Sockets and or Wrenches

They are metric, I don't know the exact size, but it's one of the drivers in my metric driver set.

Thanks GunrunnerJohn, that alone helps tremendously.  Now just must find someone that sells Micro mini wrenches and sockets.

I have the Whia socket set, and I added a couple extras that weren't in the set.  I also have the same kind of set in SAE, between them I haven't had any issues taking the drive rods off anything.

On my RK Hudson it is 5mm. You should be able to find a set of nut drivers to cover most of your needs.

"Ignition" sets come in metric and have the small wrenches that you need.

You can pick up individual sockets at Sears or the big box stores.  I use a 4mm and a 5mm, 1/4" drive socket and a driver handle.  I ground the face of the socket so it is complete flat; that way you can get a better grip in the screw head.

Thank you everyone.  For the price you pay for an engine now days, sure wish they would include a wrench for that kind of job.  Thanks again.

Some engines do come with the wrench for the drive rods.

Micro-Mark has a couple of sets of small wrenches which I don't have. I don't know what quality they are, but from the catalog they appear to look better than some of the ignition wrench sets I have seen.

The Whia tools are hard to beat (good quality items as cousin Eddie would say). I have some of them, they are very nice and some of my favorite tools.

Below is a photo of some tools I've got mounted behind my work station (within arm's reach). On the left is a set of Wiha sockets. Wonderful, and like John, I bought some extra sizes. On the right is a set of precision screwdrivers (slotted and Phillips). I bought the Wiha set first, but added to it with Ace hardware precision screwdrivers. I should have gotten all Ace screwdrivers......I find them to be of much higher quality. I bent a few of the Wihas removing some tight screws. Not going to happen with the Ace drivers. 

-Roger

I am also a big fan of the Ace screw drivers. I used them at work for several years before retiring, they became my favorites. They are very nice, but will twist, bend and break just like the others. I have gone through a few of them. Ace replaced a couple of them at no charge, but for the price I felt guilty about it and just bought new ones after that. They were only like $2 or something when they first started carrying them. I still have 2-3 sets of them I bought when it looked like Ace was switching to all Craftsman tools and stopped selling them individually. Thankfully they kept some of their Ace line of tools and these screw drivers are still available. However, the more I use the Whia's the more I like them, but I still use the Ace drivers too.

The Wiha nut drivers are the way to go. They are excellent quality and a set will last a lifetime. I've been using mine for several years.

Gentlemen,

   I agree I own a complete array of Wiha Nut drivers and also the Wiha Screw drivers/jewelers tools, IMO the best stuff on the market for our O Gauge Train repairs.

PCRR/Dave