steering shudder

[shewer]

I have a 2005WH GC 3 liter CRD. It has developed a shudder in the front end when cold and the steering wheel is turned either way. As the vehicle warms up the noise tends to disappear and is far less noticeable when driving in a straight line.
I have had 2 people diagnose as:
1. a problen with the power steering which will need to be replaced;
2. a problem with the transfer case due to the fact I have run 2 new tyres on the rear of the vehicle while 'using up' the life of 2 older tyres on the front of the vehicle. The suspension expert says this is a 'no no' as the wheels/tyres are a different diameter and will destroy the transfer case! And suggested the tyre people should have advised of this when fitting.

Anyone got any ideas???

Steve

[bodgie]

Have you checked the basics such as the serpentine belt for slippage when the engine is cold?

You could try turning of the A/C when the car is cold to see if this makes a difference.

[timbotrog]

Quote, "2. a problem with the transfer case due to the fact I have run 2 new tyres on the rear of the vehicle while 'using up' the life of 2 older tyres on the front of the vehicle. The suspension expert says this is a 'no no' as the wheels/tyres are a different diameter and will destroy the transfer case! And suggested the tyre people should have advised of this when fitting."

WJ/G & WH & WK all run Quadratrac II, Quadradrive or Quadradrive II. When driving around town, they are in 4HI.

Quadratrac II sends power to the rear wheels until it detects the front and rear wheels turning at different speeds. It then transfers power in a 50/50 split to the front and rear.

Quadradrive or Quadradrive II do the same except they can also send power to the non spinning wheel side to side, almost akin to diff locks.

The problem you are going to encounter running wheels/tyres with a differing diameter is the transfer case will start acting erratically as it detects the front and rear spinning at differering rates. It can also cause the axles to have a dummy spit if they are different diameters side to side.

With the Wranglers, Cherokee's and ZJ/G Grand Cherokee they have 2HI, 4HI, 4LO etc and do not have to worry about the tyres being the same diameter front to back as they have to manually select when to engage 4WD, with the above mentioned models it is permanently in 4WD.

With these models it is advisable to rotate all 5 tyres to keep them as close to the same diameter as possible.

I rotate mine every 5000km, (it's getting done tomorrow by coincidence).

It's your car, but I pesonally would get the tyres matched all round including the spare.

[Clarky]

Turn the traction control off and see if the problem is still there. The shudder could be the traction control adapting to what it see's as wheel slip.
When was the last time you engaged low range. I would go to a dirt road and try low range and see if you have the same issue.
Buy 2 more tyres so they match.

[vk2jdh]

Originally Posted by shewer

I have a 2005WH GC 3 liter CRD. It has developed a shudder in the front end when cold and the steering wheel is turned either way. Steve

Check the oil level in the front diff. When was it last changed? I would say you have QDII, being 05 CRD, did if have friction modified put in?

[bodgie]

ANother thing I forgot last night was does the shudder exist when the vehicle is stationary or when mobile?

If if happens when stationary to my way of thinking you should be able to discount transfer case or diff issues etc.

jason

[pmac]

With reference to Timbotrogs comments, the WH (WK in the US) and WG (WJ) actually run different TC's . The WH runs the NV245, which is an electronic set up, whilst the WJ runs the NV247, which is an hydraulic set up.

In theory the same result, although the WH is quicker to respond. Having owned both, the difference is significant.

I agree totally that you should be running the same size tyres all round on a Full Time 4WD.

I know you can run a WJ without a front drive shaft and have no problems, as the clutch pack just locks in place, thinking the front wheels are spinning at a different speed. Not sure about this with a WH though.