We have cat 225 excavator that is shearing bolts on drive sprocket for tracks. We can easy out bolts and put new ones in only to shear them off again within a few days. The sprocket was recently replaced by previous owner so something could have been assembled wrong. In the process of taking off sprocket now can anyone point us in right direction as to what the problem might be?
-
Thank you for visiting HeavyEquipmentForums.com! Our objective is to provide industry professionals a place to gather to exchange questions, answers and ideas. We welcome you to register using the "Register" icon at the top of the page. We'd appreciate any help you can offer in spreading the word of our new site. The more members that join, the bigger resource for all to enjoy. Thank you!
Cat 225 excavator shearing bolts on drive sprocket
- Thread starter 4MSU
- Start date
Nige
Senior Member
A few questions first. What model 225 is it? Are you using genuine Cat bolts (or at least Grade 8 bolts)? Is the replacement sprocket an OEM or a "will fit"?
The sprocket is tapered inside and there is a tapered sleeve into which the bolts pull the sprocket. If those two tapers are damaged or a hair off then the drive will be via the bolts rather than via the taper. That could be the answer to your problem of breaking bolts.
The sprocket is tapered inside and there is a tapered sleeve into which the bolts pull the sprocket. If those two tapers are damaged or a hair off then the drive will be via the bolts rather than via the taper. That could be the answer to your problem of breaking bolts.
I guess I cant tell you exact model other than its a 225 LC. We were replacing with grade 8 bolts. We have the cat grade ten bolts to go in it this time but want to resolve the problem before putting them in. I have no idea where the replacement sprocket came from since it was on when we bought it. We got the sprocket and sleeve off noticed right away that sprocket is and sleeve are tapered. When the sprocket is off the machine on its side the sleeve can be placed in the sprocket and it slides all the way down so that it appears there is no way to for the bolts to pull the taper in and make it tight. You can just spin it in the sprocket by hand. But my question is does that sleeve expand out when it is put onto the spline shaft of the drive axle? I ask this because that sleeve has grooves in it that appear to look like the allow it to expand or contract as it is tightend. As of right now I am almost sure just the bolts are driving the machine and not the taper. Any help is greatly appreciated. Thank You
Is there a place to buy aftermarket parts or should one stick wit cat?
Is there a place to buy aftermarket parts or should one stick wit cat?
Nige
Senior Member
I think that's where your problem lies. The spocket should not slide all the way down the sleeve to the bottom. It should stop and become tight on the sleeve at least 1/8" before it bottoms out. The slots in the sleeve are to allow the sleeve to "compress" inwards when the bolts are tightened and so to grip the shaft that the whole assembly rides on, the sleeve does not expand, it does the opposite in fact. Is there any sign of wear or grooving on the outside diameter of the sleeve that would lead you to believe that the sleeve has been worn down on the outside, thus maybe indicating that the problem is with the sleeve and not the sprocket..?
I think you might find the price of a Cat sprocket a bit eye-watering. Try an outfit called Off Road Equipment, you may have to call them to get a price. http://www.offroadeq.com/
Before calling I suggest you take a look at the machine and get the Serial Number.
I think you might find the price of a Cat sprocket a bit eye-watering. Try an outfit called Off Road Equipment, you may have to call them to get a price. http://www.offroadeq.com/
Before calling I suggest you take a look at the machine and get the Serial Number.