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[Marks DTM Calib]

Got a series Land Rover on the drive wanting new front shoes and cylinders, bloody awful setup!

[Taxi_Driver]

....
Annual task on the Bullet, bloody thing. No idea why. Even that DTM fella has stripped them, then immediate failed MOT on efficiency

So much for 'use it or lose it' then      My handbrake get used EVERY year at MOT time       

Must admit.....in the 3 years i owned my 2.2, i never used the handbrake.....it always passed the MOT.....in fact i think it was the only thing that didnt go wrong with it 

[Webby the Bear]

G'day boys, hope you're all loooving the extra warm weather  it's certainly been a tad warm in the workshop this week 

Anyhow, I don't really see taking much more about the brakes as I've covered most of what we've learned already. however I would like to quickly talk about brake servos. I didn't realise that if there was no brake servo (a line from the master cylinder to the air intake using the vacuum created to help pressurise the brake fluid) then it would be virtually impossible to depress the brake pedal hard enough to brake. interesting! In addition the actual length of the pedal is there to ease drivers' effort.... if you think about it it does makes sense as your using torque (leverage + force) to aid the driver

Ok down to the stuff we've been doing this week and I have found it VERY interesting...

STEERING:

This week we mostly been looking at rack and pinion racks 

This is a power steering rack (note the metal lines which are for power steering fluid. note also the track rod ends are attached in this photo)

the operation of the steering rack is very, very simple. the 'pinion gear' is what you see coming down in to the rack. when this is spun round (by connection to the steering wheel) this gear moves the ''rack'' gear left or right...this is connected to the hub via the track rod ends and affects its left to right motion by pushing the hub inwards and outwards.
from an alignment point of view it is important to note that in most cases the steering rack is positioned behind the centre point of the hub.... as per my awesome paint picture 


......but we'll come nore on to the alignment in a few 

Anyhow sadly we weren't allowed to take a rack out of a car  that sucked cos I know that theyre hard to do and I really fancied the challenge. but nevertheless we were tasked woth removing and replacing a track rod end.
jack up, support on stands, remove wheel.
undo the nut securing the track rod end in place. then undo the nut on top of the ball joint and use a ball joint chisel....

....to separate the ball joint and relieve it of its' place in the hub assembly. (chisel is wedge shaped so as you hammer it in, it separates further)

a pic of the balljoint clearly protruding from the steering rack and attaching to the hub assembly...


a pic of the one on the Renault Migraine Megane that I did...


a pic of the tie rod twisted off and ball joint knocked out (note the pic is of it resting on the control arm in case you're wondering about its' odd orientation. and soz for bad photos  )


before you get to this point you would have held the road wheel (with it attached obviously) and shook it to look for play. if there is any is probably this track rod end. when track rod end off look for cuts in the rubber boot (or gaiter) and press it in and move it around and look for ease of/excessive play. if so REPLACE 

We also removed and replaced the gaiters (rubber boots) on the steering rack with them in situ. look for cuts or wear. if needed to replace. not much to say about that really other than use side cutters to break the metal clip and pull gaiter off. I suppose you should replace the metal securing rings/clips but we used cable ties. is that acceptable in your opinions???

as I said I really wish theyd let us actually pull a rack  but now to the fun bit 

TOE ALIGNMENT

This, as far as I can work out is specifically the alignment of these track rod ends that attach to the steering rack. note I haven't touched the camber adjustment yet 

firstly I need to explain degrees and minutes. you know what a degree is in terms of angles (surely?  ). minutes are a fraction of 1 degree and there are 60 minutes in a degree... very small angles i'm sure you'll appreciate. I should also explain that toe out is referred to as ''negative'' toe and toe in is referred to as ''positive'' toe.

ok so generically speaking when talking about what the track rod ends do (at the front of the car)..... RWD cars tend to toe out i.e. when the power comes on they want to push outwards. FWD cars tend to toe in i.e. the wheels wants point inwards. This is reflected in the toe settings...

[Webby the Bear]

CONT...

A spec (from Autodata) for a FWD Corsa 1.6 I had to do was ''0 degrees + 10 minutes N +/- 10 minutes''. this shows that when pointing forward they should be 0 degrees (i.e, parallel) + 10 minutes negative with the tolerance being +/- 10 minutes.

So with the corsa settings you can see that they want it set up to toe out slightly to compensate for the fact that, as a FWD car, it will naturally want to toe in when driving. I hope you understand that...if not i'm confident that someone like mark/andyb/entwood etc will be able to explain it better than me  but fortunately I do totally understand it 

an easy way to view it is to use a table (like the one below). note on there your spec and your initial reading and youll be able to see how much you need to move it and give you a good sense of where you are...

as a very rough guide if youre having to adjust the toe by 1 degree or more... you've had a big problem!

ok, so now comes to setting the toe angle  ......................

by no means is it difficult...but I put a lot of cheesy faces cos I think its a bit of a dark art and despite my teachers' assurance that the gauges we've got are accurate I doubt them very much. of course I cold be wrong and they may be fantastically correct. let me know what you think but I think its a hack way of doing it and to me its inaccurate. but as said we'll see what the experts on her think 

Anyway.... to the set up...

