Engine/Gearbox Whine

Hello all,

I have developed a high pitch whine/grinding sound at speed under load. Definately sounds like metal rubbing metal. It sounds like it is coming from the gearbox or clutch area because it is loudest when I stick my head under the dash and you cannot hear it under the hood with the car stationary.

The sound is most audible at 3500 RPM and above and doesn't start until 3000. It starts when the accelerator is depressed and will stop and start, but it will always stop if the accelerator is released or eased up on. The car must be under load to get the noise to start.

The car has also begun to leak more oil than normal from the cotter pin in the bell housing but I'm having trouble determining if this is actually the leak point or not.

I did discover a leaky valve cover and have fixed that. That may have been the cause of most of the oil.

So far here is what I've done.

Changed engine oil (no sign of metal)
Changed gearbox oil (no sign of metal)
Checked plugs #1 and #2 are running a little rich but not bad
Checked compression, engine warm throttle wide open it is:

#1 135 psi
#2 130 psi
#3 130 psi
#4 135 psi

Adjusted valves (none were really out)
Replaced valve cover gasket
Oil pressure at speed is 70 - 80 lbs

I thought I might drive her for awhile and see if I've stopped the oil leak or not, but any ideas on what this sound might be? It is quite troubling and I've never heard a noise like this in all the years I've driven the car. It is definately not normal I just don't know where to look at this point.

Thanks,
Christopher

Water pump? Generator? Both are driven by the engine, of course. Have you checked/filled the rear axle oil?

Water pump was replaced last month and is OK. Generator was making a noise ealier this month it was taken apart and repaired and is OK now. No noise from either one.

I have not checked or filled the rear axle oil.

Thanks,
Christopher

Could be differential bearings. Happened to me when pulling under load and decel load.

OK the rear axle oil is OK. I put the top up and removed the battery cover and went for a drive last night for awhle. The noise is still there, but not as bad as it was before changing the gearbox oil. However when I got home there was still a steady drip coming from the cotter pin in the bell housing. No leaks on the engine that I can see. The drip from the bell housing stops after about 20 seconds.

No clutch noise or slipping.
Does this mean I can rule out the rear main?

Where would the oil be coming from?

Thanks,
Christopher

Transmission front seal

I was afraid I was going to hear something like that. Oh well, that will give me a good opportunity to see how the clutch is holding up.

Thanks,
Christopher

Still need to diagnose (pinpoint) the noise before you tear into it, i.e. make sure its in the transmission. Sounds like it probably is.

Gary,

I guess at this point I'm troubled about how to find the noise.

On the subject of the leak, is it possible to dye the oil with something to confirm it is in fact coming from the gearbox?

Thanks,
Christopher

Mine drips also not pulling it tho

You should be able to tell the difference between engine oil and transmission oil after a while of studying just be the difference in color, especially after changing the oil in one or the other. Probably the front transmission seal would be my guess also.

catch it

OK, I drove for a bit tonight and bought some UV dye from the auto parts store. The leak is definitely coming from the gearbox; the dye has proved that.

When I got home after a drive of about an hour I put a shot glass under the leak. It collected about 1/4 ounce.

So how much does the gearbox leak normally, or is it supposed to leak at all? I believe that a large part of what I saw earlier was a very leaky valve cover which is now fixed.

If 1/4 ounce is acceptable I'll just keep an eye on the level and deal with it this winter. I only ask because I really don't recall it leaking noticeably at all before now and I've had the 16 years now.

Thanks,
Christopher

I say drive it!! Check the level every so often.

Christopher,

I agree with Gary, you can probably keep driving until you are ready to pull the transmission and do a rebuild. Sounds like the layshaft and bearings are shot along with the seal. (Probable source of noise and leak.)

I also agree with Gil, mine leaks too-- but it's an old English car. The English knew that their climate was a wet so they provided a system on their cars that would automatically oil the underside to help prevent rust, corrosion and such. It has been marginally effective but a good effort. We just have to deal with the drips when we park.

A transmission rebuild is not that hard and will make a good winter project for you. Get a manual and go for it.

Good luck
Jim