Rear trailing arm issue

[AndrewS2]

Hi all,

Back on with the rebuild this weekend having received many boxes of shiny parts...

Have an issue with one of my trailing arms. Fitting the 'small bit' back on, all bolts tightened up no problem with the exception of 1. I've tried all the other 3 bolts, and they all go straight through the hole. This bolt screwed in, but didn't even offer to tighten - as soon as it bit it just started slipping.

So - what to do?? Anyone know what the normal size these are? I could just try getting another as this bolt doesn't look in the best condition... I'm wondering if it has previously been poorly re-tapped as this bolt seems very very slightly bigger in diameter than the others but only by a knats wotsit.

Help much appreciated.

Andrew

Offending bolt:



Offending hole:

[GinG15]

[magpies]

that bolt is scrap - go buy a new one

loosen the other three and there should be enough movement to allow you to fit it.

TIP = never fully tighten any bolts until all of them have been fitted

[v8s4me]

I replaced mine this winter and I think they are 5/16" UNF. When you can verify that, and get your new bolt, try running a tap through the hole to clean up the thread. Hopefully that will sort it. If not, you'll have to drill out the hole to the next size up and re-tap it. Be careful with the recommended torque setting, I think it's too high. IIRC I used 35 ft/lbs. What ever bolts you end up needing, they should be high tensile. BTW, you should really have spring washers on there.

Edited by v8s4me on Sunday 21st February 09:08

[AndrewS2]

Thanks chaps, will try with a new bolt and my fingers crossed...and add spring washers!

Andrew

[TVRees]

AndrewS2 said:

... Have an issue with one of my trailing arms. Fitting the 'small bit' back on ...

Is this the two part trailing arm set up ?

On the Bolts wiki it says :-
"2 part trailing arm joint bolts thread = 3/8" UNF ; Length = 1 3/16"

[glenrobbo]

Andrew,
The hole looks to be a bit out of alignment to me. It needs "podging" using a tapered round bar. Slacken off the three bolts already fitted, then lever the "podger" until the hole is aligned with the thread, nip up a couple of the slackened bolts to clamp it in the 'sprung' position, and the naughty bolt ( use a new one* ) should screw in ok. Make sure the female threads are OK first.
If you need a hand, email me, I'm only the other side of Stockport from you. Get my email address from Longers Eurotour email list of recipients, I think the PH Mail is broken at the moment.

• Brian S. Pope Engineering Supplies in Stockport are v. good.

Good luck,
Glen

[AndrewS2]

So turns out Rich had provided me with all new bolts....I just hadn't spotted them in the box!! Replaced all the others (replacements included spring washers) but the offending one looks like it will need re-tapping.

Glen - thanks for the offer, will be in touch by email - I've never done a re-tap before so your wisdom and expertise would be much appreciated!! I'll bring the small piece with me and hopefully arrange a time to meet later in the week.

Cheers

Andrew

[Kitchski]

AndrewS2 said:

So turns out Rich had provided me with all new bolts....I just hadn't spotted them in the box!! Replaced all the others (replacements included spring washers) but the offending one looks like it will need re-tapping.

Glen - thanks for the offer, will be in touch by email - I've never done a re-tap before so your wisdom and expertise would be much appreciated!! I'll bring the small piece with me and hopefully arrange a time to meet later in the week.

Cheers

Andrew

I was gonna say I thought I put some new ones in the box! Just check they're not too long though as I've had issues on some if the arms where the bolt bottoms out and needs trimming. I could have tapped those arms when they were here, I didn't even think to! Don't tighten those up until the arms are fitted to the chassis as the alignment is always a bh!

[glenrobbo]

Hi Andrew,
I've emailed you a reply.

Will need both parts plus the set screws to get the alignment sorted. If you bring the bits round I can have a look & with any luck, we can save the female thread. If not, may have to go up a size to 7/16" UNF. Not sure if I have a tap that size, I'll have a search in my cave tomorrow.