Backbox metal bracket snapped....can it be welded? - Saxperience

NICK2506 · 9th September 2009, 18:16

Noticed today my backbox was sitting low. looked under the car and the metal thing thats welded onto the backbox which the exhaust hangs from has snapped

Not sure whether to get it re-welded, or talk to piper and try get a new one. only got it about a year ago!
reckon i could get a new one or is it possible to re-weld it?

Dom · 9th September 2009, 18:22

Yeah should be possible to weld together again, same thing happened to mine, except my bracket snapped a inch further up so had a little room to play with when welding

Stevie-J · 9th September 2009, 19:33

I think it could be re-welded, but gotta think how it broke in the first place, usual culprit is knackered engine mounts allowing too much forward and backward movement of the engine, which will pull the exhaust back and forth too much and put strain on the clamps and mountings. Has the exhaust got a flexi section in the frontpipe or a spring loaded joint to allow for engine movement? and check engine mounts for excessive play - or the exhaust mounting could break again in a short period of time.

saxovtsmad · 9th September 2009, 19:36

yes it can be re welded

Lozza_vtr · 9th September 2009, 19:38

Sure can, no probs.

NICK2506 · 9th September 2009, 22:00

Quote:

Originally Posted by Stevie-J

I think it could be re-welded, but gotta think how it broke in the first place, usual culprit is knackered engine mounts allowing too much forward and backward movement of the engine, which will pull the exhaust back and forth too much and put strain on the clamps and mountings. Has the exhaust got a flexi section in the frontpipe or a spring loaded joint to allow for engine movement? and check engine mounts for excessive play - or the exhaust mounting could break again in a short period of time.

think the problem is the stress i put on it.

i had a bit of rubber in between the axle and the centre pipe to stop it vibrating and then cable tied over the backbox rubbers really tight so that it was really tight up against the rubber on the axle and so that it sat nice and high.

think thats why. the cable ties were so tight the couldnt take any movement up and down of the backbox. and yeah ive got springs between the centre pipe and manifold

Stevie-J · 9th September 2009, 23:01

That'll be why then - the exhaust needs to be able to move on its rubbers and not be pulled up tight to anything. The rubbers help to dampen out the exhaust movement as the engine rocks back and forth on hard throttle, and if they are not allowed to do this, something else has to give in the end, in your case the exhaust hanger has been extremely strained and eventually has failed through fatigue. Why do you need it so high up and so inflexibly mounted? - I'm assuming it grounds on speed humps maybe?

NICK2506 · 9th September 2009, 23:25

Quote:

Originally Posted by Stevie-J

That'll be why then - the exhaust needs to be able to move on its rubbers and not be pulled up tight to anything. The rubbers help to dampen out the exhaust movement as the engine rocks back and forth on hard throttle, and if they are not allowed to do this, something else has to give in the end, in your case the exhaust hanger has been extremely strained and eventually has failed through fatigue. Why do you need it so high up and so inflexibly mounted? - I'm assuming it grounds on speed humps maybe?

aah fair play. na it just looks stupid when it sits low

and it sits off to one side. maybe i should get some better exhaust rubbers. like some powerflex ones...but if the exhaust is too high it vibrates on the axle.

Stevie-J · 9th September 2009, 23:36

Get some better rubbers, and if necessary, get the centrepipe heated to red hot and bent to a more suitable shape to fit the aftermarket backbox better, rather than strain the system by forcing it with cable ties. Take it to an exhaust place and see what they can do.

Stevie-J · 9th September 2009, 23:45

Yeah, I see your problem now, cos the car's lowered and the backbox is fairly large, you need it high up for ground clearance - sorry mate, didnt realise it was lowered 40mm.
Pity it cant be modified to go over the back axle instead of under it, but I suppose that would take too much work and maybe not enough clearance over the axle?

