I've accumulated some parts, pics, plans, CAD models, etc with my eyes set on a 1-off rear LT setup for my FL470 Oddy.

Stay tuned...

that's it...nothing more...no pics...anything....


TEASE hahaha

I finally got my hands on some more parts from which to measure, observe, and get the think tank flowing. Next step is to fire up the CAD system and demonstrate some ideas, manipulate, etc. Then hopefully some chips and sparks will fly.

Tell you what, the angular travel on the Polaris RZR S 800 rear axle is HUGE. Keeping the spline shafts parallel, the axle swings 10" EACH direction. So the 12-14" of spec stock travel is well within the capability of the axles. Brand new axle with hardware and boots is $69.99 shipped from East Lake Axle (FL).

Also have some VW stuff to play with.

Premature plans include...
- Finish the shop room when the weather is nice. Do everything else when weather sucks.
- Stock FL350R trans
- 5-link setup (5 rods: 3 on the rear and 2 from mid-buggy to rear)
- 5/8 heim joints with m/a spacers, all in double-shear
- New bearing carrier (may or may not utilize existing parts from other vehicles). The less "custom parts", the easier any repairs/replacements will be.
- Aftermarket CV axles from another POPULAR vehicle (Ranger, Sportsman, VW) with plenty of aftermarket parts availability and low pricing.
- Custom inner adapter for CV axle from a used hub or inner stock axle yoke (I have several).
- Target vehicle is my FL470 Oddy project buggy. This vehicle will not use the stock fuel tank and will also get front LT a-arm setup. Does not have fenders.
- Width greater than stock, but not to the point of absurdity. The vehicle will likely about 8-10" wider in the rear, 8-10" wider in front, and also 8-10" longer than stock. I do not care about "trail rules & requirements".
- Better-than-mediocre-machining-skills required. I can do some myself, but will also have to spend some $'s on professional work.

Here are the axles I've got on hand.

• 09+ RZR S / RZR 4 rear axle
• late model VW/Audi front axle
• stock FL350R axle

And for reference, the non-S / non-4 RZR and Ranger rear axles are 5" shorter (according to the info on the RZR Forums).

The 40x74x40 axle/hub bearings are indeed HUGE. The Sportsman/Ranger/Razor all use this size rear bearing in the same style of aluminum knuckle. Very simple but the knuckle is designed for a-arms. I wish Honda would've went with a longer axle and then used only one bigger carrier bearing with a shorter outer stub -- the stock axle stub is mega huge.

My first plan of attack is to take the stock FL350 rear hub and work it a little bit. OD of the RZR axle plunge cup is 2-5/8" while the OD of the center section of the Oddy hub is just under 3". I want to hack off the hub's ears, turn the OD smooth, and then turn out the 4 pockets so there's a smooth ring in between an outer OD lip and a spline center OD. The plunge cup will get turned on the lathe with reverse geometry so the pieces will fit together and self center (I'll have to be careful and patient here). Will also turn down the cup OD just to remove the coating and create a smooth surface.

The parts will get thoroughly degreased with acetone, clamped slightly to keep the parts seated, heated to 350F in the oven (stress reliefs the chromoly & will burn off any grease), then tack welded in 3 places, and then allowed to cool slowly in the oven.

Once cooled, I want to check the run-out with the lathe and dial-indicator at hand-speed to check run-out across both parts.

If all is well, the parts go back in the oven and will get MIG welded (ER80S-D2 wire + 98%/2% Ar/O2 shield) about 3/4" at a time on opposing sides to prevent any HEZ warpage (don't want to mess up the cup geometry). Repeat the heat & weld process until done, and then allow the whole assembly to cool slowly in the oven. Per some other "experts" online, that spec wire is what you want for mild steel & chromoly joints. I hope 180A of welder is enough. Also considering a set of 3/8" OD holes in the cup sphere to get some more plug welds on the interior, then smooth out the cup with the die grinder. If needed I can always add more weld. Weld will get slightly turned on the lathe to even out weld buildup and to check for voids/cracks just under the surface.

To hold the "adapter" on the trans output shaft, I'll drill and tap 2 opposing holes in the hub for 2 set screws (will get loctite'd in place). Prob like 3/16". I don't want to do the pair of thru-holes like the stock inner yoke has simply to retain strength.

