Driveshaft balancing saga - PeachParts Mercedes-Benz Forum

martureo · #1 02-21-2012, 03:45 PM

With the 300TD project for my wife I got the driveshaft in two pieces. No markings, no dirt or oil stains to indicate how it was aligned. I've put enough time and effort into this car I'd rather not mess around with vibration issues.

So I went to the usual places trying to get it balanced and no one said they could do it.

Finally, after two weeks of searching and getting phone numbers for shops that either (1) won't touch a two-piece driveshaft or (2) don't have a way of mounting a Mercedes 3-bolt yoke. I get one place that tells me that although they can't help me, I need a new U-joint... and they can't do that either.

So I called more approved sources and I'm at a crossroads trying to figure out what to do. Here are my options.

1-Driveline Service of Portland (driveshafts.com) will build me a new one for $375 plus a $75 core. This includes front, rear and center carrier bearing.

2-Atlanta Powertrain will put on a replacement u-joint and balance the driveshaft. They won't give me a quote any more specific than "around $250"

3-The propshaft (A123 410 83 06) is NLA and "not sourceable" from MBZ, but the rear section including the U-joint (A123 410 44 02) is available from the Classic Center at $292 and at my dealer for $312.

I'm not sure where to go from this point. I've heard great things about Portland, not so great things about Atlanta and if I get a new one from MBZ I still have to balance the front portion to the rear somehow.

And remember I'm in Maryland, which means Portland is probably going to be another $60-70 shipping one way.

Any suggestions?

Simpler=Better · #2 02-21-2012, 03:48 PM

There has to be a local place, I'll ask around. Could you try rolling it around on a smooth level surface? It might not be that far out of balance

dkveuro · #3 02-21-2012, 03:55 PM

Drill a small hole large enough to install 1/8th ball bearings. Use about 2 to 3 oz for each shaft. it will now self balance.

Either weld hole shut or tap a small bolt in it.

Others have used hose clamps and moved them around but I have done this on two, a car and a NPR truck I re-engined with a Dodge 360....... with great results....and no, there is no noise.

.

martureo · #4 02-21-2012, 03:57 PM

Quote:

Originally Posted by Simpler=Better

There has to be a local place, I'll ask around. Could you try rolling it around on a smooth level surface? It might not be that far out of balance

I can give the name and contact information of 37 shops located from NY to SC that I have personally called, and each will tell you "no".

The place I got the most promising advice was the machine shop at Pennsylvania Truck Center in Wrightsville, PA. The oldest machinist there got out a huge contact book out and we spent 45 minutes calling everyone he had ever dealt with.

And I just don't want another issue on this car, it needs to get back on the road and be reliable. I'm willing to fork over a few hundred dollars if I can be sure of it working.

mach4 · #5 02-21-2012, 04:48 PM

I can't think of a reason why you couldn't just source one from a junk yard that is still intact. Worst case you'd have to put a carrier bearing on and maybe the front and rear driveshaft bushing and maybe the spline dust cover, but other than that... it's basically just a tube. Who knows you might get really lucky and find one with a good bearing and maybe even fairly new flex disks.

Out here a 2-piece driveshaft is $35 ... $18 if you catch a half-price weekend.

Just a thought. Am I missing something?

Paul

Junkman · #6 02-21-2012, 04:52 PM

Is your current shaft not OEM? The SDs and D' have marks. Mine weren't apparent & I didn't look close enough until the marks I painted came off & I was forced to look close. The attached is from the 126 FSM.

Standard procedure on other vehicles is to put a worm gear hose clamp on the shaft & move the clamp until the shaft quits wobbling.

junqueyardjim · #7 02-21-2012, 04:53 PM

Quote:

Originally Posted by dkveuro

Drill a small hole large enough to install 1/8th ball bearings. Use about 2 to 3 oz for each shaft. it will now self balance.

Either weld hole shut or tap a small bolt in it.

Others have used hose clamps and moved them around but I have done this on two, a car and a NPR truck I re-engined with a Dodge 360....... with great results....and no, there is no noise.

.

Sounds like the way to go for me. I have had the sand installed to balance front axle tires on my trucks and it worked great. I had not heard of the bearing install, but I am going to do it.