NICK2506 · 9th September 2009, 23:48

Quote:

Originally Posted by Stevie-J

Yeah, I see your problem now, cos the car's lowered and the backbox is fairly large, you need it high up for ground clearance - sorry mate, didnt realise it was lowered 40mm.
Pity it cant be modified to go over the back axle instead of under it, but I suppose that would take too much work and maybe not enough clearance over the axle?

na not enough clearence over the backbox. its not that the backbox would scrape the ground with out it high up its just that it would look stupid. looks neater in the recess. could heat the pipe up and change shape but its a supersprint. so dont really want to.only solution is meet in the middle and have it high so it looks okay but not too high so it vibrates and get some better stiffer rubbers.

Stevie-J · 10th September 2009, 00:00

Yup, that sounds the best solution - even if it only clears the axle by 5-10 mm, and it doesnt knock on the axle you should be fine. It will sound better in the car too, as you wont have the exhaust vibrations being transmitted up through the axle. I fitted a standard centre pipe and backbox to my little 1.1 the other day, and slackening off the flange clamp allows you to adjust the fit under the axle. I suppose your backbox to centre pipe joint is the sleeve design rather than the ball and cup flange that OE exhausts have though. In any case, as long as its not in hard contact with the axle and the hanger is welded properly back on the backbox, and you use good quality sports exhaust rubbers it shouldnt break again.

Stevie-J · 10th September 2009, 00:03

just one more thing - has the centre pipe got the hanger and rubber on it? if not, then maybe thats another reason the backbox hanger broke as it was taking all the weight of the whole system.

saxokid100 · 10th September 2009, 02:34

yes it can be re welded................................

NICK2506 · 10th September 2009, 11:54

Quote:

Originally Posted by Stevie-J

Yup, that sounds the best solution - even if it only clears the axle by 5-10 mm, and it doesnt knock on the axle you should be fine. It will sound better in the car too, as you wont have the exhaust vibrations being transmitted up through the axle. I fitted a standard centre pipe and backbox to my little 1.1 the other day, and slackening off the flange clamp allows you to adjust the fit under the axle. I suppose your backbox to centre pipe joint is the sleeve design rather than the ball and cup flange that OE exhausts have though. In any case, as long as its not in hard contact with the axle and the hanger is welded properly back on the backbox, and you use good quality sports exhaust rubbers it shouldnt break again.

Quote:

Originally Posted by Stevie-J

just one more thing - has the centre pipe got the hanger and rubber on it? if not, then maybe thats another reason the backbox hanger broke as it was taking all the weight of the whole system.

yeah the centre section has the rubber on it. and naa its a flange and gasket joint between the backbox and centre section as they are both OE fitments. What do you mean by slackening off the flange to adjust it under the axle?

yeah cos mine was in hard contact with the rubber i had put on the axle. it didnt make vibration noises though as it was against rubber not metal. i've got a £20 halfrauds voucher and they sell powerflex mounts. so i'll purchase some.

oh and i spoke to piper this morning and they said if i send my backbox to them they'll fix it and send it back.

got a lifetime warentee.

Stevie-J · 11th September 2009, 02:30

If the joint between the centre pipe and backbox is the OE type, then its like a ball and cup arrangement with a clamp around it to hold it together. There is no gasket with this type. If the nuts on the clamp are slackened the joint will adjust to different angles between the centre pipe to backbox, that will allow more clearance under the axle without losing the height of the tailpipe. It just means that the backbox may be angled slightly differently.
Slacken off your clamp nuts and try adjusting the pipes at the joint for a better fit and clearance.

NICK2506 · 11th September 2009, 10:45

Quote:

Originally Posted by Stevie-J

If the joint between the centre pipe and backbox is the OE type, then its like a ball and cup arrangement with a clamp around it to hold it together. There is no gasket with this type. If the nuts on the clamp are slackened the joint will adjust to different angles between the centre pipe to backbox, that will allow more clearance under the axle without losing the height of the tailpipe. It just means that the backbox may be angled slightly differently.
Slacken off your clamp nuts and try adjusting the pipes at the joint for a better fit and clearance.

ah no, mines a gasket with 2 flanges. not a ball and socket type joint...