If it turns out to be a success, I will move focus onto the hub/carrier assembly and the frame mods required for the link mounts. Would like to use a bulkhead for the mounts, but there just isn't room. So likely some additional tubing around the trans with a one-sided bulkhead that connects to two frame tubes. Also...if a success, the same could be done to pretty much any similar UTV/ATV CV axle.

If it doesn't work...back to the drawing board.

The adapter concept...

Would make more sense to run the plug welds from the hub side. So drill a hole in the hub (green) every 90 or 45deg and then plug weld to the CV cup. Then there would be the OD weld + 4 or 8 plug welds.

More to come later. This is from my lunch hour.

With (8) plug welds...

Cool, glad to see your doing this.

I still like the sportsman outers though ,just too easy to make a five link out of it.

Your going to need to think ahead here a little bit. I do agree with starting on the inner CV, but keep in mind where its pivot will be in relation to where your links CAN mount to the frame and the relation of the links and your outer carrier/CV/pivot location, its all related in order to keep axle plunge down.

Or hack off more hub and minimize OD, no plug welds...


Another idea (not modeled)...what about drilling 4 or 8 holes through the rear of the hub with matching threaded holes in the cv cup? Would result in a slightly taller adapter since the threads need more meat.

Also, don't forget you can use an outer CV as an inner CV, they are shorter and can save some space if the OD isn't too big for the trans.

Almost missed this in my CAD model image escapade!

Yes, you are indeed right B. I haven't taken my measurements and applied them to the output shaft / gearbox housing yet. With the fuel tank and battery box gone, I do have room for material. But heck...it may turn out I don't even have to remove any meat off the cup simply to get the cup out there far enough to satisfy the pivot Gods. Won't help width, but it needs to pivot perfect. Bad pivot points is the general failure mode.

I also really do like the Polaris outer. Only concern I have is the affects of dynamic forces the links would put on the upper and lower thru-holes of the aluminum carrier. The a-arms really only swung up and down and the arms transmitted the loads in two big rigid arms. Whereas the 5 link will be theoretically pulling/pushing in 2 directions from very different origins. Hence...I had sketched up some ideas for a bracket weldment that would mount to the Polaris outer. In the end its almost like making the "Gene 5-link" but using the Polaris outer as the carrier only. The Polaris outer also puts the 3 rear links in very close proximity of each other...not sure if its too close. Hence my sketch spread them out a bit.

If I actually stay awake past 8:30pm for once (I've gotten old since turning 39), I'll throw together the 5-link idea using the Polaris outer. Already got all the rod end, m/a spacer, and bung cad models from Midwest Controls.

Ahhh...your my hero D! Awesome model! Did you draw it or borrow it?

Can you explain this..."Hence my sketch spread them out a bit."?

Does this mean your model isn't the same width as the real deal?

I can take some/any measurements you need from my gokart if you need anything.

You don't need real high mis spacers either for those outer joints, just a regular spacer. The trick will be to transfer the load to the housing, Not the heim bolts. I wish I had your cad skilz, it would make this real easy. Hmm..maybe one of my awesome sketches is needed.

BTW, 1/2" heims is plenty for the links.

Bonus of the Polaris outer carrier is that you can use the stock outboard brakes.

http://www.google.com/imgres?imgurl=htt ... DsQMygNMA0
http://www.google.com/imgres?imgurl=htt ... C8QMygTMBM

http://www.google.com/imgres?imgurl=htt ... BwQMygAMAA

With that kind of adaptor and that razor axle isn't it going to be extremely wide? Or will you cut down the shafts?

Well I had a pukey kid and 2 breakdowns on my tractor snowblower so got nothing recreational accomplished before bed.

Bullnerd...Can you measure the width of the top and the bottom mounts on the Polaris outer? And maybe total length inside to outside along bearing axis? My model is just based on eyeball and some references off pics. The knuckle is stock width, and actually it will be wide enough once the bushings are there. I want to build the theory in cad before.buying the knuckles, but may just have to buy on for now. Sucks I tossed the set I had.

Would a solid shaft through the upper and lower mount holes not be good enough? Thread the ends. Then just mount the 2 rear rod ends simple. Front of knuckle will need a bracket made to accept the 3rd rear link + 2 trailing links. Again it would prob resemble the front portion of Gene's 5-link, just that it'd be a single bracket that attaches via the knuckles upper and lower bolt shafts. It should work in theory.

And yes, I guess the m/a spacers really wouldn't be needed for the 3 rear links.

