Drive Train Roughness and Wobble at slow speed. 240D - PeachParts Mercedes-Benz Forum

charmalu · #1 02-28-2014, 12:22 AM

For a while now I have felt a roughness in the drivetrain at highway speeds. sounds like coming from the back of the vehicle. Feel it my Butt and in the accelerator peddle. Thinking of the usual things like differential, half Shafts, Drive Line, Transmission/Mount etc.

Then I have noticed a slight wobble feel at times at slower speeds, like yesterday on the Freeway moving along at 25mph.

Yeah I know it is a 240D and they are slow, but this is the speed through Santa Cruz in the afternoon.

I speed up to ...say 35 and it goes away, but getting up to 50 or so and feel the vibs and or rumble from the rear.

The rear 1/2 Shafts are near new, have a good tight Differential, and new Bilstein/Sachs Shocks. Oil level in Diff is good, I see nothing loose, cracked ie trailing Arms, it`s all in good looking shape. Front and rear Flex Disk are new.

I had the Drive Line center Support and Bearing Replaced when I had the U-Joint replaced along with the end bushings. It only has 33K miles on it since the rebuild.

I notice the Transmission mount looks well worn and soft, so that need replaced. Might be the original. Push the drive line up and down and see some movement in this mount. that is now on my to do list.

Then grabbed the center of the DL to rotate it and notice it has about a good 2 1/2 or so inch`s of up and down movement.

I really don`t think it is suppose to do this. Shine my flash light on it and push up, and there is a 3" tear in the rubber along the bottom.

the DL shop I bet used a URO center Support, don`t know for sure, but should last longer than 33K miles.
Had this done 12/01/11.

Iam thinking this is the cause of the rumble and the wobble, and the rumble could be the bearing, IDK.

Looking here in Pelican, they actually sell a URO

support for $15 and includes the bearing. Febi is $17.50 and Rein for $12.47 w/o the bearing.

Did a bunch of searching on Google, and the market is flooded with URO, and there is a wide spread on the price.

I check with the Dealer in Monterey, and the Wholesale price is $95. pricy, but cheap if it will go 100K miles and I don`t have to replace it every 30K miles.

What have the most of you used for replacement Supports, and had the best longest lasting results?

Charlie

mach4 · #2 02-28-2014, 12:50 AM

Quote:

Originally Posted by charmalu

What have the most of you used for replacement Supports, and had the best longest lasting results?

You may be familiar with my technique for supporting cheap (and other) motor mounts by filling them with urethane. I know of someone that repaired torn center supports using some very tough jet fuel tank sealer. This stuff is a two part material that is flexible yet very tough and sticks like crazy. So far so good. I suspect that this technique could be used to reinforce and support new center support rubber to make even URO ones work well for the long term. I'm not recommending this, but suggesting it might be worth some experimenting by the community. Urethane probably wouldn't work in this application as it doesn't stick well enough.

cho · #3 02-28-2014, 04:22 AM

Charlie, I would also inspect visually rear tires.

cheers
ChO

.

t walgamuth · #4 02-28-2014, 05:55 AM

I haven't done any of those for maybe a decade. Prolly was a german part when I did it.

Maxbumpo · #5 02-28-2014, 08:32 AM

Quote:

Originally Posted by cho

Charlie, I would also inspect visually rear tires.

2nd. Sounds like a broken belt in a tire to me.

charmalu · #6 02-28-2014, 11:56 AM

I thought tires also, I gave them a good visual as I was rotating them. Had the rear of the car up on Jack Stands. I didn`t notice anything out of the ordinary. I just rotated the wheels about a month ago. didn`t notice the wobble before the swap, but did have the roughness/rumble feel.

Before I inspected things I was leaning towards the rear wheel bearing/s since the 240 is now up to 362K miles.

If we get a break in the rain today I`ll put her back up on Jack Stands and put her in gear and see if I see anything with the tires spinning. Like a tread wobble or bulge etc....

We put this set of tires on about the same time as the Drive Line rebuild, so they have around the same 33K miles. Iam running 195/75/14 Cooper tires on Light Alloy pressed aluminum wheels. The wheels look straight w/o any bends or damage to them.

Thanks for the replys guys.

Charlie

Maxbumpo · #7 02-28-2014, 01:54 PM

After a short drive, very carefully feel each of the shocks / struts. Be careful - if you have a broken belt in a tire, the associated shock/strut will be VERY hot!

I've only had one broken belt in a tire, and visually the tire was just fine to my eyes. Used above method to ID the tire, then removed the tire to inspect. Couldn't see any problem, but when I rolled the tire down my drive, it was clear that it was no longer round.

Mxfrank · #8 02-28-2014, 02:22 PM

If it's a bearing, the noise will change in a hard turn, as the axles are loaded/unloaded. It will be loudest when the load is on the bad bearing.

charmalu · #9 03-01-2014, 08:59 PM

Yesterday afternoon I decided to order the parts from the site here. I wimped out and bought the center Support here instead of the Dealer. $95 dealer price and $11.50 - $17.50 depending which of the 3 I pick here.

Well URO was not even in the race, that leaves Rein and Febi. Rein had two Thumbs up and Febi 4. so picked Febi.

Febi Support
Fag Bering
Febi transmission Mount
Lemforder left upper control arm to get over $75 for shipping.

