Just another barn find '72 400

[Curlymurt]

Long time lurker, first time poster.

Two years ago, I knew nothing about snowmobiles… especially vintage sleds. I came across a YouTube video of a hundred series Deere and loved the look much more than other brands. I jumped on Craigslist and like a light shining down from heaven, I found one in south central Indiana. A little haggling and 80 bucks later the all original (I think) 1972 400 was on my trailer. It’s a CCW with 1675 original miles. It was bought from Deere by this guy’s dad and he remembered scooting around the farm with it in the mid-80’s. But, it had been sitting in a barn ever since and hadn’t been registered since 1985.

After a whole lot more reading than wrenching, I was able to get it running and re-skinned the seat for the winter. I didn’t put much more than a few miles on it. Last winter, we about zero snow in Indianapolis so I didn’t get it out of the shed until a couple of days ago. The fever has set in again. I’m back to reading, tearing stuff apart, and more reading. My goal is to have the sled as an occasional rider (bc we only get occasional snow…) and not a restoration. I couldn’t care less if under the hood is the original paint, a little rust, etc. but it needs to run well and look good doing it. Something I can be “proud” of but not cry when it gets a scratch.

In the last two years, I’ve changed one crank seal but was too pansy to take the clutch/drive components off to get to the other one. To no one’s surprise, it throws a little oil so that needs done soon. I checked the compression and, if I remember correctly, it was 140’s for right side and high 130’s for the left.

I rebuilt the original Walbro carb but it was pretty dingy again this year. The crud in the metal gas tank is just too much, even with two fuel filters so I may change to plastic. For all the trouble others have had with the Walbro, I must’ve gotten lucky.

I look forward to checking out the transfer case, chain, and clutch. The white drivers have a few cracks, so I’ll eventually be looking for the black ones that might fit. But, the track is in a little worse shape than I thought, and I don’t know that I can adjust the tension much more, or correctly. So maybe I’ll wait until the drivers or track blows before dropping some coin on it. The steering is SUPER sloppy so I need to figure out the bushings situation and how to repair/replace that stuff. I saw some forum threads about it, but I might as well have been reading Japanese.

Cosmetically, I need a little fiberglass repair on the hood, all the old decals need replaced so I’ll be working on sourcing those. The rest will get sprayed green again bc green vintage sleds are my new addiction. Anything that was chrome probably won’t come clean enough so I’ll repaint them black. The headlight lens needs replaced, though I might try to put in LEDs for headlights. Oh, and the top console has been patched with aluminum due to some broken plastic.

[JoeRainville]

Hello Adam, and welcome to the board!

Not that I know everything about mid-mounts, but I have been playing with them over the past few years for some reason (I blame Brian Lindner myself). A few threads down is a post called "Bogie Bash Sled Slam" were I rebuilt a solid 72 JD400 in a 3 1/2 week thrash. It was crazy, and the exact opposite of the 2 1/2 year resto I have been doing on my 73 JDX-8. You might find some useful tips in there, as I replaced the track, all the track drive axle and chaincase bearings, serviced the bogies, tightened up all the slop in the steering, replaced the crank seals and stole a carb from Lindner to get it running for the "Bogie Bash" at the Hall of Fame last Feb.

A few useful things to note:
-the bushings at the bottom of the ski spindles, where the ski saddle attaches, are still available new from Deere
- new or NOS tie rod ends are easy to find, but most of the slop is probably the joint at the bottom the handle bars
- You can stick a needle tip grease gun end behind the bogie wheel to re-lube them, but you have to remove them first, and pop off the dust cap
- The Scorpion guys repop'd a track drive sprocket that fits the original 1" drive shaft, but has the correct 2.52" drive lug pitch. Or, you can swap out the entire assembly for 74 and newer 100 series 1 1/8" drive shaft that is easier to find sprockets for.
- Finding a good used track is easy, later versions are very durable and common at swap meets, etc.

