Suspension strut to bottom wishbone bolts - ID??
Discussion
I too have been doing chassis derusting/painting on my 96 Griff 500. To get better access I removed the suspension strut - great help, but then managed to strip the threads on the nut whilst reassembling (suspect bolt threads damaged by drifting it in/out, and then damaged nut threads).
The offending item is the bolt that attaches the lower end of the strut to the bottom wishbone. My question is simply 'what type of nut & bolt is it'?
Info I have is as follows: 3/4" socket and spanner fit it; shanks appears to be 12.5mm diameter, measured with micrometer. Bolt is 96mm long, and threaded for first 35mm. The head has raised markings of three radial lines (120deg apart) and a little triangle symbol on it.
Suspect it is an imperial type of nut & bolt, but would metric (M12)be suitable alternative, or might the smaller shank lead to movement in the strut bottom bush and hence bad handling/wear? It it a high-strength bolt or just bog-standard?
Where is the best place to source such things?
Any help greatly appreciated.
The offending item is the bolt that attaches the lower end of the strut to the bottom wishbone. My question is simply 'what type of nut & bolt is it'?
Info I have is as follows: 3/4" socket and spanner fit it; shanks appears to be 12.5mm diameter, measured with micrometer. Bolt is 96mm long, and threaded for first 35mm. The head has raised markings of three radial lines (120deg apart) and a little triangle symbol on it.
Suspect it is an imperial type of nut & bolt, but would metric (M12)be suitable alternative, or might the smaller shank lead to movement in the strut bottom bush and hence bad handling/wear? It it a high-strength bolt or just bog-standard?
Where is the best place to source such things?
Any help greatly appreciated.
1/2" UNF.
For reference the rest of the suspension other than the bolts holding the shocks on is 7/16" UNF.
Also see here www.thegriffithpages.com/content/view/97/83/
E.T.A. don't know where in Lancs you are, but JR Webster and Co Ltd, Lily Lane, Platt Bridge, Wigan, Lancashire, WN2 5LL will stock what you need, I usually use their Wrexham branch for bits and bobs.
Regards
Iain
>> Edited by chassis 33 on Monday 3rd April 16:43
For reference the rest of the suspension other than the bolts holding the shocks on is 7/16" UNF.
Also see here www.thegriffithpages.com/content/view/97/83/
E.T.A. don't know where in Lancs you are, but JR Webster and Co Ltd, Lily Lane, Platt Bridge, Wigan, Lancashire, WN2 5LL will stock what you need, I usually use their Wrexham branch for bits and bobs.
Regards
Iain
>> Edited by chassis 33 on Monday 3rd April 16:43
chassis 33 said:
1/2" UNF.
For reference the rest of the suspension other than the bolts holding the shocks on is 7/16" UNF.
Also see here www.thegriffithpages.com/content/view/97/83/
E.T.A. don't know where in Lancs you are, but JR Webster and Co Ltd, Lily Lane, Platt Bridge, Wigan, Lancashire, WN2 5LL will stock what you need, I usually use their Wrexham branch for bits and bobs.
Regards
Iain
>> Edited by chassis 33 on Monday 3rd April 16:43
Brilliant - thanks Iain for the detailed info. Wigan is not too far from Southport if I have no success more locally. Anyone happen to know if the bolts are high tensile or anything else fancy. I believe the orientation of the radial marks means something about the strength (for info, assuming the triangle is at 12:00, the marks are at 2:00, 6:00, 10:00 - means nowt to me??)
>> Edited by tvr_nut on Monday 3rd April 18:17
raw-sewedge said:
I Know that bolt.
It the one that you can only turn 1 flat at a time and you can't get a rachet spanner anywhere near it
PUT PLENTY OF COPPER GREASE ON IT
Not inaccessible on my Griff, suspect we are talking about a different bolt. Ring spanner on the bolt, and socket set on the bolt head. Hardest thing was avoiding chipping the new chassis paint with the ratchet handle. But it stripped while still just spinning it up with a light two finger grip on the wrench. In a way glad it did it now, and not the weekend before a trackday when doing the suspension checks!
tvr_nut said:
I Know that bolt.
It the one that you can only turn 1 flat at a time and you can't get a rachet spanner anywhere near it
PUT PLENTY OF COPPER GREASE ON IT
Not inaccessible on my Griff, suspect we are talking about a different bolt. Ring spanner on the bolt, and socket set on the bolt head. Hardest thing was avoiding chipping the new chassis paint with the ratchet handle. But it stripped while still just spinning it up with a light two finger grip on the wrench. In a way glad it did it now, and not the weekend before a trackday when doing the suspension checks!
