Front trunnion bolt

[Roger K]

Hmm, looks like I might have a problem here. I simply assembled the rear trunnions assuming the parts were all good.  That wasn't too clever, as I had to modify the tin washers and the rubber rings just to get them in there, and thinking back to it I'm pretty sure the metal sleeves were significantly shorter than the plastic top hats when assembled.  There is also no gap between the plastic pieces once assembled into the trunnion, and the whole thing is tight, pretty stiff to move by hand.  

I have no old parts to play with as they were completely scrap.  Both Rimmers and Canley are selling the same parts I bought so I'm not sure if anyone else has anything better - google or ebay brings up new parts in varying colours, but without buying there's no way of checking dimensions.

I'm getting more drawn to the trunnionless setup.  The plan is to do a decent mileage in this car in all conditions, so reliability and low wear are prime considerations.  Anybody got real-world experience of the trunnionless kits?

[johny]

If it is a tight fit or wrong size I would remove thickness from the flanges of the plastic top hats with sandpaper on a flat surface and not touch the washers or rings....

NOS OEM kits do come up on ebay from time to time but command a premium exactly because of the problems described with new stuff☹️   

[Roger K]

It was the depth of the pressed flanges on the washers that was wrong.  Simply placing the tin washers between the trunnion block and the vertical link, with no nylon or rubber rings, showed they were about 2-3mm too wide and even rough assembly like that was impossible.  I had half of one of the old metal washers remaining, and it was much narrower than the new ones.  I ground the flange back and managed to get everything to fit, but I don't think it's right.  These parts are clearly not fit for purpose!  Unfortunately, nobody seems to make a 'trunnionless' setup for the rear...

[68vitesse]

I fitted polybush ones to the rear of my Mk1 Vitesse after the standard ones I bought did not fit, tube would not go in. The polybush ones where also not correct, the brake backplate could be rotated to much in my opinion, reduced the length of the tube to same as the one for the poly spring eye bush fitted at same time.

Well known make of bush used from a well known supplier, been fitted a few years now.

Have not used poly on the front trunnions.

Regards

Paul

[johny]

Its doubtful how much sealing the washers and rings actually achieve and I believe the polyurethane bush kits with stainless steel tubes dont even use the these parts... 

[68vitesse]

16 minutes ago, johny said:

Its doubtful how much sealing the washers and rings actually achieve and I believe the polyurethane bush kits with stainless steel tubes dont even use the these parts... 

They don't, just tube and two top hat bushes.

Regards

Paul

[Colin Lindsay]

1 hour ago, Roger K said:

I'm getting more drawn to the trunnionless setup.  The plan is to do a decent mileage in this car in all conditions, so reliability and low wear are prime considerations.  Anybody got real-world experience of the trunnionless kits?

For the front, maybe, but they don't have one for the rear as yet. I know people complain about the brass trunnion setup but yet many soldier on for years with no bother, just regular maintenance. The only one i've seen broken - and i've never had that myself - was due to grease being used, and a collision off a kerb, which revealed the use of unsuitable grease once dismantled. Nothing against trunnionless, everyone who has tried it swears by it (although I've heard that some of those have broken in the past, too) but I'll retain the original trunnion setup but with the addition of more modern bushes ie poly, which use materials the makers couldn't and are probably a vast improvement over top hats and sealing rings.

[chrishawley]

Going back to the stem of this thread.

A blob (or two) would be a good thing to do. Originally the wishbones did indeed have two blobs of weld to lock the head end of the bolt (such that one only needs a socket on one end to tighten things up). But with repeated reassembly they get worn off.

My experience of aftermarket trunnion kits has been truly appalling. So pay the money and get either NOS Stanpart, QH, or GKN (plenty around) or go polyurethane on an SS tube. No worth skimping on a safety critical component!

[Colin Lindsay]

28 minutes ago, chrishawley said:

Originally the wishbones did indeed have two blobs of weld to lock the head end of the bolt (such that one only needs a socket on one end to tighten things up).

They did? I know the brackets have a flange for the bolt head, which is machined into the side but never knew the wishbones had weld. 

 

[NonMember]

Indeed, I've never seen a "blob of weld" unless it's been molested. The factory used a pressed tag like Colin's photo (but without the years of rust pitting!)

[johny]

I dont think a blob of weld would have been a sufficiently robust way of holding the bolt head and anyway unnecessary as its pretty easy to get on both sides of the bolt....

[Roger K]

To be fair, Chris was suggesting weld for the same purpose I originally suggested, i.e. as an anti-rotation device, to stop the holes in the wishbone ovalling as the bolt starts to turn in them due to rusting to the internal sleeve.

I haven't seen any evidence of weld on original wishbones either, but properly done and with the right materials it certainly would be very effective.  

As it stands, for some time now it is clear that my front lower wishbone pivot has been the bolt in the wishbone holes.  The nylon trunnion assembly has been doing nothing.  The wishbones are pretty much scrap as the holes are badly worn, and there is severe pitting further inboard as well so new ones are on the way.

[Colin Lindsay]

2 hours ago, NonMember said:

Indeed, I've never seen a "blob of weld" unless it's been molested. The factory used a pressed tag like Colin's photo (but without the years of rust pitting!)

Nearly as old as I am, and almost as pitted... but the sandblasting didn't help, either.