Good luck with your sled, and hope this helps,
-Joe Rainville

[WinnipegStPaul9]

Hi Adam and welcome to jdsleds!! We don't work on midmounts and have little parts for them but if we can be of help we're not too far from you as we're located in Churubusco near Fort Wayne. Check out our website www.buscobullet.com for more information and again. welcome!!

DA

[jep_800]

Hi Adam, Brian Linder is probably the most experienced when it comes to Walbro Carburetors or just mid-mounts in general. I have also been successful rebuilding two Walbros for my sleds, and they function great. They usually get a bad rap, but changing to a plastic tank will help keep them clean. The thing that I've done to help them function correctly is I start each of them at least once a month all year which keeps gas flowing through them. I also use SeaFoam in my gas which acts as a water eliminator, and adds lubricity to the fuel. Ever since I've done this, never had a fuel problem. Yes, definitely get that clutch off and change that other seal. Until then, its a burnt engine waiting to happen.

Let us know if you get stuck on something, and we'll give you a hand.

Jason

[Curlymurt]

Thanks for all the info so far. Actually, you've all helped much more than you know from your posts on the forum. So, thanks for being active members and always willing to help us newbies.

With that said, let's get to today's activity: Crank seal.

It was a day with a little wrenching and a lot of reading. I went through the JD manuals, YouTube videos, and, of course, the forums. From that, I learned I do infact have the comet 102C primary drive clutch, or whatever you call it, and not the Salisbury. Also, I have the belt that looks like I bought it two years ago and a spare. I must have huffed too much smoke in the garage but I don't remember buying one, though I wouldn't put it past me. Anyway, turns out both belts are not the same... One is thinner than the other, but I can't remember the specs off hand.

I moved on to actually trying to pull the drive sheave. Pull the belt and clamp the sheaves closer, check. See that I need a special nut and wrench, uncheck. So, I mocked a little tool out of spare parts (including the tool I made for the flywheel so long ago) to hold the sheave axle. Finally pulled the first bolt out and then I was stuck again. I knew I'd be a clutch puller bolt, though I didn't know what that actually was. Long story short, I researched and called part shops, motorsport shops, and went to hardware stores but couldn't find anything that would work. I bit the bullet and bought a puller too from Amazon, but the thought of waiting 2 weeks shipping killed me. I came across my wheel puller set from Harbor Freight and it was on. I know I was going to do what everyone warns against. *Pic shows the kit and the steel rod.

It had a hex bolt that was 3/4" with thread pitch of 16. I bought a 3/8" steel rod for under $6. After soon measuring and cutting, the two pieces should work as one while allowing nearly 1" of threads to make contact between the tool and the clutch. I didn't know what to expect so I went slow, but the tool worked perfectly! Actually, the clutch never "popped" off... It was very quiet and uneventful. Is that an issue?

Anyway, the clutch was off and I spent the next two hours trying to get the old seal out without damaging the bearings behind it; and without throwing debris into them. So, now that the seal is out and the shaft and rim are cleaned (no jokes), is there anything I need to do or check before I push in the new seal? This is only the clutch side.

Last question: The primary drive sheave has something that rattles around inside of it. Does that mean I'm going to take that apart, too?

[Matt]

The noise from inside the clutch are the weights, which move freely when the clutch isn't spinning. It would be a good idea clean & inspect it. If you take off those 6 10mm-head bolts, the top and the dust cover will come off. Be careful because this is under pressure from the spring. It will be full of dust on the inside to clean out. With the spring pressure off you will be able to move around the movable side of the clutch, and see how much play there is in the bushings. Some play is normal, too much and the clutch will jam up. Also check for too much side-side play on the weights and that the rollers are free to spin. You can use dry graphite lube if needed on the moving parts.

[jep_800]

Good work! Always nice to see someone come up with a solution with a little trial & error and common sense.

