The driveshaft fell out!!!

[Izzyblueye]

This may indicate a more serious problem. That being how the coach has been taken care of in the past. Anything can fail, but a good service profile will generally keep most mechanical items in good shape. I would have the entire chassis system carefully inspected, especially those parts that require lubrication.

[Sidewinder]

Just posible that the Dealer had the drive shaft out for some other problem he was fixing on the drive train. If it wasn't tightened back in correctly the bolts would let go.

[J Walker]

Ok, I have to ask what ride height has to do with the drive shaft angle. I believe that the engine, transmission, and rear axle are mounted on the chassis and the air bags just raise and lower the coach.
Lubrication of the universal joints is key to preventing a drive shaft coming loose. It could be that the zerks are not taking the grease even if you are lubing them, or trying to.

[ottffss]

Quote:

Originally Posted by J Walker Ok, I have to ask what ride height has to do with the drive shaft angle....

Absolutely EVERYTHING. On an air bag suspended DP, the ride height sets the operating geometry of the drive shaft/U-joint angle. Wrong ride height and that angle is too great causing massive abuse of the U-joint and its rapid demise. A couple degrees off is all it takes due to exceedingly short drive shafts in DPs... Picture this. Transmission output shaft is fixed in relation to CHASSIS. Differential input yoke is fixed to the ROAD. Change the height of the suspension (the thing in between the chassis and the road) via the air bag pressures and you alter the drive shaft angle. The shorter the shaft (especially true in DP chassis) the more acute the impact. On front engine vehicles the drive shaft length is so long that differences in suspension height alter the angle only slightly. DP chassis have drive shafts that are only a couple feet long.

BTW - I just posted proper lube procedure - especially for U-Joint and slip joints - on this thread link:

lube jobs

[Mike Canter]

This is the correct procedure for greasing driveshaft yokes and ujoints as per Dana Spicers manuals.

Driveshaft U-Joint Servicing

[num1dgh]

Our coach hadn't been properly maintained at all and suffered from serious lot rot before we got it. We had problems with our jake not working, and in addition to replacing speed sensors, OMC checked our drive shaft. It looked (I saw pictures) like it had never been maintained and was rusted and not at all lubed. The drive shaft alone was not an expensive repair in light of everything else we had done to the coach!

[J Walker]

Quote:

Originally Posted by ottffss Absolutely EVERYTHING. On an air bag suspended DP, the ride height sets the operating geometry of the drive shaft/U-joint angle. Wrong ride height and that angle is too great causing massive abuse of the U-joint and its rapid demise.

I am one of the few who have a DP with springs and shocks so I am not very familiar with air bag construction. I could not envision part of the powertrain moving up and down as the air bags inflate and deflate but apparently the engine does.

[cbeierl]

Quote:

Originally Posted by J Walker ... I believe that the engine, transmission, and rear axle are mounted on the chassis and the air bags just raise and lower the coach. ...

This was where you were mistaken. The engine and transmission are mounted on the chassis and air bags are mounted between the rear axle and the chassis, just as any other spring suspension system would be. Therefore the rear axle moves up and down relative to the chassis, and as it does so the angle of the drive shaft changes.

[J Walker]

Quote:

Originally Posted by cbeierl This was where you were mistaken. The engine and transmission are mounted on the chassis and air bags are mounted between the rear axle and the chassis, just as any other spring suspension system would be. Therefore the rear axle moves up and down relative to the chassis, and as it does so the angle of the drive shaft changes.

That cleared it up.

[OldGerman]

For those who suggested that I talk to a lawyer, wanted to let you know two things: (1) I don't want to play the "my lawyer said" card unless I have to and (2) my lawyer will work for free on this one because my lawyer is my wife. By the way, the dealer knows she's a lawyer so that might make a difference. Thanks again for all the good info and help. It is much appreciated!

[mr300ce]

Dog gone it....every time I read a thread I have to ad another thing to do or check on my Bounder. Grease U-joints. Check !

Of course I do want to make sure all is done and well while it sits here, but its cold outside now, and I only have weekends to do everything.

I did finally look under it tonight, and saw the front & back sway bars. Factory ones. Back looked about 2" thick. That is why it rides so nice, and does not seem to lean back and forth on the road. And.... I don't get any tail wagging when big trucks pass by.