I purchased a 32/11 drum rear, cleaned it up and installed it a few weeks after getting my bike running again. Its been installed on my bike for about 500 miles.
I noticed when I installed it that the screw plug or level check plug (p/n 07 11 9 919 225) was easy to snug or torque when I installed it. I used the top vent screw plug to fill add the oil. I didn't fully torque the screw plug (p/n 07 11 9 919 225) for fear of stripping the threads. Today I went to check the oil level and discovered that I could not remove the screw plug. The screw plug turns and will not back out. Even with some outward pressure on the screw it still will not catch a tread. It now wobbles about a half millimeter in place. It will no longer tighten.
I'm stuck with two dilemmas. One, to get the screw plug out and Two, how to re thread. I will most likely have to disassemble the final drive in order to get the screw out. I fear it has mushroomed on the inside. Before I start loosening screws on the rear, would anyone know if I'll need to re-shim it upon reassembly.
I assume it is best to renew the threads with a Helicoil or similar thread repair kit thats comparable to the M12 x 1.5 threading. Is it something the average shade tree mechanic can do without machinist tools. A few years ago I repaired the stripped battery ground / tranny vent screw hole on my transmission. I didn't use any rigs, just a helicoil kit and some lock tight. As the diameter of this screw is bit larger I'm having second thoughts about doing it myself.
thanks in advance for sharing your wisdom.
Scott
You might be able to fit a plug with "oversized" threads. I once used an oversized piggy back plug on the drain hole of a 4 speed transmission of a /5, with great success. A piggy back plug has oversized threads to fit the original bore and a smaller drain plug in the center. I believe that oversize plugs are available in many common thread sizes.
former Airmarshal, IL.
I would NOT disassemble the final drive.
Pull on the plug with a pair of Vise-Grips while turning and it will come out. Tap on the pliers if necessary. Pure rotation will not remove it. Once the plug is out, there are 2 modes of repair...
1) You can use a "bottoming tap" to make new threads in the aluminum housing to the next larger size. The next larger size may well include SAE inch-sized threads. Gasp ! There is not much "meat" there to tap. There is also great fear in allowing metal chips to enter the final drive, therefore great care must be taken. I like to coat the tap in thick grease, which captures the aluminum chips. Go 1/2 to 1 turn, remove the tap, remove all the grease, apply new grease, go back in and do it again. Slow is the word of the day.
2) Once the plug is out and cleaned, you can permanently install it using an epoxy, such as JB Weld. And then NEVER take it out again !! You are good to measure and refill from the top and drain from the bottom for the next 20 years.
My 2 cents: These plugs get tightened entirely too much. Yes, there is a torque spec, but that is the maximum torque. You cannot tighten to the maximum torque over and over and over, and expect the aluminum threads to hold up for 30-40 years. These plugs should have a sealer applied, such as LocTite 510, and then be torqued to about 3/4 of max by hand... so that you can "feel" what's happening. The sealer, together with the torque, will then hold the plug in place.
Heck, on both my bikes I placed an o-ring on the filler plugs and they get finger-tightened only !! It's just as oil-tight and I have never lost a plug, nor have I stripped a thread. So there goes the "it must be torqued in order not to leak" argument.
🙂
Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.
When I acquired my ride this too was stripped out. I took a slightly larger steel bolt, wrapped it with some seal tape and leave it be. I swap out the oil when I do the tranny.
Advertisement
