Max Iv resto with Kubota 2cyl diesel

[Shanex25]

Just starting my restoration on a 1978 max Iv, I pulled the diesel out of my old Kubota tractor today and dropped the max clutch assembly and Kubota flywheel off at a machine shop today to have the adapted stub shaft made for it. The max Iv is in rough shape with a busted up tub and rusty frame but I got a heck of a deal on it. Never owned a 6x6 before and have only seen one in person years ago and just happened to run across this one. It came with a 16hp Kohler magnum that ran well, but it wouldn't drive because of a stripped rear sprocket. Plans for it are to pull the frame and start rust repair and add new bearings and chains, then have it all powder coated. Once the frame is complete I'll start fixing the tub and plan on doing a military green spray on Bedliner on the top half with black on the bottom half. Then throw the diesel in which I've already mocked up and looks like it's going to fit the same as the 16hp did. Finally I'll assemble the rest of it like factory with the addition of some gauges for the diesel and a stereo system. Then just enjoy it, it has one new
23-10.50-12 tire so I'll probably just buy 5 more of those and roll with that. I was originally planning on having it done for deer hunting to start in November but we will see how fast I can come up with parts. Stay tuned for pictures.

[Mike]

Sounds like a fun project. I think the only two things I would add as an alternative to consider would be about the tires and tub. Since you have to buy so many tires anyway, I would consider buying larger tires. With a Max IV, you can easily fit 26" tires and that difference in diameter will make a world of difference in the terrain you can overcome. For the tub, I would consider staying away from using bedliner for two reasons: You want the tub to slide over terrain and the bedliner would cause some unwanted friction. Second, HDPE is tough to adhere to long-term. While bedliner willl probably hold up better than paint, it still may peel off over time. I'm guessing that you were going to use bedlinder because your tub is busted up. If you need to repair the tub, you can plastic weld the it back together or epoxy it together. Then, use a heat gun to bring out the color again.

Just talking out loud for some potential alternatives while you're at this stage in the build. Either way, it should be a cool 6x6 when you are done. Keep us posted on your progress.

[rcn11thacr]

November? Wow, u better get cracking.

[AndyL]

Sounds like a fun project. I think the only two things I would add as an alternative to consider would be about the tires and tub. Since you have to buy so many tires anyway, I would consider buying larger tires. With a Max IV, you can easily fit 26" tires and that difference in diameter will make a world of difference in the terrain you can overcome. For the tub, I would consider staying away from using bedliner for two reasons: You want the tub to slide over terrain and the bedliner would cause some unwanted friction. Second, HDPE is tough to adhere to long-term. While bedliner willl probably hold up better than paint, it still may peel off over time. I'm guessing that you were going to use bedlinder because your tub is busted up. If you need to repair the tub, you can plastic weld the it back together or epoxy it together. Then, use a heat gun to bring out the color again.

Just talking out loud for some potential alternatives while you're at this stage in the build. Either way, it should be a cool 6x6 when you are done. Keep us posted on your progress.

If I remember correctly, the 1978 Max IV's still had a similar lower tub to the RIM. I don't think a 26" tire will fit. I used to have a '78 Max IV with the 484cc Chaparral, and I don't think the 26" fit on it, but I could be wrong...

[AussieMax]

Hi,
I have a buffalo truck with a kubota diesel in it. I put a 3 cylinder d660 in it a while ago, I also added a turbo. The only 2 problems I have had was getting it to run cool firstly, and getting the clutches to shift at the right time. The radiator is mounted behind the seat with an electric fan which works good on the buffalo. I have mucked around with different weights and springs on the comet primary clutch, but I need to pull the secondary and swap the position of the spring to let it shift quicker. The diesel produces power at lower revs than the Kohler, so you need to have the clutch shift quicker. All in all it is a good conversion, and it is awesome on fuel. I reckon I can go around 3 times the distance without refuelling and it sounds great with the open exhaust! It also has an alloy tray to counter the extra weight of the engine so it still floats like it used to.
One more thing, I made an adapter to fit the comet clutch to the kubota flywheel out of a broken max axle and flange, a bit of machining and it works a treat.

[AussieMax]

Here is a pic

[miller_time]

Aussiemax do you have anymore pics of the engine install? How is the power of the d660 is it enough? I would like to add a diesel to my max iv but not sure how big to go. I would like to find a d722 and add a turbo also. Did you turn up the fuel at all? How much boost does it make?

Shanex25 I am curious if the 2cylinder will have enough power in a max iv. I hope it does as it save a good bit of weight over a 3 cylinder.

[AussieMax]

Here is a pic of the engine bay, it's not great but it will give you an idea. It is mounted on the original engine frame that I modified to take the kubota so the belt adjustment is all the same. The engine clutch sits exactly where it did before. Since this pic I have made a proper intake pipe and a better exhaust. I think a d722 would be the perfect engine, but it is just that bit too big to fit in the buffalo and still retain the tipping ram for the tray. It had to be shifted slightly as it is. You won't have that with a max IV. It seems under powered at the moment because the clutches aren't right. They shift down too easily and don't load up the engine enough. It don't have a number on the boost yet because of this. When I get some time in the next few weeks or so I'll have a go at the secondary clutch and see if I can't get it working properly.

[miller_time]

Thanks for the pic. Keep us updated on how it works out. I will be interested in how you setup the clutch when you get them working ideally.

[rcn11thacr]

How is the progress coming on your project? Any new pics or updates?

[Griff]

I am currently mocking up putting a ZB600C Kubota in my Max IV, trying to find the bolt on pulley with stub shaft. Any update on your project?