Nuts & bolts questions
 

If/when the rain dries up :shrug: I'll be slackening off the rear suspension nuts & bolts (all of which are new) and then re-torquing them with the weight of the car on the suspension.

Bearing in mind I'll only be slackening off a couple of turns, can I re-use nuts 5 & 9 here and 6 & 8 here - or should they be replaced?

Bolt 3 here came with pre-applied locking compound. Can I slacken it off and re-tighten it without applying more? (If I remove the bolt to apply new compound, nuts 9 might have to be slackened off too and maybe replaced).

And while we're here ;) my rear ARB is the 'uprated' RGB101062UR. The two rubber bushes don't close up completely when the U bracket bolts are done up - they look like this instead:

https://www.the75andztclub.co.uk/for...c0436a2d40.jpg

I don't remember a gap like that on the old ones. Perhaps the hole is too small for the uprated bar? Btw, RAVE says lubrication must not be used the bushes - whoops!

TIA. :}

ARB's come in two sizes. I'd say you have the bushes for the smaller diameter type. The fitted bushes should not have a gap.

That's correct, a flexible bush won't perform correctly if lubed.

TC

Yes, but the labels on the bush bags I've got both say RBX000180 which is the number for the ZT bush. Surely this has a bigger diameter hole than the 75's bush RGX101090?

Link - https://rimmerbros.com/Item--i-GRID001546


According to RAVE it's something to do with the bushes having a special coating. It's only on the inside.

Yes you would think so.

An anti-slip agent I reckon.


TC

I just measured the old ARB & bush (the ones I took off) and the new ARB & bush. Both bushes were measured off the car.

• Old ARB diameter = 18.49mm
• Old bush internal diameter when hole closed by hand (off the ARB) = 18.01mm
• Old bush part number = RGX101090
• Old bush closes completely around the ARB with no air gap at the joint

• New ARB diameter (after shot blasting & repainting) = 23.18mm
• New bush internal diameter when hole closed by hand (off the ARB) = 22.02mm
• New bush part number = RBX000180
• New bush does not close at all around the new ARB - air gap at the joint is 2-3mm

Here's the new RH bush on the car.

https://www.the75andztclub.co.uk/for...d456fba6ea.jpg

The old and new U brackets are the same in profile - i.e. there's no difference in size or shape of the U.

Unless there's a third bush we don't know about (one with a bigger hole than RBX000180) I can't see how to solve the air gap. :shrug:

Questions from post 1
 

TC - what do you think about these two questions:

Personally, I would re-use the nuts identified. They're standard flanged nuts. If they were self-locking type I'd renew them.


I suppose it depends on what type of locking medium is used for the locking band. If it's a metal catalysed full polymerisation type, it will not perform as before once the 'lock' is broken. A lower strength medium may accept a 'second chance'. I don't know enough about thead locking chemistry so I really don't know what the answer is.


TC

Thanks TC.

I'll go and have a close look at them all later (it's raining again).

Meanwhile, just for info, I think nuts 5 & 9 and 6 & 8 are all 'stiffnuts' (as per Brian's posts 3 & 8) in which case they should probably be replaced. And bolts 3 have red locking compound as opposed to some other MGR bolts which have blue - I've got no idea which colour means 'use once'. Maybe I should just replace the whole lot and be done with it - I don't want to have to keep crawling underneath to check the darned things. There again, it's another £30 or so down the drain. :eek:

These bushes aren't doing any work. Just retaining bushes. The bar twisting is the workhorse surely .--:shrug:

Not at all like front suspension arm bushes or lower tie bar bushes.---;)

I reckon ARB bushes are pretty loaded up when the car rolls. They don't simply act as locating fasteners - like a U-bolt_ but absorb a considerable sideways/off axis thrust. They also provide a dampening effect when driving on very rough surfaces. A pair of roller bearings for example wouldn't provide the same results. So, a large gap in the bush just seems counterproductive. Obviously the bush must be very tight to the bar, so a small gap of some size is inevitable. The gap in the photo looks a bit too much. It will work, but will fatigue faster than a complete collar. That's my take on it anyway.



TC