M

moth

Member
I am continually having issues with short service life of metalastic type bushes. Are high quality versions of these available? It seems that there is a lot of tangential twist in this part for such a narrow cylinder of rubber. I am loathe to opt for poly if there's no way of keeping grit out of the moving parts.
What is the latest thinking on this forum?
Thank you.
 
As part of my study of this.. Has anybody measured the outer diameter of the inner metal sleeve of the poly types (and if this varies from one poly manufacturer to the next)? This is the sleeve that is clamped tightly between the shackle plates by the bolt. Thank you.
 
I don;t know about the durability of polybushes - I rechassied mine before they had been in a year. The failure mode of most of the metalastic bushes I've had seems to be rust starting between the outer cylinder and rubber causing the rubber to de-bond from the cylinder. I suspect this is due to using poorer grade steels. The ones in blue bags I got as spares a few years ago had gone like that, in their bags!
 
Yes, some of these were in clear bags with blue labels so may be the same source. (Last year I had a new master cylinder containing swarf from a blue-labelled box and so I have an open mind re quality of new parts ;)) Thank you for that thought re corrosion separating the bond as I hadn't thought of that. These are not ancient though but quite new. With the last one I removed, the rubber was quite well bonded to the outer as I remember it biting on the hacksaw blade. It seems that the mode of failure is the inability to withstand the immense twist/strain and the body of rubber itself rips apart. This is exacerbated by a thinner rubber section. It seems worse in those with more movement.
Are better ones available in different colour bags?
 
How often is this happening? I've had my rear bushes in for 5 years now and they are fine. Some of these types of parts come as relatively new aftermarket spares (their quite low tech to manufacture) and older original BL/ Land Rover spares. The latter tend to come in cardboard boxes with an oil coating and newer ones in clear/ blue plastic bags. If they are failing due to twisting affect it could be due to uneven torque settings on the bolts. Is it just one side or one end or at random?
 
If the rubber itself is failing it maybe is that they've used the wrong formulation of rubber, not vulcanised or cured it properly. I've been through all manner of different combinations of engine mounts. Some of the new ones are made of stuff so tough as to be like bolting the engine straight to the chassis, just unsuitable materials and processes. The best I found were some NOS ones...

It's not just blue-bag ones bushes though. The ones in my parabolics from GB Springs didn't last long either. (< 5 years). I've just fitted polybushes. I don't hold out much hope for those either but at least they should be a bit easier to get out, if very pricey.

Maybe these? https://www.lrdirect.com/548205-supplied-by-allmakes-branded-clayflex.html or genuine LR ones at £20+ a pop?
 
Hi thank you for your replies.
I've had the truck for about 15 years now and it's always been an issue. My bolts are all done up properly! I haven't kept written records of when I did which exact bushes but it's way too frequent. 5 years would be a dream! Sometimes it seems like it's the ones that articulate most that fail more often. The spring aft end sees shackle swing plus spring flex. The chassis bush sees shackle swing . The spring fore end sees spring flex but that also has drive thrust etc so it's hard to know for sure. My premises access is a 1/2 mile unmetalled track [driven most carefully] but one would imagine that my SIIA suspension was designed with that sort of terrain in mind.
dominicbeesley said:
The best I found were some NOS ones...
Click to expand...
Click to expand...
What are NOS? I never had problems with engine mounts. If they can get that right then surely someone's got spring bushes sorted by now?
Clayflex have been flagged before - any good? Or are genuine any better - I heard that some genuine items that were originally better are now restocked from lower quality sources? I'm loathe to buy more expensive ones if they are going to be just as useless.
Any info on poly bush inner sleeve OD?
Thank you.
 
Re engine mounts: The solid ones, on idle the car shakes like a ****ting dog, the properly soft ones it's all nice until the rubber peels off the metal then the engine's trying to climb out from under the bonnet! A lot of people think that series should be rattly (which is partly true) but the rover engine is a sophisticated (for 1950's) luxury car motor and shouldn't be rough....the ride's a different story!

I'd be tempted to give the Clayflex ones a shot. I'll try and remember to measure up the polybush sleeves this aft if I go to the workshop. Did you get all your old ones out? I managed to press 3 of the 4 original rear spring ones out with sockets on a bolt this time oversize socket on one side, socket same size as bush on the other and a big stout bolt through the lot tight bolt as far as it will go and belt it hard with a hammer, repeat...

Talking to one old hand he said on tipper trucks where he knew he'd have to replace them he would ream out the hole and slart with copperslip before refitting then dab a bit of weld to stop it spinning in the chassis/spring. Made refitting easier - just grind off the weld on poke out...
 
