+2 Front Hubs

PostPost by: Hamish Coutts » Mon Aug 02, 2004 8:45 am

Morning,

Fitted new bearings to the front hubs, torqued the certre nut to 9ft lbs (approx) then turned the nut back 1 flat and put in the split pin. The nut is running freely on the hub threads.
Now, after 500 miles there is a bit of free play in the hub (like enough to rattle when going over a wee pot hole). Should there be free play? and if so how much?

Regards,

Hamish.
"One day I'll finish the restoration - honest, darling, just a few more years....."
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PostPost by: types26/36 » Mon Aug 02, 2004 11:10 am

Hamish,
Yes there should be some free play and the reason why most front wheel bearings fail is because they are adjusted to tight, I think this has been covered before in this forum. New bearings "settle in " and require re-adjusting, as far as I remember there should be + - .004" play in a LATERAL movement (in and out)
Most people rock the wheel top to bottom and this gives a feel of to much play, the correct way is to check with a DTI (dial test indicator) but in practice lightly tighten the nut then back it off + - one flat, or untill the washer can be moved by a screwdriver WITHOUT EXCESIVE FORCE or untill you can get the split pin in.I have used this method many times and not only on Lotus.
Remember better to have more play then the bearing being pre-loaded which will then overheat and fail.
rgds Brian
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PostPost by: type36lotus » Mon Aug 02, 2004 4:29 pm

Now to just confuse the issue, don't overdo it on the looseness either. After my front bearings bedded in (read got looser) I noticed my handling was a little squirrelly. As it turned out a little tightening cleared it all up. But again too tight ruins bearings, too loose ruins handling.
Mike Geiger
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PostPost by: Hamish Coutts » Tue Aug 03, 2004 11:32 am

Thanks guys,

I appreciate your experiences.

Come to think of it, the car seems a bit twitchy in that it wants to follow ridges and white lines in the road.

Hamish.
"One day I'll finish the restoration - honest, darling, just a few more years....."
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PostPost by: steveww » Tue Aug 03, 2004 2:57 pm

Having done this job myself a few times I can only comment that it is a real pain to do. :angry:

One hint though is to pull out the front pads when you set up the bearing clearance and use the largest splitpins you can get in.
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PostPost by: type26owner » Tue Aug 03, 2004 3:25 pm

On a tapered roller bearing spindle the amount of preload is deteremined by two most important factors. The type of lubrication available and the bearing loading due to the thermal expansion behavoir of the assembly at the highest temperature achieved in use. The fact is the synthetic greases available today are far superior to the original lithium based stuff the hub was designed for in it's day. Having measured the temperature excursions and done the thermal calculations on my car I've been using for many years now zero play, zero bearing preload as the value on my car without any problems. To do this requires a lathe to face cut a few thou off the end of the nut so the cotter pin slots lines up with the spindle through hole at the desired hub bearing stiffness. I don't like the associated steering wonkyiness and the brake pad kickback of running loose hubs. Just my .02 cents worth but I check for any looseness at least once a week too.
-Keith
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