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MG MGB Technical - Front End Rebuild

Hello MG people

My winter project is almost over (and the winter too; good timing). I rebuilt the font suspension of the '78: kingpins, bushes, renewing, cleaning, painting and all.
Everything went straightforward so far but now something strange happens: after a clean up of the wheel bearing I set the end float as per specs (.002, .004) with everything dry.
I then reassembled the whole thing with grease and after torquing the nut as per specs (40#) I noticed a lot of play in the hub.
So I put the dialguage back in service and measured something around .010
My explanation is that a thin coat of grease between all the components, bearing, shims, spacer, etc added these mysterious thousands in the setup.
Am I right and is this OK to let it go that way or a solution is to undo the nut and bearing and remove some shims.
Note that the movement of the bearing is not as loose as it may be when dry ; to reach the 10 thousand on the dialgauge I have to use a bit of effort.

Advises welcome
M Gaudreault

There is some mystery here. The reason for doing it dry is so that the grease does not mask the play. That is, with grease, the play might measure less than when dry. So, if you read more play with grease than without, something is wrong.

Tough as it sounds, I suggest you might want to start over with the bearing adjustment. That is, clean off all the new grease, check end play again, then repack the bearings.

However, when you read the 0.010 inch now, are you sure that is all bearing play and not kingpin play, or something else with slack giving you that reading?

Charley
C R Huff

I have just done the same thing with my front suspension. I assembled dry and, although I don't have a dial guage, I had similar amount of play in the bearing when greased as I did when dry. I agree that you have to be a bit more forceful when pulling the hub to check when it is greased. I also check it with the wheel on and check for play vertically as well as horizontally to detect any kingpin play.
Steve Church

Good evening

Charley,
I put the dialguage bas on the disk brake and the point of the dial on the top of the bearing stub so no interference between the two parts.
You also said: "with grease, the play might measure less than when dry". I suspect that grease (like shims do) might add distance between inner and outer bearing so more endfloat. Hence my theory about those mysterious thousands added to the set up. Right or wrong?

Steeve, how did you set the end float without a dialguage ? did you use the "internationnal" method which is tighten until bearing binds and back off the nut a quarter turn ?

advises still welcome
M Gaudreault

The grease won't add end float, because if you set it up correctly, you tighten the hub nut to some torque value. I don't remember the value, but it is something like 40 ft lb. It is the spacer and shims that keep the bearing from binding when it is tightend up.

Charley
C R Huff

M. I set the end float by tightening the hub nut until I can only just feel the play in the bearing. Easy to do when the bearing is dry ..not quite so easy with grease in. If the slot in the nut does not line up then I shim under the washer.
Steve Church

Steve,

Sounds like you are missing some parts.

Charley
C R Huff

You need to set the end float dry. Go to the University Motors web site and see John Twist's tech videos. He explains it very well there.You don't need dial indicators if you have a sense for what 2 to 4 thousands slop feels like. As Twist notes, you can "feel" the correct amount by the tonk noise the assembly makes dry. It a little unnerving to "sense" this the first time, but you can verify with a dial indicator.

With it greased, are you sure you don't have bind with one of the components?

If the bearing is too tight, it will overheat. If it is too loose, it will chatter and wear out.
RL Tedrow

Did you assembly the front hub without the spacer first to fully seat the inboard bearing and lip seal spacer? If you did not, then the system may have required more spacers before it was seated (sounds weird for a tapered bearing but I find it makes a difference). Also, I like to fully grease the inboard bearing and then do the initial fitting of spacers and outboard bearing dry, because at this point I'm not removing anything but the outboard bearing and spacers.

warmly,
Dave
Dave Braun

This thread was discussed between 06/04/2011 and 21/04/2011

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