Technical arb bolt problem

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Technical arb bolt problem

custard

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froze my nuts off today putting in new wishbones on the cinq.
on the drivers side when i removed the arb/suspension arm rear mount,the 2 bolts(19mm)were a sod to get out. tight all the way.
well upon inspection the threads are damaged mainly on one of them and its tight going back in.
tried another bolt but the threads started to strip on the bolt :(
dont know whether they have been removed before or if this is from the factory.

sooo i'll get a new bolt tomorrow but im wondering if i'll need to do something with the thread in the chassis as well?
any ideas?

:bang:
 

cycento

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Just a suggestion but i had the same problem with a brake caliper on a mazda 121. Had to retap the hole with a tap two sizes larger than the original but it worked. If the thread damage to the hole isnt too bad you might be able to re-tap the thread but it can be that re-tapping it strips out the rest of the thread.

Then you would need to use a slightly larger bore tap and a larger bolt to go with it.

Good luck
 

Jamieboy

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I put a sporting ARB on my 899 and had the same deal.

Try not to do what I did and break the captive nut inside the chassis off its weld!

I had to cut the floor to get at it and then cut the nut from inside.:(

I pulled back the carpet and the sound-deadening to find a layer of underseal, in turn covering a taped-over press out in the floor.

I prayed this was directly over the nut, but alas, no. I had to cut back the floor about 6-8" to get it and then about 4" across it to get the grinder in.

To replace it, I welded a beastly Nyloc nut in its place and finished the ARB install BEFORE welding the floor down!
 
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custard

custard

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right then.im obviously being naive that fiat dealers would supply an nut/bolt required on your car :( but thats another story.

anyway to cutting/repairing the thread. now i looked at a tap n die set in halfords but they are too small. they also do a thread restoring kit(£30!!!!) which looks like it would be ideal for my situation if it works.
otherwise i'll be scouring the city looking for a larger size of tap and die set.

anyone any opinions on the thread restorer? mail order isnt really any good as im off tomorrow and would really like to get this thread problem sorted. :)
 
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buy it, try it, if it dunt work take it back. (even if it does work just say it didnt) thats what i di with a valve spring compressor i bought from halfords. it was utter sh*t. only just managed to do my valves.
 
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custard

custard

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yeah thinking i'll try it.even if it works i suppose i could ebay it if im not going to need it(hopefully)again
 
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Beware of runnig a normal M12 or M10 tread restorer on any fiat suspension fitting. Chances are that the bugger's a fine pitch thread.

Get yourself a fine thread tap from somewhere like cromwells ( www.cromwell.co.uk ). Though their nearest branch to you is somewhere between Kirkaldy and Dumfirmline :confused:
 

Hellcat

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If the thread isn't too far gone you could carefully wind in and out a bolt while soaking in oil - engine oil it ideal. Heating it up too can help too.
 
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custard

custard

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Hellcat said:
If the thread isn't too far gone you could carefully wind in and out a bolt while soaking in oil - engine oil it ideal. Heating it up too can help too.
problem is its damaging the threads on the bolts ive tried :( had some spare longer suspension bolts to try it :bang:
 
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custard

custard

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right how do i work out the size of tap i need?
not got a clue on all of these god damned sizes :eek:
 

Badger_Benji

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Use the tap marked up with the same thread as the bolt you intend on using.
You probably have a selection with the same thread marking, they are the same thread marking, but they are used with the smoothest one first, then tap the hole with the next coarsest one, then finish with the coarsest one. Didnt know how else to phrase it but hopefully you get the idea.
 

arseofbox

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Get a thread pitch gauge :)

Match it against the bolt thread then go and find the right tap. These are usually in most tap and die sets, failing that, theyre about £5 at most. I got one the other day and dunno how Ive done so much work without it :)
 

rallycinq

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custard boy said:

Yup, or, if you have spare suspension bolts of the correct thread, take one of said bolts and saw a slot up each side of the threaded part of the bolt. Then, carefully grind the end of the thread to a slight taper. No need to go much beyond the depth of the thread. You can either use this as a tap in the normal manner, or use it as the bolt and leave it in once done.

Cheers

D
 
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Liam

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I'm not sure if the thread pitch can be gained from the info stamped on the head of some bolts.

Liam
 

rallycinq

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bloomfieldliam said:
I'm not sure if the thread pitch can be gained from the info stamped on the head of some bolts.

Liam


The numbers on bolt heads are the strength numbers, nothing to do with pitch sizes.

Cheers

D
 

Liam

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rallycinq said:
The numbers on bolt heads are the strength numbers, nothing to do with pitch sizes.

Cheers

D

Thanks for clearing that up D.

Liam
 
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custard

custard

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right then for anyone in the same situation the bolt in question is an M12 with a thread pitch of 1.25

now then as for the thread tap. theres this..................
12x1.25mm HSSGT STR. FLUTE TAPER TAP
SHR-085-0470A

12x1.25mm HSSGT STR. FLUTE SECOND TAP
SHR-085-0470B

12x1.25mm HSSGT STR. FLUTE PLUG TAP
SHR-085-0470C

either buying a set of 3 or they can be bought individualy.

now do i need all 3 or can i just run it with the 1st tap??
 

rallycinq

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Third one, the first two are for starting with a blank hole. You already have a thread in there that you are cleaning, I think. Its a 'plug' one cos the thread goes right to the bottom.

Cheers

D
 
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custard

custard

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excellent,just what i needed to know.get that ordered and finally get the car back on the road :D
had some **** in a golf cut me up coming out of the wrong lane yesterday :(
all i was thinking was if i had my turbo.......................:D
 
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