How far to tear down the Max IV???

[rickemd1]

2014-02-14_13.23.04.jpgSo the Max IV I recently bought that was only supposed to need "1" chain replaced and the old famous "carb cleaning" has become much more than that. Being a perfectionist I have pulled the engine and stand (to get to the gearbox chain), removed all the rusted chains, pulled the crudded up fuel tank that was preventing fuel from getting to the carb. And I found that only 3 tensioners were installed, the 2 at the gearbox and 1 between the rear and middle axle.

After reading a lot of articles on here and the disassembling my rig I have a few questions for the Max vets on here.

1. The previous owner broke the plastic throttle where the cable slip fits but told me the cable was froze up. Can just the plastic lever be replaced or do I have to buy the entire throttle lever assembly? I can't really see how the plastic could be repaired or reused.

2. The machine sat out in the weather with gunk clogging the open drains so water pooled in the belly and completely ruined the chains. Should I at this point check/replace the inner bearings? Not sure how to check the bearings for serviceability while installed.

3. The frame rails are rusted but not to the point where I can see holes. I'm thinking I should probably pull the entire frame out of the tub and clean it up and repaint. From what I can see this looks like it could be a buttload of work. Or should I just spray some rust converting primer on it and move out smartly?

4. Lastly, as previously mentioned only 3 of the 6 tensioners were installed. The tensioners that are installed are all the same and I assume original, all are 18 tooth. I've found that TSC has solid #50 idlers 15 tooth with bearings that I could make work. I think the 15 tooth idlers will work for the chain tensioners between the axles but I'm not sure that they can be used for the 2 tensioners at the gearbox. So my question is this, do I have to use the stock 18 tooth idlers at the gearbox or could I use one of the 15 tooth idlers that I've found at TSC?

Just to caveat, I'm pretty handy but don't have a full blown shop and the ability to manufacture parts as needed like a lot of guys do on here. So, I'm trying to do things right without all the cool tools and machines. Basically I have to use off the shelf stuff to get do what I need to do, I have very little fabrication capability.

Sooooo, what say ye?

And of course thanks in advance for all the pearls of wisdom that I know will be shared

[amphibious drew]

Pull the frame and clean it up. Replace all bearings, and get ahold of these guys http://maxatvs.com they can help you out with a throttle lever. Oh yeah and get your idler sprockets from them too. Those tsc ones are the wrong inner diameter too.

[Dozerlarry]

Mike, good advice from Drew. You can come down to my place and sandblast the frame if you need too. You'll have to catch me on an off weekend but you're more than welcome.

[jpswift1]

No worries, it won't be too hard to do and it'll be a good learning experience. You can do this on a budget and still have very good end results. You can get good bearings from Buffalo Bearing cheaper than most other places out there. Their number is (716) 874-1720. Tell them you're with 6X6World and you're working on a Max IV, along with the dimensions of your bearings and they'll get you taken care of.

Next, pull the frame, have it sandblasted (it shouldn't cost more than $50 to have this done) and paint it with a good primer and paint, I highly recommend Rustoleum. It'll be worth doing it.

As for the throttle cable, if you get a new one from Max it'll have an aluminum base and a plastic handle. You'll also need a to get a new throttle cable to be compatible with it. I have a few old plastic levers if you'd like one, or you can just get a new handle and cable from Max.

You can get your idler sprockets from surpluscenter. I know when MaxIVMark did a rebuild on his Max Iv, he got them from there and they worked well for him.

Surplus Center

As far as chain goes, if you check ebay for 50 roller chain, there are some pretty good deals every now and then. Get only name brand chain like Peer, Morse, Tsubaki, Diamond......stay away from the no name junk.

You won't need a shop to do this, just hand tools and a little determination. We'll all be happy to help you out along the way. Keep us updated.

[jpswift1]

Here's some great deals on Peer brand chain. I've had very good luck with this chain on my Hustler.

New in Box Peer Roller Chain 50 R Ten Feet Free SHIP | eBay

Peer Chain 50R x 10ft Roller Chain w 4 Connecting Links | eBay

[Noel Woods]

All around great advise. if you pull the frame, I would place several pieces of angle to reinforce the frame as well as the Max4s frame flexes a lot, may even be a good idea to put some gussets on the corner.

This is also an opportunity to mount an engine slider in so that you cam make alterations in belt tension. Don't know what engine you have, but for this machine I'd say 20 hp is the bare minimum. I've driven several with 16-18hp and they did ok but had no reserve for tougher going, 20hp and up had no problems.

Good luck with the build.

I would also consider gearing the machine down as the factory gear sets are fairly high.

[rickemd1]

T-20 check out

So based on everyone's advice I should pull the frame and trans. Is there anyway to know at this point if the gearbox even works?

I've looked at the position of the diamonds while moving the shifter and they appear to be right and I have verified that it does have ATF in it.

Is there anyway to know the condition of the gearbox without actually driving the machine?

Thanks

[rickemd1]

Hey DL thanks for the offer to use your blaster, I might take you up on that.

I posted below but so far no takers. Maybe you can tell me how I can determine if my gearbox is in working order without having ever put power to it? Is there a way? Gracias

[jpswift1]

Push the sticks forward while the machine is shifted into forward gear. Spin the driven clutch forward. If the sprockets move forward and when you pull back on one stick and the other each sprocket on that side should stop/lockup. If that's what's going on your T-20 is good.

[ARGOJIM]

Right on Swift, was going to reply the same with the addition of; that will tell you if the trans is doing what is supposed to do, just not how well.

[rickemd1]

Ok I knew that there had to be a way to check the gearbox without the engine. Now that I have the chains out I'll have to wait on the idlers and new chains that I ordered before I'll be able to verify it this way.

Before cutting the rusty chains out I had the gear in forward and was spinning the dive clutch forward and the machine moved forward and this was with the sticks at the neutral position or not pushed forward. When I moved the gear into neutral and reverse I had the same outcome. It seemed to move forward no matter what gear the stick was in. And of course when I spun the clutch the opposite direction I had the same results with the machine moving aft. Not sure what this means. I will say that when I was trying to get the engine running while still installed when it would fire the machine would lurch forward with no pressure to the controls. I'm sure this isn't a good thing either. Argh

[Dozerlarry]

Hey DL thanks for the offer to use your blaster, I might take you up on that.

I posted below but so far no takers. Maybe you can tell me how I can determine if my gearbox is in working order without having ever put power to it? Is there a way? Gracias

I'm home every other weekend so let me know and we'll do it. Without dismantling the tranny I think you're going to have to put power to it to get a reliable test. Mine will move forward if the tranny is in forward without pushing the levers forward. It won't pull real hard but it will still move