Thread: Balancing front prop. shaft.

Originally Posted by mike 90 RR

I know of a "well respected" mechanical engineer who puts in the time to make the shaft straight (Not bent) ... heats up the shaft and straightens it out on the lathe .... No weights required

Your right on the balance subject tho

The only way a shaft can unbalance itself is under extreme loads where it makes the shaft twist heavily and kinks the pipe further // Examples would be "Burn out Kings" or the towing of heavy caravans

I'm just fussy, and did go "just a little" over board with a "New Shaft"


The only reason i'm suggesting that he gets it balanced is because he could have up to (worst case senario) "8 positions??" to try ... to get it right as he lost the original markings

Rotating through all 8 positions is better than spending the money getting a shaft balanced

How does he heat it up and straighten it on a lathe?

All the ones we've done have been largely spigoted, useing a yoke that fits in the gearbag to fit in the shaft as the locator with a sleeve if necessary, machined to neat fit, then I just phase it and weld it up, simple and effective and I've have a few well over the double metric ton with no vibes

Originally Posted by rovercare

How does he heat it up and straighten it on a lathe?

Build new propshaft ....

Put shaft in lathe ... turn ... look for bend ... warm it up ... Turn & roll it out

Takes time ... and i'm speaking in general terms

Originally Posted by rovercare

All the ones we've done have been largely spigoted, useing a yoke that fits in the gearbag to fit in the shaft as the locator with a sleeve if necessary, machined to neat fit, then I just phase it and weld it up, simple and effective and I've have a few well over the double metric ton with no vibes

If that works for you .... wouldn't change the method for quids .. All thumbs up ... cause its "all in the eye"


Even that new one I have, is slightly bent in the middle (from a weld line in the center) ... so it has a dag weld + a weight in the center of the propshaft .. Mongrel design .... (The shaft was rebuilt by others ... not the engineer I mentioned)

When I had my rear prop shaft repaired in Darwin by transmission specialist they stated that ALL prop shafts should be rebalanced when new UJs fitted

Regards

Brendan

Originally Posted by mike 90 RR

Build new propshaft ....

Put shaft in lathe ... turn ... look for bend ... warm it up ... Turn & roll it out

Takes time ... and i'm speaking in general terms

Wouldn;t that cause alot of hardening to the steel used?, he'd have to get it cherry red, unless he's set up a stress roller of some kind on the bed?

Originally Posted by leeds

When I had my rear prop shaft repaired in Darwin by transmission specialist they stated that ALL prop shafts should be rebalanced when new UJs fitted

Regards

Brendan

Should rotate your tyres every 5k and balance them every 10k to

Originally Posted by rovercare

Wouldn;t that cause alot of hardening to the steel used?, he'd have to get it cherry red, unless he's set up a stress roller of some kind on the bed?

He has the tools ... and is old school taught
That's why he's the "engineer" and I'm just the "layman" ....

Originally Posted by mike 90 RR

He has the tools ... and is old school taught
That's why he's the "engineer" and I'm just the "layman" ....

I just wanna know how he does it, I'm curious thats all, spill the beans?

Originally Posted by rovercare

I just wanna know how he does it, I'm curious thats all, spill the beans?

I've gone as far as I can in the method


You would have to ask him yourself .... as for asking about subjects of hardening & softening of the metals // etc ....... I can't answer that, as I would be talking out of my ... well you get the last bit


There are some other engineers here who could maybe expand on this method tho