Thank you
I need to make a new tool as I broke the last one i made. I felt that a normal bolt thread wasn't really working and am looking at using a scissor jack thread.
I was going to make a large thread version for when there's no centre left in the bush and it's just the outer casing left. Then i'll hacksaw it out if that doesn't work.
Yes one of my chassis holes is a bit slack so gets the quick [no heat transfer to rubber] tack of weld to stop the bush clonking sideways.

Any way that's all secondary to getting a decent bush and is covered elsewhere.
Has anyone else used clayflex?
 
Getting those bushes out is a bastard job. I burn them out. Reaming the hole before fitting new bushes is advisable as the hole can be ovalled. Plenty copper grease and drive the new ones with a drift.
 
Hi
Thank you for your replies. I need to confirm the mode of functionality of those poly bushes. I presume that the outer surface of the poly stays still relative to the chassis hole or spring eye. I presume that the inner sleeve is pinched tightly between the side plates of the shackle. I presume that the whole thing works like a spitfire trunion in that there is some sliding movement between the poly and the inner sleeve and that it thus wears at that interface. (Or does the poly grip the inner sleeve and the poly have to twist?)
Regards |><|
 
Have poly bushes on mine currently flo-flex version only been on a year and one of the outer lips has shredded, went to fit my old ones which came with the springs 8 years ago and the tube was missing for the particular one I needed and you guessed it the flo flex tube is not the same size.
Ended up doing a bodge by using a piece of one of originals to go as a spacer between the inside edges of the flo flex ones .Back on the road but tightened all spring bushes up again , never had this problem with the originals supplied by Chris Perfect will have to have a look about to see what other makes are available at sensible costs.
 
Hi (I've been on the other SII forum for a bit.) Thanks for your reply. I'm trying polys today. My problem is that the top hat flanges seem too thick on the short ones (10off). They won't go up in the chassis gap at the front of the rear spring. In general the top hats don't meet in the middle. The inner sleeve seems as per metalastic. What happens to the flange excess as the bolt is tightened even if I do decide to go with it on the [width adjustable] shackle end? Sounds from your experience like it cuts in and shreds to pieces. Do I just jam it all in there and hope for the best. Other people seem to be adjusting the assembly. It just seems strange for a product billed as a quality part machined to exact tolerances.
 
moth said:
Hi (I've been on the other SII forum for a bit.) Thanks for your reply. I'm trying polys today. My problem is that the top hat flanges seem too thick on the short ones (10off). They won't go up in the chassis gap at the front of the rear spring. In general the top hats don't meet in the middle. The inner sleeve seems as per metalastic. What happens to the flange excess as the bolt is tightened even if I do decide to go with it on the [width adjustable] shackle end? Sounds from your experience like it cuts in and shreds to pieces. Do I just jam it all in there and hope for the best. Other people seem to be adjusting the assembly. It just seems strange for a product billed as a quality part machined to exact tolerances.
Click to expand...

Bending the spring mounts a little with a crowbar can be effective, and use lubricant, and maybe a few little strip of thin steel to guide the bush into the gap.

And just bolt up the other end, pull the bush in with the plates. It will do no harm.
Remember to let it all down on the road to settle it before tightening the bolts.
 
Thank you . A fellow Kernowbod.
Aha now we're getting into it.
I was under the impression that the sleeve rotated relative to the bush bore. When you refer to lowering before tightening are you saying that the whole poly bush twists and wrings like the metalastic rubber does? I thought it was moving more like a spitfire vertical link trunion. Does the chassis bending affect alignment?
 
moth said:
Thank you . A fellow Kernowbod.
Aha now we're getting into it.
I was under the impression that the sleeve rotated relative to the bush bore. When you refer to lowering before tightening are you saying that the whole poly bush twists and wrings like the metalastic rubber does? I thought it was moving more like a spitfire vertical link trunion. Does the chassis bending affect alignment?
Click to expand...

I think you are overcomplicating the situation. I have fitted a number of sets using the method I described.

Letting the weight settle on the wheels gets the bush, the bolt and the bracket lined up in roughly a natural position, then you tighten the bolt. Simples.
 
I am not over complicating but merely requesting a confirmation of one mode of operation or another. Sorry I don't see it like that so please bear with me. I agree that is the case for the old bushes. The two modes of operation I describe above are different. Which one is used by the poly bushes? People were talking about lubrication elsewhere. Lubrication is not needed for the old type so there must be a reason for their discussion.
 
moth said:
I am not over complicating but merely requesting a confirmation of one mode of operation or another. Sorry I don't see it like that so please bear with me. I agree that is the case for the old bushes. The two modes of operation I describe above are different. Which one is used by the poly bushes? People were talking about lubrication elsewhere. Lubrication is not needed for the old type so there must be a reason for their discussion.
Click to expand...

Oil or grease degrade metalastik bushes, they don't degrade polybushes.

Trust me, it is a simple job, and if you do a tidy job, follow the instructions and get the torques right on the big bolts, it is most unlikely you will get a problem.
 
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