Wishbone Bolts, Stainless

[Nathanlee 1]

Hi Folks,

 

I've got a day off to rebuild the suspension after I broke a wishbone, then later realised the inner CV joint failed at the same time.

 

As a bloke who used to live on a sailing boat, I'm a massive fan of stainless steel, so was thinking about replacing the 10 & 12mm wishbone bolts with A4 (316) equivilents.

 

Will they be too soft? I've got a proper bolt shop locally, and the current ones feel a little bit loose in the (new) oem wishbone bushes, so thought while it's all in bits I'd better replace them. They were being run on rose joints, so not sure if that's worn them a little?

[stu8v 68 1 Cars]

You need to run high tensile bolts.

 

Stainless has no place in the suspension.

[welshpug 1,658]

your best bet is to get a wishbone bush kit from Peugeot, and use all the nice fresh zinc plated bolts they come with.

 

I have seen some are supplied as screws however, so I would re-use the original BOLTS with the new Nyloc nuts as they are incorrect for that application.

 

 

Given Peugeot specified an 8.8 grade HT steel bolt, I don't think it would be wise to use a stainless bolt, they work harden., also, many peugeot/citroen original bolts have much longer shanks and finer threads than a "standard" bolt spec.

[Nathanlee 1]

You need to run high tensile bolts.

 

Stainless has no place in the suspension.

 

Sound as pound. I'll go ht then. Cheers.

[Nathanlee 1]

Cheers welshpug. Useful. I had no idea stainless was so pants compared to HT. Some of the loads on boat rigging is pretty insane, and 316 steel is standard. I suppose a boat doesn't have to launch 780kg up a curb at 50mph though

 

Also found this which made for interesting reading... for some, maybe

http://www.qldcorvetteclub.com.au/tech/tech_talk/bolts.htm

[oonip 4]

I'd expect a stainless bolt will be stronger than the Ht bolt after the Ht bolt has corroded to dust from all the salt!

[welshpug 1,658]

not likely, they're Zinc plated, I bet the SS bolt will have snapped from work hardening or the threads galled.

[stu8v 68 1 Cars]

I'd expect a stainless bolt will be stronger than the Ht bolt after the Ht bolt has corroded to dust from all the salt!

Wrong....!

[Plumbob 66 1 Cars]

Just to add my two pennie's worth. In the mid 90's my dad built a Lotus 7 lookalike that was made 100% from folded stainless sheet. I'm not talking stainless sheet over the top of a steel tube chassis either... I mean 100% stainless.

Within 6 months all the bolt holes on the load bearing areas like where the Cortina rear suspension bolted on had cracked between each other and basically made all the hole thing pretty unsafe. He ended up sandwiching the stainless chassis between a mild steel plate and the suspension pickups to try and spread the load a bit and take some of stress away from the chassis pickups. So from that experience I agree that its a crap material for structural areas.

Edited April 14, 2014 by Plumbob

[jdt 6]

stainless steel fasteners, A2 or A4, have no place in highly loaded applications where high tensile bolts are needed, they are also a bitch for the threads picking up so some lube is essential.

Most hex heads are 8.8 and high tensile cap heads are 11.9 and the preferred option

[oonip 4]

I need to clarify, I was referring as to why stainless bolts could be found on a boat as the Op was using that as a reference and there was confusion as to why that might be the case.

 

What I was trying to get at was stainless although weaker has a much higher salt spray corrosion resistance to even a zinc plated standard bolt and why I'd imagine it's used commonly on the sailing boats.

 

As long as something is designed to work within its operating condition then I think it's wrong to offer a blanket rule of when something should or should not be used.

[2-Pugs 57]

Presumably stainless is fine - and preferable - for areas that are either not safety critical or not loaded highly, then?

 

For instance bumper to valence bolts (rear bumper), heat shields, brake disc backing plates, that type of thing?

[Tom Fenton 1,542]

Presumably stainless is fine - and preferable - for areas that are either not safety critical or not loaded highly, then?

 

For instance bumper to valence bolts (rear bumper), heat shields, brake disc backing plates, that type of thing?

I'd happily would and do use stainless in all the places you mention. Anything suspension or brakes should be high tensile steel.

[oonip 4]

Agreed.