Replacing exhaust back box

I need to replace the back box on my Fender 90 (300TDI). I think the back box has been delivered today (am at work at the mo) but as I've never done the job before, I want to know if there's anything I might need that I haven't thought of.

A mate of mine suggested some kind of exhaust paste to join the two sections? Does this sound right? or is there a gasket I need or something?

Is there anything I'll need to do the job?

I dont really want to start it, only to find out I need more bits halfway through.

When I had to take my back box off for doing cross member, I had to get new bolts that join the two sections together as they were goosed, so took a grinder to them instead. If you're changing the back box you'll also need to swap over the rubber mount thing, which depending on how old it is could break while removing the old one. If you've got time, I'd order another one of those as it'll make you're life easier - they're a pain to get off.

the bolts are fairly common, so should be able to get them from any shop. There wasnt a gasket on mine, but that doesn't mean there shouldnt be one...

Did our one a couple of weeks ago.
I used exhaust paste and there we a metal gasket to join the two sections.
The bolts were replaced as 1 sheared and 2 suffered the grinder treatment.
Check the rest of your exhaust while under there.
Last week I needed to change the middle box on ours but luckily I had greased the bolts so one half was easy the others got the grinder again to start with.

Thanks guys.

Well pretty much changed it tonight anyway (before I saw your posts). Haven't used paste, and will have to change those rubber things as they are fecked so might take it back off soon anyway.

Yup, also replaced bolts. One sheared right on the last turn of thread and the other got the hacksaw treatment. Luckily I only had **** bolts to replace them with so hopefully they will shear easier next time.

Haven't used exhaust paste for over 25-years and never had a leak, as long as everything is clean and assembled correctly it shouldn't be required.
I always use SS fixings as it makes removal so much easier. I removed the complete system from my 300TDi 90 a few weeks ago (stripping for the rebuild) and despite being on for 5-years every nut & bolt came off easily and can be re-used as there is no corrosion.
As you discovered, always replace the rubber hangers when replacing the exhaust. They are dead cheap and so much easier to replace at the time rather than later.

any tips for getting the rubbers off? mines due to do and they are impossilbe to remove when ive tried. i know you need to lube them up.

lube ,lever bar and strighten the tabs and the end first with molegrips

lots of fairy liquid

"any tips for getting the rubbers off? mines due to do and they are impossilbe to remove when ive tried. i know you need to lube them up."

Cut the old ones off and then lube up the new ones before fitting them, dead easy.

bluehaze said:

lots of fairy liquid

Click to expand...

Ah... I just used alot of brute force!... Fairy liquid... Of course.