And so it begins…….

[Peter1450]

Wife’s just had an operation and unable to drive for at least a month so taking the opportunity to rebuild the rear end ,not even got the exhaust removed and encountering the effects of 20 plus years of corrosion.
Rear box removed ok ( although I did cheat and cut the rubbers) but the middle section where it joins the headers and cats is just a rusty mess, nuts rusted away,managed to separate but left with not much in the way of a flange to get back together later.
Is this salvageable, maybe fabricate and weld on new flanges? And how to remove what’s left of the studs on the cat side? Cheers for any advice.

 

[t-tony]

Those studs are only pressed in on splines. If you can get some heat they will knock out. You can ease the tight fit by grinding a split in the flange from the edge to the stud. IF you're going to try drilling them out you will need some quality Titanium drill bits and do use eye protection or you will end up at A&E. Good luck.

Tony.

 

[Peter1450]

Thanks Tony I did try my MAP torch briefly but didn’t seem to make any impression, plus me neck was aching ( too old for grovelling around upside down under cars), but I’ve gone past the point of no return!
Will have, another go tomorrow,just didn’t want to make the flanges any worse than they already are.

 

[Lee]

Hi Pete, cut a neat slit into each side and gently tap out the old studs, we do this with all the zeds using a fine blade with a dremel.

Same principle this guy uses.

(1) How to remove a corroded exhaust flange stud - YouTube

 

[Peter1450]

Cheers will give it a try

 

[Peter1450]

What’s your opinion on the centre section flanges? Only two of the four holes are there………

 

[Andyboy]

You can ease the tight fit by grinding a split in the flange from the edge to the stud.

Tony.

Excellent advice right there.

Some are on splines (M44's) but some are threaded in - many of these and all Z4 2.0.

A thin cutting disc on a grinder will do it. Reassemble with stainless bolts and nuts.

 

[Andyboy]

Also - given how prone these are to catalytic converter theft (i.e very) I would be very careful where you park it. New cat sections for 2.2 and 3.0 cars are not available anywhere. Not BMW, not aftermarket - just nothing.

 

[Peter1450]

The little buggers are out , great advice, probably not as finesse as some but I’ll take it for my first attempt! No match for these two…….
Now the beam support bolts want a fight.

 

[Peter1450]

Making slow progress as I’m only getting about an hour a day to dismantle the rear end, have a large pile of rusty parts for the blaster/ powder coater,hubs came out the trailing arms with the inner races ,is there a simple way to remove without a proper splitter/ puller? If not any recommendations on a cheap ish set as they’ll probably not get used again! Cheers guys