Really? I've just replace the lower wishbones on my '92 Griff and I agree with TVR_NUT. I was just going to say its easier to get to if you have the wishbone out on the bench but I'd check the 3 nuts/bolts underneath the hub before I started to remove the wishbone though, they can be rounded or rusted.
Surely the bottom strut bolt goes through lugs on the wishbone with the bolt only able to go in one way, leaving the nut and bolt sitting inside the wishbone arm. Or have I got the wrong end of the stick here?
The three radial lines mean its a grade 5 imperial bolt, medium carbon steel, quenched and tempered, equivalent to the metric 8.8, so nothing fancy, just a standard bolt.
Six radial lines would indicate its a grade 8 imperial bolt equivalent to a 10.9 metric bolt (ie high tensile)
No radial lines means it made from monkey metal.
The metric designations are in two parts, the before the decimal point is the tensile strength i.e. the load at which the material begins to fail, given in units of 100MPa. The number after is the decimal fraction of the tensile strength which is the yield strength i.e. the load at which plastic deformation occurs, ie 8.8 is a 800MPa Tensile bolt, that yields at 640MPa.
The triangle i think is a manufacturers mark, if the triangle has a line from each point to the centre (difficult to tell on such a small scale i know), then that's the mark of Armstrong Fastening Systems in Hull...
Namrick stock pretty much every size of bolt known to man, however as Steve says you pay for the privilege. BTW Steve, you haven't sent me a bill for the 4off bolts to sent me a few months ago.
Regards
Iain
Six radial lines would indicate its a grade 8 imperial bolt equivalent to a 10.9 metric bolt (ie high tensile)
No radial lines means it made from monkey metal.
The metric designations are in two parts, the before the decimal point is the tensile strength i.e. the load at which the material begins to fail, given in units of 100MPa. The number after is the decimal fraction of the tensile strength which is the yield strength i.e. the load at which plastic deformation occurs, ie 8.8 is a 800MPa Tensile bolt, that yields at 640MPa.
The triangle i think is a manufacturers mark, if the triangle has a line from each point to the centre (difficult to tell on such a small scale i know), then that's the mark of Armstrong Fastening Systems in Hull...
Namrick stock pretty much every size of bolt known to man, however as Steve says you pay for the privilege. BTW Steve, you haven't sent me a bill for the 4off bolts to sent me a few months ago.
Regards
Iain
chassis 33 said:
The three radial lines mean its a grade 5 imperial bolt, medium carbon steel, quenched and tempered, equivalent to the metric 8.8, so nothing fancy, just a standard bolt.
Six radial lines would indicate its a grade 8 imperial bolt equivalent to a 10.9 metric bolt (ie high tensile)
No radial lines means it made from monkey metal.
The metric designations are in two parts, the before the decimal point is the tensile strength i.e. the load at which the material begins to fail, given in units of 100MPa. The number after is the decimal fraction of the tensile strength which is the yield strength i.e. the load at which plastic deformation occurs, ie 8.8 is a 800MPa Tensile bolt, that yields at 640MPa.
The triangle i think is a manufacturers mark, if the triangle has a line from each point to the centre (difficult to tell on such a small scale i know), then that's the mark of Armstrong Fastening Systems in Hull...
Namrick stock pretty much every size of bolt known to man, however as Steve says you pay for the privilege. BTW Steve, you haven't sent me a bill for the 4off bolts to sent me a few months ago.
Regards
Iain
Iain,
Thanks again for sharing your intimate knowledge of bolting. Steve does indeed sound cheaper for bolts if the bill doesn't follow the goods! I note your comment about the bolt being standard 8.8 - would a high tensile bolt like 10.9 be better, or would the strength be at the expense of toughness (this is an application where a bent bolt is much better than a fractured one!)?
PS: The raised triangle on the head does not appear to have the lines to centre, but that said, there is some corrosion so it just might be an Armstrong.......
>> Edited by tvr_nut on Tuesday 4th April 17:34
When I was working as an engineer bolt strength became a very important issue (more important than usual) on one particular job involving a very large centrifugal blower. Thats my excuse, and I'm sticking to it. 
In terms of bolt strength, a high tensile bolt isn't necessarily going to fial in a brittle manner rather than a ductile one, however, i'd shy away from a high tensile bolt, because if the bolt becomes stronger than the surrounding metal, it will be the wishbone that fail if you, say, clobber a curb at speed or some such like. A new wishbone is going to be about £50more in parts than a new bolt, and you could probably limp home with a bent shock bolt, whereas you wouldnt be able to with a bent wishbone. Indeed a bent wishbone could lead to a serious crash, more so than a bent bolt.
