Drive shaft balancing, opinion

[Plasa]

Hello all.
I own a M1078 A0 from 1997, with the "D" sign on the VIN plate. The truck have now 15.000 miles on (7.000 by me) and have not really feelable vibrations, except somtimes the unbalanced tires. I have default gears, no high speed gears, but the detroit locker in back axle. All screws are tights, except 1 missing and 1 loosen screw on the starter 500 miles ago that I replaced. I replaced also the transmission coolant rigid hoses with flexible hoses due a crack on a junction. It was at 10.000 miles, now it's OK.

Reading all the threads of driveshaft failures I'm now insecure if balancing the drive shafts is a good idea, also because the U-Joints seems to be good. The hinging test shows 0.2mm (0.008 inches) front shaft and 0.18mm (0.007 inches) back shaft.

I would not touch a running system if works, so what do you think (not only for my conscience), should I dismount both driveshafts and rebalance them?

Thanks a lot!

Christian

 

[Suprman]

Alot of the failures are caused by lack of joint lubrication. If you have excessive play in your slip joints then thats a reason to rebuild. The slip joints have lube fittings also. If you are concerned you can always replace your 4 u joints and lube them well. I prefer synthetic lube on them but some will tell you regular grease works just fine.

 

[Plasa]

Alot of the failures are caused by lack of joint lubrication. If you have excessive play in your slip joints then thats a reason to rebuild. The slip joints have lube fittings also. If you are concerned you can always replace your 4 u joints and lube them well. I prefer synthetic lube on them but some will tell you regular grease works just fine.

Thank you for your replay. The hinging test say max. 0.02 inch. I'm fairly under this value (0.008 inches). I know that there are other threads discussing about this, but can be that original driveshafts are unbalanced after 15.000 miles? Or maybe a production failure?

Christian

 

[Suprman]

If you dont feel any vibration I would think they are still good.

 

[coachgeo]

TM says .2mm..... driveline shops say ZERO. If yours changes any... or you feel a vibration in near future.... get them done. (or sooner IMHO) espeicially if there is anything over 50 miles in a day in the near future.