Marinising the max

[oztrax]

Hi all,
have bought a 2007 MAX IV , well optioned with 26' wheels and the 27 HP Kawasaki engine, winch, roll cage and bilge pumps.

Intend to use the MAX in coastal area here in Australia.
Beaches and some saltwater crossings.
As a result I have ended up pulling the MAX apart for a program of corrosion treatment
and prevention to allow uses in this environment.

I also have a 2007 Honda F12X jet ski and a 19 foot fiberglass half cabin jet boat with a
Ford V8 351.

These 2 machines have been a challenge to maintain in a saltwater environment,
and I have experimented and learnt a lot about which paints, greases etc to use.

My background is in Aircraft Maintenance, so also have access to aircraft use corrosion
materials and techniques.

So pulled wheels, axles, axle bearings inner and outers, chains, sprockets and tensioners for both bearing replacements and repainting.

here are all my axle parts on the clothesline letting paint set.

File 1-02-2018 9 08 32 am_preview.jpg
File 1-02-2018 9 07 12 am_preview.jpg
File 1-02-2018 9 15 39 am_preview.jpg


regards
OZ

[john swenson]

hey oz..you should have plenty of fun riding in such a great area, beaches etc. the corrosion treatment is a good idea. it would be nice to see some videos of your area if you ever get a chance when your out riding. have fun down under !! johnboy va. u.s.a.

[oztrax]

Thanks Johnboy,

https://youtu.be/1A5T3yoqH0I

Link above is my you tube videos,
Mainly diving and boats, but this particular place could only get out of creek
In jetboat for less than an hour at low tide.
This is less than 10 mins in boat from where I live.

The Max can get here by crossing river and driving on beaches.

OZ

[oztrax]

Axle removal

Previous owners left me a surprise, both rear axles had the sprockets welded on in situ.

image.jpg

I had removed all axles except the 2 rears, and experienced the hassle of set screws,
Bearings stuck on axle etc.

Thinking of using stainless bolts instead of the set screws/Allen keys for both inner and outer bearings.

Pressed 2 outer bearings off at work with a 10 ton press and still needed propane torch heat as well.

I read other members have cut axles in situ to remove.

There is another way to remove axle assemblies without destroying them.

Splitting the hub and removing it after grinding off weld between shaft and hub would save destroying any parts
image.jpg

Cut the hub as close to axle as you dare then finish off with a hacksaw,
I used a puller on hub and some propane heat and the hub came off pretty easily

image.jpg

Still unable to remove rear axle assembly with sprockets attached,
So removed engine mount nuts and lifted up one side of the engine to allow
The axle complete with sprockets attached to slide up and out of the tub.
image.jpg

Grind weld off sprockets and I see why it had been welded, no spline material left from wear,
Axle spine was fine
image.jpg

Cleaned it all up and decided to drill thru sprocket assembly and axle and secure with a 1/4 Grade 8 bolt. Which is how the earlier sprockets were attached.

I do want to replace sprockets, they work out about $200 AUD plus freight from USA.

Thinking of making my own axles and hubs out of stainless steel 304 grade, my approach
Is any part that contacts salt water needs to be stainless steel.

OZ

[oztrax]

AXLE BOLT

image.jpgSo using 1/4 " grade 8 steel bolt, carefully drill thru both sprocket hub and axle.
The drill. Used was 0.003 " smaller than bolt so allows an interference fit and bolt fits
Tight.

image.jpgimage.jpg

So fa so good, weld hub back on axle with an arc welder, clean it all up for painting.
image.jpg

My approach is 4 steps for painting steel.
1. Phosphoric acid 30 % or stronger for 15 mins., the wash off thoroughly.
2. Used red oxide based primer spray can next.
3. Finish with silver/zinc top coat, more zinc the better,leave for 2 Days to set.
4. Paint thick fish oil on to finish and let it dry for a week.
Finally any exposed metal like axle and hub coates with Bigfoot EP2 waterproof grease
This stuff sticks well, paint on my jetboat pump, and lasts for at least 2 months doing
30 knots in The ocean.
image.jpg

OZ

[thebuggyman1]

The 1/4" grade 8 bolts are a bad idea. The older generation of max machines (mid 1970's to late 1990's) had axles that were not splined with 7/16" through bolts. Grade 8 may be too hard and therefore too brittle, you may want to stick with grade 5. Your worn sprocket tubes could be bored out to round and the addition of grease zerks helps with seizing. Instead of set screws to hold everything in place the inner bearing should be smaller dia. and the axle tuned down to fit. A bolt in the inner end of the axle holds it tight to this bearing and the axle in place. The sprocket tube can be held in alignment by cutting PVC pipe and using as spacers. I've often thought that the addition of a keyway would help the through bolt axles and their tendency to get sloppy by enlarging the holes......this causes the bolts to shear and can get very frustrating.

If you went to Stainless steel axles, I'd upsize them. Stainless is not as strong as the chromoly. How about a thin stainless sleeve from the outer bearing to the hub?

[oztrax]

Axle material

Thanks BM1,
Had another look at photos of older style sprocket, and agreed the hole seems larger than 1/4".

I don't agree the axle material is chrome moly based (wish it was though)
Seems more like a 1030 or 1330 medium carbon steel .
Makes sense as this is easier to machine and weld.
This is why the surface is soft and can't be hardened, a negative for inner race wear.

image.jpg

Here are some materials comparing tensile strength, the 4140 chrome moly is way ahead of carbon steel, but the SS 410/416 are comparable. Other considerations are welding and machining qualities.

