# Common drivetrain issue?



## JPs300

Just checking to see who else has experienced this failure. - I know this bike was run hard before I got it and I know I don't cut it any slack, just checking to see whats going to be the best direction to go in fixing it. 










After getting winched out of the hole, still in the bike: 









Notice the lack of an actuator? It's now a multi-piece/quick release model......head pipe wasn't too happy either: 










I dropped into a hole in 2wd(wifey was on back) and it started digging too much before climbing out the other side. I went to 4wd(not locked) and it didn't seem much better still trying to go forward, so I started backing out. NOT heavy on the throttle at any point of this, just turning the tires. Being as though I was backing out though and the rear had started to climb out, especially riding 2-up there was obviously a lot of stress on it at that point. 

Couple pics after we had partially winched it out: 


















Didn't know what had "popped" at first and was trying to help the winch in 2wd, driveshaft caught the frame and the moment I bump the throttle I got a cloud of belt from the exh snork followed by some sparks which appeared to be burning flurries of rubber.............oopps. 

Good news was that we knocked the rear u-joint apart after getting the bike out and I continued on for the weekend in 2wd.


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## JPs300

Talked to notso42 off HL and he knew of another bike that had done this, but also destroyed his cases when the shaft flung around and knocked the entire oil filter mounting boss off, as well as taking out his bevel gears. 

It will for sure be getting a custom driveshaft loop, but I'm curious as to whether to go back with a new yoke & just figure it may happen occassionally, or if this is going to happen often enough that maybe the old style input w/o the slip yoke would be stronger?


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## Polaris425

ouch! is that on the front? I'm guessing so since you said you rode around in 2wd the rest of the time. Ive never broke a shaft, the polaris I had, had a collar between the propshaft coming from the motor, and the input shaft on the diff. So if you ever got in a bind it just stripped the collar, since it was made from softer metal. I think the collar was only $20 or so. So if saved a lot of money. Only downside was in was inside the swing arm and you had to pull the whole rear axle (SRA) to get to it. 

Say that to say this, to bad you can't design or replace that one with something like that, that way if it happens again you just strip a cheap collar that you can keep an extra of and replace out on a ride possibly.


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## JPs300

Yeah, that's what I'm trying to figure out. The yoke is only $30 brand new, but I want to be sure this isn't going to be a common issue before I order one. - The older models didn't have the slip yoke @ the front diff. Makes it kind of a pita to pull the front diff since you have to diss-assemble a u-joint in place, but if it's stronger it may be the better way to go. Shouldn't have to be in there too often anyway.

All the other carnage(actuator & head pipe, & all else that could have been damaged) will be negated after I fab up a driveshaft loop, which will happen no matter how I go about putting it back together.


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## Polaris425

cool. so you have to pull the diff to replace it?


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## JPs300

Nah, I can put the new yoke on the DS, slip it in place, then re-install the rear u-joint caps. 

That yoke is so the diff can be removed w/o taking a u-joint apart. The older models required breaking a joint down in place to get the diff out.


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## Polaris425

oh ok I gotcha now.


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## JPs300

It seems this is definitely not uncommon with the t-cats. The big V's torque coupled with larger aggressive tires = snapping that little cast yoke. 

Waiting to hear back as to how often it seems to have happened to some guys. I don't mind changing this every year or two, but if it's more often than that I'm going to do something different. - I did verify the earlier('06 650V2 is what I cross-referenced with) direct input will swap in place, thus maintaining the larger shaft size instead of reducing down for the slip yoke. That should be the easiest fix, but need to figure out whether or not I will also need the longer driveshaft.


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## Polaris425

So the one from the 650 is a larger diameter? Seems like thats the best bet if it fits.


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## JPs300

The 650 is one piece; the diff input is direct to u-joint yoke. On the t-cats and other newer cats they made the input two piece creating the slip yoke for easier dis-assembly. - Since the shaft going into the diff is the same size, the slip yoke shaft is proportionally smaller to fit inside of it. 

I'm thinking that will be the easiest solution for me, but need to figure out if I'll need the longer driveshaft or not. Don't want to waste $80 if I don't need it, but if I do then I want to order it at the same time. 



- I'm basically looking at going backwards on the front yoke conversion; most who have done it have an earlier bike & switch to the slip-yoke set-up for easier diff access.


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## Polaris425

Ah. I gotcha now.


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## JPs300

Spent the past few hours digging through the micro-fiches. 
- all year 1000's list the same pn's for the yoke, u-joint(25mm), and ds (seems odd, since the '08 supposedly still had the smaller front u-joints). 
- 04-06 650 V2 lists a direct yoke(single piece instead of the 2-piece slip yoke assembly) the smaller 20mm u-joint & different ds (smaller u-joints but could also be different length) 
- 06-08 700 H1 list the 2-piece slip-yoke system, but the yoke & DS are different numbers yet; assumingly because it has the smaller 20mm u-joint, but still has the slip-yoke 


Doesn't appear as though anything is going to be "bolt-in" other than the stock slip-yoke. It would be likely possible to bore the 650 V2 diff yoke out for the larger u-joint caps, but not sure if there's a difference in cross width or if the joint placement would be the same as with the two piece slip yoke set-up(might require a different length DS):banghead:


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## whoolieshop

Heh. My friend you have some strange failures. Reminds me of my 650 h1. I have the oddest things break that shouldn't. 

