Anything and everything Spitfire.

Rear axle, brakes, wheels and tyres.

I'm coming back to that clanging question again........

I have a 1972 Spitfire Mk IV and for some time, I've been hearing a loud clang when I start off from a stopped position. Not always though. It usally happens when I accelerate hard. If I start off slowly, I don't hear it.

It sound like 2 pipes hitting against each other. Where would you recommend I start looking? I'm open to suggestions.

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I've followed the advice so here's what I've done: pulled the driver's side wheel off and checked the brakes to make sure there was nothing binding that might have caused the brakes to release causing the clanging sound - no problems there.

While under the car, I grabbed the prop shaft and axle to see if the u-joints had any play in them - I turned the prop shaft while holding the axle shaft - no play that I could find. Did the opposite - turned the axle while holding the prop shaft - no play to speak of. In saying there's no play, I mean there's no loose movement or rattling in the u-joint.

I will say there was about an 1/8 of an inch of movement before I could feel the axle shaft engage the differential before the prop shaft started to turn. When trying this out on the opposite axle shaft, I did not get this "slack" for lack of a better term. Is this a problem?

Canley suggested that the panel welded into the prop tunnel that acts as a strengthener for the handbrake is angled somewhat. Under load with poor gearbox/diff alignment the prop can sometimes bang against this panel. They said they think it's to the left so moving the gearbox to the right is the easy cure. They also asked if it a strap drive prop. Straps can come loose or break so it's worth checking.

Before pulling up the tunnel cover and all that goes with this, anyone have a similar experience with this misalignment and it causing the noise I'm experiencing? How do you tell if straps have come lose or have broken?

I know - a lot of questions here but it's been a difficult problem to solve as the only time I have the noise is when the car's moving!

Cheers,

Brad

Exhaust hitting chassis? Remember the engine moves when you rev it, particularly if the mountings are a little old.

I checked that too Charles - shook everything under the car in the rear end.

You can actually feel the noise - which is a cross between a bell clang and a clonk and it's coming from under the driver's side of the rear. When I see the word "clonk" in postings, feedback is usually directed to u-joints so unless I'm checking them correctly, I'm back to checking the gearbox panel as Canley suggests. Still not sure about the worn/broken straps and how to check those.

Don't think it's the differential itself though......

Brad

Hi Brad

Failing universal joints will make a sound long before there is any discernable play in them, so it *might* be a bad UJ, but I would expect a repeated clunking sound that viaries with road speed, and is worse when turning one direction or the other. If you are getting a single clunk when taking up drive, it might be that the nuts and bolts securing the ujs to the diff need tightening.

I had this on a prevous car: although the nuts and bolts had no play on them, and couldn't be undone by hand, they were not tight enough to stop the flanges on diff and UJ turning relative to each other as the car took up drive. The amount of movement is tiny - it is just the width of the clearnce between the bolts and their holes in the flanges after all, but it made a resounding clunk that could be felt through the floor of the car. 5 minutes with the torque wrench fixed it.

hope this helps
Paul

brad,

also worth checking the nuts on the studs which are on the radius arm mounting brackets behind the seats and behind the carpet as if they are not completely tight the thrust from the axle will produce a clonk here,it's very noticable if you repeatedly go on throttle then back off again.also re torque the bush bolts as they may look and feel tight but again there could be play there...

paul.

Section : Rear Axle

Coming back to that clanging question again!!!

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Coming back to that clanging question again!!!

Coming back to that clanging question again!!!

Coming back to that clanging question again!!!

Coming back to that clanging question again!!!