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MG MGF Technical - Exhaust Fitting Tips

As I eagerly await delivery of my TT exhaust, does anyone have any handy hints for getting the old one off? More specifically, undoing those catalyst nuts - I assume they are cat studs? My car is a 99 Mk1 VVC, and from the Unipart date stamp has its original exhaust fitted so those nuts have never been off (and does it show?!).

What are the chances of destroying the cat? I have a suspicion I will need to drill out at least one stud, and if that is the case what problems may I get in acheiving a gas tight seal? What size bolts have people replaced the studs with? How long might it all realistically take?

Pete Davey

Hi Pete,

Get some serious heat on them.
Blowtorch directly at the stuck nuts should do the trick and then get some of Mike Saturs Exhaust Nuts!!

And are you coming on Sunday? :)
You should of had an e-mail from me..

HTH

Kris F
Kris

Hi Pete

Just changed mine to a Blueflame, managed to get the Cat to downpipe off with lots of WD40 over a few days, the Box to Cat however were totally gone and had to cut them of with a cutting disc, then its just a case of drilling the studs out so the Cat can go back on at MOT time.

Good luck and get ready to loose some skin off of those knuckles!!!

Arron
Arron

My biggest tip would be to get someone else with a proper ramp and the correct tools to do it for you. I wasted several days lying under my car trying everything from angle grinders to blowtorches trying to get the corroded nuts off, and eventually gave it to a garage to do it.
Ian Matheson

That'd be my suggestion too Ian. Have attempted this job, struggled, swore, managed to shear one of the cat studs... and eventually decided to let someone with the correct tools for the job to do it.

Frustrating task!!!
Rob Bell

I'm taking no chances, I'll be taking mine to the garage to do. Less hassles and no nails broken :-/

Eager Fiona :-)
Fiona

just fitted blue flame, best bet is remove rear bumper ,take off exhaust at the two bolts on downpipe remove whole exhaust and cat if cat nuts are corroded grind off with angle grinder also grind off back of bolts and replace with s/steel when you refit. this job is not a big deal if you approach it like this it only took me 2.5 hrs outside my house (in the snow) to do this.good luck
richard

Thanks for the tips - I have already started soaking the nuts in penetrating/releasing fluid. I can see this being an 'amusing' little job! I'd best borrow an angle grinder in advance.

I did think about the Garage option, but was concerned that they would try to sell me a new cat which I shouldn't need.

Hi Kris - yes, I do plan on coming on Sunday (Southern F'ers), probably with the standard exhaust still on! Did you decide where to convoy from? I'm in St Denys.
Pete Davey

Hi Pete,

That's just round the corner from me!

I posted the details for Sunday morning on the MGF General section under "First South Coast Meet". Have a look and hopefully I'll see you there.

http://www2.mgcars.org.uk/cgi-bin/gen5?runprog=mgbbs&mode=thread&access=&subject=2&source=T&thread=2006010723493621120

With or without new exhaust. :)
Kris

So it could take anywhere between 2.5 hours and 2.5 days.
Good luck, Pete :-)
Russell Parslow

Not to worry, I'll just call in that Milltek exhaust fitting debt my mate Russell owes me ;)
Pete Davey

I changed my exhaust about 6 months ago. It was surpringly easy, the only nuts that were a slight problem were the lowest ones on each side of the cat (these are more open to the spray etc under the car). I tried a nut splitter but could not get it onto the nut properly due to the shoulder. In the end I used an angle grinder. Once the cat was off I heated the flange around the stud and a couple of sharp taps with a hammer got the stud out. I bought some stainless steel 10mm bolts and some of Mike Satur's Cat Saver nuts and will be re-fitting the cat this week-end in time for the M.O.T.

There is no need to remove the rear bumper as someone has suggested; using a pair of ramps gave adequate room underneath to do the job. Angle grinders are so cheap nowadays that is well worth buying one. The exhaust had been on since new (1998)
Pete Fincher

Pete, this images of the TT MK1 may be useful
http://www.mgfcar.de/exhaust_fxtreme/index.htm
from a Milltek
http://www.mgfcar.de/exhaust_milltek/index.htm

I immidiately recommend asap to replacing the standard mild steel nuts with stainless steel parts. Either get *Cat-Saver* Nuts from Satur or use 2 of M10 SS nuts to each stud, bolt on in sequence.

PS. Neil, if you read, *g* .... I'm in need for that mad BIC/IBAN numbers ;)
Dieter

The 'Yoke' shape cheap nut splitters available will not fit however the superior 'Snap-On' 'C' Shape splitter should do the job.
Geoff F.
G. Farthing

Yes Deiter I am on the case
Going to pick up the offending articles rigt now!

Regards
Neil
Neil

Neil, can you resend me your last mail, as I accidentaly deleted it and now dont know where to send the cheque.
Steve White

This thread was discussed between 11/01/2006 and 13/01/2006

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