Regards
Iain
In terms of bolt strength, a high tensile bolt isn't necessarily going to fial in a brittle manner rather than a ductile one, however, i'd shy away from a high tensile bolt, because if the bolt becomes stronger than the surrounding metal, it will be the wishbone that fail if you, say, clobber a curb at speed or some such like. A new wishbone is going to be about £50more in parts than a new bolt, and you could probably limp home with a bent shock bolt, whereas you wouldnt be able to with a bent wishbone. Indeed a bent wishbone could lead to a serious crash, more so than a bent bolt.
Regards
Iain
Hi Chassis 33,
suprised TVR Nut didn't ask me first (i'm a metallurgist and built my own Dax Rush 4.6ltr V8 super 7, so have learned much about bolts and blot markings, plus I'm his brother !): he was probably too embarrassed !
I agree with your stick to original design engineers spec philosophy. However I'd not be worried about whether bolt, strut or wishbone failed first, I 'd still want to change the lot if I wellied a kirb hard enought to shear a 12mm bolt (plain CMn steel bolt or not). Hit summut that hard and you'll be looking at serious money anyhow since tyre and rim probably jiggered in the process too. From what I know the wishbone on a Griff would probably go first anyway due to the sheet metal pressed S shape construction and the fact it's prone to corrode away the inner bush housing join adjacent to the weld "heat affected zone".
Doesn't surprise me that TVR nut stripped it - always was prone to giving things too much welly.... and then some more for good luck (rather bust it than have it come loose, and rather welly it than use "expensive" nylocks or locktite - you MISER )!
suprised TVR Nut didn't ask me first (i'm a metallurgist and built my own Dax Rush 4.6ltr V8 super 7, so have learned much about bolts and blot markings, plus I'm his brother !): he was probably too embarrassed !
I agree with your stick to original design engineers spec philosophy. However I'd not be worried about whether bolt, strut or wishbone failed first, I 'd still want to change the lot if I wellied a kirb hard enought to shear a 12mm bolt (plain CMn steel bolt or not). Hit summut that hard and you'll be looking at serious money anyhow since tyre and rim probably jiggered in the process too. From what I know the wishbone on a Griff would probably go first anyway due to the sheet metal pressed S shape construction and the fact it's prone to corrode away the inner bush housing join adjacent to the weld "heat affected zone".
Doesn't surprise me that TVR nut stripped it - always was prone to giving things too much welly.... and then some more for good luck (rather bust it than have it come loose, and rather welly it than use "expensive" nylocks or locktite - you MISER )!
RushV8 said:
Hi Chassis 33,
suprised TVR Nut didn't ask me first (i'm a metallurgist and built my own Dax Rush 4.6ltr V8 super 7, so have learned much about bolts and blot markings, plus I'm his brother !): he was probably too embarrassed !
I agree with your stick to original design engineers spec philosophy. However I'd not be worried about whether bolt, strut or wishbone failed first, I 'd still want to change the lot if I wellied a kirb hard enought to shear a 12mm bolt (plain CMn steel bolt or not). Hit summut that hard and you'll be looking at serious money anyhow since tyre and rim probably jiggered in the process too. From what I know the wishbone on a Griff would probably go first anyway due to the sheet metal pressed S shape construction and the fact it's prone to corrode away the inner bush housing join adjacent to the weld "heat affected zone".
Doesn't surprise me that TVR nut stripped it - always was prone to giving things too much welly.... and then some more for good luck (rather bust it than have it come loose, and rather welly it than use "expensive" nylocks or locktite - you MISER )!
Brotherly Love eh, innit nice!!
Suspect I started it by making remarks about RushV8 having nothing better to do at work than post on Pistonheads (possibly true as a large chunk of what is left of British manuf industry seem to be on minimal load due to the horrendous price of energy at present).
Could have understood the threads stripping if I had been leaning on the wrench at the time, but it stripped while still just spinning it up with a light two finger grip on the wrench (certainly not the 55-60lb/ft recommended). Suspect bolt thread damaged in the past by drifting it in without good alignment of shocker/wishbone, and this led to the damaged bolt threads.
The use of nutlock is a tricky one - really need some grease on the bolt to ensure it goes in freely, and also helps ensure that the torque goes into tightening and not just friction. Not a problem this time has have "splashed out" on spare nyloc nuts. In many cases, the decision to reuse old nuts is not cost (a few tens of pence even for 1/2" UNF ones) but having the time to source them (but now know a man who can...). Especially when you think about it only when reassembling!
Will bring the nut & bolt over at Easter for expert analysis too (along with shovel & pickaxe to level the lane, so you can get the Dax settled into its new home?)
>> Edited by tvr_nut on Friday 7th April 16:44
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