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Re: SP vibration

Posted: Fri Oct 14, 2016 10:18 pm
by pbrally
Thanks everyone . It is now Saturday here so I will pass the info on to my guy for attention next week. We tried undoing the mounts but the vibration was still there. I will report back when hopefully the little Vibrating Dart Down Under is smooth again. In the meantime any other advice much accepted.
Cheers Pete B

Re: SP vibration

Posted: Sat Oct 15, 2016 9:31 am
by Sydsmith
Have we missed the point here in that the vibration is there when the car is stationery or have I read the post wrongly?

Re: SP vibration

Posted: Sat Oct 15, 2016 10:22 am
by Dobbinridesagain
As it's occurring when stationary and only the mounts were changed (?only?) it has to be either the mounts or the new position of the box or the stick.
Is it an actual vibration, or just a vibrating noise?
If the latter, is the exhaust now zonking against the underside or the box against the tunnel?

With the car running on a ramp, listen underneath and look with a bright light.

Ivor

Re: SP vibration

Posted: Sat Oct 15, 2016 10:17 pm
by pbrally
It happens when stationary and same when driving. It is a vibration/harmonic.

Re: SP vibration

Posted: Sun Oct 16, 2016 5:17 pm
by Fossil
My personal experience, from over 40 years of SP ownership, of SP engine related vibration when at a standstill involves two issues, one being worse news than t'other:

Bad news first - a fine seat of the pants felt vibration between 2 and 3000 revs being the one and only warning symptom of seriously worn main and big end bearings caused by unmatched con rods. Oil pressure was normal perhaps because there was a 1/4 inch spacer under the oil pressure relief valve spring.

Good news - a similar vibration similarly the one and only symptom of a worn water pump bearing, long long ago.

Good luck in your quest for the cause.

Cheers

Geoff

Re: SP vibration

Posted: Sun Oct 16, 2016 8:31 pm
by pbrally
Thanks Geoff, I will had that to the list. Peter

Re: SP vibration

Posted: Mon Oct 17, 2016 11:10 am
by Sydsmith
Ignition problem? Plugs-points causing the engine to run lumpy and vibrate?

Re: SP vibration

Posted: Mon Oct 17, 2016 12:32 pm
by Dragon
Following up on Syd's suggestion, as the vibration occurs when stationary, is that when the engine is idling, or when the revs are faster? Is the vibration only felt at a particular engine speed, whether the car is moving or stationary?
I'm thinking of wear in the pivots in the advance weights in the distributor, following experience in the 1980s. The wear was so bad that no advance took place below 2,500rpm and then it came in, with some vibration, and then the car took off!

Re: SP vibration

Posted: Mon Oct 17, 2016 4:24 pm
by A.N.Other
Am I right in thinking that when the engine runs that unless the clutch is depressed then the input shaft in the gear box is still turning inside the gearbox.
Therefore do you get the vibration with the clutch pressed as well as with the clutch not pressed.

Re: SP vibration

Posted: Mon Oct 17, 2016 8:37 pm
by pbrally
Hi All, Apart from the fact the the drive shaft was off center because of the broken gearbox mount causing the shaft to just be hitting the tunnel when rotating , apart from that the car was running fine and not vibrating when delivered to the mechanic. Both the mounts were replaced with correct ones from Manners and the uni joints replaced on drive shaft. The gear box was not removed just supported to replace mounts. The vibration/harmonic then started when the car was first tested. It occurs when both stationary and driving . Very noticeable at idle at 1300 rpm increasing as revs increase. When stationary with clutch in or out it is always there. Cheers Pete B