s type 2.7d vibration issues

[frenchdave]

My car has a tow bar, and has been used for towing heavy trailers. It has developed viration when accelerating, and also on braking. I have chnaged various suspension parts to no avail. Any ideas on what to check on a car that has towed.

The rear end looks a little low.

Could it be engine mounts? If so how to check?

gearbox mounts?

strut top bearing?

prop shaft?

I love the car, but it is driving me mad trying to locate the problem

 

[JOE-DOT-COM]

hi

its not wheels is it, you not hit a pot hole recently, or any other wheels damage

cant think of anything else that would vibrate under power and braking

might be worth swapping fron and rear wheels see if it helps

cheers

Joe

[frenchdave]

2 hours ago, JOE-DOT-COM said:

hi

its not wheels is it, you not hit a pot hole recently, or any other wheels damage

cant think of anything else that would vibrate under power and braking

might be worth swapping fron and rear wheels see if it helps

cheers

Joe

It feels more like the engine mounts. should say that also if you hold the revs steady at say 2000, the car flicks down to 1900 and back again without a change in throttle, but that is not when it has the vibration. I have seen usa owners saying the auto box causes this issue. As it is better when not towing, assume it has worn out some part, but what. If it was just braking it feels just like a warped brake disc.

[frenchdave]

Also if you brake heavy, you can get rid of the vibration as if it hold in the same place whatever is worn out?

[Old Peter]

Having towed a caravan for over 20 years [retired now] I always checked the weight I was towing ensuring I didn't get over the 85% rule, ie that weight you are towing should not exceed 85% of  the kerbweight of the towing vehicle.  I always checked the downward pressure of the trailer on to the towbar to ensure that there was not too much or too little downward pressure on the front of the towing vehicle, and consequently  too much or too little on the rear suspension of the towing vehicle,

I did this on level ground with a firm base every single time I took the caravan out.

I would suggest that you have the rear suspension checked first before looking at the gearbox etc.  If the rear of the car is lower when not towing I suspect damage to the rear end suspension springs.

Peter.

[frenchdave]

Thanks Peter

I have been towing a car trailer normally towing a mgf combined weight is about 1300kg.

It is true to say that the rear of the car sits lower than the front when on level ground, and this is worse with the trailer attached.

I move the car as near the centre of the trailer as possible , but I agree that the weight on the towbar may be more than ideal.

Will get it on a lift and see if I have a broken spring.

Interestingly, today I drove it without the trailer. Vibration is much reduced, and on braking it feels like it is coming from the rear of the gearbox area. May look at UJs on the prop as well?

[Old Peter]

Hi David,

1300 kg is well within the towing weight of the s type.

When I found that my caravan was making the car lower at the back I would alter the weight in the boot of the car, moving it more into the centre by putting heavier items onto the rear seats, and taking a gas bottle out of the front of the caravan and moving it to a position slightly to the rear of the caravan axle, and other items until I had bother a level caravan and a level car.

Let us know how you get on.

Peter.