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On car propshaft balancing

PostPosted: Mon Jan 13, 2020 11:01 am
by JonB
Having got my Plus 2 back together with new U/Js and sliding joint fitted to the propshaft I have vibration at motorway speeds. It sounds very much like the propshaft needs to be balanced and I think I would like to try it myself, using this method:

https://www.youtube.com/watch?v=zuPSGJZpL3k

It seems fairly straightforward, but has anyone done this before? Any advice other than the usual safety issues? I the video we see a car with a solid live rear axle so it's easy to support. On our cars we would need to support the suspension arms individually, but how to do it safely? An alternative might be to disconnect the half shafts from the diff, then there would be no need to support the A arms - comments?

I should add that the only really dangerous part I can see is the step where you make the initial chalk mark on the shaft. Lying under the car with the drive train running at 70mph...

Re: On car propshaft balancing

PostPosted: Mon Jan 13, 2020 11:50 am
by 2cams70
JonB wrote:Having got my Plus 2 back together with new U/Js and sliding joint fitted to the propshaft I have vibration at motorway speeds. It sounds very much like the propshaft needs to be balanced and I think I would like to try it myself, using this method:https://www.youtube.com/watch?v=zuPSGJZpL3k


Let's start with a question. Is your car a banger that you wish to off load to the next hapless victim as soon as possible or is it something that you cherish? Why oh why would you do it? Unless you live in the back blocks of Cuba somewhere with no parts or services available please just please remove that driveshaft and take it to a specialist who has the proper balancing equipment. The last time I had it done it cost a measly $150 or so.

Driveshafts are typically balanced at both the front and rear and not just the rear. Not to mention the effects of the wheels and tyres spinning around. To quote Donald Trump - beware that video is FAKE NEWS!!

Re: On car propshaft balancing

PostPosted: Mon Jan 13, 2020 11:57 am
by Mazzini
2cams70 wrote:
JonB wrote:Having got my Plus 2 back together with new U/Js and sliding joint fitted to the propshaft I have vibration at motorway speeds. It sounds very much like the propshaft needs to be balanced and I think I would like to try it myself, using this method:https://www.youtube.com/watch?v=zuPSGJZpL3k


Let's start with a question. Is your car a banger that you wish to off load to the next hapless victim as soon as possible or is it something that you cherish? Why oh why would you do it? Unless you live in the back blocks of Cuba somewhere with no parts or services available please just please remove that driveshaft and take it to a specialist who has the proper balancing equipment. The last time I had it done it cost a measly $150 or so.

Driveshafts are typically balanced at both the front and rear and not just the rear. Not to mention the effects of the wheels and tyres spinning around. To quote Donald Trump - beware that video is FAKE NEWS!!


Plus 1.

Re: On car propshaft balancing

PostPosted: Mon Jan 13, 2020 1:05 pm
by JonB
Interesting...

It's not the first time I have seen people using hose clamps to balance a prop. Successfully I might add. The thing is, it takes ages to remove the shaft on mine, and then I have to try to find somewhere that balances them. Not easy round here, or I'd have had it done when the sliding joint and UJs were done.

Re: On car propshaft balancing

PostPosted: Mon Jan 13, 2020 1:20 pm
by alan.barker
Who changed the UJs, because before you dismantle each part should be marked. Also the Sliding Joint each side to keep the balance and orientation. I think in the Workshop Manuel it says keep orientation on Sliding Spline the same.
If you have vibration then when they were dismantled someone lost the orientation :oops:
If the vibration is the Prop Shaft then you need to get it balanced by a specialist.
Have you tried swapping rear Wheels with front Wheels. Would not hurt to try and only costs a bit of your time :wink:
Alan

Re: On car propshaft balancing

PostPosted: Mon Jan 13, 2020 1:52 pm
by 2cams70
JonB wrote:Interesting...

It's not the first time I have seen people using hose clamps to balance a prop. Successfully I might add. The thing is, it takes ages to remove the shaft on mine, and then I have to try to find somewhere that balances them. Not easy round here, or I'd have had it done when the sliding joint and UJs were done.


