New Kingpin & Trunnions - vague steering - any ideas why

[Dominic]

Hi folks

I have just spent the day fitting a new nearside kingpin complete with top & bottom trunnions. I also replaced the bushes on the tie bar. Could this have altered the steering geometry do you think? The steering wheel is a couple of degrees off centre now, and the car seems to wander a bit and feels a bit vague in directional stability. The steering also feels very slightly stiff around the straight ahead position. It will self centre up to a point, just not the last few degrees. Mind you it was like that before! It does feel much better when going over bumps however! I found that in fact the old kingpin was pretty good, the threads nicely "flatted" still, but the top trunnion somewhat worn. The lower one was replaced shortly before I bought the car last Oct.

If anyone has any ideas as to why it feels less "crisp" I'd be grateful to hear.

Cheers

Dom

[chrisd87]

Have you had the tracking re-set?

[Dominic]

Not yet Chris, I only finished the job at 7 last night Can anyone recommend any firm in Blackpool / Fleetwood area who can do the tracking?

[Peetee]

I had a similar problem with new uprights and trunions. The steering was much heavier. I put it down to tighter threads and using heavy grease.

[aupickup]

I also think this would be quite normal, maybe w eget used to driving cars etc with sloppy and worn bushes etc.
did you use poly bushes?
you do have to have a gap on the top trunnion bushes, can not remeber off hand what the gap tolerance should be, books are at my workshop, just done mine with new poly bushes all round and the eye bolt.

[Dominic]

Thanks for the replies chaps.
I used rubber bushes, and tightened the top ones as per the instructions in Technical Tips. I quote: "Only do the nut up 3 or 4 turns to allow some slop." (The gap tolerance I think was for the earlier type with the threaded pin.) ESM, from whom I bought the kit advised tightening until the nut was just touching the washer, plus a fraction more. I'm treating the car to some attention to the wheel tracking tomorrow, it'll be interesting to see what (if any) difference it makes! I need also to take off the brake drum again, I must have inadvertantly left a greasy thumbprint inside it... as it is now causing a pull to the opposite side when braking..... ahhh well..... no time to sit around bored these days!!!!

[bmcecosse]

Hope you set the trunnions on the king-pin correctly - to make sure they can swivel ok. I would tighten the top bolt much morte than that - you definitely don' want 'slop'. Almost certainly it's tracking - do it yourself - if the wheel was straight before - adjust the new side until it is again straight. It will now be close - but not perfect. make a simple tracking gauge from angle iron - I used dexion - but even timber will do - and measure in front and behind at hub level using the gauge and a six-inch rule. take 3 sets of measurements - rolling the car forwards 1/2 wheel turn each time - then decide if it needs adjusting or not.

[Dominic]

Yes BM. I tightenrd fully, then backed off enough so that they could swivel fully in both directions. It was about 1 1/2 turns slackened off. I'll have a play with some straight timber that I have. Maybe even invest in one of those laser line setting devices. For now however, I have to content myself with preparing the bathroom for redecoration!

[Willie]

there is no 'slop' in the top trunnion bushes you do it up until it will not go any
more! The only type which had any free play didn't have rubber bushes anyway and were very quickly modified. When you have the tracking set then remember that is should be 3/32" (2.5mm) TOE IN. Modern front wheel
drive cars usually have TOE OUT and the 'quick fit fitter' I used once set my
Minor to toe out!!

[aupickup]

i thought he meant the early type, not sure why i thought that doh