boxofbits Posted May 8, 2016 Report Share Posted May 8, 2016 Good afternoon all I've been taking another look at my front suspension for poor self centring. Does anyone know if the uprights are stamped with a part number? They appear visually to have negative castor but wanted to verify with a number or anything that identify's them. Also lower trunnions- are they part numbers and handed due to different shape/ angle? Any help much appreciated. Regards Kevin Quote Link to post Share on other sites
peejay4A Posted May 8, 2016 Report Share Posted May 8, 2016 Can't help with part numbers but the VLs are handed it's positive castor, they lean towards the rear. The trunnions are also handed on the 4A. Quote Link to post Share on other sites
RogerH Posted May 8, 2016 Report Share Posted May 8, 2016 Hi Kevin, I don't know if the part number is stamped on the Vl's but if you look and find numbers that are similar but out by one then that may be a clue. Righthand items have odd numbers 307215 and lefthand items have even numbers 307216 (Moss VL numbers). http://www.moss-europe.co.uk/shop-by-model/triumph/tr2-4a/steering-suspension/front-suspension/front-suspension-tr4a.html I think it would easily be possible to fit these on the wrong hand. If you think the top of the VL is pointing towards the front then it is on the wrong side. The early TR4 had 0' castor. Also it is easily possible to fit any of the wishbones arse about face. If you think anything is at fault then it would be easiest to take it all apart and start from the beginning in getting it sorted. Roger Quote Link to post Share on other sites
boxofbits Posted May 8, 2016 Author Report Share Posted May 8, 2016 Thanks guys and Roger, yes it is prob best to rip it all off and double check. My belief is that if something can be arse about face, and there's two chances, it usually IS arse about face!! I've gotta do the inner wishbone bushes top and bottom as they're beginning to fall apart so I'll give it a good overhaul next week. Regards Kevin Quote Link to post Share on other sites
littlejim Posted May 9, 2016 Report Share Posted May 9, 2016 (edited) got this bit the right way round? There was a bit of discussion on which way the upper fulcrum should go on when I did mine. Edited May 9, 2016 by littlejim Quote Link to post Share on other sites
Lebro Posted May 9, 2016 Report Share Posted May 9, 2016 Looks wrong way round to me !! but the castor angle is correct. Bob. Quote Link to post Share on other sites
boxofbits Posted May 9, 2016 Author Report Share Posted May 9, 2016 Looks wrong way round to me !! but the castor angle is correct. Bob. Looks like the top arms are the right way round as the one with the bigger angle should be on the front to push the link backwards at the top. I did check mine yesterday and they seem okay. I am sure someone on the forum said the links have a castor angle built into them also as they are handed and can be fitted on the wrong side. I had a quick look at these and the lower trunnions, and they look symmetrical at a glance, but again have different pt numbers. Anyone know the difference between the links and trunnions ( assuming you can still fit caliper/ steering arm correctly regardless of which side the link is on)? Regards Kevin Quote Link to post Share on other sites
Lebro Posted May 9, 2016 Report Share Posted May 9, 2016 It is the trunnions which have the castor angle built in. The links are straight, but one has a right hand thread & the other a left hand thread. These then have to match the threads in the handed trunnions. If your top wishbones are as in photo above then you must have the links, & trunnions on the correct side. Bob. Quote Link to post Share on other sites
boxofbits Posted May 9, 2016 Author Report Share Posted May 9, 2016 Thanks for the info Bob I'll have a good look at it this weekend. The steering is not tight when centring, but it does not really self centre as much as you might expect. Other than that, there is no tightness anywhere in the suspension, which is why I thought it must be geometry. Regards Kevin Quote Link to post Share on other sites
littlejim Posted May 9, 2016 Report Share Posted May 9, 2016 (edited) If you are talking about feel on the road, the toe in/out of the two rear wheels on the 4A affect it too. When I first got mine cornering would start off as understeer then snap in to to oversteer, which made it rather exciting on some bends. After the refurb I kept reshimming the rear suspension arms until I got as close as I could to zero toe in on both sides. The handling is great now. Neutral to mild understeer. Edited May 9, 2016 by littlejim Quote Link to post Share on other sites
boxofbits Posted May 10, 2016 Author Report Share Posted May 10, 2016 Hi Jim Cornering and feel in the road is not too bad though I'm aware that the rear radius arms are not quite parallel to the chassis and something I need to sort. I softened off the front dampers on Sunday (AVO's) and it reduced oversteer a little. I plan to do front and back geometry together and will use simple stuff like plumb bobs, chalk, a parallel bar for tracking, tape measure and a simple camber gauge. I let some lunatic loose at a tyre centre with some over complicated digital laser light contraption on my Zafira and the front tyres started scrubbing out within a few hundred miles! Quote Link to post Share on other sites
stuart Posted May 10, 2016 Report Share Posted May 10, 2016 Looks wrong way round to me !! but the castor angle is correct. Bob. No they are correct. All IRS chassis cars have top inner wishbone bracket curve facing the shock absorber mount. All earlier cars have them the opposite way round as otherwise they would foul the shock absorber top mounting as they have a different top plate on the tower.. Stuart. Quote Link to post Share on other sites
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.