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        General >> Give/Need advice to/from others >> Balancing prop-shaft bolts
        
(Message started by: Mike_Floutier on Jul 18^th, 2008, 9:52pm)

Title: Balancing prop-shaft bolts
Post by Mike_Floutier on Jul 18^th, 2008, 9:52pm

I noticed on the instructions for removing/installing the prop-shaft that the bolts (where it joins the diff.) are of differing lengths to "balance" the prop-shaft.

Does anyone know whether this is a real issue (ie. noticable) and has anyone had any experience of curing a vibration by moving the bolts around.

As you can tell I'm running out of ideas for curing my Scorp's vibration.

Thanks

Mike

Title: Re: Balancing prop-shaft bolts
Post by Highlander on Jul 18^th, 2008, 10:01pm

I've never noticed a difference refitting them in the wrong order no.

Diff mount rubber ok? The one where you couldnt get the bolt out? ;)

Definitely not a cv joint?

Title: Re: Balancing prop-shaft bolts
Post by Mike_Floutier on Jul 19^th, 2008, 8:48am

All the bolts came out fine in the end and the rubber bush on the bracket seemed fine.

With regards the cv joints and in fact anything downstream of the diff. I've already ruled out by running the drive-train with the back wheels off the ground and stopping each wheel in turn - ie the problem remains.

I'm thinking about the prop-shaft centre bearing. I did replace it by mistake about 100,000 miles ago when I mistook it for a worn wheel bearing.

Two points arise from that; 1. I think I damaged it when fitting it, and 2. I didn't add any grease to it and I'm wondering if I should have.

What do you think?

Mike

Title: Re: Balancing prop-shaft bolts
Post by scorpio_man on Jul 19^th, 2008, 2:43pm

hi mike

've forwarded you an email from the mailing list.

not sure if it helps.

Title: Re: Balancing prop-shaft bolts
Post by Mike_Floutier on Jul 19^th, 2008, 3:06pm

Thanks, it makes sense that the UJs may be worn as the car has done over 310,000 miles. I'll look at them when I change the centre-bearing.

Mike

Title: Re: Balancing prop-shaft bolts
Post by mr._floppy on Jul 20^th, 2008, 1:10am

If the vibration has appeared since re-fitting or altering the propshaft, then yes, I would experiment with refitting the flange bolts.

But if it has developed on it's own, over time, then the centre bearing or disintegrating UJ's are the likely villains.

Title: Re: Balancing prop-shaft bolts
Post by Jonnycab on Jul 20^th, 2008, 1:32am

A quick question ;).....

....Do you have budget tyres fitted ?...& if so, how long have you had them ?

Some budget tyres i.e...... Accelera, Marshall, Winla etc, are fine to start with, but seem to deteriorate rapidly over a period of a few thousand miles. It's not the tread wear that is the problem...they seem to last forever ::).....solid rubber tread ;)

Internal separation of the steel belting in a budget tyre, causing a slight warping of the tyre is more common than most people think & can cause vibration & noise that lead people to believe that there is something wrong with their car :)

You buy a Michelin or Pirrelli etc you know it's sound, but it's expensive :o..... So you buy a budget tyre ;)

Everything is fine for a few thousand miles, but all of a sudden you feel the steering is getting bad or there is a vibration or rumble :(

You get the steering & suspension looked at, then the prop, & the final drive & nothing is wrong ???....so what next ?... :-/

I've had a similar problem before & it drove me absolutely mad.....& it was all down to crappy budget tyres ::)

Title: Re: Balancing prop-shaft bolts
Post by Mike_Floutier on Jul 20^th, 2008, 7:42am

Thanks Guys,

I've tested it all without the wheels running and it still makes the noise so it's not the tyres.

I'm pretty sure now that it must be the centre-bearing and UJs and suggested by Mr Floppy and Scorpio_man.

The auto-box specialist I took it to said he thought it was the prop-shaft. It's just that when I put my hand or a bit of wood on the diff. whilst it was running at the offending speeds I could hear/feel such a strong vibration that I was convinced it was the diff.

But, since fitting the new diff., very kindly supplied by Highlander, it's become clear (since there was no change) that it must be (by a process of elimination) the prop-shaft.

The shaking I'm feeling has been very slowly developing over the last 100,000 miles (car has done over 300k) which I guess is the UJs.

In turn I'm guessing that this shaking has worn the centre-bearing which I am hearing as a steadily and fairly quickly worsening "bearing noise" which comes into play at just over 15mph. This is a metal on metal scraping and opposed to the shaking.

Thanks again.

Mike

Title: Re: Balancing prop-shaft bolts
Post by mr._floppy on Jul 21^st, 2008, 5:39pm

If you've gone to the extremely large trouble of replacing the diff then fitting a re-con propshaft should be a breeze .