Rear trailing arm hub mount bolts

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murcod
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Rear trailing arm hub mount bolts

#1 Post by murcod »

Quick question - the trailing arm hub mounting studs (6 on each trailing arm that secure the brake backing plate/ bearing carrier), are they just tapped straight into the alloy (with no thread insert)?

I've got one on each side's trailing arm which won't tension properly- they both appear to be pulling out? The repair will be fairly simple once I purchase a 5/16 UNF thread repair kit.
David
1971 MkII 2.5PI (fitted with Holden 3.3l, 6 cylinder engine and Toyota five speed manual gearbox)
Charles H
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Re: Rear trailing arm hub mount bolts

#2 Post by Charles H »

Yep! Straight into the alloy! The torque setting is pretty low for these about 12lb/ft if my memory serves me correctly. The fix is to fit a helicoil or similar. :)
Charles Harrison
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murcod
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Re: Rear trailing arm hub mount bolts

#3 Post by murcod »

Interesting design :roll: , I guess I'll be doing some helicoils in the near future. Thanks.
David
1971 MkII 2.5PI (fitted with Holden 3.3l, 6 cylinder engine and Toyota five speed manual gearbox)
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Addiston
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Re: Rear trailing arm hub mount bolts

#4 Post by Addiston »

I learned about this the hard way in my late teens, over tightening not one, but three. Discovered one of them had come out and was happily sliding around inside the brake drum for long enough to wear an angle in the end!

In the end I had stepped studs made up, with oversize UNC (coarse) threads at one end, with the training arm drilled and tapped to suit. The stepped studs were then fitted very carefully!

Another step towards being an expert learned the hard way!

Regards
David Brewster (Memb 3937)
Edinburgh

2500S in White, with blue cloth interior. Manual Overdrive
2500S in Rus(se)t Brown with beige cloth interior. Manual Overdrive, but originally auto
murcod
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Re: Rear trailing arm hub mount bolts

#5 Post by murcod »

I torqued them to 15Nm and that was enough for two of them to let go- luckily they're holding and have just started to pull out. If I hadn't checked the manual I wouldn't have realised how "loose" they need to be- and probably would have a lot more to do.
David
1971 MkII 2.5PI (fitted with Holden 3.3l, 6 cylinder engine and Toyota five speed manual gearbox)
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