4 wheel alignment

Anonymous · September 10, 2004, 13:50

I'm just off to my tyre retailer Client to have the alignment checked now I've had new Bridgestone RE720s. I've been looking at the tyre review section and some of you folks appear to have had 45mm added ie:-

Rear: 205/55/15
Front: 185/55/15

Rear wheels: 6.5"x15" (OEM Toyota Offset +45mm)

Front Wheels: 6" x 15" (OEM Toyota Offset +45mm)

Surely, that can't be right? Should the text say 0.45mm ie less than half a millimetre?

All immediate assistance gratefully received.

s:D

s:D s:D

s:D

markiii · September 10, 2004, 14:03

Roger,

offset has nothing to do with alignment.

not being funny, but what do you think offset is?

Anonymous · September 10, 2004, 14:09

The offset isn't anything to do with wheel alignment or tyre size, it's the distance between the centre line of the wheel and the surface parallel to this that contacts the hub of the axle / surface of the brake disk. If that makes sense! s:roll: :roll: s:roll: s:lol: :lol: s:lol:

Using the correct offset is down to getting alloy wheels with the correct offset. I think the offset is listed in the tyre review section so other peeps can see what size tyres fit with non-standard alloy wheels (some wheels don't come in the standard 45mm offset) and if there are any suspension modifications - i.e. lowering springs, etc.

Edit; must learn to post quicker - beaten by Mark!

Anonymous · September 10, 2004, 14:12

markiii

I always assumed that "offset" was exactly as it said - the wheel's alignment was offset slightly outside the Toyota recommendation.

If I've got it wrong would you kindly explain (in layman's language)?

s:D

s:D s:D

s:D

markiii · September 10, 2004, 14:27

ok,

thought thats what was confusing you.

lets take teh front wheel.

it's 6" wide. imagine you split it down the middle such that you now have 2 3" wheels.

thats teh centre point from which offset is measured.

+45mm, means offset 45mm positive which is towards the outside face of teh wheel.

hence teh hubs position relative to teh outside face of teh wheel is 3" -45mm

relative to the inside edge it's 3" plus 45mm.

negative offset is teh reverse and if you see a deep dish wheel it will probably have a negative offset.

Slacey · September 10, 2004, 14:27

Roger, perform a search in Google for 'wheel offset explained', this is how I learnt the secrets s:wink: :wink: s:wink:

Anonymous · September 13, 2004, 15:11

RE720, very good choice!

Anonymous · September 16, 2004, 14:05

On the subject of "4 wheel alignment" I got mine done first by a bunch of amateurs (my fault but I really wanted it done asap and they could do it on a Saturday morning...). Although their equipment was the latest laser technology (it was 3 weeks old) these idiots at "Feu Vert" (equivalent of Kwik Fit in France) managed to completely srcrew up the alignment of all four wheels.

The car still had amazing grip in the bends (thanks to TRD WayDo Sportivo suspensions), but at high speed the car became almost "scary" as it wandered like hell. In fact, I could steer the car without touching the wheel, just by using the "thrust angle" effect (turns one way when accelerating and the other when decelerating).

I have been to some real professionals since and got my '2 all fixed up again... s:)

s:)

I've learned my lesson there...

Anonymous · September 16, 2004, 14:10

It actually worries me all this stuff, having 'proper' garages mess things up as important as alignment.

Maybe it is worth paying more, or maybe these guys where just new to the machine like you said and couldn't give a monkey's wrench about getting it right. From what I saw it looked pretty full proof.

Did you get a handout of all the values afterwards?

Anonymous · September 17, 2004, 09:10

Yep, they did (the 2nd time round) manage to print out a set of figures that appeared to be OK. And that's crazy, because when the car was checked by "real" pros, the results were *really* all over the place!

I think these guys didn't have much of a clue on how to use the system. The pros took much care on setting it all up. They think that these monkeys at "Feu Vert" probably forgot to do the runout test at the beginning (something you need to do otherwise your results can be all over the place)...

Best thing is word of mouth. In fact, in my case it was a Toyota garage that actually recommended me to go to that place (they said they would probably do an even better job than Toyota).

Anonymous · September 17, 2004, 10:06

Guys

No doubt someone on here more technically-minded than me may tell me differently, but I understand that the rear track rods on our cars are non-adjustable. All that a garage does is use their specialist equipment to line up the fronts with the rears. Also, I have been told that to do the job properly the car needs to be "loaded" ie both driver and passenger sitting in it. How else could you replicate normal road conditions?

s:D

s:D s:D

s:D

Anonymous · September 17, 2004, 10:09

I'm sure they altered something on my rears before, what i don't know, but i defo saw him messing around with the axel.

no one sat in it though - thats a good point.

Anonymous · September 17, 2004, 10:12

Quote from: "Roger H"Guys

No doubt someone on here more technically-minded than me may tell me differently, but I understand that the rear track rods on our cars are non-adjustable. All that a garage does is use their specialist equipment to line up the fronts with the rears. Also, I have been told that to do the job properly the car needs to be "loaded" ie both driver and passenger sitting in it. How else could you replicate normal road conditions?

s:D s:D s:D s:D

There are a couple of excentric bolts at the rear (with a graduated ring/washer): they are used to adjust the alignment (toe-in/out) of the rear wheels.

Adjusting them in the "neutral" position will normally give something pretty close to "normal" setting (unless parts of the supension have been modified or bent)...

Anonymous · September 17, 2004, 10:25

In the Toyota repair manual for the wheel alignment you are instructed to check the height of the car first, but that's for an unloaded car.

I'm sure that the "normal" settings published by Toyota are for an unloaded car (it wouldn't make sense if you had to load say 5 passengers in a family car each time you had to adjust the wheel alignment s:P

s:P ) They should be set so that when the car is loaded with passengers (maybe based on 2 or 4 passengers), the alignment is correct.

What would make sense is if you are generally alone in the car (say on a race track) then you may want to adjust the alignment with one person in the car to compensate for the resulting "asymmetrical" effect.