Hello all

Just bought a lovely Sovereign S1 LWB. All original and beautiful condition.

However 24 hours into ownership the car has developed a horrible grinding noise when accelerating.

It sounds like the propshaft is banging against the transmission tunnel to the rear of the car. If i hold the tunnel, i can feel the vibration. Really sounds horrible - too the point i dont wan to drive the car

The car drives fine but just makes the noise

Doesnt make a noise when you come off the gas, nor in neutral nor in reverse. The frequency of the noise increases with revs when accelerating - something is rotating and rubbing I think

Could it just be a bush has come off somewhere allowing the prop to touch the underside?

Any help gratefully received!

Thanks

Simon

 

I'd suspect a u joint particularly the center one.


If so, not a big issue. many of us have lost them it is disconcerting though.


Carl

 

The over complex spring loaded trans mount could also be the cause? Your problem is in that area of the car.

 

.a

thanks Carl

forgive my ignorance but would the UJ have possibly failed altogether? what should i look for under the car? i still have drive so i guess it is still connected?

 

I had a UJ joint "go" on a RWD car once. It hadnt been greased for what looked like a long while and it'd siezed and made it sound like something was about to explode !


Was a simple fix though

 

Sshento:


There are seven Ujoints, including the center one. If you are not familiar with the architecture of a U joint, do some research. It is a cross with four arms. Each has a bearing. If one or more of those bearings goes bad, issues will arise.


They range from mild to awful. I've seen some get real bad. And, from time to time, one sees an entire drive shaft in the road. A complete disconnect!!!!


Been there, almost...


Check them or have them checked. slop in the shafts is the key, A good joint is taut and smooth.


Carl

 

yes indeed, sounds like a UJ. I personally check my ujoints a couple ways, but one way is to get the rear end off the ground and on stands(so you dont get crushed) so it is not under pressure. then simple grab the driveline and turn/shake as im looking at the UJ to see if it is wobbly or not normal. But a simple forward and reverse a couple of times(only moving around a foot each way), will make a clunking sound both ways right at the beginning of the engagement. This simple test works most of the time but not always, and only informs you that a UJ is bad. It in no way will tell you which one is bad. the sound transfers through the entire driveline and can make the noise in front and actually be in back and vise versa.
If it is not a UJ, as what happened to me, repost your results and I could tell you my story. I hope it is a simple UJ.