Thread: Rubbery Vibration at 100 Kph

Originally Posted by DiscoKym

Like I said "I got the transfer case overhauled & an ashcroft ATB fitted at the same time."

We used the Ashcroft Master rebuild kit and shim set so all bearings, seals and put in a sleeved casing bush.

Mechanic who did the work has rebuilt many LT230's over the years.

Vibration only after transfer overhaul. NOT at tail shaft frequency. More a slower shuddering like harmonic.

Wheels balanced & checked every 10,000 km. Both prop shafts new.

Didn't do it before transfer case rebuild so F&R diffs are in the clear, front output bearing was a little loose hense new bearings.

This is unlikely however if the wheel speeds we're different front to rear by a margin, the centre atb would be seeing different speeds between the front and rear propshafts. I'm no expert on those atb's however I imagine that if it were the case, the atb would try and lock up leading to a possible binding in the drive train, a possible source of vibration. This scenario would be dependent on the wheels front and back being quite disimilar in diameter. I imagine that if you have been rotating your tyres this wouldn't happen. It would explain how the vibration does not occur when the front driveshaft is out and the centre diff is locked.

Do you access to a different set of tyres?

Yes 4 tyres on at the start are same Make, Size & Wear.

The 2 tyres of my 6 that I rotated to the rear are same Make, Size BUT 10,000 km newer or 1mm more tread depth so not much difference. I did notice with tyre change speed of vibration seemed to lower a few KPH.

Originally Posted by DiscoKym

Yes 4 tyres on at the start are same Make, Size & Wear.

The 2 tyres of my 6 that I rotated to the rear are same Make, Size BUT 10,000 km newer or 1mm more tread depth so not much difference. I did notice with tyre change speed of vibration seemed to lower a few KPH.

I would try that first, find a set of tyres and wheels that are known to be good. Put them on and see if the problem persists. Its a long shot but i haven't seen any other possibility come from this thread that fits the bill.