Previous forum threads have mentioned shaft cracking/embrittlement.
This would also be a sign of medium carbon steel that has been cooled to quickly.

image.jpg

Here is a hub split I arc welded. You can see the surface flaw that looks like a crack
Thru it, but is only on surface. I needed to preheat this to 300 degrees and it probably
Wouldn't of occurred.
No quenching just let this air cool, although I read sand can also be used.

I haven't got a photo to upload of completed axles, but I have covered the exposed shaft with a rugged heat shrink and utilised the PR1422 "liquid rubber" on the exposed hub and hub backplate. So no steel is actually directly in contact with the salt water.


OZ

[oztrax]

That old chestnut !!!!

Thought I might revisit the idea of plastic axle outer bearings,
Previously touched upon in other threads.

https://www.kmsbearings.com/plastic-mounted-blocks-with-bearings/4-bolt-flange/4-bolt-flange-fitted-with-uhmw-insert-bearing.html

1.25" all UHMW. $40 USD

image.jpg

Limitation is 300 RPM max or else material can overheat.
Did an experiment today estimated the MAX4 hub rpm to be under 300
That's with wheels off ground and flat out on throttle.

I rarely open it up full throttle, no need and steering is more sensitive at high speed.
We semi guessed we would be closer to 200 RPM at 3/4 throttle which sounded like my normal cruise rpm.

They are not as strong 560 lb static load compared to nearly 2000 lb for steel bearings.

I'm going to replace just the Center axle outer bearings with these plastic ones and see
How I go.
If they work, my saltwater fears can be put to bed.

Also figured wouldn't be too hard to make SS axles out of 405 SS, I'm toying with the idea of a different stud pattern if I make them up, to suit generic alum alloy wheel hubs.

image.jpg

image.jpg

Meantime I have coated axle and hub with a PR1422 type sealant,
And heat shrink on the axle.

OZ

[oztrax]

Wheels and Rims

Interesting just found an older thread which mentions the
MAX4 26x12x12 tires utilise a 12x10'rim.

Confirmation below from a pic I took when my rims were bare metal.
image.jpg

Which means my quest to find 12x12 alum rims was flawed........

image.jpg

These are my tires Goodyear Terra 26x12x12
Which from previous threads identify them as good swimming tires.

Just to confirm please , the "V" on tires needs to face up at the front for best swimming.
This is contrary to the arrow symbol on the sidewall of the tires.

image.jpgimage.jpg

Regards
OZ

[Canadian_Zuk]

Correct, when viewed from above you want the point of the V-tread to point to the back of the machine so the thread pattern acts as a scoop to grab water (V up from the front). Those Goodyear Terra tires are a great match to the Max IV, they swim fast and work very well in mud and sand. You should be happy with those.

I'll be following your thread, I'm onto a synthetic bearing project again now for my Max IV. This time around I will be making them from Nyloil instead of UHMW for longer life and lower maintenance.

[oztrax]

inner bearings

thanks ZUK,

the MAX and for that matter most 6x6 are using very old technology for the axles and bearings.
they are cheap to replace, but i am seeing fairly corroded axles on this forum and the
usual impossible to remove set screws etc.

struck another hurdle, my new inner bearings seem to be different width (not the outer race) but the sleeve /inner race total width. can get them to fit without any shims.
i am seeing a measurement of 192 mm from the outer bearing flangette on top where the grease nipple base is, to the inner face of the hub.(this is for the original axle protrusion from tub).

thinking of a simple thin metal gage i can quickly use to check the axle extension on the
other axles as i install them.

other issue (maybe a blessing in disguise), is they gave me P206 bearings at inch + 1/4 instead of P205 at 1 inch inner diam for my inner bearings.
may stay with these and use a bronze sleeve over the inner end to take the shaft diam from 1 inch to inch 1/4, that way the inner bearings ( and set screws) i can press off if they corrode in the future.

found it all pretty hard bending over the MAX for hours on end, trying to remove axles set screws and bearings that were corroded.
i have got to improve on this design to make the machine easier to maintain in the future, or face a back ache again................


OZ

[john swenson]

oz..that's the reason i built a subframe for my max 2 and now all the bearings, chains and axles a easy access outside the tub. it's been this way for 3 years with lot's of heavy mud use. i have not encountered any major drawbacks to this setup. i can change any axle bearing , chain or chain tensioner much quicker and easier on my back...so i know what you mean about ''bending''. plus some of those bearings on the max 2 are awfully hard to reach back in the motor area. sounds like your build is going great. j.b.

[oztrax]

photos

thanks John,
do have any photos ?
or is there another thread for your mods ?

regards
OZ

[oztrax]

been a while
the max is going well
in saltwater the fastest speed i got was 7 kph .
with 26 inch terras and just me and the dog onboard

with tires set up for water i definitely
lose traction earlier in forward
sometimes in mud its easier to go thru
in reverse. eg reversing up from water
thru a muddy steep bank

the 1/4 inch axle thru bolt did fail,
when i had 3 kids on board and i pulled
the sticks back hard to brake suddenly.

gone up to 5/16 grade 8 and have spare
grade 5 bolts to fit if needed.

oz

[john swenson]

hey oz .. the max looks great and i'm glad it's working well for you. i am working on a subframe upgrade on my max 2 highboy . it's going to get upgrades and some better design changes. also i'm going to 1 1/2 '' axles , adjustable chains with no tensioners , etc. i will be doing a video of the build , so down the line it will be posted with step by step changes. i think being the designer you are you will enjoy it. johnboy va.