in short you set one side up against the rim of the car. match that up to the other side.
you then set them up so the mirror side I on the N/S front wheel and the one with the viewing tube is on the O/S front wheel. you look in the viewing tube and adjust the little dial to get the triangle lined up...once lined up look at your gauge and it will show you how much you're out by.

this next bit is important and fekking difficult to explain......

if, after taking your initial reading, you need to toe out to get it in to spec you would need to shorten the track rod and you would need to turn the track rod anti clock wise.

if you need to toe in you'll need to lengthen the track rod and turn it anti clockwise.

this is all because of the track rod sitting behind the centre point of the hub and therefore its that that dictates how you move the tie rod. ..... as its sat behind lengthening toes in, shortening ties out.

soz I know my explanations shite but ill have a think and try to explain it better.

Well in addition to the above we took apart a steering rack. pretty cool. and FULL of grease. here's a pic of the rack gear shaft


Anyway look forward to the comments on quite a bulky post.

[Webby the Bear]

OMG just noticed in that last photo josh was sticking his finger up  little b*****d! i'll smack him tomorrow for that 

one thing I shoulda mentioned..... before you unscrew the track rod end...count the threads that are showing. therefore youll get it about right when you refit it.... although you will for sure need an alignment 

[henryd]

Same set of tracking gauges that I have,old but do the job

[Webby the Bear]

Same set of tracking gauges that I have,old but do the job

Fair play mate. The reason I couldn't see them being accurate is cos when lining the pins up to the rim its not accurate at all. in fact it was more of ''if each pin touches the edge of the rim that's ok..... but how can it be when the tolerances we're talking about are 1/60 of a degree 

 

[symes]

Same set of tracking gauges that I have,old but do the job

I got a set like that too-ok but not as good as laser-however they were free

[Andy B]

.....
I didn't realise that if there was no brake servo (a line from the master cylinder to the air intake using the vacuum created to help pressurise the brake fluid) then it would be virtually impossible to depress the brake pedal hard enough to brake.....

Not quite true. If you've ever been towed in your Omega, you'll realise how much more force is needed to stop your car when there's no vacuum assistance (likewise your steering is difficult because of the lack of assistance - but not all cars have power steering  ). The Omega's brakes were designed with a servo in mind ...... but when the world was in black & white it was quite common for a car not to have servo'd brakes. These brakes worked OK in normal use because they designed to work without a servo, but you had to shove the pedal a bit harder yourself because of course there wasn't any assistance.

[Kevin Wood]

My Westfield doesn't have servo brakes. Ok, it's 1/3rd the weight of an Omega but the pedal's still reasonably light. Depends on the ratio of master and slave cylinder diameters and also the leverage of the pedal as it acts on the master cylinder.

[Andy B]

My Westfield doesn't have servo brakes. Ok, it's 1/3rd the weight of an Omega but the pedal's still reasonably light. Depends on the ratio of master and slave cylinder diameters and also the leverage of the pedal as it acts on the master cylinder.

Thinking about it, neither does SWMBO's Smart Roadster .......   

[Marks DTM Calib]

This bloody Land Rover does not ahve Sevo brakes either.....even if it did they would still be rubbish 

On the wheel alignment, on the optical setups I always put them together (rim tips to rim tips) and check that they read a zero toe angle as a quick check for accuracy before use as they can get bent and damaged!

They are pretty accurate though (assuming the wheel rims are oka dn the alloy/rim is not buckled!)

Also make sure the steering rack/box is centred before any adjustment

[omega3000]

OMG just noticed in that last photo josh was sticking his finger up  little b*****d! i'll smack him tomorrow for that 

one thing I shoulda mentioned..... before you unscrew the track rod end...count the threads that are showing. therefore youll get it about right when you refit it.... although you will for sure need an alignment 

You can do that but i always count the turns or you can put some tape on the thread as a marker , never had any problem with wheel alignment after  Having a wheel alignment will of course confirm any adjustment needed but im a tight git and never do 

[Webby the Bear]

This bloody Land Rover does not ahve Sevo brakes either.....even if it did they would still be rubbish 

On the wheel alignment, on the optical setups I always put them together (rim tips to rim tips) and check that they read a zero toe angle as a quick check for accuracy before use as they can get bent and damaged!

They are pretty accurate though (assuming the wheel rims are oka dn the alloy/rim is not buckled!)
Also make sure the steering rack/box is centred before any adjustment

Then I stand corrected  I just thought that with the fact that youre just eyeballing the rim tips it cant be that accurate.

one other thing where I feel its not very good is this..... say you have to toe in to get the setting in to spec. therefore youre going to make the rack longer if its positioned behind the centre point of the hub.... say you start off with half a turn on the O/S/F then switch and do half a turn on the N/S/F...........what happens if youre 1/2 a turn is actually nearer 3/4 cos you've got burst sausage fingers and have crap manual dexterity? yes, youll eventually bring it in to spec but surely it'll still be wrong as you wont have each side perfectly the same length 

hope that makes sense lol

[Marks DTM Calib]

The issue with counting the turns is that it assumes that the replacement part has the same distance between the thread start and track rod end pin centre.......and there in lies the issue as many OEM parts don't.