S
what should be my maximum tolerance on my crank. 800 liberty engine 2005 will be checking the run out this weekend.
crank run out
- Thread starter switchyluke
- Start date
S
got the day off today and measured my pto runout. i have 0.008 is it to to much?
That is a bunch, if memory serves me correct .004 was max. If it were mine I would not run it. How many miles are on it? Has it had a big bearing kit, or ever been apart before?
S
apart yes last owner crank broke on him 2years ago. the guy that rebuilt it, rebuilt it with brps bearings. wow if .004 is tolerence im way off. currently has 7000 miles. and yes big bearing was installed
Last edited:
Danger Will Robbins, Danger. 
.008 is a LOT. I used to tell people, you won't ever see .01... it will break before then.
Anything over .003 or so and I look to service it.
If you are really confident that you measured it accurately then you need to take it apart and have it rebuilt and have the cases checked really well.
sled_guy
.008 is a LOT. I used to tell people, you won't ever see .01... it will break before then.
Anything over .003 or so and I look to service it.
If you are really confident that you measured it accurately then you need to take it apart and have it rebuilt and have the cases checked really well.
sled_guy
S
just getting the crank trued will it be okay? case is looking good
I would have it looked at VERY close. The 800s were infamous for breaking crank pins on the PTO side. Do you know how many miles the crank has on it? You mentioned 7000 in a post, but I'm guessing that is overall, not since the crank was rebuilt?
If it was true when it went in, the case is nice and tight, and the pin is in good shape then you have to ask yourself why did it go out of alignment? What condition is your clutch in? Has it been balanced?
When I do a rebuild on an 800 like yours I send the crank to a reputable crank shop and have them completely rebuild it... they will know when they get it apart what needs to be replaced and what doesn't. I have the cases checked to make sure they are a tight fit on the bearings. Then I completely rebuild the clutch and if it hasn't been balanced before have it balanced.
Curious, are any of your motor mounts broken? That happens often when a crank is out of true.
sled_guy
If it was true when it went in, the case is nice and tight, and the pin is in good shape then you have to ask yourself why did it go out of alignment? What condition is your clutch in? Has it been balanced?
When I do a rebuild on an 800 like yours I send the crank to a reputable crank shop and have them completely rebuild it... they will know when they get it apart what needs to be replaced and what doesn't. I have the cases checked to make sure they are a tight fit on the bearings. Then I completely rebuild the clutch and if it hasn't been balanced before have it balanced.
Curious, are any of your motor mounts broken? That happens often when a crank is out of true.
sled_guy
S
previous owner broke 3 belts while riding. clutch alignment was way off. i think that is what threw the pto off. the more we speak about the crank the more i feel like letting go. feels like im into a money pitt with that engine. miles on crank i dont know maybe 200miles. when he rebuilt it he put the engine back in himself and never checked the (crooked) and went threw belts. after 4 rides he bought a new one and sold that one to me. and no mount are broken
Last edited:
S
and for the clutch it has to be rebuilt and balanced its in terrible shape. the second belt he broke was at wot i was with him when it happen.
The PTO side bearings do not get the same lubrication as the other bearings because the mfr left out the oil drip hole that directs oil to that bearing. If you take the crankcase apart, you can drill in that hole to make your next bearing last longer. Also, the 800's tend to rip apart the front PTO side engine mount. This allows the crankcase to twist, which causes all kind of bearing problems. Keep an eye on it and replace often.
S
okay. its not broken but might as well change it while im there. just dont know how to get there uneless i drill the rivets of the floating plate. is there another way? and thank for the help to all
The rubber mount and stud is screwed in to the mounting plate. You can grab it with a pipe wrench (there is actually a special tool) to turn it out and thread it out and replace it.
sled_guy
sled_guy