924Board.org

john_brunt · Joined: 07 Sep 2008 Posts: 11 Location: Manchester, UK

hi all, i am in the process of restoring a 1982 924, I have not got much experience but have managed to learn a fair bit about the car, have managed to strip the front suspension, refurbish all the individual parts for rebuild etc. However I am struggling with both the front and back bumper brackets. The back brackets are badly rusted and I had to grind through the bumper to actually hack of the existing bumper, I am now left with the two brackets that I wish to remove, however there is no way the two bolts on each bracket are ever going to free in their current state and all that I am going to end up doing is rounding the nut head, does anyone have any advice on how I should proceed, the front are the same but I dont really want to have to damage the front bumper to get it off, thanks in advance

fiat22turbo · Joined: 18 Jan 2006 Posts: 4040 Location: Portland, OR

Heat the bolts and brackets until cherry red with a propane or MAPP gas blow-torch, place an ice cube or poor a small amount of cold water on the rusted bolts only (careful we don't want them to shatter, just shrink quickly).

This should cause rapid expansion and contraction, which will break the rust bonds between the bolts and the surrounding metal.

You may have to do this a few times to be fully effective.

Alternatively, you may be able to turn the bolts slightly in the opposite direction and/or hit the heads of the bolts with a decent sized mallet to help break the rust up a little.

If the head is stripped, use a dremel tool or cutoff wheel/grinder to make new flats to get a wrench onto. You may also find a product like "GatorGrip" helpful in removing bolts and nuts with rounded heads.

Absolute worst case, you can cut the head of the bolt off and weld a nut or tab to the head of the bolt or whatever is left and apply leverage to that after you remove the bracket(s).
_________________
Stefan
1979 924 Carrera GTS (clone-ish)
1988 944 Turbo S (Silver Rose)

Smoothie · Posted: Sat Mar 21, 2009 8:44 am Post subject:

Techniques that I've used in similar situations -
I'd start by giving them a good soaking in PB-Blaster or some other liquid wrench type product.
Then after a day or so, first try a spanner (aka- box-end, ring-end, closed-end wrench). -And try smacking it with a hammer**, and in both directions (sometimes tightening a bit helps to break a rusted fastener loose).
If no luck, and/or you round the head before getting it removed, go to the Vise-Grips option... With a hammer or mallet, and standard size Visegrips, grab the bolt with the Vise-grips positioned so that when you hit it to loosen, you'll be hitting the thinner side of the handle (the release lever side)(because hitting the thicker, adjuster side tends to release the Vise-Grips, and they'll just pop off). That's it - with the Vise-Grips attached extra tight, smack away...
Third option is to grind off the bolt head, apply PB-Blaster or whatever, wait a day, and try removing the remains with Vise-Grips.
Fourth (or second option if the bolt broke during attempt #1) is to drill (oil the bit), and either try a screw extractor (this can go wrong and leave you with a broken hardened steel extractor inside the rusted bolt), or drill and tap for the next larger size bolt. Another variation of this is to use a reverse drill bit and run the drill in reverse - the heat from drilling + the reverse direction will sometimes remove the broken bolt without need of an extractor.

**- If you have access to an impact wrench, use that instead (the hammer on spanner technique is like a poor-mans impact wrench).
_________________
"..it's made in Germany. You know the Germans always make good stuff."

'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

ideola · Joined: 01 Oct 2004 Posts: 15550 Location: Spring Lake MI

Before you try anything that will round off the head, get a manual impact tool, the kind you smack with a hammer, not an air powered one. I picked one up at the FLAPS. It came with bits for flathead and phillips head screwdrivers, but if you remove the receiver chuck for the bits, it has a convenient 3/8" socket connector which can be used to drive any of my standard metric sockets.

Soak in PBBlaster as Smoothie describes, then use the manual impact tool with the correct 6-point socket (NOT a 12-point), and beat the snot out of it. I bet you get the bolt to come out without snapping off the head or rounding it off. You'll be amazed at what a useful tool the manual impact driver is. I bought it for one stupid screw on a rear brake disc, and I have used it so much, I need to buy new screw driver bits.
_________________
erstwhile owner of just about every 924 variant ever made

Vince Ponz · Joined: 02 Nov 2002 Posts: 3581 Location: Florida

Your first mistake was to hack the bumper. If I had to I would have cut a section out of the bottom to reach the bolts.
Soak the bolts many times and try to remove them.

