The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: Boxer_Bolshie on April 01, 2012, 03:45:09 PM

Title: Axle corrosion a problem?
Post by: Boxer_Bolshie on April 01, 2012, 03:45:09 PM
I got all of the rust off of the rear axle but it's etched quite a bit and I'm wondering if there's going to be any issue in terms of strength and/or bearing fitment?

(https://lh3.googleusercontent.com/-0xYsqRs3Xg8/T3i9yFkeJZI/AAAAAAAAQZQ/ibPjOPMKv_U/s912/DSC_0003%2520%2528Large%2529.JPG)
Title: Re: Axle corrosion a problem?
Post by: montmil on April 01, 2012, 03:59:56 PM
The pitted area shown in your photo is where the swingarm pass-through and pinch bolt snugs up the axle. After the machined step down to a smaller diameter, you have the 'top hat' spacers and the bearings. If the threaded end of the axle is in good shape, you will not have an inner bearing race to axle concern. Then I'd say you're pretty much OK to use your present axle if so desired.
Title: Re: Axle corrosion a problem?
Post by: Boxer_Bolshie on April 01, 2012, 06:45:10 PM
Thanks Monte!  The threads are great and so I'll keep this.  I really need to start running into parts that don't need any fixing  ::)
Title: Re: Axle corrosion a problem?
Post by: tvrla on April 01, 2012, 10:41:32 PM
Spray some Mexican dhrome on there and call it good! The important areas are fine. In the meantime watch for a better one.
Title: Re: Axle corrosion a problem?
Post by: Barry on April 02, 2012, 04:02:59 AM
Not uncommon to see a bit of surface rust there as it's the exposed part of the spindle between the left side swinging arm clamp and the wheel so other than the section that is clamped and that looks mostly OK the precise diameter of the pitted section is of no consequence.

You would imagine there is a big safety margin built in to the strength of the spindle so I would not be concerned by the small loss of material but what about crack propagation ?  Wheel spindles should be tough rather than brittle so maybe it's not an issue but in all honesty I'm not qualified to give a definitive opinion on whether the spindle strength is compromised. If it was me I'd try and source a good 2nd hand one.
Title: Re: Axle corrosion a problem?
Post by: Lucky_Lou on April 03, 2012, 11:29:09 AM
The diameter of the load bearing section is at least 10% less than the erroded section so i would not loose too much sleep about it, paint it black..........
Lou
Title: Re: Axle corrosion a problem?
Post by: wa1udg on April 16, 2012, 12:44:52 PM

I wire brushed and polished mine, then primed and painted them black.  There's a guy down in Florida who sells stainless axles.  
Title: Re: Axle corrosion a problem?
Post by: Ed Miller on April 17, 2012, 03:23:45 PM
I was waiting for Justin to volunteer to make some stainless ones up, for a price of course.  But what price?

Just another reason I need a lathe and milling machine.
Title: Re: Axle corrosion a problem?
Post by: Barry on April 17, 2012, 04:28:32 PM
Stainless axles are available for Airheads.

If anyone is going to make one you have to be careful to use the right grade of stainless as tensile strength is an issue compared to the stock axle. I'm no expert but 416 stainless might be the right stuff to use.
Title: Re: Axle corrosion a problem?
Post by: Justin B. on April 17, 2012, 10:12:45 PM
I machined one from 303 for the Dawg and it's held up well and I work down a road with tons of pot-holes.  I opted for a little cleaner looking attachment method than a nut...
Title: Re: Axle corrosion a problem?
Post by: Barry on April 18, 2012, 06:28:54 AM
Out of curiosity anyone know how the original axles were finished ?  I've always assummed they would not have been supplied from the factory as bare unprotected steel but maybe they were.
Title: Re: Axle corrosion a problem?
Post by: Bob_Roller on April 18, 2012, 08:07:01 AM
They were bare steel, when I lived in the Chicago area, a bit of rust would show up after being left idle for the winter .

A quick scrub with Scotchbrite pad would clean it up .

With living in a desert for the last 19 years, rust/corrosion is a distant memory .
Title: Re: Axle corrosion a problem?
Post by: tvrla on April 18, 2012, 10:01:01 AM
The originals are chromed - I assume it's a hard chrome like fork tubes. Any chrome will rust, but good chrome won't pit with a little bit of surface rust, which will polish off fairly easily leaving it looking like new.

Title: Re: Axle corrosion a problem?
Post by: wa1udg on April 18, 2012, 10:21:57 AM
The guy in Florida who sells SS axles also has  SS nuts and washers to go with them.  
Title: Re: Axle corrosion a problem?
Post by: montmil on April 19, 2012, 08:18:52 AM
Quote
The guy in Florida who sells SS axles also has  SS nuts and washers to go with them.  

That would be ol' Hans, owner of Hucky's Spare Parts http://www.bmwhucky.com/index.html