Question for anyone who's had these engines apart. I got the engine up on a stand the other day and I noticed it looked like the front main seal misted a bit of oil. Can I change the seal without pulling the gear cover off? Nothing else is leaking so I'd rather not distrub all of that stuff. Also, based on the diagrams
I looked at, it looks like there's an o ring and some sort of collar spacer thing on the crank just inside the gear cover. Does that o ring have to be replaced as well?

Joe

 

Update time: I'm finished for the semester so now I'm back to work which means more time and money to work on the Kubota. I finally got the engine on a stand (Harbor Freight special, pretty nice for the money) and started getting parts together. I picked up a few gaskets from a local company that has all sorts of parts for these engines, everything from gaskets to heads and cranks. Most gaskets are in sets, unless you go in and ask for it. If anyone needs gaskets, PM me and I'll see if I can work something out. I also got the Carrier manifold pulled off and I only broke one stud, which I'm blaming on Dan since he was telling me about IP tuning instead of letting me focus No matter, the stud backed right out with some mild persuasion with a hammer and vice grips. I also picked up a power steering pump to start working on the mounts for that and most importantly, I got a trans.

 

For Harbor Freight, the stand is pretty decent. I had the 20% off coupon so I didn't even spend $50 on it. The welds are pretty decent and the bolts are 8.8, so I can't complain. I did have to get bolts to hang the engine on the stand, as the supplied ones were the wrong thread pitch, no surprise there. The stand rolls nicely with the weight of the engine on there. Also, it fits perfectly between the frame rails of a 92 Bronco

 

I picked up an oil pan gasket, and exhaust manifold gaskets. The valve cover gasket was the wrong one (for an IDI), but it's pretty nice rubber nonetheless. The oil pan gasket is fairly thick, and they were reasonably priced for the quality.

 

The manifold came off pretty easy. I was able to grab the majority of the top bolts with a wrench, and the bottom ones needed a socket with a short extension. It's my own fault for snapping the one, I pulled on it wrong instead of walking around the stand to the back of the engine so I could get a proper yank on it. All the valve stems and exhaust ports look clean, minus the usual carbon. The wetness is condensation, I live not too far from the beach and in the past month we've gotten 6 or 7 inches of rain. Even with shop rags stuffed in all the holes and two tarps over the engine the water still gets in. The only questionable thing is there appears to be some type of scoring on the number three cylinder exhaust valve. It almost looks like someone hit it with a grinder, but right in the middle of the valve stem. You can just barely make it out as the shiny part on the valve. I'm assuming it's from the factory cleaning up the rough casting, as it's smooth to the touch and I can't catch anything with my nail.

Also, anyone looking for a Carrier manifold, PM me and we can work something out. All the gasket surfaces are flat and true. I will be cleaning it up, as it's a bit crusty for me.

 

And now for the fun part. After much deliberation I decided to abandon my idea of trying to cobble together a World Class 4x4 T5 or and started looking for an AX15. And then I found an NP435 and The trans has 88,000 original miles and it's out of a 1966 Ford F250 Camper Special 2wd with a V8, that was sold from the Ford dealer that used to be about four blocks from my house. Better yet, before the owner died, it looks like he had it completely rebuilt, unless 51 year old gaskets peel off in one complete piece and don't leak, and all the gears have paint marks on them and no signs of wear and the plastic shifter forks are brand new. Yeah, score of a lifetime. Oh, and 6.68 first gear, so I can climb a tree with the Jeep. I could get an adapter to run my np231, but then I have to find another one with a 23 spline input as I would like to be able to sell me drivetrain as a complete unit. And the adapter is expensive. I'm opting to run a Early Bronco Dana 20 transfer case, which is a gear driven case that is much more compact than the np231, has a similar low range, can be twin sticked by simply adding another shifter to the case, and the adapter is much cheaper. But better still, according to my research I can cut the flange off the output housing on the 435 and cut the flange off the intermediate housing on the dana 20 and weld the intermediate housing to the 435 flange and it all bolts up, making it infinitely cheaper and I can then clock the case to make it sit higher in the Jeep, if so desired. And as for overdrive: Ranger Torque Splitter. Hence, why I'm trying to save all my pennies. The perk of the splitter is that I can engage OD in every gear, my OD 4th gear will be .73, which is higher than the AX15 and infinitely higher than my AX5's .85 OD gear (yeah, borderline useless), and it's only 7 inches long, making the whole combination about the size of a AX15 np231 with a super short shaft, possibly even shorter. And infinitely stronger, as the AX15 is good to about 300ft lbs, which is a little close for my comfort. I'm also using a CJ bell housing to bolt the np435 right to the flywheel housing, and making an adapter to retain my 2.5 flywheel, as the 4.0 and 2.5 flywheels are almost the same size and the pilot bushing is pressed into the flywheel instead of the crank, meaning one less piece for me to have to machine. The bell housing doesn't have a CPS hole cut in it, so instead of trying to machine that and make up the difference between the two flywheels so the sensor can read, I'm going to rig something up the the crank pulley like how the Ranger and S10 guys do it to make my tach work.

 

The trans

 

The bell housing I was looking for I couldn't find, so I have to make this one work. The bell housing to mount a T176 to an AMC I6 or V8 has the same pattern as the np435, which is the easiest route. Mine is drilled for a T5, which won't allow me to bolt the trans on. I have to drill and tap the bell housing for the Ford butterfly pattern, which should be easy as AMC so graciously marked the holes I need to drill. If I was using an SM420 or 465, or a T5 for that matter, the bell housing would be perfect. But since when is anything bolt on with a project of this size?

 

Another update after an uneventful summer. I spent most of my time trying to get a 54 Chevy 1 ton trying to run after it sat for 10 years as an early retirement/father son project, but that's a different story.

I picked up a transfer case for the Jeep, it's a Dana 20 out of a late 60s early 70s Ford Bronco, so it has the drivers side drop. And it's a T-shift, which has the desirable 2.46:1 low range

And I picked up a new turbo, had it shipped from across the pond. It's an IHI RHF5 VJ33 off a 2.5 Ford Ranger. Seems to be in pretty good shape, and it was cheaper than a new eBay China clone, so I can't complain. Only problem is I can't get the bolts out of the compressor housing, gotta love Torx bits. I took a couple pictures comparing the VJ33 to the K03 and they're close in size on the hot side, the VJ33 looks to be maybe a tiny bit bigger, and the exhaust housing looks like it would flow a lot more than the K03 housing. If anyone is looking for a K03 to use as a parts turbo or a mockup, I'll be selling mine. I also have a downpipe flange to go with it. I also have it sitting on a 2403 turbo manifold and the pattern is close, but not the same. If anyone has a side exit manifold, I'm looking to trade mine for it as the turbo is set up perfect for a side exit manifold.

And today the Fedex guy dropped off one of the big pieces of the puzzle, an oil pan and pickup tube and all the required bolts for an L4200 tractor. Bolts right on and has a dual sump pan with a deep pickup tube to help prevent oil starvation at odd off camber angles. I also picked up a governor spring from the same tractor since based on what I've read they rev out to between 2800 and 3000rpm.

 

Question for everyone, what size drillbit did you guys use to drill the holes for the dipstick and oil drain? Also, does anyone know the torque specs for the oil pan bolts? I’m running an aluminum pan, so I’m assuming the specs for the Carrier pan are the same since it’s aluminum as well. Thanks gents.

Joe