Chain Case Access

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Bigworm.1973

Member
Joined
Feb 11, 2025
Messages
6
Hi, I have a 743 Bobcat and I'm in the process of changing out all four axle seals and bearings. I'm having a hard time getting to the rear bolts inside the chain case for the rear axles. I was able to break loose the bolt on one side, but I'm having issues on the other. I thought about cutting the chain case in the rear to access both bolts, because I know it's going to be difficult installing the bearings and tightening the bolts. I'm a welder, so there's no issue welding it back. Any suggestions on this or has anyone taken this approach?
 
Hi, I have a 743 Bobcat and I'm in the process of changing out all four axle seals and bearings. I'm having a hard time getting to the rear bolts inside the chain case for the rear axles. I was able to break loose the bolt on one side, but I'm having issues on the other. I thought about cutting the chain case in the rear to access both bolts, because I know it's going to be difficult installing the bearings and tightening the bolts. I'm a welder, so there's no issue welding it back. Any suggestions on this or has anyone taken this approach?
Put the machine on blocks, remove the wheels, put a wrench on the axle bolt and allow the wrench to jam against the housing, use a long pry bar between the wheel lugs to twist the axle while the wrench stays in place unscrewing the axle bolt.

You should keep lug nuts on the lugs to keep from deforming the threads.
 
I had all 4 bearings on my 742B changed by an independent Bobcat repair guy because I couldn't for the life of me figure out how to remove and work inside the rear access cover which is almost completely covered by the hydrostatic pump. On the 753 in the video the pump is not blocking that rear cover plate. This is different than what I remember the 742B {I think 743 is more like a 742 than 753} to be like.
Some working room can be gained by undoing the front mount and jacking up the pump end. In retrospect, If i was going to do the job on all 4 axles i would be considering lifting the chassis of the machine off the chain case.The hydraulic motors and hoses to them are the biggest items to disconnect. There are a bunch of bolts between the 2, if you have the ability to lift the chassis up, and then the chain case can be rolled out from under the chassis like a big roller skate. I do have a lift and have not done it this way myself but have seen videos of others doing it this way. HTH.
 
Okay, so I want to clean the chain case out really good. Any suggestions on getting all the oil out and best advice in cleaning case? I got most out except for the very bottom.. best cleaner solution?
 
Okay, so I want to clean the chain case out really good. Any suggestions on getting all the oil out and best advice in cleaning case? I got most out except for the very bottom.. best cleaner solution?
Prop up the back of the machine, open the front and middle chain case cover and you can clean it out very good.
 
Okay, so I want to clean the chain case out really good. Any suggestions on getting all the oil out and best advice in cleaning case? I got most out except for the very bottom.. best cleaner solution?
Here is a couple of videos on the Milwaukee transfer pump.
This pump is not meant for oil or diesel so you will void the warranty. However, it works fantastic for both hydro fluid and diesel.

And it just so happens that I used it today to transfer diesel.



 
I've used a shop vac and just reduced things to a small hose, worked pretty good or what it is

you can also flush things some with some diesel fuel too, just be careful!
 
On my 742B I put the rear wheels up on blocks, filled a garden sprayer with diesel{kerosene works good too} and hosed all the internal components down through the front access cover, working from rear to front. Before beginning I drilled and tapped a hole low in the front vertical wall of the chain case below the fill/check plug so most things would drain out. I had an oil transfer pump to suck up the rest and used rags to wipe up the last of it. Mine had water contamination and it took a few rounds of this to get clean but it worked great. HTH.
 
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