Replacing the aluminium gear and the worm gear with both bearings and race. when i put these new parts in circle drive can i just put the shims back how they were? or if i wanted to use new shims can i just check the thickness of the old ones with a caliper and get the same thickness with the new one? the bearing were good the only thing bad was the worn gear and aluminium gear because teeth of the aluminuin gear broke of damaging the worm gear. this circle drive has the clutch plates.
You should probably set up the clutch to the correct spec because that may be the reason your worm wheel broke. Set the blade perpendicular to the machine and sideshift it all the way out to one side. Drive the end of the blade against a stump or other immovable object and you should just be able to make the circle slip around against the clutch. If you can't, add a couple more shims. Rinse and repeat.
So do you do this procedure with the cover removed for the circle drive? And when you drive the blade against the stump are you using the controls for the circle or just going forward with the blade against the stump?
You need to remove the small circular cover to access the three bolts retaining the preload plate. Drive forward gently in first gear. On reflection, if you're not carrying out the adjusting procedure to reduce slip, or if you're not sure that you still have the factory installed shim pack I think it's best to start off with too many shims and remove them gradually until the amount of slip is acceptable. There is a procedure to measure the shim pack but I haven't found it reliable and prefer the above method.
Lewis12 Are you talking about the shims for the worm gear bearings or the circle slip clutch?
Both
So when you drive forward gently with the blade extended out to the side against a stump is the slip going to be seen from the pinion gear with the big nut on bottom of circle drive turning?
I think there's some confusion over terms. Conventionally, a worm drive set is collectively known as a worm gear. The individual components are the worm wheel which is the big round thing, and the worm which is the coarse screw thing. In the circle drive box there are two shim packs; one for the worm bearings and one for the clutch slip adjustment. The worm wheel doesn't have a shim adjustment. The worm bearings' shim pack won't be adjusted unless something has been replaced here. The clutch shim pack gets adjusted regularly to account for wear in the clutch. From the cab you won't actually see anything except the circle turning. The circle will be turning the pinion which will be turning the vertical shaft which will be slipping the internal clutch whilst the worm wheel stays stationary.
Pin # 5MD01618 140G. If you remove the small cover only to get to the clutch shim pack how can you tell if the worm wheel that is aluminium is stationary? Also is getting the worm wheel stationary the goal? Just asking will get help but just wanting to get informed.
Nothing wrong with wanting to be informed. Ask away. The only way the worm wheel can rotate is if it's being turned by the worm. It's the nature of a worm gear drive that it can't (usually) be reverse driven. If the circle is turning without you pulling on the lever in the cab, either the clutch is slipping or something's broken.
Okay so I extend the blade out all to one side and slowly pull up on a immovable object. At this point am not using the levers in cab. Is what am looking for is to see if the immovable object will make the blade move and if it dosent I would then remove shims?
No. If the circle won't turn then add shims. Remove shims to tighten the clutch, add them to loosen.
Okay so how much clutch slip or movement should be attained from the perpendicular blade being slowly driven into the immovable object or stump?
Not much. The clutch is a safety device to stop the box being damaged if you hit something by accident. My advice is to set it loose-ish and then run the machine. If you then find it slipping under normal working conditions, remove a shim or two until you're happy with it.
Great. So how would you go about setting the adjustment on the worm gear. The bearing on the worm were not damaged but I decided to replace with new bearings, races. The worm gear is also new because the old one did get slightly damaged from the worm wheel. So everything is new also got a new shim pack. I beleive the bearing have to be heated to seated on the worm gear?
Here's the official guff on setting the worm bearing preload. In practise if you're using genuine Cat parts, it's rare to have to have to alter a factory shim pack much, if at all. In fact if your calculated shim pack thickness is radically different from the factory one, it's best to go back and check your work because you've probably got something wrong. This applies to all shimmed bearings in all Cat products in my experience.
Heated or pressed on. It doesn't matter either way. Heating is easier.
When following the instructions on diagram does the Worm wheel and clutch plates all have to be assembled first or can you get this shim adjustment with just the worm gear and bearings installed?
Yes. Assemble the worm and set the preload first, then install the wormwheel, shaft and clutch assembly.
So while the nuts are being torqued in the diagram the shim pack has already been installed prior to the torquing right? Also if this procedure is done properly are the rollers on the bearings going to spin freely if you turn the shaft on the worm gear?
No shim pack during the above procedure. Measure the gap with feeler gauges and the thickness of the shim pack will be this measurement minus between two and eight thou. The worm won't spin freely once it's correctly assembled as there will be a preload on the bearings.