My first 6x6 Max IV project

[phabib]

I can get a good deal on a new 16HP Vanguard engine that was bought 5 years ago for a project that never came to be. Would that be a good engine in this thing or should I hold out for something with closer to 20HP, which is what I was thinking originally?

Thanks.

[SlimChance]

Hi phabib,
for me, 16 is a bit light especially of you are planning on having others along with you. I would hold out for no smaller than 18 hp as the minimum.

[phabib]

Time for an update. One of the cross bolts for the axles is stuck beyond stuck. I tried heating the bolt, the surrounding axle material, and pounded it to no end. My dad suggested his never fail method which is to drill along the axis of the bolt, then to use a punch smaller than the hole you drilled and to drive it out. As you hit the bolt, it lengthens and becomes smaller and falls right out. Or so he said. Now he says just drill it all the way out and put in a larger bolt.

I also got the transmission out so that I could have better access to the two bolts for the rear axle removal.

So far I have 3 axle bolt out, one stuck and penetration oil on the other two. I had success with removing the nut, then using the impact wrench with a 6 point socket to break the rust by going a few seconds in each direction until the rust broke free. I hope that works on the back two, they're the most heavily rusted and crudded up of all of the bolts.

When I put it back together, I plan to use enough Never Seize to paint a house.

I'm not sure if I should drill out entirely and go the next bolt size up, or cut the axle and buy a new (or used) one.

[phabib]

I'm at the point where I either need some good advice on how to proceed, or some encouragement to not give up on this thing entirely.

I have 5 of the 6 axle cross bolts out. The 6th is still stuck in place and not going anywhere. I removed the 4 bolts for the outer bearing flanges, cut off the inner bearing locking collar and attached a 4 pound slide hammer to the axle. After a couple hundred smacks, there was no movement that I could see. I heated the tube with the sprocket on it red hot and tried again, but still no joy.

I have a hydraulic porta power and I thought of putting the ram between opposing axles and applying pressure unti one of them moves, but I'm afraid that will bend my frame.

I'm not sure where to go from here. Maybe I can tip the machine onto its side and apply PB Blaster into the tube/axle interface and hope it goes in, maybe I need to give up and just cut the axles and look for replacement ones.

Once I get it apart, the rest of the project will be pretty manageable, but this part of the work is really kicking my ass.

[hydromike]

This is just my opinion, but I think you should cut the offending unit. It's not going to be difficult to either find another axle or fabricating one/have one fabricated. You can stick to it and heat/oil/slam to no end, but you might end up right where you are. You can likely save the wheel hub and have it rewelded to another piece of 1-1/4" rod. You'd have to have the end turned down for the inner bearing and drill a hole for the cross bolt, but at this point that might be less work than getting the old one out.

[phabib]

Thank you Mike. I was hoping for a magic bullet technique but I guess it doesn't exist. This thing was used for duck hunting so I think it spent a lot of time in salt water and the metal parts show it.

I'm afraid of damaging the body every time I bring out the torch, so cutting and getting a new axle might be for the best.

Can the axles be made of mild steel like a 1020, or should I look for something like 4140? I can TIG weld the hubs back on and I have a lathe so I can also turn down the ends. 4140 is usually heat treated after welding, If you've made your own axles from 4140, did you do the heat treat after welding or did you skip that step and still have a usable product?

Finally, if I can't press out the old sprocket tube, is a splined axle upgrade the way to go? I'd rather save the money and find the old parts from someone else's upgrade if possible.

[phabib]

One more question: As I looked for where to cut, I'm thinking that I can use the angle grinder with a cutting disc to cut as close to the frame as practical. This will mean shortening the tube when I cut through the tube and axle, but since the tube is held in the right place by the bolt, i don't see that causing a problem. It also looks like the critical dimensions will be from the end of the shoulder that I turn down at the inboard end where it goes into the bearing, and if the overall axle is a tad shorter or longer it won't matter much. The important thing would seem to be how far from the turned shoulder I place the cross hole.

Do I have all that right?

[phabib]

Any ideas as to the best way for me to proceed with axle removal and possible rebuild? One more option I thought of would be to cut the tubes instead of the axles, how does that work out in general? I could then either replace the sprockets/tubes or reweld the sprockets onto new tubes. Might be easier to do than re-attaching hubs to axles.

Any guidance is greatly appreciated.

Thanks.

[hydromike]

You know, if you can just cut the sprocket tube off of the axle, that might be a great option. It's just tough to slit the length of the tube without nicking the axle itself. I bet you could cut it 95% of the way through and just hammer and chisel it the rest of the way to relieve the friction on the axle. Getting a piece of 1-1/4" I.D. DOM tubing will work as a replacement tube that you can just weld the sprocket onto, but during my Swamp Fox build I had to ream out the DOM tubing (since the tubing diameter was spot-on 1.250"). You really have to ream it out AFTER welding, since the welding distorts the tube. Not really ALL that difficult, but it's step that you'll likely have to go through.