Outboard brakes would be nice so as long as I don't snap a shaft.

I did stare at the frame last night for a few minutes. Whre the cv pivot will be located...the picot.mounts.on the frame will have to be floated out a few inches off that center ttanny cage section. I think a new tube above the cv would be enough to mount a pair of mini bulkheads on each side. I'll draw up that idea at lunch. I need to.find.my step.file of thr chassis i did a yer or fee ago.

CAD is the best learning decision I ever made. I love it. Like playing with legos, lol. I use an older version of Pro/E at home, but I stay sharp on the latest version of Creo at work. Lucky they pay for an extra license. I'm the only engineer that can wield it, and it's a huge advantage especially since we've got the 3D printer. If I can think it, we can make it. Everyone else has to try to sketch their idea up for another guy to model. Boo on that. You lose the free-floating creativity when you have to sketch and explain. Cad model makes conveying ideas & relationships simple for everyone's eyes to digest.


JK...yes, the rear will be wider. The adapter adds width and the axle is longer, too. The RZR-S axle might be too long, so I can try to shorter RZR shaft (like I said 5" shorter), and takes.the same plunge cup. Or I know some of the sportsman atv shafts are shorter. And there are axle shaft people out there who can make to order. I'm trying to keep the shaft "off-the-shelf". Again...width isn't my concern. Thus buggy I'll be taller, longer, and wider than stock.

I have to have a mild surgery tomorrow, but shouldn't stop the CAD model fun.

Sweet I hope you can get this figured out

Just now saw those links. Not sure I'd use the clevis or the pre-made double-shear tab.

For the frame, I want to try to use bulkhead type plate pairs wherever/whenever possible to transfer the load to the frame and not just to the welded tabs. The tabs welded to the tubing...I've seen a lot of those break off. Right behind the trans/caliper there is room where I could run the rear half of a bulkhead plate all the way across with an upper and lower tab for the 1t & 2nd rear links. And then a partial plate for the front half of that bulkhead with upper and lower (separate plate left & right). And for the front/lower link (3rd) I would just have a pair of plates welded to the frame for each side.

Front bracket for the Polaris knuckle is my next CAD task. Has to allow the 2 trailing links to mount forward plus the 3rd rear link to mount inward.

We're on the same page,(not that it matters, this is your gig, just giving my opinion).

First link I posted would work for the front lower trailing link, low stress. The others are just for reference/description purposes.

Upper front I would machine and have it fit into the bore in the housing, to carry the load of the upper link/shock mount.

None of those links I posted are for the frame side. I agree, bulkhead, or without me having one here, maybe a skidplate type deal from the bottom with the lower mounts in it? Also, eyeball that stock upper link mount to maybe run a tube from for the new rear upper radius rod....total bolt on!

Also, if you decide to use the Polaris outer, that gives you the CV/link pivot relationship, that has to transfer to the frame side.

I'm focused on using the Polaris outer exactly for the reason you stated -- pivot geometry is DONE.

Just realized some Polaris outers use (4) separate 7/16 bolts, not (2) thru-bolts. Others have the thru-bolts and sleeves (outers #5134531 & #5134741). I like the thru-bolts over the threaded ones, and they look beefier (top mount looks wider). Threads will focus more stress on each corner. The size of the thru-bolt seems too small for a rod end...the bolts are only M10 since there is also the sleeve. The a-arm design is such that bolt is free to rotate inside the sleeve. With the link setup, you'd want the bolt fixed and then the rod end does the rotating. So I'd use a long bolt & nut, or a long rod with threaded ends + nuts (NO SLEEVE).

Got a clean outer on it way from an Ohio-based dealer. Will buy the other side if it works out. For now I can adjust my model since the width of the sleeves are in the parts' description (89.71mm and 115.11mm). Again...cad model is just to sketch up ideas. Real parts will be made on the fly based on actual parts, chassis, etc.

Good thinkin' on the "skid plate" type lower inner mount plate.

Here is the Protodie rear carrier, which looks like a biggie-sized version of the Polaris unit.

Shoot, I didn't know your an engineer, that's good, now you'll be able to understand me ! Ha!

Yeah, I don't have the Polaris parts, I always wanted to do this, but never found a cheap frame nearby. I meant dimensions from the B-B cars.

