Rear Wheel Tracking

[milliemarlin]

Re: Rear Wheel Tracking

The above dimensions were taken with a ride height of 210 mm. I measured this just in front of the rear trailing arms on the flat flooring.

I tried jacking up the rear of the car to get the rear wheels approximately vertical. Increasing the ride height by just 35mm. It made little difference (0.5 mm max) to the toe in.

Bit of a disappointing, if not expected, result.
Paul

[greyV8pete]

Re: Rear Wheel Tracking

My ride heights are 260 mm under Front X-Member and 230mm under rear floor. Even this gives only 125mm ground clearance under the twin exhaust silencers!!! I have to watch uneven roads like a hawk and some roads with the ridiculously high speed bumps are off limits completely!
Peter

[greyV8pete]

When I had my old Sierra I remember that the N/S/R wheel also appeared to have about 5mm toe in which seems to be the same as you are seeing. So is it an inherent jig error by Ford that has been faithfully copied by Marlin for their chassis jig or is there a hidden reason why Ford made it like this for the Sierra? Seems a bit odd as you would think that N/S/R outer edge tyre wear would be noticable but I don't remember this as being a problem.

For years I have always checked toe in using 4 pieces of string 2 rubber bands and 4 bent nails, two pieces of wood and a 6" ruler! No this isn't a joke!

Method: Each side of the car, use 2 pieces of string slightly shorter than half the distance from front to back tyre. Tie the centre ends to the rubber band. Tie the outer ends to the heads of the bent nails. Use the bent nails to hook the stretched string around the front and back tyres locating into the tread. Make sure that the string it stretched across the center of the wheel.

Find the track of the front and rear wheels for the vehicle**, subtract one from the other and divide by 2. Cut two 4" lengths of wood of this thickness and place them between the string and the tyre wall nearest the nails, at whichever end of the car has the narrowest track. The string will now create two parallel lines along the car.

Measure from string to wheel rim using ruler. Sapristi! You have the toe in!

** Now for my question. Do you know what the front and rear track widths are for the Cabrio? I need to know this asap as I have just stripped the front suspension on my Hunter to fit new Supaflex bushes to the ARB mounts and TCAs and need to use the above technique to check my toe in! I can also have a look at the rear for you at the same time!

Just spotted that this second post should be from me (greyV8pete) and not KitCarGirl as the post/avatar suggests. Must have been scrambled during the new website migration. Peter.

[chris_cussen]

After scrubbing my rear tyres in 7000 miles I got my local friendly garage to check the alignment of my cabrio and compare it with the standard Sierra figures. All the measurements were within published tolerance.

[greyV8pete]

I have just rechecked my toe in following the new front ARB fitment. Fronts are re-set at 1.0mm toe in each side (as per original / Sierra) but rears still give 4.0mm toe in PER SIDE! Due to the scrubbing this causes, as originally highlighted by Derek, my latest rear set of Toyos continue to show excessive wear towards the outer part of the tread and also show some finning on the outer edges of the main tread blocks. I guess the hub carrier shimming is now right at the top of my 2011 "to do" list. That's after the dual servo project of course :-) Peter.

[Mike]

After scrubbing my rear tyres in 7000 miles I got my local friendly garage to check the alignment of my cabrio and compare it with the standard Sierra figures. All the measurements were within published tolerance.

Chris

That is upsetting news!
I had hoped the correct alignment of the rear would prevent premature wear. I assume it is premature wear, and not just energetic driving on very soft rubber?
I used to knock out a pair of front tyres on my A4 in 13k miles, and was told this is normal for front wheel drive and wide tyres. My BM is doing much better - 20k miles and still on the originals all round.
Mike

[CosworthCabrioLee]

Well over the last 2 days I have fixed my Cabrio, what I found was the wheels where toeing in 7 degrees, so after various measuring with the tracking machine, and several shims later I have now got 31 thou shim in each side, giving me 0.5 degree toe in each side and 1 degree negative camber. First impression is the car pushes a lot easier.

[chris_cussen]

Well the tyres were budget ones and had done only a few miles on my wife's Mondeo before I knicked the wheels and tyres, but I suppose you could have called my driving spirited.

The wear was absolutely even across the tread with no indication of feathering.

[jpmillington]

Re: Rear Wheel Tracking

I’ve just seen this.

In another thread I described the issues I was having with my car – well, following discussions with various club members (including Danny Nelson) the car ended up with John Butler at Vindicator Cars and I finally collected it today.

One of the issues John picked up on immediately was the toeing in of the back wheels. The tyres were feathering a little, but, given my low mileage it hadn't become a real issue for the tyres. John was more concerned about the stability etc of the car over bumps and when cornering hard. To be honest it's not something I was really aware of, but then I'm not the quickest of drivers.

Like Lee he's cured this by fitting some shims he manufactured. He demonstrated the car's new road-holding to me this morning. Even I could notice the difference!

I asked John to put together a note on this which I could send to PitStop (before I saw this a few minutes ago and realised that others had picked up on the same issue).

John

[boydell]

I know I’m a bit late to this particular thread but I only learned about it a the Newark Show yesterday(23/07/2023). Have checked mine and in the process measured my track difference to be 7mm narrower on the front which made it easy as a 3.5mm drill bit taped to the front tyre sorted it for the string method. Rear toe in on my cabrio is 3mm both sides. The fronts wereall over the place which explains the driving on ice feeling in the rain yesterday - now sorted. Oh and these measurements were at ride heights of 275 front cross member and 245 rear cross member

[rhysnolan]

I have spent time today re-reading "How to make your car Handle" by Fred Pugh, one of the bibles for this. He says either zero toe in on the rear or "just a touch". Toe out will cause wandering and reaction to road surface changes. (High speed instability). There is a lot more, he pays much more attention to this at both ends of the car than camber.
He does start by establishing a centre line on the chassis, permanently marked and works from that with string lines.

[marlinmick]

A few weeks ago I went to the Kit Car Festival at Newark. It was a very wet journey from Derby and driving my normally quite stable Cabrio was like wearing roller stakes on an ice rink the back end stepped out horrendously on both left and right bends and especially on going over manhole covers. Taking it easy on slightly drier I later arrived home safely. I have known for a while that the rear tracking was out of alignment and have even discussed it with Alan Hogg a very experienced Marlin Custodian.
So referring to the MOC Cabrio Forum I set about checking and adjusting the alignment and the result was that the offside was 6mm toe in and nearside was 7mm toe in. So out came the vernier callipers and the shim material. If you could be bothered you could work out the exact shims required by maths but I just did it the practical way by trial and error.
I ended up with 0.059" shims in the o/s and 0.069" shims in the nearside, these shims left me with 0.020" toe in on both wheels.
The test drive was absolutely astonishing it was a totally different car even in the wet and over manhole covers, it now incites me to drive it even harder (I don't anyway) but it's definitely more confidence inspiring even with the feathered rear tyres.
I did a brake fluid change as well and fitted new rear cylinders.
A worthwhile day's work, now to sort the front springs out!
The next day it passed the MOT with no advisories.

Regards to all. 366355635_840965667438887_1633738290771844967_n.jpg 366359427_840978774104243_4604630577052750077_n.jpg 366364762_840965554105565_830438252771518257_n.jpg
Mick.