve body.

Diesel911 · #14 08-30-2014, 02:09 PM

A+ for perseverance!