quote:Originally posted by UFO-LOW:
Looking for guidance on reworking the door hinges to reduce slop due to wear. I am thinking just to ream out to the next standard size, but it couldn't be that easy, is it?
I measure the original pin at .332 inch, or 8.43 mm. This seems like an odd size, not a round number in inch or metric. Between 21/64" and 11/32".
Is there any hidden trick to getting the original pin out? About what clearance should I look for when fitting a replacement pin?
Thanks, Rod.
... .3320" is a Size 'Q' Letter Drill.
I would:
1. 'Wire-Wheel' all paint and rust out of the cracks around the pin, then Soak the assembly Over-Night in Penetrating Oil, 50% to 50% Automatic Transmission Fluid To Acetone. It's 10 Times more Efficient than the Next Best P. Oil.
2. DO NOT try to hammer them apart with a Drift, It won't work! IT would be Too 'Springy' and you will destroy the Parts! You MUST Use a Hydraulic Press with all pieces backed-up and well SUPPORTED, and be careful NOT to 'Mushroom' the end that must Pass-Through the Assembly.
3. If a press does Not work...the pieces may have been 'Heat-Shrinked' upon assembly, in which case You will have to Drill or, Better yet, (Center-Cutting) End-Mill the Pin OUT!
This Must be done in a Milling Machine. A drill press is Just NOT Rigid Enough!!
...A Couple of tips:
Use Cutting Oil
If the Pin is Hardened (test with a File) You'll need to use a Carbide End Mill.
Ream to a Nominal .375 (3/8") and use a 3/8" Stainless Steel Rod for the pin. This will give a .002"-.003" Clearance. And You have Only removed .022" PER SIDE, Off the 'Strength' of the Assembly!
.003"-.004' TOTAL MAX. Should Suffice without Binding.
Now, if You were thinking about the 'Future', Cross-Drill, 1/16", the Pin Exactly AT the Pivot Contact Points and then Drill through ONE END ONLY, 1/16", to connect the Ports and Drill & Tap, 5/16" DEEP, for 1/4-28 Thread for a Grease ZERK Fitting.
Then You can grease them at will, Without Disassembling.
If You wish to Ream to the very next size. that would be a Letter 'R' Reamer at .3390" You won't Find One! You would need to use a 'Adjustable' Straight Reamer, to Just 'Clean-Up' the Bores. Need it larger to clean up the wear, the next size is 11/32 @ .3438" and for that size you may be able to find a Straight Reamer.
(and remember, One half 'Press-Holds' the pin, the other half, pivots Smoothly!) And Then you would have to turn down and polish that 3/8" Stainless Rod to a Precise Custom Fit, On a Lathe.
If You need help with it, Contact Me and we'll work something out.
Best of Luck with it!