Another new noise

Post by **johnm** » Tue Jul 11, 2006 9:36 pm

We drove Maggie from Goucestershire to Cambridge yesterday at a goodly lick. All OK except on the return journey she developed a fairly loud and fairly rythmic noise that appeared to be coming from the gearbox area.

It is there only between 50 and 60 mph, which is particularly irritating since that's open road speed.

There's a small hole in the exhaust tail pipe and I fancy that's new too, but the rythmic nature of the noise made me suspect gearbox or propshaft UJ journals. The gearbox is full of oil and rear axle is OK, any thoughts on diagnosis will be greatly appreciated

Post by **Dominic** » Tue Jul 11, 2006 10:04 pm

My first thoughts John are bearings beginning to fail, this can give a rhythmic "thrumming" noise. Might be worth checking the prop shaft to gearbox joint?

Post by **bmcecosse** » Tue Jul 11, 2006 11:08 pm

Cover the exhaust hole with a jubilee clip and see if the noise goes away!

Post by **johnm** » Mon Jul 17, 2006 1:21 pm

Exhaust replaced (see other thread) propshaft UJs greased and noise still there, but only between 50 and 60 mph. No apparent play in the journals, just the usual enormous backlash in the diff.

I guess I'll have to drop the propshaft and try the journals on the bench.

Post by **bmcecosse** » Mon Jul 17, 2006 1:27 pm

Not just wheel balance ?

Post by **Kevin** » Mon Jul 17, 2006 1:31 pm

propshaft UJs greased and noise still there

But are they in good condition.

Post by **johnm** » Mon Jul 17, 2006 1:31 pm

Hadn't considered wheel balance. There's little or no vibration through the steering wheel. I did check the wheel bearings and there's no play there either.

Post by **Dominic** » Mon Jul 17, 2006 6:22 pm

You say "enormous backlash".... there is minimal on my car... I'd check carefully that area, as that could be causing the problem.

Post by **Kevin** » Mon Jul 17, 2006 8:20 pm

You say "enormous backlash".... there is minimal on my car...

Dominic how much movement do you have as I asked this question recently and nobody came up with a rotational minimum and it sounds as though yours is minimal.

Post by **Dominic** » Mon Jul 17, 2006 9:04 pm

Hi Kevin
Without checking, I'd guess from memory it's about 1/4" max rotational movement, possibly less. I'll be working under the car again in a week or so, will try and get an accurate measurement for you. I remember checking a few months ago after reading some other topic on here concerning the damage a badly worn shaft can do! I was pleasantly surprised mine seemed as "tight" as it was.

Post by **MikeNash** » Mon Jul 17, 2006 9:54 pm

Just thought but consider rear wheel balance. It often gets forgotten for ages and naturally doesn't show up on the steering wheel! But it gives a cycle of thrum that comes and goes. As the rear wheels are always very slightly different diameters the out of balnce on them goes in and out of phase giving a slow rythmic thrum around 60 mph (at least on mine).
Regards, MikeN.