Exhaust hangers

[Andrew S]

I have just had a look at my exhaust hangers and one side the rubbers don't look too bright but what I have noticed is the lower section of the hanger, being the rubbers and washers are pressing against the handbrake cable tube. Would that give me harshness or a vibration, especially under acceleration? Or, being that the hangers and tube are on the same cross member, it should be dampened by the outer mounts and diff mount rubbers?

I am trying also to work out by how the exhausts move under acceleration and presume they try and twist as well as pushing back towards the back of the car when accelerating

Cheers
Andrew

[mike@thenook]

I reckon you would get vibration between those two parts Andrew, especially as the whole lot flexes under load. While we were chatting about my similar problem at club night I have noticed that mine seems to vibrate rather less when it has warmed up, I guess as I have the Poly bush mounts they become more pliable once a bit of heat soaks through.
Whatever, when the weather warms up and I can be tempted by the garage floor I'll have a look at making some sort of mount that takes away all the vibration, the current ones don't seem to very well.

Cheers!

[Andrew S]

Just come in after adjusting the offside exhaust hanger so that it no longer touches the handbrake cable tube and hoping this is my problem solved. Will know when I drive it to work in the morning.

[Andrew S]

Well, no difference to the vibration despite making sure the hanger was not touching the crossmember hand brake cable tube.

One thought I have had driving in this morning is that should I have tightened both the hanger long bolts tight or do you guys leave the top one so that the hangers can move back and forth to allow for any front to rear engine movement under load when accelerating?

[jleyton]

Hi Andrew,

I used nyloc nuts and then didn't do the bolts/nuts up TOO tight. I reckon the exhaust will be cool enough back there so the nyloc won't get damaged.

Cheers

Julian

[DJT]

It is a while since I replaced these hangers, but I thought the spacer tube was there so that it didn't all tighten so that it was rigid.

[Andrew S]

Thanks Julian. Did you put a nyloc on both bolts or just the top one so allow it to swing off needed?

[Andrew S]

It is a while since I replaced these hangers, but I thought the spacer tube was there so that it didn't all tighten so that it was rigid.

Interesting Dave as I just presumed the tube was there to stop the bracket on the crossmember being distorted if overtightened.

Should it be that we should tighten up against the tube but the tube tightens against the small inserts in the bushes but then woudl allow the bushes to move and therefore the hangers could swing?

[DJT]

Interesting Dave as I just presumed the tube was there to stop the bracket on the crossmember being distorted if overtightened.

Should it be that we should tighten up against the tube but the tube tightens against the small inserts in the bushes but then woudl allow the bushes to move and therefore the hangers could swing?

I thought so, but might be wrong. Next time I'm under my car I'll take a look.

Thinking about it again (too much thinking is bad for my health!), the hangar plates are there so that they swivel on the bushes, so the whole assembly should swing in line with the exhaust. With the rubber hangars under the boot, the whole exhaust system should be flexibly mounted aft of the gearbox brackets.

[jleyton]

Thanks Julian. Did you put a nyloc on both bolts or just the top one so allow it to swing off needed?

Hi Andrew,

I put them on all the bolts, but more out of convenience and neatness than having thought it all through

Cheers

Julian

[jleyton]

...... the tube tightens against the small inserts in the bushes ......

ISTR seeing rubber bushes that do not have the small metal insert - may be worth checking.

Cheers

Julian

[Andrew S]

I took Jukians advice and replaced the nuts with nyloccs and lightly tightened just enough for the tube to rotate so at least I know that the hangers can move back and forth.

Unfortunately it has not cured my vibration under acceleration

If the vibration is worst when I have the kids in the back in other words under load, what is this changing in the transmission alignment? Just wheel camber?

[mike@thenook]

With load in the back the pressure on the wheels will be providing a downward force on the diff ends of the suspension arms so this could be moving the exhaust nearer to part of the arms or maybe it's the cross section of pipe at the back getting closer to the bodywork (i'm going to get rid of this piece sometime and have an exit on each side instead) which mine does.
Cant think of anything else that would move but there is so little room in the way the pipes fit through the arms it's small wonder there aren't vibrations all the time!
Surprisingly, with load mine seems to get better and it certainly gets better when the system has heated up - awful at cold......