I've built axles out of 1045 TGP (on the Swamp Fox, holding up great to decent abuse) and out of 4140 (the front two on my 980). The 1045 didn't really need much preheat or fancy cooling, but I did preheat the 4140 and let it cool slowly in sand after welding the wheel hubs on. They're holding up fine, too. I'd stick to one of these materials if you can.

[phabib]

Thank you. If I cut the axle instead of the tube, am I best off cutting as close to the body as possible to the tub? If I cut at the inboard end, I'm taking the bearing out of the equation, but doing nothing about the friction between axle and tube. If I cut inboard, I'm shortening the tube, but I don't that will really matter since the sprocket position is dictated by the bolt hole.

[hydromike]

You're right. The length of the sprocket tube won't really matter that much. I'd say just cut the darn thing wherever you have access, if you decide to go that route.

[phabib]

I talked to Jay at RI and he was very nice and helpful, but could only offer sympathy rather than solutions. Here's my current plan.

1. Try to remove all 6 wheels just to be sure I don't waste time on other methods if I don't need to.
2. Remove the outer bearing bolts and remove the 4 bolts that hold the inner bearing holders.
3. Try to use a 3 jaw puller on the inner bearing, then the sprockets.
4. Try slitting and removing as much of the sprocket tubes as I can and try again. I would then make new sprockets using sprockets from Surplus Center and some DOM tubing.
5. As a last resort, cut the axles. Recovering the hubs and welding them to good round bar stock seems like more work than making new sprockets so I'd rather avoid that.


Finally, what do you think of this as an engine: It looks like an opposed twin rather than a V, but the power looks reasonable and the price is right. The seller thinks its an 1800 RPM engine since it came off a generator so I'm not sure if its just a matter of getting a different pulley or if I just need to find a 3600 RPM engine. Onan motor 20 hp

[Uncle Vin]

Try this method. It worked for me. My machine was all rusted up when I purchased it. The axles were rusted to the sprocket tubes as well. Soak the axle and sproket tube with PB Blaster. Then get two large pipe wrenches. I have a pipe wrench which is 3 feet long. The three footer goes on the axle outside of the tub. The samller one goes on the sproket tube inside of the tub. I held the smaller one in place on the sproket tube with my foot anf full weight on it, while my 200+ pound nephew was literally jumping down on the 3 foot pipe wrench with all of his weight. I loosened each and every sproket this way. It takes a lot of time, but with persistance, it works. It also saved my sproket tubes and axles for re-use.

As for the inner axle bearing, cut if off with a cut-off wheel. But be careful to not cut into the axle.

[phabib]

Thanks for all of the help I've gotten so far. As it turned out, I had an idea very similar to Uncle Vin's the same day, but his method with a pipe wrench was better than how I was going to do it. I wound up bending the 5 ft bar I was standing on and still not breaking the parts apart so I just got out the recip saw and cut all 6 axles off. It now turns out that my 20 ton press won't separate the tube from the axle either and since many of the sprockets are shark finned, I'm just going to make all new.

Here are my current please for information and advice:

1. Any information on the critical dimensions for the axles? length? hole placement, and so on. I can probably get very close just measuring the old ones, but knowing its right would be nice.

2. I have heard that 4130 is the stuff for axles so I'll use that unless there's a reason not to.

3. As far as the hubs, I have a lathe so I can turn off the old ones and weld onto the new shafts, or I could make new. Any reason not to re-use the old? If I do make new hubs should I use 4130 for that too?

4. As for the axle tubes, I imagine I'd want that to be out of 4130 as well since they take at least as much abuse as the axles.

5. Finally, it looks like I have 62mm bearing both inboard and outboard. For some reason I thought the inner were a different size than the outer.

[Tomo]

hi,
Engine choice would be preferable to be a 23 B&S vanguard v twin
After discussions with RI about gearing etc hp was mentioned also .
Eg max iv typically carries more people and is a heavier machine in general and from my observation current model uses up to a Kawasaki 29dfi [plenty hp ] .
A few commercial mowing brands only include kohlers in there lesser models etc
Many brands of high end mower use Kawasaki
[be carefull with the model of Kawasaki as there are many ,some domestic ]
Once kohler vtwins are up in hour of use there reliability is in question .
The crank journals donot have bearings or sleeve bushes etc there fore are not rebuildable .
My opinion is not to appear bias but the vanguard is very well proven unit

Parts were cheaper for my b&s vanguard compared to the Kohler
The 23hp vanguard can be purchased with a 1inch crank this there fore makes the clutches cheaper eg 700 series Salisbury setup 780 drive ,770 or 780 or 790 driven
RI use the 780 driven

hope this helps
tomo: