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Front suspension- lower wishbone queries


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Finally adding things together the chassis rather than taking them off!

 

I had two questions re the front suspension.

 

1) can I check: the lower wishbone brackets attach to the chassis at the front of the four holes in the chassis?

 

2) the bolt that runs through the lower wishbone and trunnion. Workshop manual says to torque it to 60lb/ft. But that's for rubber bushes not poly. Given poly need to rotate and it's a castellated nut also, how tight should this be?

 

On mine, too tight and it locks up. Also, however, it has to be pretty tight to get the castellated nut on far enough to put the split pin in.

 

Thanks all.

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Here is a good description on how to do this:

 

https://www.scribd.com/doc/842185/Front-Suspension-Rebuild

 

 

About your first question I am not sure but I think the lower wishbone brackets was attached to the rear pair of the four holes.

 

Regarding the second question 50-65 ib/ft seems to be correct, I tightened until it was too tight and then backed off until I could get the locking pin in, it needs to move freely. I remember when I did mine I had a problem with the trunnion was pivoting on the bolt itself, which is not correct. The trunnion should move together with the bolt, and pivot on the steel sleeves/bushings, if not the trunnion will wear out quickly so make sure this is correct. I had to redo one of mine but got it correct in the end, I think the problem was with the order of the washers.

 

 

Magnus

Edited by TRseks
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Hi Mark,

 

Just looking at the breakdown pictures of mine and it is the front set of holes...

 

Nick

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Hi Mark,

 

Just looking at the breakdown pictures of mine and it is the front set of holes...

 

Nick

 

You are correct, checked on my car and it is the front holes, thanks good to get that clear!

 

 

Magnus

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Thanks all. Thought it was the front but relieved I don't have to take it all off again. I did take a photo on breakdown but it wasn't clear which side it was of!

 

On the trunnion and poly bushes, I'm still a little confused. At 60 lb/ft, that pushes the outer bushes firmly against the wishbones so there's no way they will move. Same goes for the outer washers which are located under the bolt head and nut respectively. So I'm puzzled, at that torque, on which bits are supposed to move?

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I had this problem too. It was the water shield washers/o-rings that was squashed and prevented the trunnion to move. The o-rings needs to go around the bushings on the outside, and the metal tubes inside needs to protrude from the bushings so they will lock together and allow the trunnion to move together with the bolt after its torqued up. Also important to lubricate everything as it goes together. The main thing is that the though bolt should not under any circumstance rotate in the trunnion, the wishbones should rotate on the bushings.

 

 

Magnus

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Thanks Magnus. That's really helpful. In effect, your are saying that the bolt, the metal sleeves, the metal washers and the trunnion are all locked together, and rotate around the polybushes which remain static in the wishbones.

I can see that my problem is that the sleeves don't protrude, hence the bolt and washers lock to the wishbones and the trunnion rotates around the bolt.

I've seen people talk about some kits doing away with the water shield washers. I will look into that and also look into shaving something off the end of the polybushes. Frustrating, however, that it doesn't seem fit for purpose. ( and that I've also wrestled the springs back on now!)

 

Thanks again for the input.

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  • 8 months later...

now being in the posistion to fit all my front suspension together... has anyone got any pictures of top wishbone posistion and also the fitting of polybushes... i'm a little confused.... bag full of split and cotton reels type bushes but not knowing what gose where and if i need to omit anything from original while replacing with poly.,.. bush not the parrott.... :)

 

thanks

 

nick

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Hi nick.

 

See post above. I left the water shield washers off mine having spoken to a few polybushes suppliers. That way , the metal sleeves protruded as they're intended to and the whole lot (metal sleeves, metal washers and trunnions) all locked together as intended. Will see if I can dig out some pictures, but the bottom line is (I think) the polybushes stay static in the wishbone and all the metal bits I've listed above rotate together. At least that's what I figured.

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Seems to me that there was nothing wrong with the original design which used nylon bushes, water shield washers/o rings AND chromed sleeves. Anyone know if the chromed sleeves are available?

Whatever bushes are installed I would think that at least a stainless sleeve would be prudent rather than the bush rotating on a corroded carbon steel sleeve. So are there any decent kits out there?

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  • 1 month later...

The original design was a mess! End of. Road salt, water and dissimilar metals along with poor sealing a recipe for corrosion. I wasted a lot of time removing the trunnion bolts. A 9X rivet gun wouldn’t touch them. I had to resort to copious amounts of Freeway and heat and a 3/4 inch breaker bar and socket.

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I wouldn't say it was a mess. Nothing wrong with the nylon bushes and using plated bolts and copperslip along with a bit of maintenance usually resolves the corrosion issues. A stainless sleeve would be an improvement, but I don't know of any suppliers.

As this thread identifies, the replacement poly bushes cause the suspension to lock up which can only contribute to something breaking or bending. I pointed this out to the suppliers several years ago when I returned them.

Polybushes are fine almost everywhere else, just not in the trunnions where the original nylon is perfectly serviceable.

The bolt should not move with the trunnion as that would cause wear and oval holes in the wishbone. The bolt clamps the wishbone ends together using the sleeve as a spacer making it all rigid.

Jerry

 

 

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So, a ‘plated’ bolt, stainless steel or whatever sleeve, ‘copperslip’ bright steel nut, and steel washers, salt, water, some acid rain........ enough potential energy in that battery to start an engine...... while it all nicely corrodes together!:ph34r::lol:

Now JC5a or Mastinox..... highly dangerous and now banned I admit might help delay things for a while!

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6 hours ago, DaveN said:

So, a ‘plated’ bolt, stainless steel or whatever sleeve, ‘copperslip’ bright steel nut, and steel washers, salt, water, some acid rain........ enough potential energy in that battery to start an engine...... while it all nicely corrodes together!:ph34r::lol:

Now JC5a or Mastinox..... highly dangerous and now banned I admit might help delay things for a while!

Is this the sort of jointing compound you mean? - I recall using it where the airframe hung off our powerplant pylons.

LAS Aero offer it.

https://www.lasaero.com/products/article/Q01V6G0YD

 

Peter W

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55 minutes ago, RogerH said:

Hi Dave/Pete,

             I was wondering if it is possible to wrap that area of the wish bone assembly with Denso tape.

Not a lot of room to manoeuver.

https://www.ebay.co.uk/itm/Denso-Tape-2-50mm-X-10m-Tape-SU190/183376577628?hash=item2ab218845c:g:eq4AAOSwgQVaw7uD:rk:2:pf:0

Roger

My old man had a 4.3 alvis with the leaf springs wrapped in that stuff !!!

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Well Dave,

Maybe your suspension had not been maintained, and maybe off the road for years?

In my case I don’t know if they were the original trunnions bushings (going on 50 years) or replacements but the sleeves were chromed but worn.

I had no problem removing the trunnions bolts.

I do have reservations about the water seal washers and O rings, particularly the aftermarket ones that are round instead of square making assembly almost impossible.

So I would be willing to try poly without the seals, preferably if I could obtain, or knock up, stainless sleeves.

Suspension on our cars needs regular maintenance, and not just waiting for something to go wrong.

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@Peter that is interesting that you can still buy JC5a. I was under the impression that it had been banned due to its carcinogenic properties. At work it was replaced with Mastinox and that in turn was replaced with something called Corban 27.

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