23 replies to this topic

[Steve220]

Hi all,

 

Something I've noticed recently that is beginning to bug me as I can't find what it could be.  Essentially the car drives perfectly, however over small/minor bumps and rough roads I get a knocking, a kind of D-D-D-D-D (like a rolling tongue) at the front end from both sides. It definitely sounds like its the suspension. It's there on large bumps also, but more apparent during the lighter bumps/rough road.

 

What I've checked so far:

 

- Ball joints, upper and lower, greased, no excess play.

- Track rod ends - good movement, no play in ball joint

- Tie rod - Bushes are sound, no lateral movement, bolt to lower arm is tight

- Lower arm - bushes are in tact, bolt pin and nut tight, ball join nut tight

- Upper arm - greased, no lateral play, ball joint nut tight

- Damper - 450 miles old, set to 8/13, upper nut and mount are solid, lower bolt to top arm slightly lose, done up with Loctite.

- Wheel bearing - checked for play when the car is raised, no movement.

- Brake calipers - all torqued to spec

- Top arm - torqued to spec and tabs in place

- CV's - checked for play, no excessive play

- Subframe mounts - all tight

- Engine mounts - all tight

- Engine steadies - all tight and adjusted correctly

- Physical check of the hi-lo/cone/top of subframe mount, all sound and tight.

 

I am at a loss to what It could be!

Edited by Steve220, 29 April 2019 - 11:25 AM.

[nicklouse]

I would remove dampers and go for a very short drive. not safe etc but then you can eliminate them. but I would say it will be the shocks or their mounting.

[Steve220]

I would remove dampers and go for a very short drive. not safe etc but then you can eliminate them. but I would say it will be the shocks or their mounting.

 

Thanks Nick, will give it a go tonight. Probably a really dumb question - is it quite bouncy without the dampers? The road I live on isn't exactly runway quality

[nicklouse]

 

I would remove dampers and go for a very short drive. not safe etc but then you can eliminate them. but I would say it will be the shocks or their mounting.

 

Thanks Nick, will give it a go tonight. Probably a really dumb question - is it quite bouncy without the dampers? The road I live on isn't exactly runway quality

 

perfect you will not need to go far. seriously drive as short a distance as you need.

 

as a side thought you could also wind the shocks to their extremes and see how the noise changes. but a patter noise does seem to be a damper one to me.

[hhhh]

I had a knock that took me a while to find and it turned out to be the bulkhead subframe mounts which were tight, but the rubber had shrunk enough to provide clearance to knock.

[Steve220]

I had a knock that took me a while to find and it turned out to be the bulkhead subframe mounts which were tight, but the rubber had shrunk enough to provide clearance to knock.

I'm solid mounted, chap

[richmondclassicsnorthwales]

I see you said CV's, do you have inboard CV's or the rubber coupling ?

 

I have had issues with both of these and them being the inboard units, are a bit harder to check though

 

The rubber couplings break internally, and can fly apart with the rotation of the driveshaft. Inner CV's - the cage and balls fail and rattle.

[Steve220]

Outer and inner are brand new and show no sign of wear. The noise is from the outer side of the car and happens under different load.

[leyland73]

Could be the steering rack spacer Bush? There is a nylon type bush in the passenger side of the rack to support the rack. Over time these collapse and allow the rack to rattle inside the steering rack tube. Common fault on BL vehicles and very annoying to track down. These get replaced with bronze bushes and never rattle again!

[Steve220]

Could be the steering rack spacer Bush? There is a nylon type bush in the passenger side of the rack to support the rack. Over time these collapse and allow the rack to rattle inside the steering rack tube. Common fault on BL vehicles and very annoying to track down. These get replaced with bronze bushes and never rattle again!

Rack is brand new and this feels a bit bigger than just a lose bush.

Edited by Steve220, 29 April 2019 - 08:36 PM.

[leyland73]

Could be the steering rack spacer Bush? There is a nylon type bush in the passenger side of the rack to support the rack. Over time these collapse and allow the rack to rattle inside the steering rack tube. Common fault on BL vehicles and very annoying to track down. These get replaced with bronze bushes and never rattle again!

Rack is brand new and this feels a bit bigger than just a lose bush.

No guarantee that the nylon Bush has not perished in storage, apparently low mileage or limited use cars suffer most with this fault. With the car safely jacked up try rocking the track rod arm to determine if there is any movement, I had the same problem on an Allegro and a new rack was just as bad, currently have my rack waiting to be rebuilt with the brass Bush.

Hopefully you’ll get it sorted

[Steve220]

Just tried, no movement and feels fine. Thanks for your input!

[imack]

Have you checked the tie bar to lower arm bolts are tight?
Brake pads rattling in calipers? Jack the car up and thump the tyres, usually makes the pads rattle if this is the case.

[Spider]

I had one that took me a while to track down.

 

Turned out the 4 bolts holding the disc to the drive flange had come loose (or I didn't tighten them!).

[Steve220]

Have you checked the tie bar to lower arm bolts are tight?
Brake pads rattling in calipers? Jack the car up and thump the tyres, usually makes the pads rattle if this is the case.

Tie bar bolt as per original post.
pads are good, this sound is felt through the front of the car, so heavily doubt its pads as it is also there during braking.