That clutch (both primary and secondary) was called a Comet update kit (there's an actual name given by JD which the guys know), so someone has spent time getting things updated for a good rider.

The rattling you hear is most likely the fly weights inside. Normal. They work on rollers as the force of spinning the clutch moves the sheave closer to the shaft which in turn changes the position of the belt to the outside while the belt moves from outside to inside of the secondary, which of course is how the sled shifts into higher gear and increases speed. But, you've probably read this already in your manuals under Principle of Operation.

So, you need to position the seal over the shaft and need a striking tool to push it into position. This MUST be driven as straight as possible so you don't damage the seal or screw something up. The manual says how to accomplish this. The seal and shaft should be lubricated first to help move it into position. I have seen several instances where guys will fill the back side of the seal with white lithium grease first. The key is to take your time and don't rush it. If it starts to kink, bind, or doesn't drive straight, stop and start over. Let us know how it goes. Good Luck!

Jason

[Curlymurt]

Thanks for the helpful info. I reinstalled the seal using a piece of 1.5” pvc pipe. Tapping slowly and around the outer edge of the seal made it go in straight. I pushed it in by hand until it was almost flat with the outer rim of the crankcase, so I pushed it about 1/8" further. The old was about 1/4" inset originally. I used two stroke oil as the lubricant for the seal and later read in the manual not to use snowmobile oil. Whoops.

Because I won't be running this a ton yet, I'm trying to be conservative with my time and spending, so the clutch tear down might wait.

Speaking of funds, I've purchased new decals, spindle bushings for the steering, and some ski wear bars. That extinguished my PayPal balance so now everything I buy will be scrutinzed by the wife, so some discretion needs to be used. I've made a list of needs vs wants:

Needed:
Fuel filters (Amazon)
Fiberlass repair kit (Menards)
Pull start handle (Menards)
Various bolts and nuts

Wanted:
Brake and/or throttle handle
Emergency shut off
Poly gas tank
New gas cap
Ski leaf springs?
Console top without tach hole
Black drive sprockets for 1" shaft (future project)
Foot grip pads

If you have any of these, let me know... If I batt my eyelashes at my wife well enough maybe I can purchase them.

For the leaf springs, I had planned to transfer them to new used skis, but it became evident that I might have to due to spring damage/fatigue. They aren't even close to the same height anymore. I broke out the power tools to cut the bolts holding the springs to the ski. One was welded on and the other was just rusted stuck/bent.

I've peeled all my decals and stickers off, so other than a lot of sanding to do for paint prep (and waiting for parts), I don't have much I need to do before I start putting stuff back together. Actually, I've started to lose tools in my mess of parts scattered throughout the garage so maybe a little mid-project cleaning is in order.

[Curlymurt]

Upon further review, wanting a new gas tank has turned into needing a new gas tank.

Looks like it's leaking at the seam.

[JoeRainville]

I can help with some of the parts. I know I can spare a set of NOS ski springs, a kill switch, possible others...

-Joe Rainville

[Curlymurt]

I feel like I'm moving right along on this project... I walked into the garage to grab a tape measure and somehow ended up scrubbing rust off the bumper with a wire brush. I never made it back in the house with the tape.

That bumper was brown with rust and I'm amazed at how well it cleaned up! I had planned to paint so I used a really rough paper (50 grit, I think). I used an old headlight lense restore kit to see if it'd polish, and while it's not perfect, I'm actually debating leaving the chrome now. I'll research how difficult it is to get good adhesion to chrome if I paint. If it's a headache, I'll leave it chrome and finish polishing once it's back on the sled.

I also continued with sanding the body of the sled and popping out some dents. It looks like someone shot a pellet gun at it because there's a ton of dents on one side. It won't look pretty painted, but oh well.

I'm basically only painting what you'll see, so I'm not concerned with how it looks under the hood even though that's a travesty to restoration gurus. I didn't even bother with taking all the bolts out. I figured I can always touch them up later after wrenching on 'em. And, I used two different primers bc that's what I had. The hood will get primed and painted eventually, but I just started the fiberglass repair, so I've got some Bondo work yet.

