Rear prop/shaft vibration/noise

[DennisM]

I have had this ongoing issue with 112-587 aka 'Wee-Wullie', so as I'm on unpaid leave from one of my places of employment and I'm also helping swmbo to renovate our bedroom  LOL I'm also making time to try and find the cause of this annoyance. A quick inspection showed that the shaft was out of sequence by 1 spline, that was rectified quickly, so now I needed to know if the problem was the shaft or elsewhere.
Everything is fine with it at speeds below 35mph (60K's) above that if you back off the throttle it sets up a vibration/noise (growl++) which lasts a few seconds, so last weekend I removed the rear shaft and took 112-587 for a run, no noise full stop..
I refitted the shaft and no prizes for guessing, the noise was back, so being 1 spline out of sequence didn't make all that much difference. I have quite a few propeller shafts so I decided that I would shorten one of them, first of all clean it up somewhat to show alignment marks, then scribe a line, marking it with a center punch marks, check the length of original rear shaft, transfer that measurement to donor shaft

cut shaft using pipe cutter,

Once that was done I set it up in the lathe and squared off the end and introduced a small taper, now to the other end of the donor shaft.
This was put in the lathe, I ground a right hand cutting tool, to remove the original weld, then put the machine in back gear and set about parting it off the shaft

once I had gone through the outside of the prop/shaft, I removed the shaft and punched the yoke out using a suitable bar, that part is now in the freezer, hopefully that will shrink it enough, and when I heat the shortened shaft, they might just go together with minimal fuss, well that's the game plane anyhow LOL, anyway other things to do ATM, cheers Dennis

[DennisM]

I have no idea Diana, that's just the way I did the last one about 15 years ago, but now you have mentioned it, it could be easier LOL cheers Dennis

[DennisM]

Well it went together like the proverbial finger, a really good interference fit

only now needs to be welded, cheers Dennis

[Tommy]

A quick inspection showed that the shaft was out of sequence by 1 spline, that was rectified quickly, so now I needed to know if the problem was the shaft or elsewhere.

G'day Dennis

Nice modification work . Aren't pipe cutters a wonderful tool.

What do you mean by 'one spline out of sequence'?

[DennisM]

I had planned on doing this tomorrow or later, but a chance call from a mate (who is a welder by trade YEHAA) anyway to cut a very long story short he welded the shaft together in about 2 minutes , I didn't have time to blink and it was done

now just need time for another 'Op Rubic's Cube' and I can't see that happening for at least 2 daze!!, anyway we will just have to wait.
Stuart, what I meant by 1 spline out of sequence, the prop shaft parts have an ARROW ------> on the sliding section and also on the prop/shaft itself<----, if these are not aligned, it can cause vibration in the drive line, I was not aware that this was the case with 112-587, as I said it was just 1 spline out of alignment, all I had to do to rectify that was unscrew the grease collar, separate the shaft from the slider, move it 1 spline and slip the two ends together with the ARROWS alinged , screw up the grease collar, but in my case it still didn't stop the growl/noise, I would suspect that somebody in it's distant past has had the propeller shaft in 2 sections and wasn't watching closely what they did, anyway here's hoping that I may have fixed the problem, cheers Dennis
ps yes pipe cutters are are a great tool, especially when I can't fit it in my lathe!! LOL,,.
pps Diana, I wasn't that concerned about the loss of the balance weight, as the other end also had balance weights on it, and with the shaft being so short, well FINGERS XXXXX'd LOL,,.

[Minikeg]

Castrol had that same growl on backing off, was attributed to the transfer case?