Serious shake @ 50mph+

Hi and Thanks for reading.
I have a p38 2.5dt and it shakes like crazy from about 50mph, it's got 20 inch RR wheels on it.
I have already put new discs, pads, panard rod bushes, shocks, steering damper and checked for play in bearings, hubs, cv joints, uj's and there is no noticable play even put it through an mot to double check, it passed!
I have rotated the wheels, balanced them checked for uneven wear (slight wear on front inside edges) but shaking continues and feels worse.
Can anyone help i've run out of ideas as to what is causing it, i'm open to any ideas even it seems small. Thanks for help.

You didn't mention if you have location shims (rings) on the hubs. If fitting later wheels you need to use them to ensure wheels stay concentric to hub, and use the later wheel nuts too.

Hi thanks for reply, got the later wheel nuts with the wheels, dont no about the location shims only started reading up on them 20 mins ago, i'm down the workshop tmw i'll get it up in the air and have a look, is there any way to check they are adjusted right? if they're on it. (2000 model expect it will have them)

There's no adjustment necessary, they are just solid rings that slip around raised centre of hub to compensate for the different center bore size of the wheels. L322 and newer have a larger centre bore than P38 therefore there's room for them to slop about and end up slightly off centre.

I'm with you, yer the wheels have a 70.1mm centre bore the same as the P38 hub no need for the rings, wheels cant be genuine L322 then!?! Thought you ment the preload shims.

They must be aftermarket p38/disco2 wheels then. You seem to have covered almost everything else I can think of. Are you feeling the shaking through the steering wheel or whole car? Has it been there since you had car or is it new? Couple of other things worth checking might be not just condition of propshaft joints but balance of prop itself. It would have been pre-balanced with a weight, is there any sign of a clean space on shaft where it might have gone from? The other is the condition of the engine/gearbox mounts.

i had same problem just needed balancing

it's been there since i bought it, felt like it had lost a wheel weight and i found one on the drive where i bought it from so wasn't too worried, til i got the wheels balanced and the problem continued. Its odd some times it feels like its in the back and other times the steering wheel is shaking out of your hands. The wheels and tyres were brand new when i got it which made me think it's not them hence doing everything else. I'm now thinking he was chasing the same fault although everything was orignal when i replaced it. i'll check for weights tmw as well as mounts, I'll let you know what i find tmw, Thanks for your help

b16dod said:

i had same problem just needed balancing

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I had the balancing done at 3 diff place's makes no diiference, Would balancing show up an out of shape tyre? I have heard of tyres coming apart from the inside but no idea how to spot this.

If you're feeling it move front to rear etc. it could be weak engine/gearbox mounts allowing the whole drive train to move out of line.

lezbrucelee said:

I had the balancing done at 3 diff place's makes no diiference, Would balancing show up an out of shape tyre? I have heard of tyres coming apart from the inside but no idea how to spot this.

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If the tyres delaminated on the inside you might see a bulge in the tread you might not, only real way to tell is strip wheel off rim and look.

Thanks i'll try and see if there's any movement in it, better have about 20 weetabix in the morning!

kernowdragon said:

If the tyres delaminated on the inside you might see a bulge in the tread you might not, only real way to tell is strip wheel off rim and look.

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my mates got a mobile tyre bussiness might try and get him out of bed tmw then haha

I wonder if a seized viscous coupling would do that? I only mention it because of the wear on the inside edge of the tyres. Easy to check, jack one front wheel off the ground, you should just be able to turn it with a lot of effort. If you can't turn it at all, the VCU is seized and you will bust a diff eventually.

could be DMF as mine even sat still and reved will get a vibration

Evening, I had the car up in the air today and theres nothing wrong with the engine and box mounts. Didnt get time to do hubs and everything else, however when i drove it to pick up missus i now can hear a heavy clunk when turning left, which i felt through the steering wheel and shaking stopped. On the way back heard same clunk and shaking started. So doing 60ish hung my head out the window like a dog and looks as if the front drivers wheel was moving left to right or it's buckled. Could this be the steering rack? as dont think its track rod ends or ball joints.

Datatek said:

I wonder if a seized viscous coupling would do that? I only mention it because of the wear on the inside edge of the tyres. Easy to check, jack one front wheel off the ground, you should just be able to turn it with a lot of effort. If you can't turn it at all, the VCU is seized and you will bust a diff eventually.

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Hi thanks, i'm sure when i was doing the discs and pads i checked that as someone else suggested that too me too, i'm sure it was fine but i'll double check on monday to be sure

lezbrucelee said:

Hi and Thanks for reading.
I have a p38 2.5dt and it shakes like crazy from about 50mph, it's got 20 inch RR wheels on it.
I have already put new discs, pads, panard rod bushes, shocks, steering damper and checked for play in bearings, hubs, cv joints, uj's and there is no noticable play even put it through an mot to double check, it passed!
I have rotated the wheels, balanced them checked for uneven wear (slight wear on front inside edges) but shaking continues and feels worse.
Can anyone help i've run out of ideas as to what is causing it, i'm open to any ideas even it seems small. Thanks for help.

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hi my son is a MOT tester and i had this problem when he check it out the front left damper had a slight leek on it and it was this ide that was getting the problem so maybe get the damper / shocks checked again,
the other thing a had trouble with was the car would suddenly try to go from one side of road to other when it caught the tamac over lap in the middle of road or drag to the left of the road, could not find a fault for this untill i put new tyres on the to my surprise it had all dissapeared so i think some tyres once they get a little wear on the edge they have had it unless the make up of the tyre was crap !

i would be inclined to try another set of wheels first standard size.
also another thing to try is turn the wheel on full lock and jack it up and listen to the front cv joints as they could be damaged causing the vibration too

Thanks COOL CRUISER, i put new shocks put on it at the beginning of december and it wasn't that. I know what you mean about the car pulling across the road mine does it now and again i just assumed it was because it had fat tyres and was catching ruts in the road.

I'll try and borrow a set of wheels from some one next week and try it out.