Continuing with the body work theme, I cleaned the windshield and popped off the rest of the black strip surrounding the windshield. I had to run a razor blade between the strip and the shield to break it apart. There's a ton of little wiping scratches on the windshield, and it's a little yellow, so eventually I'll do a restore on it with a headlight lense kit in hopes it doesn't look like I'm looking at the trail through beer goggles. Oh, and it was broken when I bought it, so I sheared off the bottom 1” or so of the shield and redrilled the holes. It obviously doesn't fit as perfectly as it did, but it's functional.

It's always a wallet shock when starting a project like this, and considering how much I'm not going to be able to use it, I might try to rebend the leaf springs and seal the gas tank with por 15. I found a broken saddle in the process of prepping the skis and hardware for paint, so I'm in the market for one of those, too.

The bushings have arrived so I'm excited to get those on. I think I'll end up needing to only replace one side of the tie rods, but I'll reassess once I actually get some skis on it again.

In the crank housing, I found the chain rubs the metal inside of the housing and is biased towards one side of the tensioners. I need to figure out why and what to do about it. So, it's back to reading!

[jep_800]

Adam, Nothing wrong with doing these resto's a piece at a time, and just what you are able to do with what you got. Sometimes life or funding doesn't allow us to do it full blown. Looks like you really want to make this a rider, so I think you're going about it right. Fix what needs to be fixed.

Regarding your drive chain that is just a bit off and rubbing inside... I would check the part of your manual that addresses the sprockets and the drive shaft itself. I believe there is a spacer on the upper one which aligns it with the bottom sprocket (need to check that). If that isn't installed properly that chain cannot run true like it should.
The other thought is how the drive shaft is bolted to the tunnel and chain case. Or the shaft itself may be a little bent. Could be the secondary shaft is bent. You'll have to check things one at a time and eliminate each step until you figure out what is causing it. Good news is your tensioners look really good with not much wear, so you shouldn't need those.

Let us know what you find out.

Jason

[Curlymurt]

I've slowed down a bit on the sled; partially due to life getting in the way and partially because I put myself on a spending freeze for the rest of the month. But, I did get most of the sled and the skis painted. The little odds and ends that were rust are now gloss black. The hood was patched with fiberglass, Bondo, sanded, and sanded some more. I'll spray one more coat before I call it "good enough."

As it turns out, the tractor green from Rust-Oleum isn't the correct color, but that's the cost of being cheap and impatient. That really wasn't much of a surprise. "Good enough."

I decided to start putting some parts back together on the sled. The skis won't be ready for awhile as I'm needing a saddle, but the money freeze will be over in plenty of time before snow comes.

Two years ago I bought a used replacement seat from a similar Deere. After I replaced the wood, I decided I didn't want to have to do that again due to rot, so I made it easily removable. I bolted a couple of hinges (with removable pin) towards the front of the seat and added a bracket to the back tunnel. Slide the back of the seat on the tunnel and then lower the front and insert pins. Having the pins in this direction makes it easy to pop them out with a screwdriver. A couple of bolts in the osb at the rear of the seat keep it in position without it sliding from one side of the tunnel to the other.

The extra weatherstripping is to help keep moisture out from under the seat, but it fails at that. It does keep the staples from grinding against the tunnel and/or rusting, so I'll take it. I'd prefer darker stripping, but I already had white.

The "tractor green" isn't as big of a difference as these photos make it seem.

[Curlymurt]

I was back at it again tonight. Got a little spraying done and moved into reassembling the skis and spindles. Now I know what spacers are, but I decided to put them back on. I've heard not to, but not really why. Granted, I haven't researched it. Anything that improves stability is generally a friend of mine. I've got one ski neck together and at least the leaf springs ready. I installed the new carbides bc my old ones were worn halfway through the bar.

