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[Tick Tock]

I'm planning on replacing the cat-back exhaust on my F/L 2.5 estate - just something to get it through another couple of years, as it's still a great drive. If we're going to keep them on the road, it's a given that most of the jobs we have to do ourselves, at a tenth of the price quoted by the local tyre & exhaust place in the case of the exhaust.

No spring chicken, but I think I can still grovel around under the car for a day. Front end up on ramps with back end jacked and blocked to bring it level - say 18" ground clearance to the bottom of the sill.

Is it possible to get the middle sections over the axle - or will I need to go higher?

Has anyone done an exhaust in the street / driveway and know the minimum height the car needs to be?

[Nick W]

I did mine in the street, on my own, with the rear on ordinary axle stands. That's enough room, if you don't need to drill the cat flange bolts. That might mean swapping the stands to the front to gain a bit more space.


The entire system hangs under the car, so there's no need to get it over the axle.


My cat bolts undid, so I cut the rubber hangers(I always replace them) and dropped the system complete. You fit the new one by loosely attaching it to the cats, then the centre hangers, then the rear pipes and finally the back box. Once everything is attached, you tighten all the bolts/clamps starting at the front. That's about 30 minutes work.




Edit: having had a car that was on ramps at the front and stands at the back roll off and pin me underneath, I don't lift them like that anymore. I was about to manage a 40minute one-man clutch change before that happened

[dave the builder]

I'm planning on replacing the cat-back exhaust on my F/L 2.5 estate - just something to get it through another couple of years, as it's still a great drive. If we're going to keep them on the road, it's a given that most of the jobs we have to do ourselves, at a tenth of the price quoted by the local tyre & exhaust place in the case of the exhaust.

No spring chicken, but I think I can still grovel around under the car for a day. Front end up on ramps with back end jacked and blocked to bring it level - say 18" ground clearance to the bottom of the sill.

Is it possible to get the middle sections over the axle - or will I need to go higher?

Has anyone done an exhaust in the street / driveway and know the minimum height the car needs to be?

Mid boxes /sections go UNDER the "axle" on a V6 
I've replaced my complete zorst system including cats, mids and back box with the Omega on ramps and axle stands 
where the mid pipes join the back box is the lowest point of the zorst .

just take your time , WORK SAFE and assemble it all BEFORE tightening everything up 

preferably NOT in Novenber ,when it's snowing and you're MOT is about to run out 

[dave the builder]

Also, a 1 to 2mm hole ,drilled into the rear of the mid sections (the lowest point of the system) will allow the water to that collects to drain .
smear a blob of gum gum over the drain hole for MOT  once MOTed , clear the hole

crazy idea you say 
many exhausts and back boxes come with a tiny hole in to drain water 

[Tick Tock]

Doh!! of course it's underslung, what was I thinking?

This is the arrangement I had when I did the handbrake cable a couple of years ago, ramps front, chassis resting on blocks and axle stands under the back. No need to take the rear wheels off to do the exhaust, so will be safer with ramps at the back.

[johnnydog]

I cut the rubber hangers(I always replace them)

If your car has the original GM rubber exhaust hangers, and they are not deformed or damaged, I would recommend reusing them on your new system.
From past experience, I replaced my original GM rubber hangers with aftermarket ones, thinking at the time it was sensible to change them at the same time - at the next MOT, the tester pointed out the hangers were perishing and cracked / spliting.
Fortunately, I had kept the GM ones as they had appeared ok - I refitted them and they are still on the car to this day.
Cheap replacements are just that - cheap. Just a few quid compared to the far more costly GM ones, but the rubber is undoubtedly inferior to the genuine GM ones.
So I would recommend reusing the hangers if genuine GM and are serviceable.

[Nick W]

Reusing the hangers is like reusing tyre valves to me. I always replace them because my experience is exactly the opposite of yours: they're old, loose and ready to fail, even if they survive the removal process. I hate doing things twice on my own stuff, and won't have avoidable comebacks on paying jobs. Cutting them saves time too. If I was going to spend OE prices, I'd upgrade to polyurethane hangers and some silicone spray to help fitting.


I dislike doing half a job to save some money right now, so tend to replace all the wear components at the same time like we recommend for Omega front suspension rebuilds.



I apply similar thinking to parts too: I've never found a reason to worry about oil brands, or for filters. I buy NGK plugs for preference,  am happy with Bosch but won't touch Denso. I've had too many bad experiences with Apec brake pads so won't buy them, but don't care about the discs. I don't get any value out of the extra expenditure for premium tyres over mid-range ones, and often buy budgets. I avoid Intermotor where possible, especially ignition parts.


Some of this is down to me and how I use things. I've never been hard on machinery and some of the short life certain people here get from expensive consumables astonishes me even when I'm not paying for them

[TheBoy]

I'm with johnnydog on this one, and have always tended to use the original GM hangers, rather than the shitty ones that are supplied with new exhausts.  Obviously, thats after inspecting the originals, but I don't ever recall one ever failing or becoming too saggy on the Omega.

[Migv6 le Frog Fan]

Same here. Kept some spares from when I used to break them for parts so I dont have to use cheap pattern hangers if I need one.

[Nick W]

Ever seen an exhaust that's fallen off due to failed hangers? I have. Several of them, as jobs. Some of those were recent systems that were now scrap.


So I always replace them. Always.


I've had similar experiences with NOS brake and rubber parts, and prefer to buy current stock instead. One of the classic brake specialists I've bought from said "It's NOS, but comes with a new seal kit. We strongly recommend you use it...."

[VXL V6]

I cut the rubber hangers(I always replace them)

If your car has the original GM rubber exhaust hangers, and they are not deformed or damaged, I would recommend reusing them on your new system.
From past experience, I replaced my original GM rubber hangers with aftermarket ones, thinking at the time it was sensible to change them at the same time - at the next MOT, the tester pointed out the hangers were perishing and cracked / spliting.
Fortunately, I had kept the GM ones as they had appeared ok - I refitted them and they are still on the car to this day.
Cheap replacements are just that - cheap. Just a few quid compared to the far more costly GM ones, but the rubber is undoubtedly inferior to the genuine GM ones.
So I would recommend reusing the hangers if genuine GM and are serviceable.

That echo's my experience as well. The Polish eBay exhausts are brilliant value and work well but the rubber hangers are best binned and stick with the original GM ones.

[Doctor Gollum]

Apples and oranges. The 20 year old original ones might be better than cheap new tat. But new poly ones will be better than both.