Vvvvvvibration

[Sheepdip]

Sorry to hog this forum chaps but I'm off on a verly long jaunt soon and my trusty Stags have never let me down so don't want it to this time.

Having just opened up my completely rebuilt engine a little I'm getting a strong vibration at 3K+ in O/D top. It doesn't seem to appear in other gears so I reckon its speed related possibly prop balance. I did replace Uj's when converting to manual, but didn't rebalance. I read somewhere this should be done - whats the opinion?

From my distant youth I recall a trick of fitting a jubilee clip and moving around - anyone tried this?

Any other opinions welcomed.

Paul

[stagstr]

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Hi Paul,

Youconclude thatthe vibration might be speed related, so I assume you have driven at 3k revs in all other gears and the vibration is not there. If you have, then that is a reasonable assumption - proving that it is not the engine.

But to prove it is speed related, and aft of the O/D (as the propshaft is),you must drive at the speed which equates to 3k in O/D top (circa 72mph?) in other gears and prove the vibration is still there - thoughthismight not be the best thing on an engine that is not run in - your decision.

I haven't followed your other posts so I don't know if you did the manual conversion, the UJs and the engine rebuild all at the same time. If you did the engine separately, and last, did the car run OK beforehand? If so, you may only need to turn the propshaft to its original position - maximum of 3 possibilities, assuming you didn't undo the diff end.

A handy tip when undoing any UJ flange, whether it's on the prop or half shaft, is to mark the flanges so thatyou can put themback together in exactly the same place. I know that might be locking the stable door after the horse has bolted for you Paul, sorry.

The jubilee clip is a tale I've also heard but never tried. Keep us posted with how you go on.

Ray

[Sheepdip]

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Hi Ray, thanks for the help and info.



Unfortunately its resolved itself - the gearboc broke, pin selecting reverse gear idler came out of its slot on idler, lots of slack on pivot thread for some reason. Unfortunately have to strip mainshaft to get the pivot out....anyone else ever had this? I doubt this was the reason for vibration tho.

I must have beaten all records in removing box/clutch/backplate etc and reinserting my trusty BW65. My faith in the stag has reached the depths of despair after spending months on this box conversion, if it holds out for 2k touring France over the next couple weeks I'll be happier!!!

[Crocodile Gunn D]

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I had the exact same problem for all the time I've had my car, except it showed nearer to 4k rpm. Didn't say anything at the time cos I hadn't anything to contribute then.

After returning from my trip to Italy, gave the car it's head down the A30 and ignored the vibration. A couple of days later noticed oil leaks from overdrive and diff. Suspected the prop out of balance and that it had stretched the seals. Took car to my trusty garage man and told him the story. He suspected prop balance too, said there are 2 arrows on prop components for alignment, don't ask me, I don't know. Anyway, he replaced seals and nose bearing, then found arrows not lined up. Marked prop (just in case), then realigned arrows.
Just back from trip to England, (local joke), run engine up to over 4k, problem solved. Car has never felt so good.

[Sheepdip]

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Many thanks Zardox - I've never looked at prop that closely to notice arrows, but do ensure the yokes are aligned. I reckon I'll get the whole prop checked out as you say looks like this could be the culprit.

Cheers

Sheepdip