Pirate 4x4 banner

Cutting external threads on a lathe

1K views 9 replies 6 participants last post by  PTSchram 
#1 · (Edited)
My friend needs new threads cut for the filter base that an air dryer filter threads on to(basicaly looks like a large oil filter). This is an air dryer system for the air brakes on a unimog.

He swears that the new filter he gave me is American with standard threads, but on further inspection it looks like it's metric. So I set up the lathe for metric and cut the threads, but it's still a no go.

How can I figure out the thread count when I have nothing in the shop for determining metric threads, I'm 99.9% sure I have it correct at M39 x 1.5 . Maybe I don't have my cutter shapened properly, is it okay to assume that the threads are still cut at 60 degree Sharp-V. Or is there another thread pitch I should sharpen it to.

Thanks in advance, Chad
 
#7 ·
I would call a supplier and ask them to look in the catalog for replacement dessicant cartridges. The catalogs will sometimes list the thread dimensions. If it uses Bosch components, I can't help more than that because I've only worked on Bendix air driers.

If all else fails, see if you can plumb the Mercedes system to use a Bendix AD-9 drier. About $250-300 complete. Parts are easy to get, because it's a very common drier on U.S. trucks.Looks like this. Here's a plumbing schematic and "how it works" (for an AD-4, but they work the same)

You might also want to invest in a metric dial caliper.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top