For the spindles, I bought new bushings but couldn't remember for the life of me where. It was from Dennis... That's all I know. But I wanted to look up instructions bc, I couldn't figure out which or how many washers to use once the bushings were in place. I decided on 1 at the bottom, nix the one between the lower bushing and the body, and just one on top. Originally, my sled had two bushings on the bottom and two on the top. Maybe someone in the past was trying to tighten up the bushings by smashing them down.

Truth be told, I didn't read how to install the skis... I just went for it. One side of the tie rods were pulled nearly all the way in, so I mirrored that on the other side. I used the saddle bushings inside the spindles and found the left over 3/8th rod from another project, I think. I don't really remember what I needed that rod for. Anyway, I pushed the rod all the way through to the other spindle so they were perfectly straight (photo). After a little tie rod adjustment, both ties slid onto the spindle splines nicely. I tightened everything up and it feels pretty good. A little stiff and squeaky, but much of that is the upper bushing on the steering column. Once the skis are actually on, I'll jiggle them to know if I need new tie rod ends.

[Curlymurt]

I'm singing with excitement!

The biggest bane of this sled (for this year) has been the secondary shaft... and the chain rubbing against the chaincase. Finally got it figured out with a ton of help from Matt in the Tech section. Someone has definitely fiddled with this sled more than I thought.

Long story shorter, my left side bearing (bearing that's actually in the chaincase) on the secondary shaft was turned the opposite direction, with the locking flange (looks like an attached spacer on the bearing) facing out; it needs to face towards the secondary clutch. That bearing had caused a little damage to the shaft including a rib that wouldn't allow either bearing to slide on one side of the shaft and off the other... it always got caught on this rib. Doubly important to note: apparently the shaft isn't supposed to be flush or protrude from the edge secondary clutch. After a couple of purchases from Matt at New Breed and JD, I had everything I needed to put it back together as it should be. It didn't have and o-ring or the spacer between the gear and the bearing.

I don't think I've mentioned the repainting of the hood. I couldn't get the sheen correct with the spray can on the hood. It was blotchy and looked terrible, so I tried to add a clear coat finish from a spray can and it actually peeled the paint. So I ended up using a stripper and stripped it off, along with some of the original green, and tried to sand it down. Unless I sanded it completely clean of the original green, I wasn't going to get a good, smooth finish. So, I decided I didn't care that much (bc it's a damaged/repaired hood anyway) and re-primed and painted. The sheen came out perfectly, but the up close all the imperfections are hard to tolerate. From a few feet away, it looks great, so that's how it's staying unless I get a new hood. I'll probably rub a little car wax over it to give it a little protection because I'm gun shy about trying to use the clear coat again.

Let's see how much of this thing I can get thrown back together today. I need to put the gas tank back in, replace filters, and reinstall fuel lines (just two years old). I used POR 15 and that stuff seems legit. I used CLR and rough cut gravel to shake inside the tank, let it sit, and shake some more to remove the rust deposits. I did this two years ago and it was back, which is why I used POR15 this time. After rinsing the tank with a hose, I poured some 91% rubbing alcohol in, sloshed it around, and dumped. I did that so it would dry faster than rinsing with water... again, rust prevention. To accelerate drying, I put tip of my heat gun in the fill port and turned it on low. Once dry, just dump the small can of POR in, slosh it around, and I turned it upside down to dry. I'm pretty sure I ruined a couple of gaskets on the fill port and fuel level gauge due to the POR getting on it. I needed a new gauge anyway.

Oh, the windshield... It wasn't as bad I thought. I probably should have just used a polishing compound and soft rag on it first, but I went straight to the headlight lens restore kit to try to freshen it up. It actually left a bunch of swirls (that it didn't leave on my headlight lenses) that I can't buff out. But, I can still see through it better than before and it looks clear, so again, good enough.

Hopefully I'll get some photos up soon!