Lotus Elan

More Balancing Woes

PostPost by: david.g.chapman » Mon Dec 08, 2008 7:35 pm

I purchased a set of s130 +2 alloy wheels for my +2 to replace my old steel wheels, but I am still having problems with wheel balance :(

The wheels balance to within 5 grams on the balance machines, but I am still getting steering wheel shake at 70-80 mph. I have now tried two tyre shops with the same results.

One thing has occured to me - the new wheels are a tight fit on the 5 pegs when mounted on the car. If the centre of the 5 pegs is not the same as the hub nut centre then the wheels would be well out of balance in situ (the balancing machines use the hub nut hole only, of course).

I do not want to enlarge the peg holes in the alloy wheels - but is there any alternative? Any thoughts as to what else it could be?

Dave Chapman.
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PostPost by: rjaxe » Mon Dec 08, 2008 8:38 pm

Dave, you are experiencing similar problems with those I have encountered with the steel front wheel on my +2. Numerous balance attempts by different tyre suppliers has made no difference. One even gave me a handful of stick on weights to use by trial and error having admitted he could do no better.
I tend to agree with your theory on the wheel location, the studs must provide the real on-car location not the central hole which modern balance machines rely on.
So I have designed an adaptor that fits on a balance machine spindle but locates the wheel on 5 studs and only uses the centre hole to clamp the wheel like the spinners. However although the parts are in manufacture I am relying on the good will of a friend to make it in his spare time so it will take as long as it takes to make. I am keen to find out how well this will work and add to the thread as and when it happens.
I will be interested to hear other peoples view on this problem and how they have tackled it.
Richard
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PostPost by: Craig Elliott » Mon Dec 08, 2008 10:55 pm

Dave

Have you checked that the wheels run true and that it's nothing to do with the tyres themselves (e.g. has the car been left standing for a long period)?

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PostPost by: 1964 S1 » Tue Dec 09, 2008 3:46 am

Did you have this problem with the old steel wheels? Have you tried switching the rears to the front? Some folks have run into a problem where the wheel center is dished and the nut doesn't hold the wheel to the hub snug enough, but with alloys that shouldn't be a problem (?).
What about placing a small shim sleeve around the centering pegs to make sure the wheel isn't shifting?
I rarely take my +2 up to that speed, it's stock steel wheels haven't produced any steering wheel shake at highway speeds and I've got crap tires on it that haven't been balanced in years.
One slight bend in an alloy rim can cause your prob....
Good luck, Eric
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PostPost by: ppnelan » Tue Dec 09, 2008 10:02 am

It has been posted in the past that the tyres themselves (even new ones) can be the problem, when the 'internals' shift slightly at road speeds to cause an imbalance that doesn't register on a low speed balancing machine... :?

I found the best way to solve it is to try different wheels until you find a good set... :shock:

If you search the archives there's plenty written about wheel balancing problems, including a typical piece at http://www.lotuselan.net/forums/viewtopic.php?t=4923 :roll:

Also, distorted hubs (typically caused by using standard 'legged' pullers to remove the hubs) can cause out-of-true & balance problems...

:arrow: Matthew
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PostPost by: Alex » Tue Dec 09, 2008 10:47 am

Mathew has a good point about the hubs. Easy to check with a magnetic base and dial indicator.

One thing I remember from my Dads +2 years ago was that the 5 peg holes can become elongated over time. He had a machine shop set the wheels on a rotating table, bore the holes over size, press fit steel plugs then re-bore them. This strengthened the holes and guaranteed they were correctly located to the centre hole. Might or might not help balance problems, but improves the life of alloy wheels.

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PostPost by: peterako » Tue Dec 09, 2008 12:46 pm

Could it be a Prop shaft imbalance (spelling?)?

Was the problem there before the new Alloys too?

Though I have not had teh problem myself with propshaft balance I have seen it mentioned on the forum numerous times.

And the mostly state that teh wobble appears at 70 ish mph.

Having said that, very slight imballances in the wheels, wrong air pressure (even 1 - 2 lbs) etc can affect the car dramatically.....

