Topic: Any tips on how to repair threads on my steering stem?

[Toxic]

I didn't drop the thing but when assembling the triple trees, the 30mm nut won't go on cuz of some striped or damaged threads.

Any tips on how to repair?   It is cross threaded for sure.  Getting a die in that size and thread pitch is probably going to be more expensive than getting a used triple tree from ebay.

Or should I just see if anyone here has a used 77 CB750 triple tree for sale that is in good shape.

[flyin_]

I was able to work the damaged threads back into original working condition using a sharp chisel and small hammer.  Just take your time and work them back into place with light taps of the hammer. 

[sangyo soichiro]

You can get a set of really small diamond files that may allow you to work at the threads.  It might get tedious, but I'd give that a try.

Otherwise, you could get a new one probably fairly easy.  I had to replace the upper triple tree.  Got it from cycle-recycle in Indy.  You'll have to give them a call.  Mine only cost $20 or $25 if I recall.

[Toxic]

Real bummer after having spent a couple of hours striping, painting and building a new dash only to find the effing stem is buggered up.

I've never had any success in the past using the diamond files.  I guess I don't have a delicate touch.

[Toxic]

Just had a look at how fine that thread is, I don't think I have much of a chance repairing that. That's a real fine pitch for sure.

I have a 72 lower triple that won't work with my 77 upper so I'm going to see about having a machine shop cut the upper half off of the 72 and weld it onto the buggered up 77. So long as the overall length stays the same I should good.

[Steve_K]

Try using a thread file.  That is square file that is about 3/8 of an inch thick.  It has different thread pitches on each side.  Get the metric one with the pitch that suits the stem threads.  Works only on external threads.  Saved my butt several times working on bikes, tractors, etc.
Steve

[Alan F.]

I'll trade you a 78 lower tree for that 72 tree if you'd like. Send a pm if you're interested.  I don't know much about shipping to Canada though.

[754]

Trust me, thread file is the way to go, this job will pay for it if you cant beg/steal/borrow. VERY easy to use..

 Get the wurst of it out of the way with a triangular or diamond file.

[Steve F]

Try one of these thread files, 8 different pitch files in one.  We use them at work on occasion and they work fairly well.  There's one that goes down to 0.8mm pitch.  Not bad for around $12.

http://www.mcmaster.com/#thread-repair-files/=25d26c

[Toxic]

Thanks Steve

Thanks for the link for the thread files.  I'm going to pick up a set.  For now I had the good thread on the 72 welded onto the 77.

The guy did such a good job you can't tell where the weld is.