Good vibrations....
 

Hey all, as per title my XJ has some lovely vibes. Theyre pretty constant, but you can feel it through your ass badly at 75 and 100kmh. Would I be looking @ dshafts and unis? Also my wheels got balanced and aligned the other day.... any recommendations? all stock, new gearbox mount too (do I need to loosen this?)

Should I jack it up, chuck it in drive on stands and get it up to speed to see if it vibrates without the front driveshaft in the way ? Cheers .

Hamish could be a number of things might be the uni at the diff if the back end is sloppy could be your rubbers hard to say check for play in the uni joint xjs are getting on in yrs rubbers sensors and bits n pieces need replacing
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I had the rear driveshaft out not long ago, the uni felt good. Can the front one cause similar issues?

Also I have messed with the gearbox mount. Does anyone know the distance between the TC and their bash plate?

Also as my diff is shit, could it be a worn pinion causing bad vibration?

Thanks.

did you mark & keep rear driveshaft in same orientation during R&R ?

apparently the trans space is ~1", mine is a bit less from age, needs replacing

I doubt a worn pinion bearing would cause vibration unless it was terminal, is there excessive freeplay...like 1/4"?..would be awful noisy

mine vibrates a bit at ~90-95kmph (it needs a wheel alignment)

the trackbar joints can be worn

I would start with the basics things

There's a lot of noise from the diff.
I had it up in the air the other day running in drive, the rear wheels looked to be not rotating on a solid axis. They looked like they were moving slightly off centre like both axles are bent. Unsure if this is the case... Is this normal?

All my driveshafts feel okay, didn't spend too much time down there as it burnt the shit outta my arm and took a heap of skin off :(

How do I check the suspension components?

Also I didn't line up the DS but can only spin one more rotation. I think it was correct as I just removed the uni joint on the diff end (the 4 bolts) but didn't pull it out of the DS.

I'm pretty sure it's the diff. I think the axles are bent.

Diff
 

Hey mate
Did you grab a wheel whilst it was up in the air to check for play in the wheel bearings. If they have gotten bad enough they will quickly wear through the thin hardening on the axle into the softer metal and you will possible get that appearance of the axle being bent.

Thanks mate! I definitely did. Didn't seem to be much movement if any which worried me even more. I have a new diff assembly on the way (second hander) with a 12 month warranty. Hopefully this will sort my XJ out quite well. Hope the LSD works still too. If not a rebuild on a traclok isn't that hard is it?

Go Hamish(DIY)W96.........................
Lots of things are not as hard as you would think just takes Time..$$ if you are paying someone
End of the day we all end up with brand new XJs LOL!
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/__l_l_,\____\,___
l_---l_l__l---[ ]llllll[ ]
_.(o)_)__(o)_)--o-)_)

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/__l_l_,\____\,___
l_---l_l__l---[ ]llllll[ ]
_.(o)_)__(o)_)--o-)_)

Hahahahaha always diy especially with the Jeep 😂 would love to learn to rebuild the LSD but want a truetrac or lunchbox too hahah

Diff changed today. Fixed it. Yay!

Okay so still getting some wobble... My seats shake, my floor does too... At set speeds all of it. Do I need to check for play in the front end? My unis on the driveshaft seem fine, no odd movement. Can the front driveshaft cause vibes?

I took mine to pedders for a check up last weekend as i get similar vibrations at 80kmh +

they said a tailshaft balance might do the trick

vibs
 

take the front drive shaft out and drive it, easy test to see if its the problem.
Also when testing for play in drive shaft uni's don't rely on using your hand to turn it back and forth, stick a big screwdriver in between the uni and get some leverage on it. I've been caught out where the unis were so dry and worn in position you couldn't feel the play by hand, 2 weeks later it dropped one end of the driveshaft from a collapsed uni ( was on a yard forklift that always worked in dirt yard).

Cheers guys, appreciate it. I am leaning towards shafts... Will remove the front one ASAP and see what difference it makes. Also, is this pinion angle incorrect?

After some research, its not. Should be 'parallel' to the Tcase. Ill realign it tomorrow. Ill drive it, most likely feel no change and remove the front DS. Go again and change the two rear tyres with my spares.... if not I'll put new Unis in the rear shaft (I have 2), then if not Ill have to get it balanced.

My rear tyres are out of round, most likely from sitting for years, then me refitting to a new set of wheels. Also my driveshaft unis aren't the best. Dropped the front driveshaft and vibes went away a bit. The rear tyres were the biggest culprit. I'll do both 2 rear tyres and all 5 driveshaft unis.

I had the same issue, as you and replaced all 4 tyres with supposedly good used ones, but had a rear one delaminate at 90kmph, causing lot of damage and risk

be warned!, a front blowout almost certainly would have been disastrous

My tyre man said that a big delamination was just bad luck, (if you can attribute a cheap Chinese tyre to luck)

was in some luck though, as he had a very good set on hand, nearly new that he put on for 35each, put 20k on them still look like new

I have a good relationship with my tyre guy as I have some older cars that dont see much use, so brand new tyres are liking flushing $

My dad knows people so I'm gonna get a matching set to the fronts. They're 4 yo, I'll chuck them on the back and put newies on the front (matching ones) shouldn't cost a mint but will look a lot better. The current bad ones have tonnes of tread but sat for a long while and I locked them up a fair whack due to never having a non ABS car lol.