I've been out driving my 74 144 for the last two days. It has a noticeable whine from somewhere in the drivetrain. What I can tell is that it's louder on flat road than shallow downhills and it disappears if I press the clutch pedal. I would like to say it's coming from the rear differential, but am not 100% positive. It definitely sounds like it's coming from the rear of the car, so I would rate the transmission itself as unlikely, but not impossible. Shifting in and out of gear also is relatively effortless. Should add that there is no vibration associated with this whine. Any ideas? Would it make sense to check diff oil level and refill if needed? If this is found to be the culprit, are there any snake oil products out there that can be added to the oil to quiet it down? I do not know the age or condition of the rear wheel bearings and I guess that could be another source.

Thanks,

Kåre

you will need transmition oil any kind or if it is the bearings which is highly unlikly just a bit of molly grease

If it's the rear diff... You could put a lot more soundproofing under the reas seat and carpet.
--
MPergiel, Elmhurst, IL '74 145e T-5 'Orange Alert'

Sounds like typical diff noise. It typically sounds the worst at the speed that the car was driven at the most.

...I switched to wider wheels and tires. Beats me.

I had gone through everything, including the front wheel bearings, where the noise seemed to originate. Replaced carries, rear wheel bearings. Finally suspected the differential, and decided to live with it.

Then I swapped out 165-15s on 5 inch rims for 195-65-15s on 6 inch rims and the noise is gone. Blimey.

What I think happenned: that right front inner bearing is loaded differently now, due to different offset or alignment stresses.
--
MPergiel, Elmhurst, IL '74 145e T-5 'Orange Alert'

A bit far fetched here, but do you happen to have Goodyears on your car? They tend to howl and whine as they wear out, the more they wear the noisier they get. On the 99 Mustang GT that I had, it came with 4 Goodyears Gatorbacks, and as they wore out, they produced a whine so loud that I was sure I'd be picking up pieces of my rear axle if I'd do a burnout. The sound vanished when I replaced all 4 tires. Had the same problem on my present Mitsubishi.
--
...and the bricks keep on rolling

Agreed... I've had Michelin's on a 760 and Pirelli's on an 850 do the same thing. Both were very quiet when new, then noisier as the tread wore down.

But the noise was not sensitive to load, as described above by Kare. I would think that would more likely indicate gear noise, with the ring and pinion at the top of the list.

Gary L
--
1971 142E ITB racer, 1973 1800ES, 2002 S60 T5

Good to see the thread picked up some steam...
About tires, it's true I didn't notice any whine with the old tires, but then again I have also changed all door gaskets which made a big difference.
I forgot the brand of the old tires. The fronts were good, the rears pretty worn and they were on 240 rims. There are brand new tires on the car now, Kumho 165/80 758 Star something on 15" 140 rims. As pointed out above if it were tires I don't see why the sound should depend on drivetrain load.
I did open the diff drain plug three nights ago and the reservoir was as full as can be. The oil was pretty black, but at least plentiful. My daily driver is currently borrowing the Rhino ramps, so it'll be a few days until I can check the transmission. As mentioned in the first message, no vibration associated with this whine. I did change one front wheel bearing a year ago, but the sound really sounds like it's coming from the rear.
Don't be shy to throw out wild ideas, cause I'd really like to try and nail this down.

Kåre

Maybe a rattly (rattley?) throwout bearing? That would be fun and easy to replace. ;)
--
MPergiel, Elmhurst, IL '74 145e T-5 'Orange Alert'

I have the EXACT same tires in my 74 144 with stock rims, and NO, they do not whine as they wear out. Mine are about 50% wore out, and they are still quiet. I guess the driveline components remain the prime suspect in this case.
--
...and the bricks keep on rolling

It was definitely not a tire whine that I heard. I had noticed that on occasion, when I was severely off camber (tilted to the right, pushing to the right) the the definite gear whine abated, very distinctly cutting out.

It was bearing load. I beleive it is due to different offset of the wheels.

There is tire whine now, with these fancy Michelin Artics.

--
MPergiel, Elmhurst, IL '74 145e T-5 'Orange Alert'

Well, I checked the oil level in the transmission. I topped off 3-4 ounces I'd guess. Man, the stuff that came out looked pretty gross. I have to change out all the gear oil. I took the car for a drive and it did not affect the whine. I noticed this time it always comes on at 45 mph and disappears when I go back below 45. The other thing I noticed is the big rubber driveshaft bearing support, about half way between transmission and differential, was starting to break up. So I'll definitely change that one as the next step. I did a search on the brickboard and it seems the u-joints and pinion bearing are other possible culprits. Is there a way to check if the u-joint is bad while the car is jacked up?

Kåre

I'd first check the diff and tranny oil and fill if low, especially if
there are signs of leakage. The driveline support bearing is less likely
but possible, also wheel bearings.
--
George Downs Bartlesville, Heart of the USA!