Drivetrain vibration

[DassaW]

Guys a few questions hopefully someone can answer for me.

After changing a uni on my front drive shaft my pinion seal has started to leak, coincidence? or have i put the shaft out of balance causing the seal to leak?

Also would a unbalanced shaft give me steering shake at about 80km?

Thought it was just the tyres, got them balanced the other day (one of them was 700gms out!) but still have a slight vibration through the steering.

Cheers

[LandyAndy]

Is there any chance it got put back together "out of phase"
The shafts are balanced and need to be assembled as they were before dismantleing.Look for alignment marks on the sliding yoke.
Any chance you have bent the shaft slightly off-roading???
Goodluck
Andrew

[DassaW]

When I changed the uni i didnt actually remove the sliding yolk from the shaft, and the uni's should be symetrical?

There are no obvious dents or anything from offraoding.

Im guessing there are places around that balance shafts? maybe I just take it down and get it checked?

cheers

[PeterM]

Always a safe bet. I believe that the shafts get balanced with the unis attached.

[mike 90 RR]

Always a safe bet. I believe that the shafts get balanced with the unis attached.

Yes balanced with the uni's

I would also recheck that the uni joint's are installed centered to the tailshaft and the caps are in position correctly

Also did you install the tail shaft with the sliding yoke in the correct direction /// IE pointing to T/C case and not to the diff ... or vise/verse for your model???

[PhilipA]

Probably coincidence.

An unbalanced shaft would not cause steering
"shake" ie side to side.
You could feel a gravelly vibration maybe.
There are numerous things that can cause a steering vibration with the starting point of tyre balance/out of round. Try the rears on the front.
Next take the front shaft off and see what it feels like to drive .
It is not possible to put the yolk on the wrong way as it only goes on to teh diff flange two ways both of which are correct. You may have stuffed up the uni fitting it in the driveshaft.
Regards Philip A

[JohnF]

Guys a few questions hopefully someone can answer for me.

After changing a uni on my front drive shaft my pinion seal has started to leak, coincidence? or have i put the shaft out of balance causing the seal to leak?

Also would a unbalanced shaft give me steering shake at about 80km?

Thought it was just the tyres, got them balanced the other day (one of them was 700gms out!) but still have a slight vibration through the steering.

Cheers

we had a front uni yoke colapsed when it was not properly greased. Probably nothing to do with your problem though, but make sure you grease them. stearing shake likely to be something else.

[DassaW]

Thanks for the replies guys.

Yes I did put the shaft back on the right way, (sliding yolk to t/case) so it must just be the tyres still.

Ive only got the silverstones static balanced and I cant swap front to rear as one of the rear tyres we had to put about 500g of weight on to get it close to balanced as it had a heavy spot.

The vibration is not too bad now but just thought it may have been an issue as the pinion seal is now leaking. Will replace the pinion seal and see if it starts to leak again.

Cheers

Darren

[Bush65]

You failed to mention what vehicle it is.

The u-joints on front tailshafts for RRC, 110, defender and disco are out of phase about 45* (not in-phase like rear tailshaft).

This is to compensate for the un-equal angles between the front and rear u-joints. The angles are un-equal because the engine and transmission are angled down to the rear, while the front diff pinion is angled up to the rear.

The rear diff pinion is angled up to the front (parallel with the engine and transmission) so the u-joints on the rear tailshaft are in-phase as expected.

Disco II have a double cardan joint at the t/case end so not the same as the above.

If you take the front tailshaft to a shop that does not know about coil sprung rovers they may make the mistake of putting the u-joints in phase. Then you will have a vibration problem.

[rovercare]

Coincidence;)

Drop the front shaft out, lock CDL, does it still vibrate?

Wheel shake could be panhard rod bushes, radius arm bushes, swivel hub bearings, wheel balance, loose wheel bearing, stub falling off, earth tremor:D

Pinion seal, check pinion bearings, tug on the pinion and see what happens, does it clunk?, maybe its just cactus or incorrectly installed

But to be honest, its likely you've muffed up the uni install;)

[lokka]

Rovercare has mostly knocked it on the head but id also look at the rod ends on both the trac rod and drag link as vibes will either be there or in the panhard but running them silverstones on tha black top at speeds of 80k and above is just asking for vibes to show up :D:D:D

[DassaW]

Thanks again for the comments guys,

Sorry, the vehicle is a 97 300tdi disco.

