Disco Bad Vibes

[Reddo]

Got a nasty vibration in the Disco when accelerating or decelerating, enough to shake the whole dash. Came on from no where. Checked all the obvious stuff, tyre pressures, even replaced a wheel bearing (oh no not another one, that makes um ah .....3 sets in 14 months. Checkeds the control arm bushes (new), no probs.

Found that the handbrake drum was loose, tightened the bolts, road tested and it was still there!

Checked the front and rear prop shafts, all good except a slight amount of slop at the TC end on the front. Removed the shaft, road tested and no more vibes.

Hard to believe that a small amount of wear on the upper universal joint would cause such a vibration, enough to shake the whole dash. I'm hoping there's no more bad news, eg., in the front diff.

[justinC]

Vibes are worse exponentially with a lift/ angle change. On a standard disco, you would probably have only just felt it.

JC

[Reddo]

Thanks JC. Yes you are right (of course).

Interestingly, according to the parts supplier, our's is fitted with a 'rear' prop shaft on the front - and of course the Uni's are different front to back so...had to buy a couple of 'rear' UJ kits for the 'front' prop shaft.

Wonder if it came out of the factory like this

Life is never boring owning a LR

[cloughy]

Uni joints, use hardy spicer only and make sure your shaft is assembled so the uni's are in phase

[Reddo]

Thansk for the advice.

Interestingly, was told HSpicer UJs were crap, and was recommended to use Toyo only. So seeing as how I got the Toyo advice earlier, I went and bought them. They are in now. So we'll see how we go.

I've used them before on other machinery and they seem OK.

The originals did around 200 000 k's before one of them let go - no doubt cause the grease nipple was missing and it ran out of grease and water entered I guess.

[cloughy]

Fair enough, i've used toyo tojo and all sorts of jap made uni's and never had as much success as i have with hardy spicer and thats all i use now

[Reddo]

Noticed the joints were not quite in phase, so it neded a little rotation - one or two splines.

Pulled the thing apart and noticed the splined shaft is coated with plastic or nylon, some of which has of course worn in places. Bloody plasticky stuff did not want to go back in though, and some of it disintegrated on entry no matter how carefully it was inserted.

Could not notice any addtional movement in the slip joint when in its normal posi, so I'm hoping it will hold up.

Plastic or nylon or whatever, seems strange to put this material in a place where sliding/friction/wear and torque loads are high. Oh well, I guess it's lasted 12 years so far!

[cloughy]

Yea its like a weird wax coating, i just wire wheel the loose bits off , no excess movement.

[Maggot4x4]

Don't rangie and disco shafts run 1 spline out of phase from the factory, I know mine do.

[Reddo]

yeah I thought that too and spent ages trying to confirm this.

However, the rear is in phase and I found only find one reference saying that the RR Classic ran them out of phase, and nobody knew why. Some ven have arrows on them to set them slightly out of phase.

Mine had no arrows or other marks and as everyone said it is best to put them in phase, I did that. Plus the repair manual shows a picture of them in phase.

Anyway, the vibes totally gone and everything is really good now.