05sprcrw
Well-Known Member
This will be mainly a helpful post with a little back story about a few things I learned with this rear main seal.
Earlier this year I pulled the motor and pumps from my high hour bobcat. I got a good deal on it knowing it would need to be overhauled. I bored it out and honed it to the .050 over that allows for the factory oversized pistons and rings. I re-sealed everything while it was out as well, I noticed the wear sleeve had a small wear groove in it, but it never leaked so I figured with a new rear main seal it would still be good (trying not to purchase the driver for it at the time). I got everything put back in and it fired right up and has been perfect since the rebuild.
Then about a month ago as I was cleaning up dirt from adding some drain tile to my place I found out my fuel tank had developed a crack stemming from the fuel filler neck. So for the second time this year I took the pump and motor assembly out the back and swapped the tank, and gave as much of the chassis a good cleaning as possible. I want to add pulling the motor and pump assembly is not anywhere near as bad as I thought, I had the whole process done in 8 hours start to finish.
Then back to pushing dirt, after a bit of rain I was removing a small "damn" I had built to hold the water back while shaping the retention bowl for the water in an area until it can drain out of the tile. I got too close to the edge and dropped a set of tires in the mud soup up to the axle. I used the bucket to push my self out, but when I was shutting down for the day I was cleaning the mud out of the corners, and opened the rear compartment door to clean any mud that may have built up from that incident. And I noticed a small amount of oil on the frame next to the battery dripping out from behind the belt shield which leads me to the point of this post.
The seal was definitely leaking from what I could tell but now that it is winter and I don't have a heated shop I was really not looking forward to pulling the motor and pump assembly again then I got to thinking about it and figured I could do it with the motor still in. It went way easier then I ever imagined and was done in just a few hours. I just mainly wanted to share a few tips that may save someone else some time and effort.
In the service manual it didn't state if you could do it with the motor in or not but it showed the work being down with it out.
I pulled the battery, and air box to create extra space. I then took the belt cover and belt off, and pulled the flywheel off. I had to put a 3/8 x 4 bolt in the hole to lock the fly wheel in place to undo the bolts. Then with a pry bar and a little effort the fly wheel roll guide pins eased out of the crank and the fly wheel was off. This exposed the cap with the seal in it, I took the bolts out and ran the 2 bolts back in to push the cap/seal off the block to break the seal of the gasket maker.
When I got the seal off I could see the leak was from the seal getting folded over on itself when I originally re-built the motor, and not from the groove in the wear sleeve, but I had already purchased it and the special driver so might as well do it right this time.
This left the sleeve itself, the book says to use a puller and a part number that I couldn't find. So I first thought I would try heating it a bit with a torch, I got it red in a few spots but it wouldn't budge. I was getting ready to try a cold chisel to try and give it a hard whack and see if I could split it but then it came to me to use a carbide burr in a rotary tool. I started to grind away nice and slow so I didn't nick the crank and when I got 3/4's of the way through the pressure from the press fit split the wear sleeve and I was able to pull it off by hand with only about 2 to 3 minutes of work start to finish (easiest sleeve I've removed to date).
old sleeve after removal
new sleeve
Then I used the driver (k line tools makes one for the v3800, but it fits the v3300, v3600 and v3800 series motors from Kubota) and heated the sleeve to 390° in the oven (service manual calls up to 392°) and drove the sleeve on the crank.
After it cooled completely I slid the new seal/cap assembly (just bought both pieces with the seal pre installed by bobcat) onto the driver, lined it back up on the crank and slid it over the sleeve and against the block and re assembled everything.
All in all pretty painless, compared to most repair's I have done on this machine to date. I just wanted to share this info, because there was not much info on replacing the wear sleeve on these cranks. I don't think I would try the carbide burr on a thin wall sleeve but these are close to an 1/8" thick so there is a lot less chance of damaging the crank.
