The MGA With An Attitude

At 10:05 PM 4/2/04 -0500, Chuck Jackson wrote:
>"My local British car mechanic informally diagnosed my wire wheeled MGA with a left rear wheel hub problem, that the splines were worn and causing a clicking as they moved clockwise and counterclockwise against the splines of the wheel. "

Welcome to the club. Prepare to spend some money.

>" I “confirmed” that problem by rotating the spare to the left rear, and the same clicking could be heard going ~20 mph and pressing down/letting up on the accelerator. I bought a used hub, and ...."

And you goofed already. You might have just bought a part you may not need. Always do the diagnostic work first to determine the exact problem before you start throwing money at it. Maybe the male splines are okay and the female splines are bad. Also a loose u-joint in the propshaft can make a clicking noise under the same circumstances (but that's on another page).

>".... thought I’d give the clicking noise one more check. With the emergency brake tighter than Dick’s hatband, ...."

I presume the emergency brake actually works?

>"I was in fact able to rotate the LR wheel 0.35” (measured almost at the bottom edge of the tire)."

Sure enough, bad bad bad. Anything over 1/8" is a concern to watch. More then 1/4" is serious. More than 3/8" is life threatening. At 1/2" it may shear and allow the wheel to free wheel on the hub the next time you hit the brakes hard at speed.

>"The RR tire would not rotate at all."

I'm hoping you loosened the knockoff's for this test? No free rotation should indicate good splines, both male and female.

>"So I got out the spare, and put it on the LR. I could still rotate it, and resigned myself to changing out the hub."

Unless of course you have a good hub and two bad wheels. Keep going, you're not finished checking yet. To verify good or bad for a male spline, you need to test it with a known good female spline. To verify good or bad for a female spline, you need to test it with a known good male spline. When you find a corner where the wheel has very little or no free rotation on the splines, then you can figure that those splines, both male and female, are good parts. Try all wheels on that hub to test condition of the female splines. Take the wheel with the least free play, and try that wheel on all four corners of the car to test condition of the the male splines.

>"To be absolutely certain, I took the RR wheel off and put it on the LR hub. NO ROTATION!"

So much for being absolutely certain. That makes it look like a good male spline on the LR, implying that the female splines in the other wheels are worn and sloppy.

>"I took the original LR wheel and put it on the RR hub. ROTATION! It therefore appears that my original LR wheel and my spare have worn splines."

Now you got it.

>".... I think I need a new wheel. Not a new hub. Agree?"

I think you need to replace at least two wheels, the original LR, and the original spare. And while you're checking things, you should try that RR wheel on front hubs to check the condition of the male splines there. And you should check both of the front wheels on the RR hub to check the condition of the female splines. If you already know you have two bad wheels out of three at the rear, then odds are the fronts may have a problem too. So now you get to find out how much new wire wheels cost, and splined axle hubs are not a whole lot cheaper.

Hub spline moderately worn - but still rounded on the apex.

Hub spline very badly worn - skewed flank and sharp apex.

On 23 August 2017, D Quinn in Michigan, USA wrote:
"My advice would be to measure the hubs. Actually I do mine every couple years. It's best to use vernier caliper to measure the hubs:

New part: 2.450"
Good part: 2.440"
Operative: 2.430"
Borderline: 2.425"
Dangerous: 2.410"

I recommend taking the average of four measurements on each hub as you can sometimes find flat spots".

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