I think I will take off the front shaft when I get a chance and go for a drive, if its not the shaft I will then look at panhard rod etc, hopefully getting a new drag link and track rod soon from lokka;). Wheel bearings are good.

Yeah I dont think you can balance the 35"s real great either so that may be all the problem is, when I get me some A/T's for my trip ill also see how they go.

Cheers

[adnic]

hi all
i am having the biggest haedache at the moment with driveline services at brendale in brisbane over my double carden front shaft in my 99defender 110 extreme.
i am running the scorpion racing extreme set up & had the front shaft rebult by them less than two years ago.
just got back from a big trip out west & had a bad vibration at around 80kms or 2000rpm.
gave it to them & they made me pay another 550.00 to have it completely rebuilt again.
this time the uni had completely disintergrated despite bi monthly grease.
they only have a three month wty so it was pocket pain time again.
got it back & it sounded like a gnome was strapped to the bottom of the truck with a hammer every time i moved.
they took it out after much arguing with me & said they rebuilt it again.
guess what?...it is just as bad now as last time.
they now claim my trans case is stuffed, but i just held the shaft & rotated the top joint & i can make it vibrate in my hands let alone in the car.
with no front shaft fitted it runs smoothly with no vibration...coincidence ro not..you tell me!
next stop transmission specialist for second opinion.
any ideas?

[catch-22]

I do know you can buy new OEM shaft for the same price.

I have the opposite. Take out the rear and no shake. But my rear shaft was perfectly in balance as checked by shop. So I will be watching this thread..

[stig0000]

a gen d2 front prop at 550$??? can't even get aftermarket ones that cheap, they are 1200ish new,, and about 6-700ish SH,


i have just had one made up for my fender at $202:cool:, new double cardan with HD joints all round,:D:D (its who you no, not what you no some times):D

[catch-22]

a gen d2 front prop at 550$??? can't even get aftermarket ones that cheap, they are 1200ish new,, and about 6-700ish SH,

haha...nope. OEM $530 delivered. LR packaging and all :p

[stig0000]

haha...nope. OEM $530 delivered. LR packaging and all :p


from uk i guess,, good work;),, first thing tho,, take it to a shop to change it to grease-abull uni's,, and you be even happyer for yrs to come

[stage one]

Did the universal have a name stamped on it? Like nsk, skf or something like fag? Or was it one of those off centre, unmarked, cheap yanfungs? Can’t see how it would create steering wobble, but I know on my beast, when I bent the front prop shaft it felt like it did! And that too was at 80ks!Just a thought.

[TimNZ]

Regarding the vibration, when the wheels were balanced were they checked for bulges/being out of round/runout etc?? I spent ages trying to chase down a vibration on my 110. I got the tyres balanced and found the vibration was less, but it got worse again quite quickly. I got the tyres re-balanced at a different shop, one was miles out so I put that down to the guys who did the first balance. Anyway, the vibration soon returned, the third place that I had the tyres balanced at noticed that the same one tyre was slightly out of round. I changed the tyre and all has been well for 40,000+ k's.

Cheers,

[aRRon]

Evening all,
I'm watching this thread too as just had front and rear tailshafts rebuilt with new unis and balance - all up $450 (removal and replacemnt in vehicle done by self).
Both came back with the alignment arrows on the sliding yokes correctly aligned, however my markings to match to previous position on diff and transfer case flanges had disappeared as the shafts were repainted.
Reading all the above posts I'm really nervous now - the tailshaft guy reckons it doesn't matter about the match up to flanges as it is all rebalanced.
Couple of the unis felt sticky/rough in one plane of movement, even after greasing - can I hope this smoothes out in use?

[catch-22]

If the shaft has been perfectly balanced and everything else is in balance then it should not matter which way they go in. If they go in and there is still a shake then the issue must be elsewhere - not the shafts.

[aRRon]

One further thought...
Had an XJ6 with a drivetain vibration and in addition to replacing unis and balancing shaft and replacing centre support bearing the bearing cage was adjustable allowing lateral adjustment to its position. So you simply moved it incrementally and took it for a road test after each adjustment til it was all smooth.
Made me think of the possibility of the axles shifting on worn locating arm bushes or bent arms. Or is this drawing too long a bow???