| Author | Message | ||
     Larry Halpert Unregistered guest Posted From: 24.190.200.204 |
I've had my 27593 LHD '89 Silver Spur for about 1.5 years, and have been trying to figure out this evenly pitched hum that you can feel in your feet, but not the steering wheel. As a hopeful cure, the front wheel bearings were replaced but this didn't work. It occurs at about 35, then stops until about 45, and then stops until about 55, etc. Releasing the gas pedal, or accelerating doesn't affect it. Oddly enough, at one point turning to the right increased its occurance, and to the left didn't affect it, now it is reversed where turning to the right reduces it & left increases its occurance. Obviously driving me nuts, does this sound like any of the typical Spur problems? The car has just turned to 60,000 miles and all correct maintenence is up to snuff. If you like, you can email me as well to tbird@consultant.com Thanks, Larry | ||
| William H. Trovinger II Experienced User Username: bill_trovinger Post Number: 9 Registered: 8-2003 |
Larry; If the noise is more pronounced when turning one direction then the other it could indicate a bearing or a u-joint. I know you said the bearings where replaced but have you had the u-joints checked? I have not had a problem like this on my Shadow but have had very similar problems on my 4x4's. Once was a bearing and twice the tyres. Uneven wear of your tyres can either cause weird noises or vibrations but not always both and 4x4's eat up tyres unlike RR's may be it is because we (in the States) call them tires rather than tyres.  I would try moving your tyres front to back first to see if that effects the noise. If not I would have the tyres re-balanced. | ||
| Larry Halpert Unregistered guest Posted From: 24.190.200.204 |
Hi William- Thanks for your suggestions. I am also in the states, and in the service history of the car before I got it, the U-joints were done. Also, I thought a U-joint vibration was more of a fast rhythmical slight "shaking" type vibration, as opposed to this resonance hum. (Am I wrong?) Also, the tires are new, and the hum/resonance was there with the old tires. Larry | ||
| William H. Trovinger II Experienced User Username: bill_trovinger Post Number: 10 Registered: 8-2003 |
Larry; You may not be wrong. However, my belief (or what I have been told in the past) is that depending on the u-joint/s and in what way they are going can effect the type of noise/vibration created. The effect you are talking about I thought was related to the main drive shaft u-joints, wheel u-joints may have a different effect. Knock on wood this I have not had problems with on my Shadow, just on Jeeps. Well if the tires (sorry tyres) have been changed I guess that rules that out. I understand how you are feeling, vibrations can be as mysterious as electrical shorts and just as frustrating. Sorry I couldn't be of more help, hope some of the others can help you. Bill | ||
| Richard Treacy Prolific User Username: richard_treacy Post Number: 50 Registered: 4-2003 |
That could be your fuel pumps, a very common problem with these injected cars. Mine hum annoyingly at low petrol tank levels, and you can feel it through the floor. I will visit southern Germany shortly to speak to a mechanic who has cured this on a friend^s Mulsanne S, and I'll let you know. | ||
| Bill Coburn Prolific User Username: bill_coburn Post Number: 38 Registered: 4-2003 |
Got to have my fourpence worth. Another possiblity is the alignment of the engine and gearbox to the drive train. When removing engine brackets etc we are asked to scribe locations. Perhaps someone has not done so and popped the unit back where he thought it ought to be. This must be fairly critical since I note in the manual that variations in the front engine mount are adjusted by relatively miniscule shims. I have never seen any instructions or guide as to how to align the unit up in the subframe. One old Shadow I did fiddle with which had a bad vibration I moved the engine up and down until the relevant gaps in the front universal were even. Seemed to work. Lastly an afterthought check that there is no misalignment in the front subframe and take particular note of the frame mounts which are well known for coming loose! | ||
| Richard Treacy Prolific User Username: richard_treacy Post Number: 51 Registered: 4-2003 |
Caution is required with all the rack and pinion SSIIs and SZs other than the later Bentleys when raising or lowering the engine height. If the engine is too low at the rear it will foul the steering column and you will have no steering at all when accelerating hard with a RHD car. Worse, on a LHD car it can happen when slowing down, and you have to hit the gas and brakes at the same time. This happened two years ago when I lazily had a garage replace the engine mounts on my '87 RHD Turbo R. The problem was corrected on Bentleys from 1989 with a narrower lower steering column part number UR70827. I now have the revised lower steering column and steering rack on my car. |
