Proud P38 Owner

Hi Everyone,

I'm a proud owner of a new (to me) 1999 P38 4.6HSE.

The car has masses of history and in the last 2 years has had:

New Recon Engine
New Airbags, compressor and Valve block
New cooling system
new Gearbox Oil Cooler and Pipes
New Fusebox
Steering work including bushes

She drives beautifully on both LPG and Petrol, with no obvious issues i've picked up so far. I have got a couple of niggles which i would appreciate some advice on.

Steering wise there have been new poly bushes fitted. I've noticed when doing a 3 point turn, there is an obvious clunk on full lock as you start of stop moving. Driving normally there is no clunking or noise. Any ideas what this could be and should i be concerned? If its major i'll get is fixed ASAP, otherwise i might hold out a bit as i've just spent out on the car.

The only other bits are a squeeky break pedal, nothing major but a little annoying.

I've also noticed that the air suspension "settles" when parked, not quite into access mode but does drop a but below normal when stopped. Once started it rises straight back up and sits level. I've not owned one before, so wondered if this was correct.

Thanks in advance.

Steve

Not sure what the exact dimension is, but acceptable drop is either 5 or 10mm in 24 hours...anymore and the bags are getting old and worn!

:nopics:

its difficult to describe but it feels like its settling "under control" when you turn the ignition off as the 4 corners seem to adjust and level off slightly. I've noticed a couple of times when starting up the ride hide indicator flashes in normal mode and is lit in access mode for a few secs (but i havent put it in access mode, and it doesn't look low like its in access mode). The airbags were brand new and replaced 12 months ago (roughly 10k miles) along with the compressor and valve block.

[url=http://postimg.org/image/quu9c9oxn/][img]http://s1.postimg.org/quu9c9oxn/image1.jpg[/img][/url]

Tasty looking motor, well done!

The car wil level itself to its lowest corner when you turn off the ignition, step out and close the doors...this is normal.

The system then will relevel itself to the lowest corner every 6 hours or so while switched off.

It will also carryout a relevel each time the doors are opened and closed and while driving, when you come to a stop at traffic lights it will also relevel to equalise the pressure across the front axle after a nose down moment!

WHat the acces lamp lit and Standard flashing means is the car has settled to a point it considers to be between access and standard, so it decides that it is in access (hence the solid light) but the commanded position is Standard (which is why it is flashing)...once you close the doors and the engine is running etc, she will then hop up to standard.

This could mean your airbags are getting tired and leaking a bit.

Mine will drop an inch or so over night which is vastly excessive and my air bags do nee replacement.

You say it has had new air bags, have you physically checked them, if they are new looking, time to get the soapy water out on the valve block where the air pipes go to make sure they are seated correctly.

Perfect thanks I'll check it out! Any thought on the clonk anyone?

Check your prop shafts bolts are tight, play in u/j's, V/c in transfer box, worn c/v joint or loose wheel or drive shaft nut's for starters. Do the easiest first.

Is the noise a single clunk when you change direction and have the wheels turned? If it is it could be related to this technical service bulletin I found a while ago.

My car also does that clunk and I find the easiest way to reproduce it is to go from one direction to the other with the wheels turned. I.e. reverse with the wheels turned - it should clunk, then drive forward again with the wheels still turned and it should do it again.

I haven't got round to trying it yet but other people on different forums report it works.

Suspension sounds normal to me, it also re-levels every 6 hours when parked.
Check the VCU isn't seized.

+1 on the suspension being normal. The self levelling really can have a mind of it's own. If our P38 is reversed on to the drive (which I do) it will sit at that height without moving. It even does this when it's left in that position for over a week. This proves the system is air tight. However when it is driven on to the drive (as the wife does) it starts to self level almost immediately. It has done this 100% of the time in the 3 years we have owned it.

Thanks guys! Sorry to sound think what's the vcu?

stevej69 said:

Thanks guys! Sorry to sound think what's the vcu?

Click to expand...

Viscous Coupling Unit

In the transfer box is the VCU, this is the centre differential and allows the front and rear axles to turn at different speeds when cornering, else the drive system will tear itself apart.

It works automatically....in the VCU are two rotors, one connected to each propshaft...as the propshafts urn they spin te fluid inside at the same speed, but when it allows a certain amount of speed difference between the two when cornering.

Now lets say you are off road, and the front axle starts to wheel spin...it is now turning much faster than the rear...so the front prop rotor starts churning up the fluid in the VCU, this in turn starts to turn the rotor attached to the rear propshaft and essential locks the front and rear props together for maximum traction.

Sometimes the VCU can lock up which means the front and rear props turn together at the same speed all the time, this can wreck diffs and drive shafts....

Easy check.

Hand brake off, GB in Neutral, jack up ONE wheel....
Put a long bar on one of the wheel nuts of the jacked wheel and begin to turn it.....it should be stiff but not solid, it can take an effort to turn depending on your stature.

Solid means the VCU is locked and requires replacement....but if you can turn it (albeit stiff and slow) your VCU should be fine!

Thanks so much for the explanation I'll check that! If it needs replacement is it mega money? What are the implications of not?

stevej69 said:

Thanks so much for the explanation I'll check that! If it needs replacement is it mega money? What are the implications of not?

Click to expand...

Ashcroft list at £295

Ashcroft Transmissions

If yours is duff, get it changed else risk damaging a lot more money than £295 as it will destroy diffs, UJ's and potential the transfer box and gear box....

Cool thanks! It does sound exactly like the noise jacckk described although tyres bulletin seems to suggest the issue is at the rear.

As I said check the easier options first, don't want to be shelling out to find a worn u/j or loose prop shaft to be the cause of your problem

Leave the handbrake on and jack one front wheel, box does need to be in neutral. You should be able to turn the wheel very slowly with a great deal of sustained effort.
The VCU is on the front of the transfer box behind the plate where the prop connects to the drive shaft, easy enough to replace. It's not in the centre diff which is inside the transfer box.