Can You Name That Sound In One?

[sloopjohnrb]

A while ago the rear axle sump developed a leak and "Gladys" ran hot,for about 5 miles, although I discovered the fault pretty quickly.
I fixed the fault, and refilled the axle sump with a high-grade oil, the type that attaches to the parts rather than just flows on and off the parts. This was a recommendation I followed to compensate for the hot running axle.

Since the incident, there's a whining noise at speeds over 28 mph-but, this is the puzzling thing, the whine does not come from the rear axle, but seems to be coming from the front-the clutch/gearbox/transmission/prop shaft area.

I have changed the gearbox oil, topped up the front damper oil and made sure the regular greasing was done thoroughly.

I am really stumped on this one-I'd like to find what's causing the whine so as to evaluate the problem and hopefully remedy it.

Gladys is a 948 cc, March 1962 4 door.

[cadetchris]

their is the possibility that the lack of oil had knackered one of the bearings in the rear axle and the vibration has traveled up the prop shaft and is manifesting its self within the large cavernous expanses of the gearbox and bell housing.

[newagetraveller]

Your back axle should have Hypoid 90 oil in it. From your description it is not clear what sort of oil you are using but running it with engine oil it it will not do it any good.

[sloopjohnrb]

Hiya,
Yes it is Hypoid oil in the back axle.
Best wishes

[newagetraveller]

Then you may have damaged a bearing.

[sloopjohnrb]

Hiya, thanks for replying.
If it's a damaged bearing, would that explain the sound seeming to come from the front?
I suppose that a damaged bearing could be putting strain on the prop shaft and thus making the noise at the front end as the shaft "deals with" a damaged bearing?

[kittyfell]

I would think that the gears would be damaged with the low oil running, not so much the bearings. And yes, the noise can easily travel along the prop into the gearbox. But I would check the gearbox oil level in case it is running low.

[bmcecosse]

Just pick-up another diff. The 4.55 units fitted to 948 cars are cheap as chips. Although I would take the chance to upgrade to at least a 4.22.

[sloopjohnrb]

Hiya again,

Please may I check that a 4.22 "upgrade" would fit my current 4.55, 948 cc?
Where's the best place to look for either of the diffs?

TNhank you for your patience
best wishes

[kittyfell]

Yes, a 4.22 (or 3.9 or 3.7) will bolt straight in. You may have to fill the oil through the axle breather, and a different speedo will be required if you are bothered about deadly accuracy. Either ask on here or search ebay. there are at least two on ebay right now, but they both seem expensive to me.