Propshaft balancing near Oxford / Newbury

There's a company in Chiseldon, just off junction 15 of the M4. Not used them myself but they've been recommended to me by several sattisfed customers. Of course now I say this I'm buggered I can find the contact details....... Cheers, Bill.

I've just come back from hols so don't remember the start of this thread, but how did the vibration start? I wouldn't have thought a prop would go out of balance on its own, unless a weight fell off. If it started after the prop had been removed, try replacing it at 90 degrees to its current position.

It's not that hard to balance a prop at home using a pair of jubilee clips - just time consuming. I'll try to remember how I did mine if you want to give it a try.

If Paynes of Eynsham are still on the go, I'd use them. When I lived in Oxford (till 13 years ago) they had by far the best reputation of anywhere in the area for all machining work. Cheap, friendly and helpful. And they'd rent me an engine crane for a fiver a day.

Ian

you didn't miss the start of the thread, I just started it with a non-sequitur. relatively brief summary of how I ended up with a vibrating car:

Main bearings went on the M40 a year and a half ago. I was moving house at the time, and there was no way I could rebuild my first engine & move at the same time, so I had a professional do the job. when I got the car back some months later, I noticed a really bad vibration at about 55mph. called the builder & he asked me wtf I was doing running the car that fast already (3 speed auto box, so that's probably getting on for 3000rpm). time passed, I completed the run-in (during which time the fuel-pump eccentric on the cam droped off & the car was returned to the professional to do the bolt up this time... "let's hope I remembered to torque up the mains properly - haha!"). I replaced the wheels & tyres on the back as they were shagged anyway. no change definitely road speed related (not rpm), not the front wheels (steering wheel feels fine) rear shocks & springs only a couple of years old. front springs relaced recently. rear bushings all checked and look fine, no play. front uj felt a bit sloppy, replaced both front & rear uj's & the rear seal on the transmission. pretty sure the vibration was a lot better when I took it for a test drive. could be i didn't stick at around 55mph long enough to get the vibration / resonance going ( i was accelerating pretty briskly). took the car to work a couple of times, and on these longer journeys with more variation in speed I can definitely still feel the vibration... i think it is a little better than before the UJ replacement, but its definitely still there.

there's a ding on the propshaft, which I guess could be causing the problem. figure if I get the propshaft balanced I can rule the whole thing out.

Paynes are great, but they don't do propshaft balancing themselfs (anymore?). IIRC they said they send them away to have them done...

If you have a set of strong, high axle stands, I'd recommend doing it yourself with the aforementioned jubilee clips. It's been a year or so, but from memory, this is what you do: Support the back of the car as high as safely possible with the rear wheels removed. Make sure the prop and wheel hubs turn freely.

Fit a jubilee clip onto the propshaft. Run the car in gear (4th?). It'll vibrate like hell.

Move the jubilee clip around a few degrees each way and keep testing until you find the position where the vibration is minimised. Mark this position clearly with a marker pen.

Now fit the second (identical) jubilee clip at 90 degrees to your mark and move the first one 90 degrees the other way, so that they are opposite each other. Vibration should now be as it was before you started.

Move both jubilee clips increments of the same small distance towards your mark and keep testing until the vibration goes away.

Job done.

Simon,

It is possible that this "professional" did not replace the prop shaft the way it was taken off. You could try it in the other positions - rotate the mating flanges to each position in turn and try it to see if the vibration is better or worse. You might find that in one position the vibration goes away.

The good news is that if you succeed, you only have to mark the flanges and you will always know how to replace the shaft if you ever take it off again. The bad news is that in the worst case, no position is ideal, and finding this out could take longer than the Jubilee clip method Willy suggested.

If you do use Jubilee clips, make sure that in the normal direction of rotation, the loose end of each clip is trailing, not leading. Otherwise, sooner or later a leading end will hook a plastic bag lying in the road and wrap it around the prop shaft!

Jim