Lagondaforum

Subject: Vibration due to the fit of spyder to the spline on the gearbox input shaft

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I have problems on my V12 with vibrations in the drive train. Starting at about 2500 rpm. It comes definitely from the drive between cardan shaft an gearbox. All part from the engine to the rear flex coupling are new. The cardan shaft is balanced. The problem boils down to the fitting of the spider to the spline on the drive shaft into the gearbox. I am investigating to have a new spyder and shaft manufactured. If someone is interested please let me know. e.mail: fabricius@fabricius.de

Subject: Re: Vibration due to the fit of spyder to the spline on the gearbox input shaft

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Hi Eckhard,
We've met a number of times at the AGM, I also have V12 drophead, which you probably haven't seen as it's been off the road since 1982 ... my engine rebuild is finally happening now, by Mel Cranmer.
The problem you refer to is I understand fairly common with V12s. My understanding is that this vibration is nearly always caused by incorrect alignment of the engine & gearbox. There was an article I believe by Michael Valentine on this subject many years ago in the club magazine. I strongly suspect this will be the case with yours in view of the amount of work you've done. You will find washers (or should!) between the engine bearer arms and mountings, likewise shims under the gearbox mountings. Hope this helps!
Laurence