As for the rust clean and paint them. I don't think they rusted through did they?

I have both bumpers FG and alum and on one car I shortened the shocks. Now the alum bumper is thisclose to the body but I got the bolts on and off. Patience, my boy.
_________________
"Never let them see you sweat"
77.5 924 modified track car
79 931 Euro stock
88 924S SE
87 911 Targa stock

john_brunt · Joined: 07 Sep 2008 Posts: 11 Location: Manchester, UK

hi all, thanks for all the help, i know its only a general problem and not specific to my 924 but i will try your tips tomorrow.....incidentally the front two came off no problem today, I just did a lot of staring at the back two....with regards to getting the bumper off i did grind away two sections to get at the brackets...so for a novice it wasnt a bad start....I do however still now need a back bumper..luckily I have two other donor cars but I guess I am going to have a similar problem with those...oh and by the way what is pbblaster...is this like WD40??...spent most of today just flatting off the bodywork well six hours anyway....if i knew how to post pics i would get a couple up....i noticed most of you guys are in the US but where do you tend to buy replacement bolts..do you get from porsche or just a motor factor?...as for tomorrow think it will be sanding ending up covered in guards red dust from top to toe!!!!!!

fiat22turbo · Joined: 18 Jan 2006 Posts: 4040 Location: Portland, OR

PB Blaster is only available in the colonies apparently (US, Australia and even Canada)

http://forum.brit-cars.com/showthread.php?t=6480

Sounds like Plus Gas would be an option for you.

I agree that WD-40 is only for displacing water (helpful when attempting to prevent rust) not breaking down rust.
_________________
Stefan
1979 924 Carrera GTS (clone-ish)
1988 944 Turbo S (Silver Rose)

john_brunt · Joined: 07 Sep 2008 Posts: 11 Location: Manchester, UK

http://www.facebook.com/home.php?#/photo.php?pid=1462877&id=737039720&ref=nf

Smoothie · Posted: Sat Mar 28, 2009 5:08 am Post subject: Re: not sure if this will work

john_brunt · Joined: 07 Sep 2008 Posts: 11 Location: Manchester, UK

http://img18.imageshack.us/img18/8499/n7370397201462890512422.jpg

http://triton.imageshack.us/Himg141/scaled.php?server=141&filename=n7370397201462878961167.jpg&xsize=640&ysize=480
http://triton.imageshack.us/Himg141/scaled.php?server=141&filename=n7370397201462877649176.jpg&xsize=640&ysize=480
http://triton.imageshack.us/Himg21/scaled.php?server=21&filename=n7370397201466822668927.jpg&xsize=640&ysize=480
http://triton.imageshack.us/Himg19/scaled.php?server=19&filename=n7370397201462887870010.jpg&xsize=640&ysize=480
http://triton.imageshack.us/Himg4/scaled.php?server=4&filename=n7370397201462881644807.jpg&xsize=640&ysize=480

Smoothie · Posted: Mon Mar 30, 2009 1:05 am Post subject:

Very nice, and nice shiney wheel there - had to polish it yourself?
The whole thing reminds me of some fun I had not in '06. Have a look if you get a spare hour or so - http://www.924board.org/viewtopic.php?t=19177
_________________
"..it's made in Germany. You know the Germans always make good stuff."

'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

john_brunt · Joined: 07 Sep 2008 Posts: 11 Location: Manchester, UK

it looks like you put a great deal of effort into that baby.....its a real credit to you...do you still have it?

Smoothie · Posted: Wed Apr 01, 2009 9:23 am Post subject:

Yessir, still have it. Approaching 17 years of ownership now. Have been "recycling" cars by owning only used (totalling 6 over 32 years), and have always had two in the "stable" at a time - one that's better for hauling stuff, and another smaller one for zipping around more economically. Never bought a car new, but eventually refinished 5 of the 6 cars I've owned. The only one I didn't re-paint was the first, a 1970 Fiat 124 Spyder. Would have done it too eventually, but it caught fire and burned to the ground before I got around to it.
Also have rebuilt the engines in all those cars except for the Porsche 931 (not afraid to, it just hasn't needed it).

_________________
"..it's made in Germany. You know the Germans always make good stuff."

'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox