Tyre wear

[Boris64]

I need a bit of advice please.

The following photos show near-side front, off-side front and nearside rear tyres. All are 3,000 miles old.

Front tyres are both wearing equally and consistently all round on the outside edge rather than across the full width.

Rear tyres are fine and wearing consistently across the width.

Is this a fault in the front setup (suspension, wheel/tyre) or junior mechanic's over enthusiasm?

Thanks

Pete[frame][/frame][frame][frame][/frame][frame][/frame]

[bmcecosse]

Looks like excessive toe-in at the front. But could also be excessive +ve camber -check with spirit level or plumb bob. . Very slight -ve camber is best we can hope for. Note - if you live in a town with many roundabouts - the nearside front will always take a pounding on the outer edge. Worth swapping them over from time to time.

[Boris64]

Bmc

thanks for the reply.

I've had a quick search on here and on Youtube.

It looks like a chance to learn another couple of diy skills

Pete

[kennatt]

why not just take it to a tyre depot and have the tracking checked/adjusted,it's not that expensive,then swap the front to back,because once they start to wear unevenly they tend to continue on the front,but don't seam to do so if on the rear.

[bmcecosse]

That front nearside is pretty much illegal now....... Tracking not expensive ??? Aye right.... it's a 20 minute DIY job..and often upwards of £25 in a 'garage' ....

[Boris64]

Kannatt, Bmc,

Thanks for the replies.

I had exactly the same thought on moving the tyres around but as I'm a diy fanatic I'll go the bmc route and hopefully learn a bit along the way.

I have a real belief that if someone else can then so can I.

That's me just to the left of Neil Armstrong

Pete

[autolycus]

The trouble with taking it to an ordinary tyre place is that they probably won't know how to adjust the camber by packing under the eyebolt, and until this is right there's no point in adjusting the toe-in, as varying the camber changes the alignment. They probably won't have a Whitworth open-ended spanner for the locknut, either, so will either use a spanner that rounds the corners or stillsons.

A compromise, given that toe-in is harder to measure than camber, would be to set the camber yourself, wire brush and get the PlusGas on the track rod ends, slacken and re-tighten the locknuts, then take it to a garage for final toe-in setting.

Kevin

[Boris64]

Autolycus

thanks for the reply - I wondered if the Whitworths would ever see the light of day again

Can you advise what depth of shims/washers I need to change from factory +tve to appropriate -tve camber?

Also what is the hole diameter of packing washer? Junior mechanic has the car at the moment.

Thanks

Pete

[IslipMinor]

Unless there is significant wear in various parts of the front suspension, your tyre wear has most likely been caused by incorrect tracking - too much toe-in. The toe-in should be 3/32" (2.5mm). Whether you do anything with the camber or not, that needs to be corrected asap.

Radial ply tyres work better without positive camber - just look at the current F1 cars. The amount of shims required depends on what camber you have currently, and what you want it to be. Very roughly you need 1/8" shim for each degree of camber change. If it is a standard height car and has the original +1° camber, then you will need around 1/8" to get the wheel vertical. Quite often the ride height is lower than original spec and up to 1/4" can be needed to get the wheel vertical.

The lower the front suspension is set to, the more shims are required to get either zero or negative camber. On a lowered car with wider rims/tyres a small amount of negative can be useful, but much more than a 1/4" spacer will leave you with insufficient thread on the back of the eye bolt to get the required spring washer + nut + 1 full thread through the nut. If you really need 3/8" or more, then you will need negative camber trunnions, which either have a longer body, eliminating the need for spacers, a longer thread so that more spacers can be fitted or a combination of both. A few people on this forum have made them, but they are not commercially available as far as I know?

The original spacers were sometimes 'U' shaped, so that they can be fitted without removing the eye bolts - these are not a good idea at all, as they allow water, salt and other undesirable things into the space between the eye bolt pin and the chassis tube, followed by severe corrosion.

[autolycus]

Very good points from Richard. I'd add that I think the eyebolt shank is 9/16", but I could well be wrong. In any case, I'd prefer to make my own spacers rather than use washers, which may not be big enough to spread the load properly. If you did go for U-shaped spacers - and they do save a lot of faffing around - you can, to quite a degree, reduce the problem of water ingress and corrosion by very generously slathering them, especially the open end, in a waterproof grease such as water pump grease.

Are the eyebolts currently available forged or machined from solid?

Kevin

[IslipMinor]

Kevin,

The eye bolt shank is 9/16" diameter and the thread is 9/16" BSF. The negative ones that I made were machined from solid.

[bmcecosse]

Someone needs to be running off these longer eyebolts - they would sell well!

[Boris64]

Richard, Kevin

Many thanks for the clear and concise info

I'm planning on fitting poly bushes so I'll set up -tve camber with washers.

I'll also swap front and rear tyres to start with even tread wear at the front.

Thanks for the advice.

Pete

[morris1961]

Pete

Did you get it sorted?
i'm having the exact same issue and i think i'm running the same tyres as you, 155 continentals. Checked my tracking and it was perfect so just need to sort the camber to hopefully sort it!

Ed

[bmcecosse]

You should always 'sort' the camber before even worrying about tracking. But if you drive on many roundabouts - the nearside front will always take a hammering. Swap the front tyres over regularly......and/or turn the tyres on the rims....

[Boris64]

Ed, Bmc,

Thanks for the messages.

I'd forgotten this thread having posted the update just now in 'Boris 1964 2 door saloon' restoration thread so I can keep the story together. It's towards the end of a general ramble with a bunch of photos if you want to look.

In short the front end poly bushes and 8mm of washers on each eyeblot have absolutely transformed things.

This is a must do job worth every penny.

I haven't tackled the tracking yet but will do as various websites appear to show it to be at around my level of incompetence.

[frame][/frame]
This was my basic check of the camber before changes. I did this with the wheel rotated to various positions (on the ground) to counter any variations in the rim alignment and the camber was consistently positive on both side - now 'corrected'

Ed, yes, same tyres, let me know if you need anything/photos. Good luck. Use ear defenders when you knock the cast link back along the torsion bar if you have your head inside the wing ouch.

Bmc, just as you describe, front tyres worn on the outside from +tve camber and worse on NS from roundabouts. A lucky guess?

Pete

[bmcecosse]

Well done getting it sorted, sorry -I don't have time to read 'resto' threads - and the work done just makes me so envious.... Tracking is EASY! Just make a simple gauge, and make sure the track rods are equal each side. We have East Kilbride 'new town' near us - with MANY roundabouts - so I have suffered NS edge wear for the last 50 years or so...

[Boris64]

Bmc,

Thanks, my resto thread is more of a how I got it to stop/go, body work is a job for later.

I'll take a look at the tracking tomorrow.

Pete