Rancher 420 Rear end rebuild

[Ahren Longo]

Well I finally had to take the rear end apart on my 07 Rancher 420. Man it was nasty on the inside!!! I didn't take any pictures, too concentrated on the task I guess. The tools are retarded expensive, after I spent $280 to get the socket and puller for the pinion, because no-one makes them other than Honda. I figured out the pinion was shot due to the needle bearing being completely destroyed, it ground it down pretty bad. The bearing and seal set was cheap enough , $70 on ebay. I got the pinion on ebay too for $95, I took the nasty looking ring gear and sand blasted it, although a little pitted, still perfectly usable. I had to turn the sealing surfaces down about .015" to get them smooth enough to seal. Then for the icing on the cake. I found a brand new rear diff. assembly for $400 on ebay. Dang it!! Coulda just popped and swapped and saved $50. Oh well I have the tools to do honda rear ends now maybe I'll get my buddy who own's a CNC machine to copy them for me and I'll sell the other ones to get my money back.

Edited January 13, 2019 by Ahren Longo

[Frank Angerano]

Wow nice work brother.  Expensive but nice. What a shame about finding the other rear afterward.  Oh well, now you at a rear ended specialist ! 🤣 

any pics ?

I have two ranchers now.  I am going to make it a point to check the fluids on the axles!

Anyway great job. 

[Ahren Longo]

Nah man I didn't take any pictures. I was too funky and didn't want to get my phone nasty. Too concentrated on task. Word of experience though. Don't do what the manual says about installing the snap ring on the pinion needle bearing before you put it in. It will pop out of the grove and get jammed. Its a royal pain in the as* to get the needle bearing out w/ out destroying it. I had to pull my old needle bearing out by welding a long bolt inside of it and using a slide hammer. Its mostly back together now. I'll take some pictures of my ride when I'm done.

[ericmaruba]

interesting. I have a rancher that I recently purchased and the rear end darn near shot is what my buddy said and was planning to rebuild it soon. (only after I rebuild the front diff first which is completely shot!) Anyhow the manual is not perfect? One would think its spot on. Hopefully I can circle back to this post when I disasymbol my rear end. I did change the fluid in it though, and man was it bad. Full of muck and water that stunk to high hell!. I hope it can run for a few more rides before I get around to rebuilding it. 

Curious where do you buy your bearing kits from? I need to replace my front diff bearings but its so hard to choose from the internet. I would love to replace with OEM but cost is just out of control. I would say Im a cautious driver but still enjoy a little fun. I dont try to break my atv though, If im stuck then im stuck. 

[Frank Angerano]

So curiousness has me going a little sideways right now. Not only bc I have two ranchers but just for the knowledge.  

Would you both @Ahren Longo and @ericmaruba say that the axels were not maintained? Bad seals? Mistreated?bad design? 

What’s Your take on what failed here.  I have two newer ranchers and just trying to see what’s going on and why they fail.   

[Ahren Longo]

I got my kit on Ebay for $70 its a complete kit with bearings and seals. Its the tools that really suck to buy. They're stupid expensive. The Socket to remove the pinion bearing nut was $60 or so. The other tool for pulling the pinion(unless you can make an attachment for a slide hammer with a nut(go to Fastenal), long rod and a welder) were $220 what I found on e-bay. I'm gonna see if my machinist buddy can copy them and change them slightly so I can sell them because I haven't found any aftermarket ones, only Honda. I wouldn't wait too long on the rear one. It'll chew the tip of the pinion right off. I wish I hadn't waited on mine. Maybe I wouldn't have had to replace the pinion and saved $100. Hell I woulda just bought a factory replacement rear end assembly for $350. There's one on Ebay right now(found it after I bought all the other stuff DAMMIT!!) It'll save a whole lot of headache, just pop & swap, done, waaaaayy less time spent. Especially if the pinion has play in it already.  The ring gear sealing surfaces are probably pitted as hell too. Mine was. I don't think its the design. Its way easier to take apart a Honda rear end than an Arctic Cat I'll tell you that.  I'd say it was due to abuse and not being maintained properly. It had gotten some H2O in it at some point, probably got rode in the creek and didn't get checked afterwards. Corroded the hell out of it, trashed the seals, all the oil leaked out and it overheated. Its not a big deal to get H2O in the diff, you just have to get it out ASAP. I run Lucas Oil Stabilizer with the gear oil. It coats nice plus keeps the gears and bearings lubricated really well.

Edited January 16, 2019 by Ahren Longo

[Ahren Longo]

The kid I got on Ebay was an "ALLBALLS" kit. It worked great.