Ever see this happen??

[oler1234]

Soooo..... i got a problem. Anyone have a idea what would cause this?? My own diagnose is that this is from power given the crack is directly above the engine bump stop... the engines in these chassis tend to do 2 things under heavy loading, shift towards the mag side of the chassis as well pull up with a rotation back. Heh anyone who has rode with me knows this sled rocks as it kills other BB with 3" tracks. As well i run a pretty agressive clutch setup which may have alot to do with it too.

I am thinking the solution to this is, pull the engine, pull it back together and weld it. As well make some L bracket for the back side and epoxy it on. Got some stuff we used as a skid plate on the bottom of the jet boat that should hold. Any other ideas for a fix besides a new chassis lol

 

[Caper11]

Are you sure you didn't hit anything, or may have in the past, i've only seen this on sleds that have had front end damage and the e-module cracked the brace looks like its been broke for awhile.
I also think you should look into the grease coming out of the crank seal. Its not supposed to do that.

 

[revbyu]

Guess there would be alot of stress from the engine torque - could it possibly be from an front end impact stressing it and then eventually cracking - Looks like its time for cracnk seal!

 

[teeroy]

as much as I would love to say it was raw horsepower that did that, I'm going to say it was more likely from a shock of some sort. you can replace that e module though, I'm not sure welding cast aluminum isn't a waste of time. I'll ask Zal....he has a welding shop and will know for sure.

 

[POWDERSLUT]

Did you hit anything.Are all your motor mounts good.I had to replace 3 of mine last year,and 2 + that wedge piece on a buddys.That wedge was no where to be found,all 3 bolts snapped off.
Thats a replacable part.You should be able to have ripped apart and back together in a good night(with atleast a pilly 8 pack).I broke mine but on the other side way worse,the crack overlaped by a 1 1/2".I got that peice,as i just replaced the hole bulkhead/tunnel.
I woulndnt try to band aid it.

 

[oler1234]

negative to front end impact. i baby this thing up the trails, and well on top the skies are too far in the sky to really hit anything.

 

[tex78]

Man do u every clean the belt dust ever? Might have seen the crack sooner with it clean

 

[Boondockordie]

Be a really good idea to check your runout too. My seal was leaking like that and my runout is 0.009"

 

[Sun Sport]

Check motor mounts,runout,and the primary clutch, it could be a bad vibration. Just a thought.

 

[fredw]

i would say you hit something on the other side with the ski, they are the weak spot, not that big of job, but looking at your crank seal, i would say that is the bigger issue you have, time to rebalence crank

 

[oler1234]

no nothing has been hit on the sled. The seal is due this year, it has been leaking since day 1 of operation. Crank runout i have checked every year and has stayed at 0.001" for the last three. Will check it again, i'd expect it to be around 0.0015 or 0.002" given i let the clutch wear get bad last season. Seeing how i have the engine out i might just send it to someone as i got over 5500km on origional bottom end with 4800+ of those with the big bore.

What is the spec for crank run out and who "trues" these cranks and does PTO side bearings around here??

 

[teeroy]

I'm thinking .0024 is the runout spec

 

[ferniesnow]

I'm thinking .0024 is the runout spec

They came out with a new spec during the summer as most of the short blocks weren't perfect either.....so the new spec is 0.004 (from what I read).

 

[teeroy]

They came out with a new spec during the summer as most of the short blocks weren't perfect either.....so the new spec is 0.004 (from what I read).

lol....new runout specs and dirt cheap TRA rebuild kits.....hmmm

 

[Warhawk]

Common spot to break. Have guys around here that have done the same

 

[Sun Sport]

CVTech have cranks ,they retail for 680.00 ,if you give them your core ($200).You can even call them and ask to have it welded at little or no charge,just for piece of mind.I get about 10-20 rebuilt cranks from them every year and never seen one over 0.0017 so far ,it should only take about 3 days for you to see one.

 

[tex78]

Motts in st Albert. New Doo crank and installed bottom end. 1000.00.

 

[neilsleder]

You wont get a good weld with cast aluminum, thet are aloyed with something that doesnt like to be welded! I have tryed to weld many cast alum things with not very good luck. And if it does manage to weld up nice it will crack just above the weld again later.

 

[oler1234]

Thats why we are bonding on aluminum plates on both sides. Should be stronger than the origional setup once complete.

So crank runout is at 0.002 or slightly less. After talking with a couple engine builders, and being laughed at given that i have so many km on a BB setup and have the engine out already, i am gonna split the case. I have been told these engines are really hard on inner bearings, anyone else see this? Worst case sceario the two inner bearing are shot and i need a new crank. If there ok, do a repair, repack with grease, and re install.

I have been hearing alot of the doo reman cranks are a crap shot when it comes to runout.

 

[Warhawk]

Alot of times miss handling a crank can throw it out. do the run out tests when you get the new/rebuilt one and all should be good. If its WAY out when you get it you might want to send it back or if you know somebody who is good with a hammer they can bring it back into spec for you. Make sure when you have your old one out you clean the grease out and check the cages in the bearings. common problem.