I swear mine had to be built on a Friday or monday, I love my arctic cat but it's had it's fair share of things grenading for no good reason!


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## whoolieshop

Fwiw the 650 h1 engine uses two u joints and no slip joints you have to remove the diff or u joints to get the driveshaft out. 


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## Swamp Star

on a V2 you have to break both u-joints down to get the drive shaft out. Its a pain to get them out cause there isnt but so much room. I have never broke the drive shaft but have grenaded a joint or two though


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## greenkitty7

I always found it easier on mine to pull the two diff mounting bolts out and slide it forward and take the nose cone off. But i always pull the whole suspension off the front (axles and all) when i work on that area. I takes me like five minutes to pull all that off (so its worth it so i dont have to get down and try to fit in behind the tire and all that.) i've pulled so many front diffs and driveshafts, i can have the whole front end apart in about twenty minutes. And thats no exaggeration.

I say all that to make this point. Going back to a solid drive shaft instead of a slip yoke style shaft wont be that bad. Im sure its quicker to pull a slip yoke but it may take 5 more minutes to break down a u-joint and all that.


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## JPs300

I wouldn't mind switching to the solid ds set-up, but it doesn't seem as though anything will be "bolt-in". The solid shaft bikes all utilize the smaller ujoint(20mm caps instead of 25mm) and I have no way to know if the DS length would need to be altered. 

At the same time, only being $30 I don't mind changing this yoke from time to time as long as it will last at least a year or two.


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## JPs300

Ok, so still poking at this. - A guy off "the other" forum said he'd send me a V2 driveshaft & yoke if I want to try it(freebies, just the freight). I'm interested, but not sure about making the different u-joint sizes work, or even still if either DS length will work with the other yoke. 

dstelly noted it's only $8 per pound to have it cryo'd by his guy. - BUT, I had another thought yest evening. 

- The diff side of the yoke(female slip coupler) has a large cone shaped entry flange that basically butts up to the outside edge of the yoke's "fork" at the u-joints. I could easily put everything together, then weld the two slip yokes together. Welding cast isn't the strongest thing, but being at the 2-1/2" outside diameter of the yokes it would have plenty of leverage to relieve *a lot* of stress off the shaft/spline section. - I could even go as far as welding them together, then remove it as one-piece and send it off to be cryo'd. The cryo would then not only strengthen the material, but would also help the welds. 



hhhhhmmmmmm :33:


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## Polaris425

sounds good on paper!


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## JPs300

LOL, no doubt there. I'm just debating which route to take right now. 

- Cryo the new slip yoke, assemble as original and hope it holds
- Put OE yoke in, weld outer edge and hope it holds
- Put OE yoke in, weld outer edge, take out & send to be cryo treated, then hope it holds

......the common denominator ^ is what I'm concerned with.......


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## greenkitty7

well it can be a problem, that thing letting loose can cause a great deal of heartache. i wouldnt weld on any drivetrain part simply because any kind of heat makes metal weaker. i think the new yoke cyoe'd would be your best bet unless you can get the solid DS setup to work.


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## JPs300

I think I'm going to try that route first, if I break it again then I'll get another new yoke, weld it, and then cryo it as a whole. 

I have a 1" long section of 3" schedule 80 to put a driveshaft loop around it as it goes back together. I'm not dealing with it taking out another head pipe or actuator, or anything else it could eat when it breaks like that.


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## greenkitty7

that tcat torque sure can cause a lot of mayhem... lol ive seen them twist diffs out the frame, knock holes in the cases and all that jazz... speaking of, do you have a billet cover or brace for your rear diff? with all that power the rear diff is bound to clamshell.


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## JPs300

Billet cover & custom HD bracket. - It's fighting me on keeping water out though. All new seals and bearings & bearings and cleaned up all shaft sealing surfaces, but keep getting moisture in the rear. The input has a lot of end-play, even with a new AC bearing. The multi-slip fit design of the SLD just leaves too much room for shaft play. 

Just re-bearing & sealed the front diff before this happened. I was suprised to find no water in the diff after riding w/ the actuator busted off, but the "tube" part with the seals was still in the diff where it broke off. - Did find far too much metal shavings on the magnet though, so I'm gonna pull it out/apart again to see whats up. I've got metal shavings every time I've changed the fluid, but didn't find anything wrong when I had it opened up before?


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## greenkitty7

Ive always had metal shavings on my diff plug. Always extremely fine shavings. Ive always been told that if it is more like slivers, than something is wrong.


