Vibrating Truck

[N_WOF]

Hello,

I drove up to Exeter on the weekend - it was the first long bit of motorway driving I've done in my new truck. I pretty quickly noticed some fairly heavy vibrating when the truck gets to about 60mph. It starts to come in at about 50mph, peaks at 60mph and starts to drop off as I get up to 70mph. I thought it might be badly balanced tyres, but I only had a new pair of fronts (Nexen 265/70R15 AT) fitted last week and they were balanced at the time. It's not just the steering vibrating (in fact, that doesn't seem to vibrate at all), it's the whole truck - I'm wondering if the rears need balancing; could that cause such bad vibration?

Hopefully it's not something expensive like a bent driveshaft or something!

Any thoughts would be much appreciated,

Thanks,

Paul

[That Ruddy Squirrel]

It's worth checking your UJs too


Trev

[surfenstein]

yep have to agree with trev there first port of call check your prop shaft ujs.

[That Ruddy Squirrel]

yep have to agree with trev there first port of call check your prop shaft ujs.

[Falls off chair] You AGREE ????

Nursey, can I come back, I'm hearing those voices again

[surfenstein]

[Falls off chair] You AGREE ????

well someones got to trev.but then what do i know.

[N_WOF]

Thanks for that - can I check it myself (is it just play or movement I'm checking for?) or does it need a trained mechanics eye?

Paul

[fatfires]

Thanks for that - can I check it myself (is it just play or movement I'm checking for?) or does it need a trained mechanics eye?

Paul

try moving one part against the other, should be fairly obvious - often pumping full of grease might highlight the worn bit, and if it isnt that then at least you have greased the UJ's!

[N_WOF]

Well, I spent a lovely morning under my truck, greasing my universal joints. I didn't find as many grease nipples as the sun-visor diagram seems to suggest. It says I should have ten - I found 6 in all. Anyway, I also sprayed all the UJs liberally with WD40 and the vibration has almost gone - it still comes in a bit at about 75mph...

Should I have all the grease nipples on the diagram, or are some trucks not fitted with them?

Cheers,

Paul

Oh, one quick question.While greasing the nipples on the drive shaft to the front diff, I found I could happily turn it by hand, so it's not locked at either end. Is that normal?

[N_WOF]

Sorry to blatently bump this back up to the top again, but does anybody know about grease nipples and drive shafts?

Thanks,

Paul

[MattF]

Oh, one quick question.While greasing the nipples on the drive shaft to the front diff, I found I could happily turn it by hand, so it's not locked at either end. Is that normal?

That's normal.

Sorry to blatently bump this back up to the top again, but does anybody know about grease nipples and drive shafts?

Which ones didn't appear to be there? It may have had sealed joints? fitted at some point in the past. Some of those nipples can be buggers to see, however, wedged in the joint as they are.

[Tallyman]

If there is still vibration but at a higher RPM then you'll probably find one of the rear propshaft UJ's is close to seizing, even with new grease in there. Had exactly the same symptoms with mine a few years back. The propshaft didn't have any movement in it which you would expect if the UJ bearings were worn but that was because there was plenty of rust in them taking up the slack but still having enough movement to cause the vibration.

Changing the UJ's is a fairly straightforward exercise and doing both shouldn't take more than a couple of hours. You can get the parts from Milners or Roughtrax. Just remember to refit each piece to the prop as it came out (to retain balance) and refit the rear flange to the same holes that it came out from (i.e. mark them before you remove the prop from the car). The difference is a smooth drive and worth it for little expence.

[N_WOF]

The ones on the outside of the joints seemed to be missing - the diagram shows them in the circle areas of the UJ's, but my UJ's seem to have caps over those bits, so you can't get at the nipples.

I greased what I could get at, though, and that seems to have stopped the vibration...

Paul