Diesel911 · #8 02-21-2012, 04:53 PM

If you get one from the Junk Yard make sure you mark it before it is taken apart.

Diesel911 · #9 02-21-2012, 05:03 PM

If you get one from the Junk Yard be sure to mark it before it comes apart.

Thread with driveshaft alignment marks post #7
rebalancing driveshaft?
rebalancing driveshaft?

I replaced the U-joint on My Drive Shaft. I did not have it rebalanced; if there is any abnormal vibration I do not notice it.

Someone who knows about this can Chime in: Is there only 3 Positions the Yoke can go in compared to the Yoke on the Rear?
If so it could be a matter of a maximum of 3 trys to find the position it was balanced at. A pain to do but Cheap.

engatwork · #10 02-21-2012, 05:44 PM

I have always been very pleased with their service.

Driveline service of ATL

sixto · #11 02-21-2012, 06:26 PM

Getting back to the neutral balance debate, can the shaft sections be balanced independently so clocking is irrelevant?

Sixto
87 300D

martureo · #12 02-21-2012, 06:56 PM

Quote:

Originally Posted by sixto

Getting back to the neutral balance debate, can the shaft sections be balanced independently so clocking is irrelevant?

Sixto
87 300D

If you live in a perfect world, yes. Or if you pay someone enough to balance a shaft so that it has no moment whatsoever....

Diesel911 · #13 02-21-2012, 11:57 PM

I tried to copy this word for word from the Factory Service Manual:

"The components of the Propeller Shafts are individually pre-balanced at the Factory. To eliminate any residual unbalance which might still remain, re-balance the complete propeller shaft including the companion plates. For this reason, when disassembling the complete propeller shaft (e.g. when changing the propeller shaft intermediate bearing) mark individual components in relation to each other (if no marks are in place) and reassemble to the original shape.

On vehicles up to July 1982, mark the individual propeller shaft components in relation to each other.
On Vehicles starting August 1982 the front and the rear propeller shaft are marked in relation to each other

Note: The identification as been partially already in place on propeller shafts prior to August 1982, but has not been taken into consideration during assembly. For this reason, propeller shafts on which the marking is not in agreement, must be identified prior to removal and the two parts must be plugged together again following this identification."

So on one hand it tells you the parts are balanced as individuals. On the other hand it tells you if it is not marked by the Factory and lined up you should make it yourself and put it back together that way.

On the other hand it has "To eliminate any residual unbalance which might still remain, re-balance the complete propeller shaft including the companion plates."

I am not sure what Companion Plates are or why there would be residual unbalance.

Apparently the complete drive shaft is not Balanced as a unit by Mercedes.

The above is only concerned with disassembly and re-assembly.

If the U joint is removed it is going to be necessary to grind off the Staked Metal otherwise the U-joint Bearing Caps are not coming out and new ones are not going in.

I theory that should mean that at the very least the Yoke The U-joint goes into should be rebalanced.
And, I have no idea if that means the U-joint should be installed prior to balancing.

I did not balance mine when I changed the U-joint and I ground off the Staked Metal and that should have unbalanced it. So far so good.

martureo · #14 02-22-2012, 11:19 AM

As an update:

I stated in the OP that my driveshaft is NOT marked with any factory or repair markings, which is the reason for this thread.

I was pointed toward Driveline Specialist (drivelinespecialist.com) in Lorton, Va by another board member. I have contacted them and verified that they will NOT balance a w123 driveshaft but they will sell you a "rebuilt one" (their words) for $650

.

The two options that I am still pondering over are buying a new rear section of the driveshaft from Mercedes or getting a custom one from Portland Driveline. Has anyone ordered and installed one from Portland Driveline?

vstech · #15 02-22-2012, 11:27 AM

Quote:

Originally Posted by Diesel911

Someone who knows about this can Chime in: Is there only 3 Positions the Yoke can go in compared to the Yoke on the Rear?
If so it could be a matter of a maximum of 3 trys to find the position it was balanced at. A pain to do but Cheap.

nope...
there are 32 positions the driveshaft yoke will assemble on...
and the flex disc bolts are one time use... so... that's a LOT of flex disc bolts to replace... I understand what you are thinking, but no the yoke ends are totally independent from the center connections. all of the splines are even, and if no markings are found, it'll need to be balanced.