1985 300TD Project - Page 4 - PeachParts Mercedes-Benz Forum

Air&Road · #46 07-31-2014, 12:13 PM

Quote:

Originally Posted by cek1

So my old motor mounts where completely shot. The engine was sitting on the crossmember. I had the shop replace both mounts and trans mount. I thought this would cure my shake at idle. Well, still have the shake, especially after the engine is at full temp. After some research, one of the culprits could be the rack damper on the injection pump. Going to look into adjustment of that as my next step. Car runs great, just to much shake at stops. I'll report back if I make any discoveries. Just to let commentors know, all filters are done and an independent MB shop adjusted the valves.

Replacing mounts wont cure a shake, but it can darn sure cure lots of irritating noise and vibration from it. Getting them freshened up is a good step though.

cek1 · #47 07-31-2014, 08:28 PM

I ordered a new rack damper and oring. I'll replace and adjust then see where I'm at. Hopefully this weekend. Any tips would be appreciated, I'll read up on adjustment as much as I can.

toomany MBZ · #48 08-01-2014, 07:14 AM

I used the instructions shown below.

ROLLGUY · #49 08-01-2014, 10:12 AM

I would add that my experience has been that the idle speed needs to be lowered so the idle is being adjusted by the rack damper bolt. If the idle is too high, the rack bolt adjustment does nothing......Rich

cek1 · #50 08-01-2014, 09:25 PM

New parts. Extra fuel filter, spare volt. Regulator, rack adjustment bolt and new o-ring.

Hopefully I'll get to it this weekend.

cek1 · #51 08-02-2014, 02:01 PM

I'll have to try lowering the idle because the new rack bolt did nothing in or out. I have it basically all the way in.

cek1 · #52 08-02-2014, 02:53 PM

I may have spoke to soon. It feels a little better. Problem is now I can't remember how smooth it should be. My last benz was in 06. I'll put some miles on it with the new rack and see how it does. I have a big trip coming at the end of next week. Going to be putting a few hundred miles on it.

ROLLGUY · #53 08-02-2014, 03:09 PM

Quote:

Originally Posted by cek1

I'll have to try lowering the idle because the new rack bolt did nothing in or out. I have it basically all the way in.

Both the RD and the idle adjustment act upon the same mechanism inside the IP. If the mechanism is acting upon the idle adjustment first, the RD bolt does nothing. Lowering the idle before adjusting the RD allows the mechanism to respond to the RD adjustment. At least that is how I understand it to work. It seems that if you have the RD all the way in, it is very close to working. Lowering the idle should give better results from the RD.....Rich

cek1 · #54 08-04-2014, 10:14 PM

After a bunch of trips around town and finally having the wife along she commented on how much the shaking has gone away. I'll continue to observe. I have a big trip to the shore this weekend and will be hauling lots of people to the beach and back all weekend. Looking forward to break in the motor mounts and give it a good run on the highway with a full load. If no more improvement I'll look into dropping the idle then adjust.

cek1 · #55 08-10-2014, 02:41 PM

Ok, had a nice drive this weekend. Took the TD to the shore. Put over 200 miles on which isn't much but the most I've put on in a weekend since I picked it up. Shaking is still mild. Still much better then it was. Filled up the tank. 325 miles on 11.74 gallons of fuel. 27.6 mpg with about 2/3 highway, 1/3 city. Ran awesome, did great on the highway, carried lots of stuff and people. That's what it's all about.

Need to get cruise going, still leaves some oil drips, and the accumulators need to be replaced. But the TD is getting along pretty well.