Thumping when changing gear

[Tapitha]

My Moggy makes a thumping noise after changing gear and letting out the clutch. It seems to come from middle or towards the back of the car. I thought it might have been the exhaust hitting something but it is secure and away from floor. Could it be play in the crownwheel and pinion? Ideas please to help me discover the cause.
Mike

[bmcecosse]

Exhaust was my first thought. Axle moving on the springs/spring bushes worn out/damper link arm bushes worn out/loose prop shaft...... Or just something rattling about in beside the spare wheel?

[taupe]

I had this once in my MG and eventually traced the problem to be following bmc's advise and keeping a trolley jack in the boot

Strapped it down and problem solved

[bmcecosse]

[Tapitha]

Back in August when I first bought Tapitha I asked for advice about a thump when changing gear. I didn't find out what the problem was until two days ago when getting her back on the road after hibernation. I discovered that the rear bumper bolts were very slightly loose and also the bolts holding the towbar to the boot floor underside. Half a turn on each bolt and, magic, the noise disappeared. Amazing how such a simple thing can make difference. The bumper and towbar didn't feel loose. Hope this might help another member.
Mike

[kennatt]

get under and check that the universal joint at the prop and rear axle flange is ok just turn the prop by hand and watch the joint,there will be some play in the axle,normal,but there should be no movement between the prop and flange.the usual noise is a clunk but check it just in case.

[alainmoran]

Take a look at the point where the exhaust passes from the engine bay to the underside of the car, if your engine mountings are on their way out the exhaust can clunk against the corner of the hole ... Try rocking your engine and see if the exhaust pipe catches.

If it does, you can either a) tighten your engine steady, b) make the hole bigger, or c) replace your engine & gearbox mountings.