Stripped Chaincase Drain Plug? FIX

[diamonddave]

Working on a my buddys 07 RMK and had the drain plug strip during the removal. It broke loose and then just kept spinning never coming out. Had to pull the cover and beat the plug with a hammer and screwdriver while turning the ratchet to get the drain plug out while worrying that the housing may crack. It didn't.

Anyway, the original plug only has about 2-3 threads that hold it in and measures 9/16"X20. After talking to EricW, I took his advice and went to NAPA for a self tapping drain plug. I normally like to repair things the proper way but thought I'd give this a shot. They didn't have anything listed in 9/16 however, showed a "one over size" 14mmX1.5. It looked like the threads may be a little long but purchased it anyway.

After chasing the threads with the new plug, I removed it and blew out the aluminum shavings, used a little anerobic sealant and fully installed the drain plug. It made very nice threads and took 20 ft lbs. no problem. The 18mm head of the plug is no more than 1/8" taller than the original so clearance shouldn't be an issue. Installed an Avid billet chaincase cover and filled with oil. So far, no leaky, should be good to go.

The part number for the self tapping drain plug from NAPA 14MMX1.5 is 704-1362 and lists for $3.67

Special thanks to EricW and Super Dave3

[m8magic]

good info...thanx

[WHITEOUT]

Saved buying a new cover/case. Thats what its all about.

[XC]

Another option if you have a complete tap and die set is to drill and tap it for a #8 Boss o-ring Hydraulic plug. That's what they are using stock only it's a #6. The plug is avail from any hydraulics shop or McMaster carr etc. I'll have to do some looking for the thread size and pitch.

Edit: thread is 3/4-16

[diamonddave]

Originally Posted by XC700116

Another option if you have a complete tap and die set is to drill and tap it for a #8 Boss o-ring Hydraulic plug. That's what they are using stock only it's a #6. The plug is avail from any hydraulics shop or McMaster carr etc. I'll have to do some looking for the thread size and pitch.

Edit: thread is 3/4-16

Good idea, I had the same but unfortunately this won't work due to the closeness of a casting ridge that runs north-south right next to the rear side of the drain hole. I was going to try this, but this casting ridge prevented me from doing just this.


Not to mention, the cost of purchasing a tap might just lead a person to buying a new housing at $66.00 from Carls.

Not to mention that if you're

[XC]

hmmm I had planned on the same but didn't get around to it yet, I thought there was room on mine but maybe not.

And yeah, if you didn't already have the tap and drill for it, would be more expensive.

[Rob1334]

Good excuse to buy more tools tho...

[diamonddave]

Originally Posted by Rob1334

Good excuse to buy more tools tho...

Agree but a 3/4"X16 tap ????

Plus this was a buddys sled. I can think of other cool tools to buy then a tap.

[diamonddave]

Since posting this, I've now installed 3 of these Napa self-tapping oversize drain plugs. In fact, Eric W has found 2 more alternatives to the 14mm 1 size over plug.

2 potential fixes, Napa Part # 704-1011 is a 1/2" 2 oversize self tapping plug. Napa part # 704-1019 is the same size 2 over with an internal drain plug incorporated.

[BigJake]

Another solution is to use a 3/8 NPT tap and tapered brass plug w/ teflon tape. My chain case plug stripped out a while back and this is what I did to fix it. Worked great and is very inexpensive. The tap was around $13 and the brass plug around $3 at Ace. The factory hole is just the right size so it doesn't need to be drilled out before cutting the new threads with the NPT tap.

One worry I have with the self tapping drain plugs is that they can leak. A tapered brass plug will not leak ( as they are used for both liquids and gases). The other nice thing about the brass plug is since it is tapered it wont thread in any more than the factory original. Nice plus since their is no worry that it will go into far and cause an obstruction. IMO the fix is way better than the poor Polaris factory design.

I also want to add that my sled is an 08. I believe that some older model Polaris's have a smaller drain plug. In this case a 1/4" Npt tap and brass drain plug will work instead of the larger 3/8". Whatever the case one of the taps will work and will be a great fix.