clonking noise

[driller]

I get a single "clonk" (can''t really localise it)when I pull away sometimes and then sometimes when I start to reverse. A friend reckons it''s just the drive shaft taking up slack in the opposite direction, which does sound reasonable. Anyone else get this or any suggestions? I have been reassured that it''s ok by the dealer. Car is 2.5 yrs old, I've had it 3 weeks. Driller Ice Blue Griff500 Edited by driller on Tuesday 12th June 11:56

[philr]

Is it a clonk or more of a thump ? I used to get very worried about my Chimp 500 making the "random" loud thump - especially when I'd parked it and the set off. It turns out that this is just pressure in the fuel tank and a bit of equalization. Its fine now that I know, but it used to scare the C**p out of me before !

[manek]

Could be worn wishbone arm bushes allowing the arm to contact the chassis as you reverse. Does it also happen underbraking?

[JSG]

Could be driveshaft UJs or slack in the differential. If you jack up the rear on axle stands and turn the rear wheels you should be able to identify it.

[driller]

Thanks for the replies. Are these things any thing to worry about? Driller Ice Blue Griff500

[darrenlens]

philr I get this quite a lot, does your chimp not do it anymore? What did you do to stop it? Griff500

[dan]

I know this sounds stupid, but but its worth checking the spare wheel is secure (if you carry it). If it does move i.e. when you reverse then go forward it can make a mechanical type thump.

[IPAddis]

I had this noise for 2 years. A wierd clank from the back when you reverse or go from engine braking to accelerating. I pestered the dealer and the TVRCC mailing list and went through the usual panic of it being something expensive. It was not the petrol tank under pressure, the wishbones or the ball joints as suggested by other people. In the end, I was having a bit of accident damage checked out and the mechanic who moved the car onto the ramp noted "you're front diff bolt was a bit loose mate, I've tightened it for you". No more clanking! To check, you need the car up on a ramp and you should see if the diff bolt is loose as the paint will have been rubbed off and the metal will be shiny. Ian A Griff 500

[trefor]

I can't believe this went so long undetected. At both my recent services they replaced the diff bolts and tightened everything up (first service - Tower View) then I had the diff bushes replaced as it was moving around too much (second service - Thames Racing, Hurst). This was without me asking them to look at that area.

[philr]

quote:philr I get this quite a lot, does your chimp not do it anymore? What did you do to stop it? Griff500

It still does it , mainly after I have been driving, park for a while and then set off again. It is not something to worry about at all. I had a full explanation from Fernies about this, but the gist is that its to do with equalizing pressure in the tank. It is an off putting noise though as it sounds like the handbrake has stuck on and just released or someone's hit you from behind. Phil

[trefor]

Some TVRs do this fuel tank popping thing, some don't. A Griff 500 I borrowed while mine was being serviced did it (on a cold, rainy day so it wasn't heat related). Mine has never done it (although it does a good impression of tummy rumbling sometimes when the pressure equalises). Typical TVR features!

[driller]

Thanks a lot guys, I'm passing my dealer next week and I'll ask them to check this. On another note, I think the county council have just received their annual road repair money (all 3 pounds of it)in Bath. They've gone resurface crazy and I can't avoid some of these roads. They don't send a road sweeper round afterwards and the noise of chips-on-paint is horrific! Driller Ice Blue (+ stone chips)Griff500 Edited by driller on Wednesday 13th June 23:09 Edited by driller on Wednesday 13th June 23:11