More help with fan hub.

I posted a similar question and didn't get much help. I'm trying to remove the fan as a start to replacing a cracked pulley. Does that pin in the water pump driver need to be removed for the driver to come off its shaft? If so ... can I bang on it?

Yes. The pin is tapered with a flat spot machined on one side to match a flat on the pump shaft. By the time you have it far enough out to slide the driver off, the pin is in your hand.

The pump shaft is pretty hard and most likely brittle enough to break. A few light taps might work but be very careful. Short of that, I have had success with a C-clamp. Leave the nut flush with the end of the pin threads and hold a 1/2" nut over the other end of the pin. It works best with a third hand to hold everything in place while you tighten the clamp. Once it moves a little bit, it's loose.

The pin needs to come out. It is a tapered pin (bolt) so may be very tight, support opposite side with like a large hammer or equiv and give it a rap. When you get to the hub, the rear pulley is pressed on and is held with a pin, need to take out bearings and seal, find pin in edge of pulley and drive right on through , then press off pulley. It is necessary to remove rear pulley to get adjustable pulley off. I could not tell from your post if that adjustable pulley is what is broke but that is what usually gets busted and they are available on-line. If bushings or impeller are bad you are in trouble, may need to get a rebuilt unit. I used to rebuild many but it can be very expensive and not all parts are readily available now days.

OK ... sounds like I"ve got a job for tomorrow. Tell me ... this may sound like a dumb question ... but how does one normally replace a fan belt on the H? By loosening up the water pump? Given the responses I got back I don"t think I"m gonna replace the cracked hub - it seemed to work OK before I began taring stuff apart - so perhaps I"ll just leave it. Tell me though how you normally replace a fan belt. Thanks.

Remove the locking set screw and jam nut on the cracked half of your water pump pulley and (carefully) turn the pulley half toward the fan blades. The threads are right-handed.

This movable half of the water pump pulley when turned forward will let the fan belt loosen enough to come off of the crankshaft pulley. That's why it is very important to clean the water pump hub threads and use spray lube before attempting to turn it.

I'm confused. I did get that pin out today and was able to remove the fan and pump drive. The fan is screwed to what looks like a threaded hub with some sort of large nipple on it. Behind that is another hub with a big set screw. Behind this is the pump belt and then the generator belt. Are you saying that the first hub (with the nipple) will screw off? And then the channel within which the pump belt sits is actually formed by two hubs - one forward (that I'm to remove) and one back which is pressed into the first? Boy! So remove the hub into which the fan was bolted (I do this by screwing it off). And tell me again ... what? Sorry to be stupid about this. I need help - I don't want to bust anything up beyond repair - but do want to get the cracked hub off. Again .. the cracked part is just behind the hub that had the fan on it.
Dave S.

You have things pretty well figured out. Just a few details might help clear up what you can expect. The rotating hub is made of three pieces. The front hub contains the bearings and seals. The middle one with the set screw is the belt adjustment. Lastly is the stationary half of the fan pulley and the generator drive pulley. All threaded parts are right-handed.

To get all of this apart, it has to come off of the pump housing. Now, it doesn't matter if you want to remove the radiator or take the pump off the block. You'll have to do one or the other.

To remove the hub from the housing, remove the gland nut from around the impeller shaft. It holds the pump shaft packing in place. You don't have to dig the packing out, but plan to add a few new pieces back upon re-assembly. Behind that is a nut that looks like a spacer. It has two wrench flats machined on it. Once the nut is off, the hub can be pulled off the housing. The bearings are a light press fit around the 'snout' and might need a light tap depending on the amount of grease the hub bearings received during its working life. Use a non-marring hammer as the spindle is threaded both internally and externally at the end.

Now to remove the fixed half of the pulley from the other end. There is a locating pin about 1/8" in diameter that is in a hole drilled at the step between the generator pulley and the pump pulley half. It can be difficult to find if there is still paint on this area. Drive the pin on into the center of the hub with a small punch. You can retrieve it later when you clean everything up to put it back together. The fixed half of the pulleys can now be pressed off the back. Be careful because the end of the hub runs against a felt dust seal that is in a recess in the housing and if you nick the end it will chew away the felt and there won't be a seal any longer.

Now you can remove the cracked hub. If you clean the parts up well - I use a glass bead blaster - assembly is easy. I recommend new bearings and seals now as you probably don't want to go back into it again - ever.

Sorry for the long post.

And now that I have the hubs freed ... how to I get them off the shaft given that the water pump belt is still holding them fast?

Also ... what's packing?

Thanks.

Remove the set screw and turn the movable front half of the water pump pulley toward the front hub. This will loosen the v-belt so it can be just slipped off of the crankshaft pulley. Once the belt is off, you can pull the entire hub assembly off.

The packing goes around the impeller shaft to keep it from leaking coolant out the front of the pump. Here's where a copy of the parts book can really help you see what's in there. The exploded diagrams can also help during re-assembly.

Last questions, I promise. I've been looking for the pin which you described as anchoring the generator pulley. Can't find it for the life of me ... say again where it can be found? I've had my hands and eyes all over this hubs with no luck. The adjustable hub is deinately cracked so I'm glad you were able to walk me through this to get to this point. Can I simply purchase 'packing' when I put the thing back together? Is packing simply grease? Thanks. Dave.

The packing is a normally graphite impregnated rope-like material. It is compressed under the packing nut to seal between the turning impeller shaft and the housing. It is pre-formed and you place it around the shaft. You can buy it from your CaseIH dealer packaged individually. The newer ones are white instead of black but they have worked as well for me. Sometimes several pieces are needed - it depends on the condition of the old packing. Like piston rings, stagger the gaps so a better seal is formed. The nut needs to be snug but not excessively tight. That only causes premature wear of the shaft. Make sure there is enough packing in place to allow for future adjustment of the nut.

On the pin, there are two ways you can find it. From the outside, it is at the transition between the front of the generator pulley and the back half of the water pump drive pulley. It may even appear as a machining burr or even an old paint run. From the inside, remove the seals and bearings and clean it really well with solvent to reveal the other end. This will help you locate it to drive it in from the outside. Note: The hole for the pin is not perpendicular with the hub centerline and I don't remember which way is slopes. Sorry.

Would you believe I got the pulley off today? Once I found the pin it was easy. I'm now looking at the parts schematic and can't determine how the sleeve (part #10) that holds the shaft (#9) is actually held into the housing. I figure since I've got the thing apart this far perhaps I should unbold the housing to perhaps clean is up (inside that is)then I will have completed the rebuild of the pump. How do the sleeve and shaft seat so firmly - what's holding them? And, what about the felt washer #12 that you mentioned before? Should I simply leave well enough alone or continue to disassemable? I'll rely on your advice. But thanks very much for helping to get me this far - I almost gave up a few times - but am glad I stuck with it.

Dave