Eyebolt dimensions/Metalastic bushes

[Declan_Burns]

Does anybody have accurate dimensions of the eyebolt-internal diameter and width and /or metalastic bush external diameter?
Regards
Declan

[katy]

FWIW, I believe that they’re the same as the rear spring shackle bushings. BMC gives them the same part #, ACA5242

[Declan_Burns]

Katy,
Yes I know they are the same-it's the exact dimensions I am looking for or a drawing showing the same with tolerances. My mate is considering manufacturing "Metalastic" style bushes if economically feasible, although thre is a company local to me who make such bushes. There seem to be no reliable source at the moment and we are looking for the best alternative.
Regards
Declan

[taupe]

Hi

I have a couple of new Metalastik bushes that Im waiting to fit. The o.d. is 22.40mm BUT you must bear in mind that these are rubber on the outside (there is a tube down the middle only) So there will be some compression of the o.d. required to fit them

If youre planning to have an outer tube you will have to measure an eye bolt. My guess is that the hole will be 7/8" or 22.225mm

[mike.perry]

I have some spare eyebolts somewhere. I will have a look tomorrow and measure the hole diameter. You need to find someone with the suspension stripped down to measure the diameter of the fulcrum pin.

[David53]

I am finishing off my front end rebuild tomorrow and will measure it up for you if you like

[Declan_Burns]

Much appreciated David.
Thanks
Declan

[Declan_Burns]

I have some spare eyebolts somewhere. I will have a look tomorrow and measure the hole diameter. You need to find someone with the suspension stripped down to measure the diameter of the fulcrum pin.

Thanks Mike.
I've already measured the fulcrum pin with a micrometer-it' 12.64 mm- ie 1/2"-0.06mm.
Thanks

[Declan_Burns]

Hi

I have a couple of new Metalastik bushes that Im waiting to fit. The o.d. is 22.40mm BUT you must bear in mind that these are rubber on the outside (there is a tube down the middle only) So there will be some compression of the o.d. required to fit them

If youre planning to have an outer tube you will have to measure an eye bolt. My guess is that the hole will be 7/8" or 22.225mm

Taupe,
Thanks a million, and I appreciate the support,-that's exactly what I need to know. The bushes we are looking at are metal on the outside and are probably hard faced. That's why i'm asking for exact dimensions. If they need to be machined on the OD we would loose the hard facing what we want to avoid.
REgards
Declan

[fussyoldfart]

I happen to have a couple of new eyebolts at hand. The ID is .875" or 7/8". The closest I could come on the second sample was .8745" but there may have been a bit of paint in there. That's 22.22 mm if you must go metric.

The pins appear to be 1/2", they measure .495".

Hope that helps.

Darrell

[Declan_Burns]

Thank you Darrell,
Great help.
Regards
Declan

[Declan_Burns]

Hi

I have a couple of new Metalastik bushes that Im waiting to fit. The o.d. is 22.40mm BUT you must bear in mind that these are rubber on the outside (there is a tube down the middle only) So there will be some compression of the o.d. required to fit them

If youre planning to have an outer tube you will have to measure an eye bolt. My guess is that the hole will be 7/8" or 22.225mm

Hi Taupe,
Interesting to hear that your bushes are without the outer tube. In a way I think that might be the better way to go as I recall reading somewhere on here that the outer metal tube can be very difficult to remove if the bushes need replacing. The thickness of the rubber is only about 4 mm and if an outer tube is fitted then there's even less. What do you think? We can make both.
Regards
Declan

[mike.perry]

I found my eye bolts and measured them by passing drill bits through the hole and 7/8 was fractionally tight and 27/32 was loose. 55/64 should be about right = 0.859

[IslipMinor]

Is the hole in the eye bolt a parallel hole, or does it have a slight taper in from each end? Or is that just wear??

[taupe]

Declan

If you go for an outer tube there wont be much space for the rubber!

The rubber on mine is about 3.5mm thick - so I would go for tube down the middle only if I was doing it.

My guess is that the bush will pivot on the metal tube anyway and the rubber will just provide some vibration damping.

[IslipMinor]

A Metalastic bush is designed to have all the turning movement within the rubber - if there are metal tubes, inner or outer, they must be prevented from turning within the eye bolt or on the fulcrum pin. Any metal to metal rubbing will cause instant wear. Equally if there is no outer tube, but the rubber turns within the eye bolt, it will wear out extremely quickly.

Apologies for being a pain, but what problem are we trying to solve? Yes, the rubber bushes wear out or perish, whichever comes first, but if you fit the polyurethane ones, which is very straightforward, the reputation is very much 'fit and forget'.

I had to remove both sides of the front suspension last year, and the polyurethane eye bolt bushes were perfect. I used Superflex bushes, and fitted them, along with polyurethane everywhere else, 13 years and almost 40,000 pretty enthusiastic miles ago as part of the restoration. I used the original eye bolts and fulcrum pins (now 52 years old), and they also are still perfectly OK. I did fit new rear spring shackles with the new bushes, as they were definitely past their best.

[Declan_Burns]

Apologies for being a pain, but what problem are we trying to solve? Yes, the rubber bushes wear out or perish, whichever comes first, but if you fit the polyurethane ones, which is very straightforward, the reputation is very much 'fit and forget'.

Richard,
Thanks for the info. This is all an experiment really as there has been a lot of discussion about the longivity of these bushes but they seem very difficult to source and that's why we want to make them ourselves. If it doesn't work it doesn't work but we are going to give it a try and test it. The chemicals are ordered and the prototype is scheduled for the week after next. I have uploaded a sketch of what we intend to do followed by a datasheet on commercially available bushes -but they don't fit the Moggy-just for info as you can see the set-up and the angles of rotation depending on the size. (The sketch will need correcting-the thread is shown wrongly)
Regards
Declan[frame][/frame][frame][/frame]

[mike.perry]

All the best on your experimental production. I fitted metalastic bushes on my Series MM many years ago and I shall repeat the exercise on my Traveller. I intend taking the eye bolt and fulcrum pin to my nearby bearing stockist and getting them to match a bush. I seem to remember having to shorten the bushes on the MM.

[Declan_Burns]

Thanks for the input. What do you guys think of making a bush without any inner tube and simply casting the pin straight into the bush? We were discussing this option this morning and it's far easier to do.
Regards
Declan

[MarkyB]

Sounds better than having the bush cast inside a tube.
Is there a particular type of rubber for use in this sort of application?