Sorry for the long winded post, just want to help someone else out as much as everyone else has helped me with previous posts on here.
Earlier this year I pulled the motor and pumps from my high hour bobcat. I got a good deal on it knowing it would need to be overhauled. I bored it out and honed it to the .050 over that allows for the factory oversized pistons and rings. I re-sealed everything while it was out as well, I noticed the wear sleeve had a small wear groove in it, but it never leaked so I figured with a new rear main seal it would still be good (trying not to purchase the driver for it at the time). I got everything put back in and it fired right up and has been perfect since the rebuild.
Then about a month ago as I was cleaning up dirt from adding some drain tile to my place I found out my fuel tank had developed a crack stemming from the fuel filler neck. So for the second time this year I took the pump and motor assembly out the back and swapped the tank, and gave as much of the chassis a good cleaning as possible. I want to add pulling the motor and pump assembly is not anywhere near as bad as I thought, I had the whole process done in 8 hours start to finish.
Then back to pushing dirt, after a bit of rain I was removing a small "damn" I had built to hold the water back while shaping the retention bowl for the water in an area until it can drain out of the tile. I got too close to the edge and dropped a set of tires in the mud soup up to the axle. I used the bucket to push my self out, but when I was shutting down for the day I was cleaning the mud out of the corners, and opened the rear compartment door to clean any mud that may have built up from that incident. And I noticed a small amount of oil on the frame next to the battery dripping out from behind the belt shield which leads me to the point of this post.
The seal was definitely leaking from what I could tell but now that it is winter and I don't have a heated shop I was really not looking forward to pulling the motor and pump assembly again then I got to thinking about it and figured I could do it with the motor still in. It went way easier then I ever imagined and was done in just a few hours. I just mainly wanted to share a few tips that may save someone else some time and effort.
In the service manual it didn't state if you could do it with the motor in or not but it showed the work being down with it out.
I pulled the battery, and air box to create extra space. I then took the belt cover and belt off, and pulled the flywheel off. I had to put a 3/8 x 4 bolt in the hole to lock the fly wheel in place to undo the bolts. Then with a pry bar and a little effort the fly wheel roll guide pins eased out of the crank and the fly wheel was off. This exposed the cap with the seal in it, I took the bolts out and ran the 2 bolts back in to push the cap/seal off the block to break the seal of the gasket maker.
When I got the seal off I could see the leak was from the seal getting folded over on itself when I originally re-built the motor, and not from the groove in the wear sleeve, but I had already purchased it and the special driver so might as well do it right this time.
This left the sleeve itself, the book says to use a puller and a part number that I couldn't find. So I first thought I would try heating it a bit with a torch, I got it red in a few spots but it wouldn't budge. I was getting ready to try a cold chisel to try and give it a hard whack and see if I could split it but then it came to me to use a carbide burr in a rotary tool. I started to grind away nice and slow so I didn't nick the crank and when I got 3/4's of the way through the pressure from the press fit split the wear sleeve and I was able to pull it off by hand with only about 2 to 3 minutes of work start to finish (easiest sleeve I've removed to date).
old sleeve after removal
new sleeve
Then I used the driver (k line tools makes one for the v3800, but it fits the v3300, v3600 and v3800 series motors from Kubota) and heated the sleeve to 390° in the oven (service manual calls up to 392°) and drove the sleeve on the crank.
After it cooled completely I slid the new seal/cap assembly (just bought both pieces with the seal pre installed by bobcat) onto the driver, lined it back up on the crank and slid it over the sleeve and against the block and re assembled everything.
All in all pretty painless, compared to most repair's I have done on this machine to date. I just wanted to share this info, because there was not much info on replacing the wear sleeve on these cranks. I don't think I would try the carbide burr on a thin wall sleeve but these are close to an 1/8" thick so there is a lot less chance of damaging the crank.
Sorry for the long winded post, just want to help someone else out as much as everyone else has helped me with previous posts on here.