Suggest you ask a place that does truck modifications or body fitment who they use for driveshaft work. It's very common for trucks to have their wheelbase changed (hence the propshaft needs to be altered to suit) and for driveshafts to be custom made for running ancilliary equipment, etc.

Re: On car propshaft balancing

PostPosted: Mon Jan 13, 2020 2:05 pm
by oldelanman
2cams70 wrote:Suggest you ask a place that does truck modifications or body fitment who they use for driveshaft work. It's very common for trucks to have their wheelbase changed (hence the propshaft needs to be altered to suit) and for driveshafts to be custom made for running ancilliary equipment, etc.


+1 We used to use Bailey Morris in Cambridgeshire for propshaft mods.

Re: On car propshaft balancing

PostPosted: Mon Jan 13, 2020 2:28 pm
by JonB
The shaft originally had a worn spline and was vibrating much worse than it is at the moment. On inspection it was found that the cup was ok and it just needed the male section to be replaced. The firm who did this checked for true running but as they lost their balancing kit to a fire it wasn?t balanced. As to the maintaining of positions at the joints, it was too late. Best I could do was ensure the yokes at either end were oriented the same way, per advice I was given.

So no point crying over spilled milk!

I don?t see any reason not to try this. Swapping the front / rear wheels did occur to me, to discount rear wheel balance issues. I think I will try it next though I doubt it?ll help. But who knows, I might get lucky, for once!

Re: On car propshaft balancing

PostPosted: Mon Jan 13, 2020 7:19 pm
by RichardHawkins
John,

I don?t remember where you live, but I used a company in Birmingham, I can look up their name if you would like to know.

Whilst the video was interesting, access was easy, our prop shafts are within the chassis, making access difficult. I would love to know how you get on.

Richard Hawkins

Re: On car propshaft balancing

PostPosted: Mon Jan 13, 2020 7:45 pm
by JonB
My car has a Spyder chassis so might be easier than you think. The only thing I?m concerned about is making the initial chalk mark. I have to be under the car with it running to do it. At 70 mph. :shock:

Re: On car propshaft balancing

PostPosted: Mon Jan 13, 2020 9:37 pm
by Donels
Try Dave Mac Propshafts in Coventry. They fitted a new yoke, new U/J and rebalanced my +2 propshaft with a two day turn round. They do a courier service. Check out their web site.

Re: On car propshaft balancing

PostPosted: Mon Jan 13, 2020 10:03 pm
by c42
+1 for Dave Mac, great service.

John

Re: On car propshaft balancing

PostPosted: Mon Jan 13, 2020 10:52 pm
by mbell
Not watched the video yet but sounds like a choice between lying under car with drive line travel at 70mph trying to draw on the prop shaft it or spend ~200GBP.

I would stronely suggest paying the money. 200GBP is a lot easier to earn than the amount damage to yourself and property the other root could cause.

With a Spyder frame you should be able to unbolt the prop at both ends easily and I've read here it is possibly to slide them out past the engine but likely not that easy.

Re: On car propshaft balancing

PostPosted: Tue Jan 14, 2020 2:03 am
by 2cams70
200GBP sounds very expensive for a propshaft balance. Should be able to have it done for much less than that especially if you remove it yourself first.

Re: On car propshaft balancing

PostPosted: Tue Jan 14, 2020 8:54 am
by JonB
Yes you can take the shaft out without removing the engine with a Plus 2 on a Spyder chassis. Trick is to remove the gearbox support plate, leaving the box held up by a jack. It takes ages, mostly because the eight flange bolts are a real pain to undo. The nyloc seems to bite into the threads mightily, and they are fine threads (so more turns required to undo). Add to that the awkward position and you have a certain reluctance to get on with it. Also consider that I?ve done this twice in succession and I don?t feel like doing it again just yet!

That said, I?ll will look into this firm you mentioned. If they?re not too expensive I might go ahead with them. Any suggestions for South Coast firms?

(Edit: just asked them for a quote)