[johny]

It does sound like the bolts are becoming loose over time and, even if prevented from rotating, the impacts from the road surface will damage the wishbone holes. Seems a very good idea to check their tightness on a regular basis....

[Roger K]

A nice double-needle-roller bearing in there would have been nice, like the Jag IRS uses on the lower outboard fulcrum pin.  Probably wishful thinking for a cheap-as-chips small car, though... nice winter project for someone!

[johny]

hey our front suspension was good enough for Colin Chapman and his Lotus!

[Roger K]

3 minutes ago, johny said:

hey our front suspension was good enough for Colin Chapman and his Lotus!

I'm talking about the rear - Jags use balljoints at the front.

You're right about the front end and Lotus, of course.  Not sure about the very early ones, but most Lotus racing cars I've seen had the thread machined off the upright and a rose joint fitted.... sound familiar?  Albeit with a redesign of the lower wishbone, an option we don't really have cost-wise.

So many of these modifications and performance parts come with label of 'racing spec', as if that's a good thing.  Racing cars are stripped, checked and any worn or damaged parts replaced every few hundred miles they cover.  'Racing', or 'competition' parts, don't have to last long at all, so I've never understood why this is considered a selling point (except to racers!).  The real world, with traffic jams, weather extremes, 12 months between services etc. is a far harsher environment than any race track, I reckon.

[Colin Lindsay]

1 hour ago, johny said:

Seems a very good idea to check their tightness on a regular basis....

There used to be this thing called the MOT...

[Peter Truman]

I think from memory the Herald/Spit front upright was also used by Brabham in his Formulea 1 cars, looked very similar not sure re the trunnion set up tho. 

[Roger K]

1 minute ago, Peter Truman said:

I think from memory the Herald/Spit front upright was also used by Brabham in his Formulea 1 cars, looked very similar not sure re the trunnion set up tho. 

Brabham used rose joints.

[Roger K]

I've got a set of polybush replacements for the nylon from Paddock to see what they're like.  As someone said earlier, decent quality with s/s tube and none of the tin washer/o-ring parts.  I can see that these should work just as well as the over-complicated parts that no-one seems able to reproduce, so will give them at least a trial fitting to see how they look while I'm waiting for the trunnionless kit.

Could someone confirm for me, or give their opinion, as to which parts are supposed to be the rotating bearing surfaces?  Is the tube supposed to rotate on the bolt (unlikely, given there's a torque figure which seems designed to hold the tube tight in the wishbone)?  Or is the nylon/poly supposed to rotate on the sleeve?  Or rotate inside the trunnion?  It seems an odd design to have a nylon bush rotate against metal as a bearing surface, although I suppose that's what a poly (not a rubber) ARB bush does...

[NonMember]

The steel tube is clamped solid, the nylon bush rotates around it. What's odd about that? Nylon is inherently slippy and makes quite a good bearing.

[Roger K]

Fine - I'm just more used to a more positive joint, I suppose.  That said I guess there's a lot of movement in rubber bushes, and a little bit in the screw thread*, come to that.

The trunnionless kit has just arrived, so I've had a play with that too.  It seems pretty well made as far as I can judge.  The upright link has 'Stanpart' cast into it, and is obviously a solid link that has had the thread turned off the base (on one, there is a faint hint of the remainder of the thread, just at the tip.  The spherical bearing is pretty heavy-duty in appearance, and is fitted from below - the internal circlip is on the underside.  My main concern is as noted on other forums, in that there is no real location of the lower part holding the bearing.  It is retained by the single bolt that previously held the trunnion, but does not pick up on the shock absorber bolt, which would have stopped any chance of the mounting rocking if the bolt should come at all loose.  I've attached a photo of it loosely assembled to a new wishbone.  I saw a post on one of the US forums in which two 'ears' had been welded to the new piece extending back to pick up on the shock absorber bolt, which seems a good idea.  Alternatively as the wishbones I'm using are not the originals I could run a weld along the top of each side, and beneath, to tie the bearing housing to the wishbone solidly.  The bearing itself would still be replaceable via the circlip below.  

Thoughts?

 

 

 

*  I don't mean play here, I mean movement as the joint moves, albeit a very small amount.

 

[johny]

Yes the original Triumph design isnt great especially as the bronze trunnion thread wears (exacerbated by lack of lubrication) and the play increases.

Your new sperical bearing assembly looks as if its shoulder plate is held against the bottom wishbone arms (it should be tilted more to the left than in the photo) by the action of the suspension spring against the resistance of the wheel on the ground. Then even if the bolt was loose I think it would always be held in that position so theres no need for any further fixings. However it does look like it should only be done up tight with the wheel fully on the ground....

[Roger K]

2 minutes ago, johny said:

Your new sperical bearing assembly looks as if its shoulder plate is held against the bottom wishbone arms (it should be tilted more to the left than in the photo) by the action of the suspension spring against the resistance of the wheel on the ground. Then even if the bolt was loose I think it would always be held in that position so theres no need for any further fixings. However it does look like it should only be done up tight with the wheel fully on the ground....

Yes, in the photo it's just loosely in position and without tightening the retaining bolt it droops to that position on the bench.  If I were going to weld it, I would do so with the shoulder parallel to the wishbone top, I think.  I take your point though, it may not need bracing anyway.  The recommended torque for the carrier nut and bolt is 55ftlbs.