front tie rod bushes .. guidance and spanner size?

[xpress]

hi there.

picking your brains again, i have the front bushes to do, the ones where the tie rod meets the front chassis box section of the car, (just under the radiator). best procedure for doing this, should i count the number of threads so i can put it back on identically, and will i need some heat on that nut? also what spanner size would i be needing/tools for the job so i can be prepared? just wanting some guidance so i can be prepared from someone that's done it before.

thanks.

[bmcecosse]

3/8" Whit IIRC - same as wheel nut. Just do it up tight as you can! And yes - if it's not been touched for many years - may indeed need heat to get it off.

[jonathon]

You should re-assemble the tie bar assembly then lower the car onto its wheels, then tighten the bolt to just pinch up the bushes.Ideally measuring the KPI angle whilst doing so, If you simply tighten up to the stop this will damage the bushes and corrupt the KPI angle and subsequent front end geometry.
Not many folk bother about this aspect of their car, but it can make a huge difference to the handling and enjoyment in driving the car.

[xpress]

cheers for the replies!

jonathon: what would i use to measure the kpi angle, should i measure it before taking them off and then after? what would the process be for this?

thank you.

[jonathon]

If the bushes are already worn, then there is no real point in measuring the KPI at this stage.
We need to remember that Camber,Caster, and KPI are all interlinked,ie the more caster you use the less KPI is required.
Most DIY people will not have the correct mesuring gear to check all 3 elements of the front end geometry. They can be measured individually but you will need an angle finder and know the correct requirements for taking these. So for most and ourselves you are best to use multi set up guages.
Before doing this you need to make sure that the trunnions are in good condition the eyebolt is not worn,it has the pin and bushes in good condition, The top trunnion pin and bushes are in good condition. There is no play in the top lever arm, The tie bar link has no play and the through hole foe the tie bar bushes is sound and not ovaled, the cup washers here need to be in good condition. You will also need to account for wider wheels, or different offsets if these have been fitted.
Or as most Minor owners do, simply fit the bushes and tighten up the nut and not bother too much

[bmcecosse]

As far as I know - these should be tightened up right to the end of the thread - same on Minis. This will pull the castor angle up as much as possible - but if you want more, you can always take out the little rectangular washer (if it's not been lost already) which will pull the lower arm forward another 1/8" or so. Increased castor makes for more negative on lock (which is a GOOD thing) but also makes the steering heavier! Remember to re-track the wheels after doing any work in this area.
Do you have full suspension alignment equipment at JLH Jon ?

[Declan_Burns]

I tried replacing these bushes last week but I found the rear rubber tie bar bush impossible to fit. The new one (rubber) seems to be far too thick and there is no way I can fit it without cutting the bush to size. Any ideas or should I go for Jonathan's adjustable ones as my rear bushes are pretty shot and I would like to replace them?
Regards

[bmcecosse]

The rear bushes do little - the front ones take all your braking forces on the front wheels. A method of getting more castor is to use reduced thickness rear bushes - and washers under the nut so the arm can be pulled forward even more before the nut bottoms on the thread.

[jonathon]

Roy, yes we have full 4 wheel alignment facilaties, I did post images some time ago, which I have since lost due to puta crash
. The trouble with fully tightening the nut and retaining washer is similar to that of overtightening the top trunnion bushes when the car is not at laden weight , it compromises the bush performance and can lead to premature wear.
Declan the reason we designed the adjustable bar was to eleviate this problem as the bushes ( Superflex poly included) can only be tightened to their optimum position and then the rod adjustment will give you an accurate KPI measurement.

[Declan_Burns]

Thanks Roy,
I'll try cutting them back when I get the chance and see how I get on.
Regards

[bmcecosse]

You probably will do better to have the tie-rod disconnected from the lower arm - so you can line it up straight through the hole - get the bushes on - clamp them up and get the nut started! Sometimes works better if fitting an old bush on the rear - and a new one on the front - where it matters.

[jonathon]

Does this issue with the bushes , not indicate that all is 'not' as it should be. Surley there is no need to cut bushes ??
Roy, I can only say that if you tighten up as you say and the KPI is spot on then fine, but if the bushes are distorted as would be in Declans case they will not last long nor perform well.
If you find that the KPI is wrong then how do you adjust it, were only talking 5-8 degrees as a std set up.
I'd prefer to let the bushes do their job correctly and adjust the tiebar, that is if you have an adjustable one

[aupickup]

i used superflex tie bar bushes and all fitted well

[bmcecosse]

The 'cutting' of bushes would only be to increase the castor to a setting rather more than standard , and yes - by pulling the base of the kingpin forward. The KPI is to do with camber - if we pack the eyebolt out slightly - we increase the KPI and the -ve camber (or at least - reduce any +ve camber!!) . I'm convinced these tie-rod bushes should be fully compressed - by tightening the nut to the end of the thread. However - this may not be possible with poly bushes front and back because they are so stiff and I believe an acceptable solution is to use an old rubber bush at the back - and a new poly bush at the front. If the castor is still not sufficient - remove the rectangular washer at the lower arm mount- i've never been able to understand what it does there anyway !
Take some new pics of your suspension setting gear - and post them up Jon! I have to make do with a spirit level - and a tracking gauge made from Dexion. It works! Same readings if I do it 3 times!!

[bmcecosse]

And - did you tighten your nuts up fully ( ) Dennis ??

[les]

The rectangular washer spreads the load; the front lower arm is pressed steel.

[bmcecosse]

There is no load on that side - any load on the tie bar is a tension reaction to the braking forces - and so the 'pull' comes on the back arm - the heavy forged one ! If it was a front wheel drive car - I could maybe see some sense........

[Declan_Burns]

Declan the reason we designed the adjustable bar was to eleviate this problem as the bushes ( Superflex poly included) can only be tightened to their optimum position and then the rod adjustment will give you an accurate KPI measurement.

Sorry Jonathon, I overlooked your reply and only noticed it after I wrote that I'll cut the new bushes to size which I'm not keen on doing. Seeing that I have teflon eybolt bushes fitted makes it even more difficult getting the tie bar back in. Thanks for the info. I' go and check the piggy bank next.
Regards
Declan

[bmcecosse]

Oooh - 'teflon' sounds very hard ? Are you sure ?? It's normally used for bearings (in industry) - but a bit too hard for a bush like this where some compliance is required.

[Declan_Burns]

Roy,
I'm sure. The Swiss Morris Minor club sell them. I fitted them three years ago and I agree they are a bit hard and they do not flex. I have had absolutely no problems with them and I do check the set-up regularly. If I ever have to replace them I'll go for Poly. The Swiss have better roads than we do-ours are in a terrible state!
Regards
Declan