rcholmes56buick
Member
I need a crankshaft for a 1956 special automatic transmission 322 cu in. Mine has pitted on rear main seal area and leaks there. Or if someone has a solution for a repair
1956 special automatic crankshaft
- Thread starter rcholmes56buick
- Start date
Many ways to approach this:
Can the machine shop TIG weld it(~1900F) and machine it? Also, brazing(~1600F) with brass or copper would be at a lower temperature. you might want to discuss this with the machine shop in regard to welding and ask if they need to bake the crank after the work to maintain the hardness. If you don't have any money, you could solder(~400F) in the pits I doubt you would need to bake it afterwards.
Generally speaking, steel can be soldered it is possible, but engine parts I haven't done. Just a tip, I have used wood to control the solder very much like it is done in leading body panels. Flux is important and cleaning the area.
I want to mention that on 60s vehicles there was a rope crank seal and it was designed to soak in oil and swell up to seal out leaking. I'm not familiar with your car, but you could explore upgrading to a viton(not rope) seal for the rear main if you can find one or adapt it.
How deep are your pits? You can sand out the pits. 100(150 micron) grit, 220(~85micron), 400(30 microns), 1000, 2000.
100 micron=.0039 in.=.1mm. Depending on the pits, select the grit for starting point. It has to be done by hand: To sand the crank use a rope wrapped around sandpaper and pull back and forth. If you use a machine you can make it out of round. Use very soapy water otherwise the sandpaper will clog and the crank will rust. Wipe clean after working it.
High temperature epoxy pits.
Can the machine shop TIG weld it(~1900F) and machine it? Also, brazing(~1600F) with brass or copper would be at a lower temperature. you might want to discuss this with the machine shop in regard to welding and ask if they need to bake the crank after the work to maintain the hardness. If you don't have any money, you could solder(~400F) in the pits I doubt you would need to bake it afterwards.
Generally speaking, steel can be soldered it is possible, but engine parts I haven't done. Just a tip, I have used wood to control the solder very much like it is done in leading body panels. Flux is important and cleaning the area.
I want to mention that on 60s vehicles there was a rope crank seal and it was designed to soak in oil and swell up to seal out leaking. I'm not familiar with your car, but you could explore upgrading to a viton(not rope) seal for the rear main if you can find one or adapt it.
How deep are your pits? You can sand out the pits. 100(150 micron) grit, 220(~85micron), 400(30 microns), 1000, 2000.
100 micron=.0039 in.=.1mm. Depending on the pits, select the grit for starting point. It has to be done by hand: To sand the crank use a rope wrapped around sandpaper and pull back and forth. If you use a machine you can make it out of round. Use very soapy water otherwise the sandpaper will clog and the crank will rust. Wipe clean after working it.
High temperature epoxy pits.
suntreemcanic
Experienced Member
Consider a speedi-sleeve.
rcholmes56buick
Member
Thanks for the info