Exhaust hitting crossmember and rear axle

[Rhodrich]

My car has been fitted with what looks like a one piece exhaust, which appears to have been badly fitted, as it clunks whenever I go over a speed bump.

Clearance between the exhaust and centre crossmember is about half an inch, and I can see tell-tale marks where it hits. It also appears to hit the rear axle, plus the nearside rear shock absorber.

Given the general lack of adjustment, is there anything I can do to fix this, or would I be better off just buying a new 2 or three piece exhaust that'll have more adjustment built in?

[philthehill]

The Minor was originally fitted with a one piece exhaust system.
It has always been a job to get the clearances right but it can be done.
Are your engine mounts and engine steady bar in good condition? If not - excess rocking of the engine can cause the exhaust to foul.
A two or three piece exhaust system will give additional wiggle room when fitting the exhaust.
Make sure that your exhaust mounts/straps are in serviceable condition.

[Rhodrich]

Engine mounts and steady bar are all in good condition. I think it's just that the exhaust is a poor quality pattern part that doesn't fit properly.

Are the exhausts that you can pick up on eBay for £45 including postage any good (https://www.ebay.co.uk/itm/143432987260 - the car is fitted with a 1098cc engine), or should I be paying nearly double that for a quality one from ESM? I don't want to end up with the same problems with any replacement that I get. Will buy a full fitting kit at the same time.

[Chipper]

I would say that half an inch clearance is pretty good. Maybe just fit a stiffer set of hangers, to prevent it bouncing upwards so much...

[Rhodrich]

It's more that it gets hit every time the rear nearside spring compresses. Axle and/or shock absorber hits exhaust. Exhaust hits crossmember. Clunky-clang!
And I can't seem to get any more clearance over the axle, as there's nothing that can be adjusted, unless I were to cut the exhaust behind the silencer, reposition the 'arch' over the rear axle, and reconnect it with a double slip joint? But getting a good gas seal, especially given that the exhaust is not in the first flush of youth would be challenging.

[Chipper]

Maybe you need to use a shorter rear hanger, so that it raises the arch section above the axle - as long as you have a few mm of clearance at the crossmember, it's usually sufficent in my experience.

[philthehill]

Personally I would be fitting the 3 piece exhaust system from ESM and be done with it.
https://www.morrisminorspares.com/engin ... c-p1238736

[oliver90owner]

I might have checked the spring and spring hanger bushes etc before condemning the exhaust pipe, if it is the axle hitting the exhaust which then hits the bodywork.

[Rhodrich]

That is a good point. All looks to be in good order on that front though, and the axle bump stops aren't hitting the bodywork, so it looks to be moving in the 'normal' range. I will take a good look this weekend however before I go spending any money.

[kennatt]

it could be the spring hanger(rear one)hitting the chassis not the exhaust. If the spring has sagged it lengthens and the rear hanger hits body. Simple to check the hanger should ,more or less point down,not to the rear. And there will b e a mark on the chassis leg.

[Rhodrich]

OK - here are some photos. Spring hangers look fine. Clearance between exhaust and crossmember is fine. It's definitely the rear shock absorber body and rear axle that's hitting the exhaust - you can see the tell-tales. (Apologies - the pictures appear to have been rotated when they've uploaded)

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I've double checked that there aren't any slip joints on the exhaust, and can confirm that it's a one piece affair. There just doesn't seem to be any means to rotate or adjust it in any way.

[philthehill]

Thank you for the photos.
Are both exhaust strap hangers in place? I cannot see if the one under the rear N/S passenger seat is in place. I can see a hole but no strap.
I would be tempted to cut and sleeve to the rear of the cross member the exhaust pipe if rotating the rear end of the exhaust would cure the problem.

[Rhodrich]

Cheers - I can confirm that all hangars are in place.

If I go down the sleeve and rotate route (plus I think it needs to be extended a bit so that the top of the 'arch' is aligned with the axle), I guess I'd need one of these?
https://www.morrisminorspares.com/engin ... 01-p830088

Plus two u clamps and some exhaust paste?

[philthehill]

Using the sleeve in the link will do the job.

[Rhodrich]

Well... job done. I've cut the exhaust, put the link in, pulled back the rear section, rotated it slightly, and there's a lot more clearance. (Pictures randomly rotated by the forum software, despite me trying to rotate them back myself!)

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Does it work though? We shall see - it started raining. Will take the car out when it stops. It may need a bit more adjustment, as I think the sleeve joint doesn't quite have a gas tight seal, even with the use of exhaust paste. A pinhole leak shouldn't cause problems though.

Thanks all for your help and suggestions.

[philthehill]

Well done

[Rhodrich]

...and I've now been out for a drive, and driven over my local speedbumps quite aggressively, all with no clunking. Great success!