Replacing suspension bolts
Discussion
Hi,
I've got a bit of a problem with my project. After removing the Trailing arms etc and having them shotblasted and repainted, I took the old Bolts (which are threaded into the Chassis) to get them replaced. Fair play to the bloke in the fixings shop, he measured the thread and compared them, but upon trying them in the holes, it seems they don't want to go in (they "start" but then will not tighten anymore by hand). I've no idea why this is but as the old bolts are 30+ years old, will it be ok to re use them?.
They're a fine thread, Metric, on an 80's Jap Saloon.
Secondly, I was going to use Stainless bolts but was informed that Stainless has a lower tensile strength than regular steel (and as such is not suitable), but they can also seize in easier, so instead of going for aesthetics it's best to use regular Steel.
Thanks for any advice,
Cheers,
Pete
I've got a bit of a problem with my project. After removing the Trailing arms etc and having them shotblasted and repainted, I took the old Bolts (which are threaded into the Chassis) to get them replaced. Fair play to the bloke in the fixings shop, he measured the thread and compared them, but upon trying them in the holes, it seems they don't want to go in (they "start" but then will not tighten anymore by hand). I've no idea why this is but as the old bolts are 30+ years old, will it be ok to re use them?.
They're a fine thread, Metric, on an 80's Jap Saloon.
Secondly, I was going to use Stainless bolts but was informed that Stainless has a lower tensile strength than regular steel (and as such is not suitable), but they can also seize in easier, so instead of going for aesthetics it's best to use regular Steel.
Thanks for any advice,
Cheers,
Pete
You say they won't thread anymore by hand, did you try getting a ratchet or a spanner onto them? Sometimes if there's crap in the threads or the threads are corroded it will just take a bit more persuasion. You could try some thread grease on the new bolt and spray some WD40 into the threads on the chassis to try and loosen any dirt or corrosion.
If you are sure the threads on the two bolts are an exact match then there's no reason for the new bolts not to thread in.
If you are sure the threads on the two bolts are an exact match then there's no reason for the new bolts not to thread in.
SnailTrail said:
You say they won't thread anymore by hand, did you try getting a ratchet or a spanner onto them? Sometimes if there's crap in the threads or the threads are corroded it will just take a bit more persuasion. You could try some thread grease on the new bolt and spray some WD40 into the threads on the chassis to try and loosen any dirt or corrosion.
If you are sure the threads on the two bolts are an exact match then there's no reason for the new bolts not to thread in.
Bad advice, this is a sure fire method of completely buggering threads if the pitch turns out to be slightly wrong. If you are sure the threads on the two bolts are an exact match then there's no reason for the new bolts not to thread in.
SnailTrail said:
You say they won't thread anymore by hand, did you try getting a ratchet or a spanner onto them? Sometimes if there's crap in the threads or the threads are corroded it will just take a bit more persuasion. You could try some thread grease on the new bolt and spray some WD40 into the threads on the chassis to try and loosen any dirt or corrosion.
If you are sure the threads on the two bolts are an exact match then there's no reason for the new bolts not to thread in.
Bad advice, this is a sure fire method of completely buggering threads if the pitch turns out to be slightly wrong. If you are sure the threads on the two bolts are an exact match then there's no reason for the new bolts not to thread in.
BritishRacinGrin said:
Bad advice, this is a sure fire method of completely buggering threads if the pitch turns out to be slightly wrong.
That's why i said if he is sure there are an exact match, although I probably should've put that at the beginning rather than the end. If the old bolt threads in fine and the new one doesn't the threads are obviously different.If the bolts are old and rusty, so will the chassis mounts be old and rusty. Best to get a tap to match the bolts and run in into all of the mounts before using the new bolts.
Stainless bolts are also more brittle than "normal" steel bolts, which is bad for suspension shock loads. 8.8 grade bolts will generally be fine unless the manufacturer spec'd something stronger for some reason.
Stainless bolts are also more brittle than "normal" steel bolts, which is bad for suspension shock loads. 8.8 grade bolts will generally be fine unless the manufacturer spec'd something stronger for some reason.
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