Whining may have more than one cause, so it’s important to try to understand where it’s coming from in the first place. It’s important to stress that whining that slowly asserts itself over a period of time is not generally a sign of imminent collapse. A sudden onset of noise might be a harbinger of doom – bit first check the oil level isn’t critically low due to a failed shaft oil seal or missing casing bolt.
Test-drive the vehicle while listening carefully to the types of noise produced and when they occur. A moaning, grinding or whining that’s present all the time might be down to worn gearbox bearings. Gnashing sounds tend to be caused by gear teeth that are worn or not meshing correctly – or perhaps by a bearing in the terminal stages of wear. Incorrect meshing can be caused by a collapsing bearing or a broken bell-washer (a sprung concave washer that keeps everything in place on a shaft). The gnashing may briefly abate when the throttle’s released, then resume as the drivetrain goes into overrun. This is sometimes accompanied by a tendency to stick in or jump out of gear.
Noises that come from the final drive may be due to worn or slack bearings, or from incorrect adjustment of its crownwheel and pinion. Grinding or rumbling noises might implicate rough bearings, whereas whining, howling or moaning when accelerating or decelerating point to poor adjustment.
A heavy vibration in the instant of transition between acceleration and deceleration is often caused by insufficiently preloaded pinion shaft taper-roller bearings. This can be cured by retightening the nut on the end of the shaft or adjusting the shimming of the bearings. A whine or gnash that’s only obvious when coasting in neutral or when dipping the clutch may be down to overtightened pinion bearings.
Clonking between acceleration and overrun points to too much backlash between the crownwheel and pinion, cured by adjusting the position of the crownwheel bearings. First, though, check for excessive play in propshaft or driveshaft joints and worn hub spines. Grinding noises that occur when accelerating hard with the steering on full lock may indicate wear of the sun and planet gears of the differential.
In 2013-14 did a V8 conversion on my 1980 MGB roadster. Rover v8 engine LT77s gearbox all the work I did myself until it came to the back axle which needed converting to a 3.07:1 from the standard C/W& P. I asked Moss to do the conversion. when fitted it was fine on "drive" but on overrun it whined loudly. Was returned for adjustment and when refitted it whined all the time.Returned again to have new gears fitted, on refit it was just the same. Moss offered to have another go but I had lost faith in their skills. Found a specialist company Salisbury Transmissions they changed everything again including bearings also having to machine the carrier to fit standard v8 gears. On fitting, noisy again. Returned and still the same. They offered to take the car and fit all new gears and bearings again. It was away for about 3 months. When I went to collect the car from Hounslow was told although not totally quiet it was better. I used the 210 miles drive home to run it in. I have to say below 40mph it was great but the faster it gets so does the noise. It is now on the fourth set of gears and bearings with no end in sight. I am really disappointed with British engineering that I cannot find anyone that will guarantee a quiet Diff. Having spent nearly £2000 so far on the axle, I don't know what to do! It the only thing I have not rebuilt myself, it would seem I could not have done any worse.
Differential unit on 1971 Triumph TR6 runs quietly enough, has sufficient and correct oil and is not close to the exhaust pipe. However the unit runs very hot, following even a short trip. The casing is almost too hot to touch with the hands and transmits this through the tub to the rear shelf carpet (and, of course, anything resting there). Could this be due to worn thrust washers or over tightened bearings?
I have a Bedford cf2 and have a whine on the gearbox. A engineer said put some additive in.What do you think?
I have a late model MGB GT that clonks on uptake of drive. There is a slight movement in the sliding spline of the propshaft but I am not sure if that is enough for the clonk. I am tempted to buy a new propshaft but it is a big outlay if that is not the cause. How can I be sure?