Shift Cable End Gude in Bell housing Spins but Won't Come Out

[PeterB26]

I'm working on my Alpha 1 Gen 2 shift cable. I got the special tool to remove the cable end guide in the bell housing. The tool (Mallory) promptly broke with almost no torque at all, so I chased around for a day and found some one to weld it back together. Then the brass nut seemed to break free with only moderate torque, 3/8 breaker bar, one hand, no biggie.... Looking good....

BUT the cable spins as I turn the brass nut. Maybe this is supposed to happen, but no one mentions it. After pondering it I decided it doesn't matter because the whole cable jacket spins inside the boat so that fitting should still unscrew and back out, Right?

Wrong.

the end fitting is now showing about two threads backed out and it just spins and spins, (spinning the cable jacket inside the boat with it.) It will not back out any further. I can't get to it easily to seriously yank on it, but pushing on the cable from forward of the bell housing (between the bell housing and transom by the shift cable bellows) does nothing. Pulling on it with what force I can from astern does nothing, though I haven't tried destructive force with vice grips on the plastic tube sort of thing yet. I tried to slip a screw driver behind it a bit so that it would catch the threads as I turned the nut. No dice.

It is as if there is a non-captured nut behind the bell housing that I can't see that wants to be held by another wrench , but I don't think there is supposed to be anything there. Alpha 1 Gen 2, I've never seen any reference to that sort of thing.

So I figured maybe I sheared off the brass fitting inside the threaded hole. It sort of looks like that might be the case, but it is hard to see in that deep hole..... but if that is the case how come the broken off outer end doesn't just fall out in my hand and leave the rest stuck in the threads?

So I'm feeling pretty stupid at this juncture. It seems like it should either just come apart properly, or if its broken just fall apart. I can't see what is hanging me up.

What is the next step? If it is broken how do I fix it? Cut the cable jacket behind the bell housing and get the whole thing on my bench and maybe drill the old fitting out and re-tap the hole?


Grrrrr....

Thanks,
Peter

 

[duped]

It's broken off. Been there, done that. It sucks. I was able to get the "remains" out of the bell housing with an easy out and it didn't give me too much trouble.

 

[Bt Doctur]

 

[Bt Doctur]

cut the cable just at the rear of the housing and remove what you can, get the correct tap and drill and retap the hole . the tap is 1/4 x 18 NPST.
A "straight tap" not tapered like a pipe thread tap.

 

[PeterB26]

Thanks for the info.

I'll try an Easy Out first.

Great help on the straight tap size, I assumed it was a tapered pipe thread.... so you saved me that mistake! Also the pic helps a lot because I couldn't tell until now if there was some sort of provision for the brass fitting to spin about the jacket.... kinda like a flare fitting on a brake line or something. Looks like there isn't.

I'm still not sure whey the broken end won't just fall out, but so be it. Something on the inside of the fitting is preventing that, either the jacket or the plastic tube up the center bore must be holding it past the fracture line. Either way it hardly matters.

Thanks again.
Peter

 

[PeterB26]

A follow up so that anyone else with this problem finding this thread knows what I did and how it worked:

I pulled the bell housing with the shift cable jacket still in it so that I had the bell housing and the shift cable together on my bench.

I was then able to use a Dremel with an abrasive cut off wheel to make a cut through the shift cable very close to the point where it enters the brass fitting on the forward side of the bell hosing....the side that is normally toward the boat with all the bellows attached.

From there I was able to run a small diameter drill (maybe ? inch... I don't really recall...) which was a bit smaller than the OD of the shift cable jacket into the cut off end. This instantly “removed” the remaining shift cable jacket form the brass fitting.

This freed up the opposite sheared off end of the brass fitting with the hex nut on it and that came out. So now I had the remains of the brass fitting still threaded into the hole on the bell housing and it was time to either remove it with an Easy Out, a nipple remover, or drill and tap.

No dice on the Easy out.