Peter
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PostPost by: david.g.chapman » Tue Dec 09, 2008 7:15 pm

Thanks for all your replies.

I have just swapped the rear wheels with the front, and....

Success :lol: :lol: :lol:

The steering wheel shake has gone! I did 10 miles on the A12 Chelmsford bypass (on salty roads in the dark) Grrrrrr! - and there was only a residual vibration at 70 ish which could be the propshaft - the steering wheel stayed put. I will be marking the wheels and hubs to maintain the position.

One thing with the +2 allloys - to fit the 7 inch backing plate on most UK balancing machines I had to grind down the interior raised ribs by about 0.5mm from a 6.5 inch to 7.5 inch radius. Otherwise the ribs foul the balancer and destroy any correlation between balance machine and car.

Dave Chapman.
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PostPost by: 1964 S1 » Tue Dec 09, 2008 8:58 pm

If switching the wheels rear to front helped, it would make sense you'd still have a bit of vibration but it's probably the rear wheels, not the propshaft ? Could be a U-joint loosening, does it clunk at all, when going from first to reverse, sitting still with your foot slightly on the brakes?
Last edited by 1964 S1 on Thu Dec 11, 2008 3:35 am, edited 1 time in total.
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PostPost by: david.g.chapman » Wed Dec 10, 2008 10:08 am

I am laid up with a bad back at the moment - it must be caused by moving all those wheels about!

I will try the first into reverse trick when I can, and also give the UJs a good shake in situ. I might have a problem with the hole in the chassis for the gearbox extension being too small to remove the propshaft. Please refer to separate post.

Thanks again,

Dave Chapman.
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PostPost by: Foxie » Wed Dec 10, 2008 11:56 am

david.g.chapman wrote:I purchased a set of s130 +2 alloy wheels for my +2 to replace my old steel wheels, but I am still having problems with wheel balance :(

The wheels balance to within 5 grams on the balance machines, but I am still getting steering wheel shake at 70-80 mph. I have now tried two tyre shops with the same results.

One thing has occured to me - the new wheels are a tight fit on the 5 pegs when mounted on the car. If the centre of the 5 pegs is not the same as the hub nut centre then the wheels would be well out of balance in situ (the balancing machines use the hub nut hole only, of course).


I do not want to enlarge the peg holes in the alloy wheels - but is there any alternative? Any thoughts as to what else it could be?

Dave Chapman.

David,

I have this problem all the time with my Minilite copies. A good way to check one aspect of wheel/balancer compatability is to balance the wheel on the machine, remove it, and then replace and check the balance again. A repeatability check will often show up modern electronic readout errors ! :D

Ideally the wheel should then be balanced on the car; this balances the complete wheel+hub +brake disc combination. I have not yet been able to locate anyone with the old on-car balancer here in Ireland, so I do a trial and error rotation of the wheel on the hub, and mark it when I feel it's nearly right. :)

Sean
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PostPost by: rjaxe » Tue Mar 17, 2009 7:48 pm

Well the 5 stud balance adaptor I rambled on about in a previous post arrived last week and I have had four wheels balanced. They all needed significantly different weights than had been used when balanced using the centre hole. More to the point the difference is outstanding, no signs of the annoying steering wheel shake I had suffered before so I am really delighted with the result, this will make driving even more of a pleasure. :lol: :lol: :lol: :lol:
Richard
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PostPost by: tdafforn » Tue Mar 17, 2009 8:03 pm

any chance of borrowing it?
Tim
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PostPost by: stuartgb100 » Tue Mar 17, 2009 8:38 pm

Tim,

After you, please !

If we can keep this up, rjaxe won't have a clue who's got his new tool !!

............. as I look around my garage, to find absent specialist tools ..... and when not
finding .......... trying to remember which "old friemd" / b***std ...... 'borrowed' them !.

Regards,
Stuart.
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PostPost by: elanmac » Wed Mar 18, 2009 1:35 pm

Try one of the main agents eg. Ford or Vauxhall for on car wheel balancing. They balance the wheels on FWD cars. I had a set balanced a few years ago at the local Ford main agent.
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