I put the order in around 4PM Friday, and Fedex dropped it on the front porch at 11:14AM this morning. Wow that was fast, figured maybe next week sometime.

Date/Time Activity Location -

3/01/2014 - Saturday
11:14 am Delivered
Soquel, CA
Left at front door. Signature Service not requested.
8:24 am On FedEx vehicle for delivery
WATSONVILLE, CA
6:25 am At local FedEx facility
WATSONVILLE, CA
2:17 am Departed FedEx location
SACRAMENTO, CA
1:04 am Arrived at FedEx location
SACRAMENTO, CA
-

2/28/2014 - Friday
8:51 pm Departed FedEx location
SOUTH SAN FRANCISCO, CA
7:50 pm Arrived at FedEx location
SOUTH SAN FRANCISCO, CA
6:37 pm Picked up
SOUTH SAN FRANCISCO, CA
5:59 pm Shipment information sent to FedEx

Both Febi boxes have a sticker "Made in China" and Febi Germany. Febi is just a reboxer, probably a URO part too. Oh well I have the part and it is going on. this should give me another 30k miles or 2 yrs of use.

I was thinking it is meyle that is the reboxer, but maybe they both are.

The Fag bearing is made in Korea, and the Lemforder Control Arm is made in Italy.

So if tomorrow is a rain free day, the DL is getting dropped. Rained off and on today.

Charlie

charmalu · #10 03-10-2014, 12:58 AM

Wed march 5th I replaced the center Support and the bearing along with the Transmission Mount.

Took her out on a good run from Santa Cruz up Hwy 17 to Scotts Valley and over to Felton for my weekly P,O, Box mail run. then down Hwy 9 back to Santa Cruz, a few errands and a run down Hwy 1 up to 80mph. She runs as smooth as a new born baby`s rear. Put a good 30 miles on her. had he out again today, and wow is she smooth, and think I gained 10 more HP.

I removed the whole DL from the vehicle to work on it. first mark each 1/2 with some paint as reference points. You will have to separate the two sections to remove and replace the Support/Bearing.

Remove three bolts at each end of the DL where it bolts to the Flex Disks. leave the Disks attached to the Differential and transmission.

Loosen the 46mm nut and loosen the two 13mm bolts at the Center Support, so the DL will compress as you pry it off the disk and the centering pin. Tighten the 46mm nut and remove the two bolts.

Pry the DL off the Trans end, and walk it out towards the rear. Take it out in one piece or separate the two sections which may be easier.

On the ground, I laid it on a piece of old carpet to work on it.
Separate the front piece. then remove the Snap Ring with you Snap Ring Pliers.

Note: early 123`s used a Snap Ring on the shaft. after 82 there is no Snap Ring. MB used two pieces of metal like a washer that flair outwards on each side of the bearing.

I first pushed the rubber back by hand to see how bad it really was, and it was ready to come apart all the way around. this was scarry, and only with 33K miles.

I used a 2 Jaw Gear Puller (FSM mentions a 3 Jaw) to the outer ring of the support. Pulled it back gently to slightly stretch it, and the rubber was deteriorated all the way around. I Mean it was really cracked.

really don`t know what held it together.

The rubber tore off, so had to reset the puller for the bearing., came off real easy. I decided to use the new Fag Bearing and not try to remove the old one from the rubber even though it is still good. I will keep it to use at another time. looks like it is a Fag also, made in Korea.

I set the Support on a block of wood, placed the bearing in the center, and using a 42mm Socket, seated it into the rubber up to the shoulder.

I have a length of 1 1/2" exhaust tubing about 12" long with a big socket on the end to drive the bearing onto the shaft. once seated replace the Snap Ring.
Slide on the Rubber Boot that protects the Splines, and apply some grease to the Splines. Slide on the front section lining up the paint marks. compress it and tighten the 46mm Nut. Slide the protective boot onto the nut.

Then went onto replacing the transmission Mount. Place a jack under the trans, remove the 19mm nut that bolts the trans to the mount.
Remove the two 13mm bolts in the center of the X mount. then remove the 17mm Nuts on each side and remove the X mount.

I washed the mount on a pan of gas, along with the bolts/nuts to get the years of grease/oil and grime off it.
Put the new rubber mount, screw in the 2 13mm bolts loosely, and bolt it back up to the Trans and body.

I noticed the original mount had a round metal sleeve in the center and the replacement Febi has an oval center hole. the original was probably factory with 362K miles. the center sleeve just fell out.
OH there is the bolt that goes through the X mount and the center hole. think it is a 6mm hex.

Might be a good ides to fill the center of this Febi mount with that liquid urethane that Mach4 used on his 380SL Diesel mounts. Might stiffen it up and last longer.

Slide the DL back in, bolt it up to the Flex Disks. leave the 46mm nut loose as well as the 2 13mm bolts. Put car back on the ground that you safely placed on jack Stands. Rolled it forward 10ft, back 10ft and forward 10 ft or what ever. Jacked it back up and tightened the 46mm and 13mm bolts/nut.

I`ll probably be replacing this damn China bearing again in 30k miles.

I first practiced removing the bearing on a spare DL in the shop. the support/bearing is a MB original one. I did have thoughts of using it even though it has some minor cracks in the rubber. it looks beefier that this Febi I just installed. Think maybe I`ll start removing these in PNP and keep the good ones. Still in the thinking stage.

Charlie