OK.. hindsight here.... If I had known.... I could have removed the bell housing with the shift cable jacket in tact before I broke the fitting off. Then it would have been easy to heat the area from the forward side with a torch on my bench. Sure this would have cooked the shift cable jacket, but that was going to be trash anyway.... and with plenty of heat on my bench applied to the forward end of the hole and fitting, and the special tool applied to the fitting from the aft side, maybe I wouldn't have broken the fitting. Something to think about next time... But it didn't take any great force to shear off the fitting, so it wasn't like I had a big red flag that said “Hey, this thing is really stuck in there and might shear off!”

So back to my predicament. I was now committed to the drill and tap.

Down to the drill press where I set the bell housing up so I could rest it on the studs sticking out of its aft end and drill down form the forward end, since I had a better shot at that. The tap drill for the ? X 18 NPS threads is listed as 7/16. Some places list 29/64. Instead of going for the full on 7/16 in the first shot I started with smaller bits. I wanted to “sneak up” on that diameter because I have had screwed in things finally “give up” once you pretty well gut them out and that way you don't have to re-thread the hole. Also no drill makes a hole smaller than its stated diameter, but on a drill press with a little runout ( and most DO have some runout), or a poorly sharpened bit makes a hole a little larger... so I wanted to avoid that trap too.

No dice on the fitting giving up. I had to drill as large as I dared.

Meantime I ordered the right tap. No one locally had anything like that. A lot of tool suppliers had decent taps at decent prices until you got to the shipping charges. A $15 to $20 tap and shipping at $30. I wound up ordering from Amazon.

I stopped drilling at 27/64 diameter. I had just revealed the aluminum tips of the threads on one side of the hole and left a skinny bit of brass on the other. Not a perfectly centered, but pretty close. Close enough, I hoped, once the tap started to “find” the old threads. I crossed my fingers that the little bit of brass left in the old hole off center would just machine out of there without giving me too much trouble.

While I waited for the tap to arrive I did some research on pipe threads. I wanted to know if I could use an NTP tap to start the threads as the NPT taps are tapered and might find the old threads more readily.

It turns out that the thread form of NPT (National Pipe Tapered) is the same as NPS (National Pipe Straight) so they only differ in diameter... because the NPT is tapered it obviously has a range of diameter.

ASIDE: In case you were wondering NPTF is “National Pipe Tapered Fuel” which is an adaptation of NPT. The NPT and NPS threads have flats on the tips of the threads and in the bottoms of the valleys. This makes it easier to create them. NPTF eliminates these flat spots instead coming to a full-on pointed profile. This creates an interference fit tip-to-valley which eliminates the spiral leak path along the threads. That way you don't need to use pipe dope. They also call this DrySeal or variants of that name. It also exists in NPSF form. The threads are fussier to cut and the tooling more precise (read expensive) but essentially they have the same thread form.

My next problem was determining what the diameter of an NTP tap was as compared to an NPS tap. Turns out that for the TAPS only (NOT the dies) the largest part of the NPT tap is the same diameter as the NPS tap. This is NOT true for male threads and NPT dies. The middle of the die is the nominal diameter, one end of the formed threads being smaller and the other end larger. But in a female hole tapped with NPT the starting thread is at the nominal diameter, which happily for me is the diameter of the NPS threads I needed.

I got my NPS tap today. It didn't have much of a starting taper to the end so I couldn't get it to take up in the old hole and follow the old threads. BUT I had a1/4 18 NPT tap, and that was easy to get started because of its tapered profile.

I ran the NPT tap into the hole to form enough threads so that I was able to properly start the NPS tap. Then the NPS tap “caught” and went through-and-through forming new threads. I did it by hand, slowly, often clearing the threads as I went with a little ? back turn because I was cutting out a lot of brass from my undersized hole as compared to what you normally would cut... and I was glad it was easy-to-cut brass and not something less forgiving.

The new shift cable jacket threaded in (bell housing still on the bench) and took up to a decent torque. Light wrench pressure but firm. No dope this time because it isn't the final fit. I set the entire thing aside so that the cable fitting was oriented vertically and flooded around the fitting with PB Blaster to see how far it might “leak” down along the fitting and new threads. I'll know tomorrow if I have a bad leaker from poorly formed threads or if it will be good to go with a bit of pipe dope or Perfect Seal. This does have to be water tight to keep water from the forward end from leaking into the shift shaft and shift cable cavity