Incorrect spindle or rotor?

[Sovereign]

During my investigation into determining what the previous owners have done to my truck, I have discovered that the front wheel play is way too much. I have drop spindles on the front for sure. I can find no markings that indicate where or who they came from. They appear to be the typical 2.5" cast iron drop spindle that you can find all over the place. They are correct light duty spindles that match the light duty brakes. I determined this by measuring the inner bearing area which is 1.25"

The rotors are 1" thick and of unknown brand.

Inner and out bearings are correct from what I can find. Timken M2649 outer and Timken LM67048 inner.

What's happening is the bearing nut and washer are bottoming against the shoulder of the spindle before contacting the outer bearing so I'm not preloading the bearings at all. I realize they shouldn't be and that play should be in the neighborhood of .005 -.008 which is normal for GM cars of this era. I don't need to measure to know I am way over. Like, scary safety hazard over.

Does anyone have any measurements to help me determine if the rotors are wrong or that the spindles are wrong? I'd rather not simply throw parts at it and hope for the best.

The one thing that does bother me is I can't seem to get the bearing races out of the rotor to confirm that they are correct.

Thanks

 

[bucket]

The light duty brakes use the same bearings as the heavier duty brakes if I recall. What you are describing sure sounds like you have light duty rotors on a heavy duty spindle.

 

[Sovereign]

The outer bearings are the same. The inner bearings are larger due to the spindle itself being 1.375 versus 1.25 for the light duty. I'm not sure about length of spindle differences if there are any. I haven't found any information about that dimension.

Thank you

 

[Sovereign]

I forgot to mention that the back of the spindle is stamped C10LD which I take to mean light duty.

Thank you

 

[Sovereign]

I think you're on to something, bucket. The HD rotors are thicker overall from hub snout all the way to the backside of the friction surface. My guess is that while the spindle has the correct diameter for the smaller bearings and LD rotors, it has the length for the HD rotors. I'm still investigating though.

Thank you

 

[bucket]

I think you're on to something, bucket. The HD rotors are thicker overall from hub snout all the way to the backside of the friction surface. My guess is that while the spindle has the correct diameter for the smaller bearings and LD rotors, it has the length for the HD rotors. I'm still investigating though.

Thank you

Maybe someone has a couple factory spindles laying around and can take a few quick measurements. You never know with aftermarket parts if something might be manufactured incorrectly.

 

[Sovereign]

It was the spindle. From the base of the spindle to the shoulder/chamfer at the end of the threads, you should have approximately 3.125" according to the McGaughys spindles I installed on the truck. The spindles I took off were 3.25" approximately. I just used a tape measure as it was that obvious that they were wrong. Overall length was basically the same though. I'm not sure if it would be longer for HD brakes. Regardless, I found my issue and corrected it. Maybe this information will help others in the future.

Thanks

 

[AuroraGirl]

As for spindle, would metric vs SAE switch over change this at all? I know the 78 or 79 or so model year the cars or maybe just one platform went metric to my recollection, I think my electra would be SAE but my 1980 cutlass would be metric, and the spindle and rotor from a 2wd square on the ground is probably SAE if they did that too