Warped Hubs

[DragBean]

My hubs are warped.

I recently got rear ended, put my wheels on without a torque wrench, and mounted my tires myself.

I seem to be getting about 5 MPG (8% less) than expected when I should be getting 5% better MPG ( I put on narrower tires when I mounted the tires myself).

... The hubs are visibly warped.

I can see a sway when I spin the back tires jacked up.
Between 60-75 I feel a more than noticiable vibration.

How much MPG do you lose from something like this?

And also do I have to replace the whole entire hub assembly + the rim (will the rim be F*cked if it is mounted on a bad Hub and Vice Versa for a bad rim and good hub?)? That would include the brake drum rotor. Or can I just get away replacing the hub or the rotor.

Maybe I could use washers on the lug bolts to space this.

Hopefully someone else has had the same problem and can give some info on the lost MPG and any potential easy quick cheap solutions.

[oldtamiyaphile]

Try taking the wheels off and rotating the wheel 90* on the hub. Torque correctly. Might help.

I've fitted a lot of wheels without a torque wrench just going by 'feel' and never had issue. Perhaps the accident caused the issue?

Remember that new tyres give poor MPG (compared to worn) so even if you swap to narrow LRR tyres you won't always see an immediate improvement.

[DragBean]

@oldtamiphylle

Tha'ts a good idea. It sounds like i might be able to put fender washer spaces to compensate.

Or do you think everything could warp back into place?

It's defintely robbing MPG - I can feel that tires' are hotter the normal when I get done.

I did pick up $10 wheels that I pre-spun to check for any visible deflections and didn't see any. Once I mounted them on the hubs (one had a visible deflection), both the back tires had visible side to side deflections when I spun them up jacked off the ground. (I noticed this midway between a 800 mile trip). I kept on stopping to mix and isolate wheels and to take off the pizzaboy rims.

Seems like the warp may be contagious to nearby associated parts...

[user removed]

Did you measure runout in the hubs themselves? I've rebuilt 200 totalled cars bought at salvage auctions and never seen warped hubs.

I have turned impact (hammer) damage on a lathe when I turned the rotors

regards
mech

[mcrews]

Of course the tires are hotter, they are wabbling back and forth at speed!
Don't think narrower tires are going to give you a 5% increase unless you are also going a size taller.
(unless you were running 45s and went to 70s)

[freebeard]

Front Macpherson strut? Semi-floating rear axle? Something inbetween?

With a dial indicator or equivalent, you could measure the run-out on the hub itself, axial and radial. Washers are probably not the answer, you'd need washers with a minimum of two different thicknesses to shim it. (Assumes five lugs, two unwashered, one the correct thickness and two about 0.6215 of that)

Tighten the lug nuts progressively, in a star pattern.

[RedDevil]

It is not just like something got in between the hub and the wheel?
When you put the wheel on the hub it should feel like it seats firmly, not wobbly.
Obviously the wheels should rest on the bed, not the axle cap or whatever.

Is the tire seated properly? If not the rim runs straight and the sway is in the tire. Or maybe the rims were damaged after all.

If it is the hubs you should be able to see the warp and possibly the damage on them without the wheel. Inspecting them closely may be a good idea.
(Sorry if you already thought of all this, hope it helps if you didn't...)

Best of luck, hope it is an easy fix. And +1 on the higher fuel consumption in the first 2000 km on a new set of tires. You may need a higher tire pressure to compensate for the narrower track anyway.

[jamesqf]

Originally Posted by Old Mechanic

Did you measure runout in the hubs themselves? I've rebuilt 200 totalled cars bought at salvage auctions and never seen warped hubs.

Second that. I'd think it would be next door to impossible for the hubs to be warped significantly from a impact that still leaves the car driveable. Much more likely to be frame/suspension damage.

I'd also check that the tires actually are mounted straight on the rims, and balanced. That'd be my guess for your vibration.

As for using a torque wrench to put the wheels on, are you serious? Never done that in my life. Usually use one like this: http://www.harborfreight.com/media/c...mage_14831.jpg

[freebeard]

Impact wrench? I've had a tire shop put on the wheels with a pneumatic wrench that I couldn't get back off by hand.

[ksa8907]

I never use a torque wrench, just go around in a pattern 3 times. I use a 4 size "tire iron" and if you pay attention you can feel when yhe metal starts to twist, thats when i know its tight.