FIA Bar lower mounting bolt

[JP]

Hi

I'm converting to an FIA bar on an imperial chassis as part of my rebuild.  I've noticed that the lower mount holes in the chassis are almost as large as the bolt head.  For now I've used a large washer, but given that the FIA bar for the imperial chassis uses special shallow head bolts, will adding a washer cause the bolt head to sit higher and foul the rear shock when I come to refit the rear suspension?  Should I just bin the washer and accept the large hole sizing?  Pics below:

 

[Wrightpayne]

Yes - no washer. The shocks have been known to 'tap' with just the bolt fitted. The cage uses a bigger bolt with thin head. Many FIA bars have been found to have this bolt absent :-0

Copious amounts of coppa slip on the bolt! Also, it is adviseable to modify a socket for this by grinding the face of the socket flat removing the chamfered edges, to get better purchase on the bolt head. Same bolts are used on the dedion rear disc to drive flange attachment. I 'think' I used a 14mm socket which was a very snug fit (and I had an odd socket available to modify) but the actual size is 9/16"

Ian

[JP]

#2 - Thank you.

I'll whip the washer off tomorrow when I go to fit the rear axle and suspension.  Hopefully my shocks will be OK.  I've gone for Protech with rose joint rather than bushes...

I'm also going to change my rear discs when I reinstall so I guess I'll have a go at grinding an old socket.  Better dig out my angle grinder and see if I can find a suitable disc...

[Paul Richards]

Changed the roll bar on 3 factory built imperial cars and no bolt fitted. 

[ECR]

The third bolt is there to satisfy msa requirements but it would be a smart scrutineer that spotted that one was missing above the damper

[JP]

#4 - It sounds as if it's not really necessary.  Anyway I'll fit the rear suspension tomorrow and if the shock fouls, then I'll bin the 3rd bolt...

[Wrightpayne]

When modifying the socket I attached it to an extension bar so I could have better control when pressing (gently) against the side of a bench grinder disc. (Which I know is poor practice)

[JP]

#7 Sadly I don't have a bench grinder.  I'm thinking I'll hold the socket in a vice and try to grind flat with the flat surface of an angle grinder disc - I'm wondering if a coarse flap wheel disc might do the trick...

I've also dug out my Land Rover prop shaft tool which is a thin wall 9/16 socket on an extension piece - it still has a bezel at the end, but it is a shallower bezel and a 6-point socket.  I'll try that first.  I also want to replace the rear discs, so hopefully that will also do the job as it looks as if there is little clearance around the bolt heads...

[JP]

Update: as warned, my protechs with rose joints will not fit with the washer in place.

The Land Rover prop shaft tool seems to do the job so far...