More on that .020 Neck Cup Gap

[Hauula Pan]

I read the post from VT about the neck cups bottoming out and having a .020" gap. Also another about V-Twin working to resolve the problem with their frames. Well It ain't resolved yet!!! I just put a set of their cups into one of their 49 frames and ended up with the same .020" gap. So unless someone has an easier fix I guess I'm looking at trying to get the cups back out without doing damage to them or the frame and then doing the angle grind to the top & bottom of the frame neck to enlarge the width & depth of the chamfer to allow the cups to seat that last .020". I have one question though, I was wondering that since the cups are definitly straight and bottomed against the existing chamfer is there any harm in just leaving the gap???

[Moose]

don't know about the gap being left, but I got mine out with no damage just using an old axle and a 4 pound sledge hammer. maybe once out get some quality measuring devices and see where the difference is I sure it would not be hard to grind some off the cups

moose

[VintageTwin]

Read the article I labored through and do what mbskeam suggested. Chamfer the neck, top and bottom. You can drive the fork cup out with the edge of a 14" piece if 1/2" galvanized pipe......easy.....just make sure that the bottom of the steering head is always in contact with the top of a sawhorse, or your flailing hammer blows will not move the cup out of the neck, even a smidgen.

If you leave a gap(s), your s/s fork cover holes will not line up with the trees.
The sawhorse and 1/2 pipe method is so positive, works so well, that once you've done it, you'll look for excuses to have to remove the cups again, just because it's a thrill.

Don't touch the cups or stems. Chamfer the neck bores or I'll reach over there and smack ya'.

Plus, if your V-Twin frame has a fitment flaw, send it back to the pit of Hell, painted or not. It's the repop life. They can correct frames in Conn. at the Frame Factory (aka Northland Industries).
Of most recent, a parts supplier told me his customer's V-Twin frame had the lower (of the two) top frame bars, installed too low. With the motor in the frame, the customer couldn't pull his Pan heads off the motor. They would hit the frame bar above it. The heads couldn't even clear the cylinders fire ring.
This frame is a prime candidate for the Northland "finishing school". Call them first. Sometimes FedEx will ship your frame up without a box. It's all in the draw. Some stations are cool, some aren't.

[Hauula Pan]

OK Problem solved. I want to send a big THANK YOU to VT for his original post that clued me in to this problem, and everyone that helped with replies, especially mbskeam. So for anyone else that runs into this here is what I did. After revewing VT's post & pictures I knew I needed to alter the chamfer on the frame neck. What I did different was instead of using a burr bit I used a 2" dia. flat press on type sanding disk on a 1-3/8" dia. flat rubber arbor. The sanding disk will fold over the edge of the arbor and is a perfect fit against the existing chamfer. You don't need to take out very much material at all. Actually a few thousandths will do it. Start with about 60 grit and finish up with 100, I used 60 then 80 grit and finished with 100 & the result is a perfectly smooth wider and deeper chamfer. I also used a brake cyl. hone to clean up a couple scratches I made inside the neck bore either putting the cups in or taking them out the first time. Everything ended up looking like it was originally machined that way & The cups went right in. Where you could slide a .020" feeler gauge in the gap before, now it is completely flush, I couldent even get a .002" gauge in after the fix. I did not touch the cups, so VT you don't need to reach over & smack me. I knew from all that you went through that the problem was not the cups but the frame chamfer was the culprit. So thanks to all the trouble you went through and your posting your experience you saved me a whole pack of headaches, so Thanks again, and I hope your discovery of the problem and my trick for getting a smoother finish helps anyone else that encounters this little problem. P.S. don't expect it to go away, I talked to V-Twin and their attitude is basically you have to expect to do some fitment, adjusting, etc. when dealing with after market parts and I guess consider it a minor inconvience. I accept that you can't always expect after market parts to just bolt right on, but this is a bit more than a minor inconvience.

[VintageTwin]

but this is a bit more than a minor inconvience.

But this is the way it is. Yea, it was mbskeam's fix. If we layout the problems and fix what we can of them on line, then little by little we'll detect the finite amount of mistakes there are within repop 1949-1957 Panheads.
By the time the new 3.5 tanks get here, we'll all be rolling. Any pics of that tool(s) you used to make the counterbore? I read it but my mind needs a pic.

[Hauula Pan]

I haven't quite figured out the process for uploading pictures to the site yet but I will take some pics of the tools & finished neck tonight & see if I can figure things out & get them uploaded tomorrow.

[panhead]

I haven't quite figured out the process for uploading pictures to the site yet

That's easy: How to add a picture/attachment to your post

[Hauula Pan]

Here are 5 pictures. Chamfer is of the tools used to reface the neck, finished is the neck surface after rework, closeup is another shot of reworked surface, installed is the cups installed and flush after rework, tools are my home made remover & installer.