There are three plugs on the oil pan.
Two of them have hex heads, one is an allen plug on the front of the pan.
Thats the one I am using. It is the forward side of the pan.

I didnt buy the adapter kit. As I will be installing a Oil Cooler.

 

HarleyPingman has the right "scope" on the install

Good Luck

 

rocknrod, do not intall the temp sender close to the oil cooler. The oil pan location is the best place for the sender.

 

Thats the plan.

 

All of you are talking about down at the pan and to me that is the easy part. The scary part is when I looked behind the batwing and thought about how in the he!! and I going to get that useless air temp gauge out of there. It seems to be behind a major bracket. Any thoughts on how to proceed up there on the top end?

 

I installed the oil temp gauge on my RG a few weeks ago. I bought the 3/8" adapter at NAPA and it was too small. I had to take the Allen plug with me to NAPA for the right one and of course, all my oil drained out. Your most difficult part will be getting the wiring harness tucked under your fuel tank, unless you want to completely remove the tank. You'll have to drain it, so I would recommend ride it till you’re almost out of gas so you won't have too much to mess with. I only unbolted my tank and lifted it a bit while pushing the harness up along the right side of frame back bone. I ran the harness to the sensor down the right frame leg behind the tranny to get it to the oil pan plug. The other wire to the fuse block doesn't click into the fuse block as easily as you would think. Mine fell out while putting the fuse block back onto its mount, so of course the temp gauge didn't work. There is a picture in the installation instructions about the grounding wire. That picture is actually of the area just forward of the battery in that hard to reach area at the rear of the frame back bone. I had one of the little tiny nuts missing from my kit that hold the three wires to the back of the oil temp gauge. I found a replacement in my coffee can of spare nuts and bolts. You can come over and sort through them yourself if you are missing one from your install kit. 8-)

 

I used a 1/4" drive deep socket with a long extension to get the fasteners off the back of the gauge. No problem. Gauge comes out the drivers side.

The fuel tank on an 08 doesnt have to be drained. Mine came off easily. It has an interior cross connect in the tank
My wire cover comes off easily after that.

 

When I installed the new plug, I had everything right there beside me, removed old plug, put finger over the hole, dropped ole plug picked up new plug with same hand, installed new plug after removing finger from hole (very important). Lost less than 1/4 pint of oil, so little that it barely showed a difference on the stick. Love the new oil temp. gauge and have a useless air gauge for sale if anyone needs one, why anyone would want one I do not know, but I have one. Really simple matter to change out plugs just have everything right at your side so youdo not give oil time to flow out, also change out when cold oilis stiffer and does not flow as good.

 

Yep, working on changing gauge is the tough part, hands to big andnothing goes straight in, I just took my time, when back to the house a few times whenI got flustered had a beer, watched some of the game, relaxed and went back after an hour or so. It's like everything is in your wayand you do not want to take off more than you need to. You just need to take it slow and easy, those 1/8 turns will eventually get it in or out if you keep at it, sometimes you have to bit the bullet and remove something you did not want to, just remember where it goes and how to put it back with what screw or bolt.

 

Just a suggestion

A couple of digitial picture closeups of the parts you are working with/removing is a great way to "remember" where everything goes

Good Luck