Balancing driveshafts?

[Blue60]

Just finished pulling apart front and rear driveshaft/u-joints...blasted and POR-15...should they be balanced before I reassemble? How critical? If so, is that done with just the shafts, i.e. no slip yokes and u-loints, or flanges? Any insight/opinions always appreciated

SOR lists a dust boot for the driveshafts...anyone have'em on their rigs? Pro/Cons?

79 renovation moving along...slowly!

Dave

 

[LukeZero]

Yes the entire assembly should be balanced professionally before you reinstall it in the truck. Particularly the rear driveshaft. It's the one that spins at high RPMs for extended periods of time. The front, I would balance anyway, but you could potentially skip it because the front is typically only engaged for short periods of time and at fairly slow speeds. Luke

 

[skyshark186]

Depends on how you use the truck. I used to have all my shafts balanced. But now that im workin on my cruiser there are farrrrrr more things to cause vibration im worried about. No real need unless you drive alot on the highway/interstate IMO. If you do alot of high speed driving i would get her done, otherwise i would just slap her back on.

Side note. I somehow managed to sheer all four bolts on the rear pinion. So you might want to use good hardware to reinstall em. Driving home the other day clunk clunk clunk SNAP. Ooooops.

 

[dd113]

You should always mark the shaft prior to splitting it so you can get it back on in the correct orientation. The flanges need to match as do the joint caps. Easy to put it on there wrong. This is called getting it into phase. Balence is a good thing but if it did not vibrate prior to removal and you get it back in correctly you should have no issues. Never hurts to do it though.

 

[cruiser_guy]

I somehow managed to sheer all four bolts on the rear pinion. So you might want to use good hardware to reinstall em. Driving home the other day clunk clunk clunk SNAP. Ooooops.

You should use specific drive shaft bolts to mount the drive shaft. They have a higher strength rating so they will not fail as easily and can take the torque required when tightening them.

 

[skyshark186]

They were the originals that failed. I used grade 8. If it breaks those.....i guess i need a lighter right foot.

 

[Blue60]

Follow-up question

So...

I put'em back together with the new u-joints, phase 'em, then bring them in to the shop to have them dynamically balanced? This can be done without being bolted in place to the diff's I assume...

Thanks for all the feedback...


Dave

 

[CruisinGA]

Yep
I'm sure the shop would install the u-joints for you too. (what i would do).

 

[Blue60]

Near real-time info requested...

Had the rear drive shaft balanced after letting the shop (excellent reputation) install the u-joints, and phase them. I supplied them with a diagram out of the FSM showng the orientation of the zerks (grease nipples). From the non slip yoke end to the slip yoke end the FSM depicts the orientation of the nipples as: rear ujoint at the 1:00 O'clock, slip joint fitting as 12 O'clock and the forward ujoint (on slip yoke) as 11 O'clock. They installed the u-joints such that both u-joint nipples are oriented at the 1:00 O'clock position. TO BALANCE they put two HUGE (did I say HUGE!!??) weights on the slip joint yoke and the driveshaft.

My question... is this correct? OR....because of the similiar orientation of the zerks, were they required to install the HUGE weights? Should I have them reinstall the u-joint so the zerks are orientated in accordance with the FSM? I plan on taking it back to them tomorrow morning if the consensus is they screwed up.

All new territory for me, sorry for lengthy, appreciate any input!

Cheers,

Dave