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## JPs300

^ that's my worry, I got slivers this last time. Only been on this one ride since being open for new carrier bearings & all seals. Didn't get any water in it this time, but got some questionable shavings. 

I'm just gonna pluck it/open it up and check it out. - I had the cross pin trying to come out when I opened it the first time, so I welded that. Not really sure what else it could be, I didn't even change the pinion bearings(zero slack & dead smooth) to have altered the shimming/pattern. 

The rear I'm thinking of getting a new input shaft. That sealing surface is the only one that is really questionable, so it's the only place I can think of to be letting water in.


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## greenkitty7

did you grind the weld on the spider pin smooth? unless you got the ring gear shimmed too tight, you shouldnt be getting slivers. you want some back lash but not too much, too little back lash will wear on the gears more.


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## JPs300

I ground a V across the top of the pins and into the carrier, then welded through the channel, then ground it smooth. - Same carrier shims were put back and I never even removed the pinion, so pattern & backlash would have to be the same as they were before. Only thing I can think of is that it wasn't dis-engaging very well, thus maybe I caught the throttle a time or two when it was only partially engaged and ground a little of the shaft splines and/or collet splines. - Seems pretty odd, won't really know till I open it up.


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## greenkitty7

Have you opened it up yet?


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## JPs300

Just did - thought about posting another thread but here goes - 

Anybody ever broke the cross pin? Apparently on top of breaking the front yoke, the cross pin broke into three pieces; split across the cir-clip spots just inside the spider gears. - the pin was welded and neither outside piece come out, just broke the center loose. 

Nothing else appears damaged. the spider & axles gears have no marks, neither does the carrier itself. 

I'll get some pics up tomorrow, just seemed like a really odd breakage.


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## JPs300

AND since apparently it's not available separate from the entire carrier assembly, does anybody happen to have a loose one they'd sell me? - just need the cross pin itself.


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## greenkitty7

I'll look in my broke ring gear collection. If I have one, i'll give it to you. just pay shipping.


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## JPs300

cat 952 over on HL said he still had some of the solid ones he had machined w/o the cir-clip slots. Awaiting a PM from him for a price, but unless he's way ridiculous that should have me covered. 

Thanks though for sure, will let ya know if that doesn't pan out for some reason.


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## JPs300

Diff carnage pics. - Sorry, apparently 2 years is about the life expectancy of a $300 nikon cool pics camera....stupid auto focus stopped functioning and apparently there is no manual mode. 










partially taped out so you can see the break line at the spider gear


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## greenkitty7

i dont understand how that carrier pin could even break. it doesnt seem like theres a whole lot of stress on it. thats crazy.


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## JPs300

To break being on the inside of the spiders is what I find so odd. If it sheared between the spiders and carrier I would simply attributed it to load; as it transfers all power from the ring gear to the axles. 

cat 952 is graciously sending me one of the custom pins he had made and won't accept any payment for it, so I can't argue with that $. - Said he broke a few across the cir-clip grooves just as mine did; if you don't catch it in time the side load will break the pin welds and push the pins out enough to grenade the diff. He had the custom ones made to eliminate the cir-clip grooves, thus being stronger w/o the recess.



The new front yoke arrived today and will be sent out before the weekend to dstelly's cryogenics guy for treatment. 



I really hope this is the last of my troubles, at least for a while.


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## greenkitty7

yea you got some juju with that bike... lucky for you that you didnt grenade the front diff or that you didnt get hurt from one of those things locking it down. some people have been hurt because of the weak welds on that carrier pin...


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## JPs300

Yeah, been a lot of issues with this thing that there shouldn't have been. My fault for not following my own preaching on buying a used atv, "only if you intimately know it's history/maintenance or only if you get it cheap enough that you can afford to rebuild it from one end to the other". - As it is, I've rebuilt it from one end to the other and I'm still fighting some gremlins. Gave up a heck of a nice harley for all these headaches. 


I can imagine where that failure could easily hurt some things/some one. I had just welded one side, but the new pin will be welded at both ends. No reason for it to ever need to come out anyway.


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## JPs300

Gotta give huge props to "cat 952" on HL. Sent me one of the custom pins he had made and didn't even let me pay the shipping. 

After 3 phone calls/voicemails & 2 emails w/o response from Cajun Cryogenics I'm going to just weld the yoke halves together and roll with it. 

Got a friends' car in the garage right now to do a roll-bar install, then back on this thing as well as bringing in another friends' new 700 grizz to do snorks & a rad relocate.


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## Polaris425

sweet... tell all them cat boys to bring all their info over here and hang out here instead of HL  haha..


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## JPs300

^ I try to hint about this place from time to time, not looking to get myself banned from there doing so though, LOL.

Gotta watch them nazis.....er uh moderators over there.


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## Polaris425

haha... :-D


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## JPs300




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