Is this driveshaft condition dangerous?

[Shortsguy1]

I have a 1968 220D automatic transmission with the following driveshaft problem:
A local MB-focused garage said I had a worn u-joint on the driveshaft and asked for $1000 to fix it. While not terribly familiar with these myself, I was able to feel play in the spline just in front of the u-joint, but not in the u-joint itself. So I believe my u-joint is fine, but the spline has developed some play (just the tiniest bit of movement). I don't have wrenches large enough for that bolt, but I was able to use a pipe wrench on the spline bolt and tighten it down. After tightening it down, I still feel a little play. So my question is: how unsafe is it to drive this car? I would normally drive this vehicle alone, but on occasion I may have my family in it. Your advice on how to proceed is appreciated. As an aside, the support bearing and rubber driveshaft couplers are in good condition. I don't know the mileage on the vehicle because the odometer died many years ago. Thanks.

[t walgamuth]

Is it vibrating or squeaking?

[Tony H]

If you deceide you have a driveshaft problem you can have your driveshaft rebuilt at "Driveline service of Portland". They specilaize in Mercedes driveshafts. They will rebuild it better than new and use servicable u-joints of their own design. They will send you a shipping tube to ship your driveshaft. For mine with 3 u-joints and 2 center bearings they charged $550 so yours would be less. They may even have it in stock.

[Shortsguy1]

It is neither vibrating nor squeeking. In fact, had the shop not claimed I had a bad u-joint, I would not have even known about this problem. But I should also say, my vehicle is not particularly quiet otherwise, so thing thing could be making noise at high speeds and I would never know it.

My best guess is that if it failed, it would simply slip, which doesn't scare me as much as a driveshaft flopping around under the car or possibly pole vaulting the car a few feet in the air. That would be an interesting sight, but a terrible experience.

Thanks for the driveshaft shop recommendation. I am hoping to avoid major costs right now, but it is nice to know there is a quality solution out there.

[mercmad6.3]

While I dont have any facts of your situation, t it sounds to me like the shop just wants $1000 to empty your bank account. The spline always has a bit of slop, it has too. if it were tight it would lock up over time and transmit some noise into the car. The only way to check a uni joint is to drop the shaft and twist the joint with your fingers. Any tight spots indicate wear.
I have only ever seen the rubber flex discs fail and the worst was a 6.3 which ripped the rear of the trans out.
Save your money,get a more honest shop and if you can afford it,replace the flex disc sometime as it is possibly the original .

[tram]

Originally Posted by mercmad6.3

While I dont have any facts of your situation, t it sounds to me like the shop just wants $1000 to empty your bank account. The spline always has a bit of slop, it has too. if it were tight it would lock up over time and transmit some noise into the car. The only way to check a uni joint is to drop the shaft and twist the joint with your fingers. Any tight spots indicate wear.
I have only ever seen the rubber flex discs fail and the worst was a 6.3 which ripped the rear of the trans out.
Save your money,get a more honest shop and if you can afford it,replace the flex disc sometime as it is possibly the original .

Agreed. I'm thinking the shop is trolling for extra $$$. If your driveshaft had a problem, you'd know it. Get a second opinion.

Oh, and lube it while you're at it.

[Shortsguy1]

I am showing my ignorance here, but what needs to be lubed on the driveshaft? My maintenance books suggest that the U-joint isn't serviceable, which I assume means it cannot be lubed. I worry sometimes about grease attracting/holding dirt which could increase wear potentially. I don't think my u-joint has any grease ports or anything like that.

Thanks for all your help. I will try to get it to a different shop sometime soon. I will post their advice as well, to let you know if there are any conclusions from this.

[tram]

Originally Posted by Shortsguy1

I am showing my ignorance here, but what needs to be lubed on the driveshaft? My maintenance books suggest that the U-joint isn't serviceable, which I assume means it cannot be lubed. I worry sometimes about grease attracting/holding dirt which could increase wear potentially. I don't think my u-joint has any grease ports or anything like that.

Thanks for all your help. I will try to get it to a different shop sometime soon. I will post their advice as well, to let you know if there are any conclusions from this.

Look for grease fittings. If there aren't any anywhere, then don't worry about it.