78 Spitfire project

[400brian]

So the new shock shaft arrived. This shaft is part M67802 and was used on the early Spits both as the lower shock shaft, and the shaft at the front of the rails that the suspension limiter strap attached to. On the later Spits it was used only at the front. It is a 7/16" diameter shaft drilled and tapped for a 5/16" bolt on each end. Cleaned the surface rust off, and still need to chase the threads. Some nylon bushings went on either side of the shock to keep it centered, but they were sacrificed to heat the shaft for removal. Probably going to use aluminum tube in its place.

[400brian]

Matt Gabler had suggested that a dingleberry hone was the way to clean up the bore of the tubes. I had never owned one, so I got on-line and rectified that. This 3/4" hone is advertised as 120 grit, and was less that $20 plus shipping of course. I had to use an extension to reach to the center of the longest tube. Really worked slick, I lubed it with a little 2-stroke oil cause that is what is in the oil can, and in just a few seconds, the bores were looking 100% better. I don't think these hones are hard to come by, but if anyone is looking for a 3/4" model you can go here: https://regismanufacturing.com/3-4-x-19 ... 1ZW9dje6nY

[400brian]

I used the same setup to remove the pivot bushings from the spindles. One ski bolt had come out, the other was stuck and twisted off. With heat and a lot of pounding, I did get the bolt out, so it was on to the bushings.

I took an old ski bushing I had sitting on the bench and sanded it smooth on the bench sander. I set up the puller as shown and wound everything up tight. I then heated the spindle until it was turning red and tapped the bushing end using a impact socket on the nut, that way I was impacting the end of the bushing through the washers.

I got it to move slightly, wound up the nuts and tapped on the end again. I had to heat it several times to keep things moving, if it cooled too much it would stop. Both bushings were removed this way, and I think all is good.

[Mark633CSi]

I hate to be like my wife and bring up things from the past but, have you made any headway on this since the last post!? This has been, as always, a fantastic write up!

[400brian]

The spitfire went on the back burner for a bit. I built a 76 Cyclone for my wife last winter, and I am working on a 78 LF CC clone right now. The grandson is 8 years old now, so the Spitfire will have to be next I think. I was hoping the reproduction tracks would be available to go into the build.

[Mark633CSi]

The spitfire went on the back burner for a bit. I built a 76 Cyclone for my wife last winter, and I am working on a 78 LF CC clone right now. The grandson is 8 years old now, so the Spitfire will have to be next I think. I was hoping the reproduction tracks would be available to go into the build.

Excellent!

Reproduction tracks would be nice! We had a conversation at work the other day about “What would you do if you won the lottery?” Quite a few of the guys looked at me funny when I said “I’d pay for a run of out of production JD snowmobile parts. Especially Spitfire tracks.”

[400brian]

I had to do some digging to find this thread again, it has been 5 years.

But we are back baby!

I had told the soon to be 11 year old grandson that when I got back from the RWTC, that his Spitfire was going into the garage.

We pulled the tunnel out of the machine shed where it had been resting and brought it down to place it on the horses. We went right to work cleaning.

The search will be on to find the suspension parts and pieces, and putting together a plan to move the project forward. We also have a 1937 JD B that were are two years into that we would like to have running by August.

[Cdnturboz]

Nice! That’s the next project in our household too, my daughter is 10 and wants a sled to drive on her own, gonna pull out the 82 spitfire and go thru it later this summer.

[400brian]

Just to start at the beginning, I dug back through my photos and found the pics of the Spitfire when I got it, September 7, 2009.

Bought it sight unseen, my brother hauled it home for me.

[400brian]

Looking at the suspension. It was disassembled 5 years ago, so I needed to refresh my memory of how this goes together, and if I had all the parts we need.

It appears I need some hardware, a pair of new driveshaft bearings, I need to find the NOS limiter straps I have around the shop somewhere, and I need the bearing kits to replace the bearings in the little idlers.

[400brian]

today I dug through the stash and found a NOS limiter strap, and picked this grab bar off the floor. It is a Spitfire bar, it is straight and the one on the sled is not, and I have no idea where it came from. Obviously it needs to be stripped clean and repainted.

I drilled the eyes in the new shock out to 7/16". I think this is at least the 10th shock I have done this on, to the best of my knowledge with the same drill bit.

So other that a few new bolts I have yet to source, all the parts are here. The suspension is ready to come back apart for clean up and paint.

[400brian]

Galen was disappointed to see that the Spitfire had a plain black snow flap, and wondered if we could rectify that.

I found a used flap Sunday afternoon that had been lying around here. I cleaned it up and late in the afternoon he was here for a few minutes, so I had him paint the yellow back on.

I think we can make this work. it is a little taller than the Spit flap, but if we have trim it a bit we will not feel bad doing it.

[Cdnturboz]

That’s always been my pet peeve with spitfires is the snow flap being plain. Let me know how much you trim off

[Cdnturboz]

Brian - do you happen to know the correct size of the bearings for the driveshaft offhand?

[400brian]

I haven't bought them yet. What I do know is that the OD is the same as all the other 72 - 78 sleds I have worked on, the flanges are the same size. The IDs are not the same on both sides like all the rest though. The brake side is the normal 1" bore. But the drive side is 7/8" to match the secondary sheave bore. That is what I have written down here for stuff I need to obtain.