I agree, through bolt, but theres two ways to go about it. 3/8" bolt with spacers(don't have to mod the housing) in the 1/2" heims, good because you can place the heim load right into the housing with a shoulder on each end. Or 1/2" bolt, good because you don't need any spacers inside the heims. Either way I would try to find a stock, high strength bolt and put the head towards the front, under the trailing links heims.

Also, I don't think you'll need it if you make the upper trailing arm mount the right way, but you could tie the upper and lowers mount together with sheetmetal to share the load.

"I have to have a mild surgery tomorrow"

Still with us?

Hope the surgery went well.

Ha, yes. Let's just say I spent Friday thru Sunday with a bag of frozen peas! lol

Got the knuckle today. It's beefier and about 1" taller than I thought. The assembly is a nice tight package. Anxious to lay it out next to the stock suspension on the buggy for a comparison.

The holes are 5.25" apart ctr to ctr. The top hole is 3" wide with 1/4" spacer on each side. Bottom is 4" wide plus a 1/4c spacer on each side.

that's cool.

Some UTV/ATV CV axle information...from shortest to longest:

Compressed Length, Inner/Outer Spline

2007-2013 Yamaha Grizzly 700 FI Auto, rear, 19.813", 21/27
2003-2007 Sportsman 500-600-700, rear, 20.313", U-joint inner, 22/20
2006-2010 Can Am BRP Outlander 800 HO 4x4, rear, 20.500", 21/26 (inner is both splined & flanged)
2009-2013 Yamaha Grizzly 550/700, rear, 20.750", 23/27
2002 Yamaha Grizzly 660F, front, 21.625", 21/27
2003-2006 Sportsman 700, 2001 Sportsman 500, rear, 21.688", 36/26
2012-2014 Sportsman 850 HO, rear, 21.750", 22/26
2011-2014 Can Am BRP Outlander Max 400 EFI, 22.000", rear, 24/26
2014 Polaris Razor 570, front, 21.165", 22/26
2008-2010 Razor 800, rear, 22.313", 22/26
2008-2014 Ranger 800, rear, 22.375", 27/26
2010-2014 Ranger 800 6x6, rear, 26.016", 27/26
2010-2014 Ranger 800 Crew, rear, 26.313", 28/26
2012-2013 Can Am BRP Commander 1000, 26.859", rear, 24/26
2013-2014 Ranger 900, rear, 27.094", 22/26
2008-2014 Ranger/Razor 800 S-4-SWMilitary-Gordon, rear, 27.172", 27/26

Go figure, I started with the longest effing one! No worries. Polaris axles are mostly 22/26 and I could easily swap out the machined adapter to another axle length,

BTW..Don't let me talk you into a five link and out of something else, just my opinion. Would be real easy to make a 3 link/RZR style trailing arm out of those knuckles also.

No pressure, no problem. I love the 5-link. 3-link trailing and even a-arms are still an option. They all have their pros/cons, but I love the 5-link.

I modeled up a couple different ideas for the front bracket that would go on the Polaris carrier. Essentially it would be a pair of double-shear mount brackets, bolt through the middle thru carrier, lower sticks out for the front lower rear inner link, both mount brackets are welded together at the base. trying to make it so its like a 3-piece weldment I can just farm over to the cnc plasma shop.

Upper trailing arm I was thinking 1" x .095 DOM with a slight bend and a triangle plate pair for the lower shock mount. More cnc plasma parts.

I started pricing up 5-link hardware today (rod ends, tubing, spacers, jam nuts and bungs). Standard materials its $100-$120 per side, but go chromoly and its like $230+ per side. Yikes! There's a lot of hardware in the 5-link, obviously. This is 3/8 on the 3 rear links, lower trailer link, and then 1/2 on the upper trailing link (carries shock). So that puts me upwards of $200 or so per side for 5-link, carriers, hubs, and new axles. Would still need calipers, rotors, and wheels. Eek. May have to sell of a couple things from my parts stash to fund my work, sheesh.

Then I found a Sportsman front & rear gearbox set for like $200 and started getting crazy & retarded thinking 4x4 crazy talk. Haaaaaa...but I'm back to reality! It was a very short trip, lol.

Dropped the stock FL350 hub at my machinists desk today to get it "in queue" for the next gub'ment project. If he doesn't get to it this week, I'll come in this weekend and do it. Just some easy saw hacking plus some quick lathe turning. The adapter is the keystone to the whole operation!