wobble at 65mph in p38!

Has anyone experienced a similar problem? I have a 1996 P38 4.6HSE. It is nice and smoth to drive and changes gear well with no problems. When I increase speed to about 65 I get a gentle wobble in the front seats. It then fades away as I increase speed to over 70-75. There is no steering wobble and the car itself doesn't wobble as such. It is noticeable in the seats as it seems to make the internal organs shake vigorously with no apparent movement on the outside of the body!! No noises accompany this wobble.

There are no noises present except at about 50mph it sounds like there is an exhaust brake being applied. No wobbles or movements, just noise. This disappears at about 55. They may be connected but am unsure.

Any help would be appreciated.

Sounds like it could be wheels.

P38s can be a bit fussy with wheels and tyres. What size have you got fitted? If they're 18 inch rims from a disco or a later rangey you might need spiggot rings to locate them properly on the hubs.

Have a search on here for spiggott rings.

Not sure about your noise though.

Guy

Any wobble thro` steering wheel?
If not could it be some transmission vibration? Maybe UJ on prop-shaft on way out? Is harmonic damper intact on axle?
If wobble thro` steering then as Guy says could badly fitted wheels/out of balance wheels/ distorted tyres/ U/S steering damper/ U/S bushes/ETC.

gtland said:

Any wobble thro` steering wheel?
If not could it be some transmission vibration? Maybe UJ on prop-shaft on way out? Is harmonic damper intact on axle?
If wobble thro` steering then as Guy says could badly fitted wheels/out of balance wheels/ distorted tyres/ U/S steering damper/ U/S bushes/ETC.

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Definitely no wobble through steering - just the seats!!

kooky_guy said:

Sounds like it could be wheels.

P38s can be a bit fussy with wheels and tyres. What size have you got fitted? If they're 18 inch rims from a disco or a later rangey you might need spiggot rings to locate them properly on the hubs.

Have a search on here for spiggott rings.

Not sure about your noise though.

Guy

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They are the standard fit wheels for this model - I think they are 16"? Can't remember and I'm not home til next week!

Not sure if it`s your problem but I`d put on overalls and have a crawl underneath. Grab hold of prop-shafts and see if both attached ok. With car chocked on level ground & handbrake off, twist props and look for play in UJs. Dunno if it is that, but think possible, and it`s an easy free check.

Hmm. 65mph is about the right speed for spiggot rings but if they are original wheels then that probably isn't it. You don't always get vibration throught the steering with this.

I'd check your propshaft ujs as gtland suggested. Mine vibrated quite badly when the front prop joints went but mostly when accelerating.

Land Rovers in general seem to have an harmonic response around 55-65 mph. Usually wheel balance. If there is no steering shake try having the rear wheels rebalanced.

kooky_guy said:

Hmm. 65mph is about the right speed for spiggot rings but if they are original wheels then that probably isn't it. You don't always get vibration throught the steering with this.

I'd check your propshaft ujs as gtland suggested. Mine vibrated quite badly when the front prop joints went but mostly when accelerating.

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I will have a check of UJs later in the week. As for the spiggot rings, what are they, Where do I source them, what do they do and what sort of price are they?

http://cgi.ebay.co.uk/SPIGOT-RINGS-location-RANGE-ROVER-P38-alloy-wheels-/3

?cmd=ViewItem&pt=LH_DefaultDomain_3&hash=item45e966b7e1 HERE U R DINO

SORRY SPARKYSTU.:frusty::frusty::multiply:

Sparkystu said:

I will have a check of UJs later in the week. As for the spiggot rings, what are they, Where do I source them, what do they do and what sort of price are they?

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You don't need spigot rings unless you fit later wheels to your vehicle. If it has 16 in wheels they are not required.

Had bad seat vibration in mine. Wheel balance, it must be spot on. Get mine checked every 6 months. As wammers says, won't be spigot rings on original 16" wheels. Mine did not like the Pirelli Scorpion STR's either, but balance is most likely, whatever tyres are on.

Had this on mine at 55mph and happened when I picked it up on my first drive in the car
You will find it will go with a full set of new tyres inflated at the right pressure.
If one is slightly smaller or out of shape it will cause some sort of vibration around the car at a specific speed. Try swapping around front to back . remember to change the pressures.


. I hated the Scorpions as they wore quickly . Put on continental more road bias and been great. Saying that I still have wear on the outside edge of the nearside front

Did you sort out this seat wobble problem sparkstu?
My 2000 DHSE is doing exactly the same and Ive replaced the uj's on both props but its still there. Its on 16 inch rims with BFG all terrains.

Rangie427 said:

Did you sort out this seat wobble problem sparkstu?
My 2000 DHSE is doing exactly the same and Ive replaced the uj's on both props but its still there. Its on 16 inch rims with BFG all terrains.

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Wheel balance, a duff tyre or the steering damper. Try swapping the wheels front to back and see if it changes the problem.

datatek said:

wheel balance, a duff tyre or the steering damper. Try swaopping the wheels fron to back and see if it changes the problem.

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+1

Thanks guys, your were right!
Changed whole set of wheels and tyres this afternoon and seat wobble gone at last
Although the tyres all have good tread depth I have noticed that the rubber has started to perish in between the tread, so looks like a new set of all terrain tyres is on the list.

usually wheel balance, but mine had an intermittant wobble and shake, Figured out that when suspension dropped on motorway mode it was leaking and trying to refill, strange experience lol