1250 hydro fan replace

[MrRazz]

Hi all.

I broke the hydro cooling fan on my 1250 the other day when a stick got up under my cub. I need to replace it. What is the process of removing the shaft? I tried using the search on the site but it keeps taking out the word "fan" on me. Also how does the old fan come off and the new one go on?

Thank you in advance!

[finsruskw]

You do not have to remove the driveshaft, only dis-connect everything on the rear end of it and slide forward enough to raise the shaft and then slide the old fan, flex disc joints and couplers off.'
Do not loose the ball bearing centering spacer between the couplers.

You may have to re-use the snap ring that secures the old fan if the replacement does not have one. Make sure it is in the correct position on the shaft as to not interfere with the lift linkage.

Also a good time to replace the spirol pins if they appear worn as well as the flex disc joints if they are hard, brittle and distorted.
Be sure to use spirol pins and NOT regular roll pins
Be sure to support the driveshaft with something solid when driving out the spirol pins using a 1/4" pin punch with the centering tit on the end.
Good luck!

[ol'George]

Originally Posted by finsruskw

You do not have to remove the driveshaft, only dis-connect everything on the rear end of it and slide forward enough to raise the shaft and then slide the old fan, rag joints and couplers off.'
Do not loose the ball bearing centering spacer between the couplers.

You may have to re-use the snap ring that secures the old fan if the replacement does not have one. Make sure it is in the correct position on the shaft as to not interfere with the lift linkage.

Also a good time to replace the spirol pins if they appear worn as well as the rag joints if they are hard, brittle and distorted.
Be sure to use spirol pins and NOT regular roll pins
Be sure to support the driveshaft with something solid when driving out the spirol pins using a 1/4" pin punch with the centering tit on the end.
Good luck!

If I may add,
make sure the fan is put on correctly so it cools the hydro and the curved blades are facing correctly or it will not have the airfoil effect.
I have seen a few on wrong.

[mortten]

I’ve found the fan likes to wonder a bit over time. I wrap some electrical tape around the shaft in front and behind the fan.

[MrRazz]

Thanks guys! How hard is it to get that pin out and slide the coupler off? I doubt the shaft has ever been removed before.

[ironman]

Originally Posted by MrRazz

Thanks guys! How hard is it to get that pin out and slide the coupler off? I doubt the shaft has ever been removed before.

Compared to going to see my proctologist, I would have a tough time deciding which I'd rather do.

[finsruskw]

You have to remove both the pin through the driveshaft coupling (part #5} and the coupling arm (part #2) then slide the whole works forward enough to raise the shaft along with the flex disc joint and fan for removal.
Some cleaning of rust, scale and paint may be required to slide these parts forward, shop emery cloth is good for this.

Then reassemble in the reverse order

This would also be a good time to inspect the front rag joint along with the driver and bushing on the rear of the engine as well for wear and/or deterioration of the flex disc joint. Easy enough to remove once the rear parts are loosened up and slid forward.

See link attached, upper right hand corner.

https://www.cubcadet.com/en_US/ari-p...3cb861d601fd/y

[twoton]

Disconnect the negative battery cable.

Remove the side panels.

Remove the tunnel cover.

Sand the drive shaft clean in the areas in front of the driveshaft output yoke and the cooling fan. Apply some sort of lubricant such as WD 40 to the driveshaft.

Remove the snap ring in the front recess of the cooling fan and slide it forward on the driveshaft.

While rotating the fan on the driveshaft, move the fan forward about 3 inches.

Put a jack under the rear end and raise the tractor about 3 inches. Put a block between the housing and the jack to distribute the weight.

Install a jack stand between the frame rails and up under the drive shaft, just forward of the driveshaft output yoke, the one that attaches to the rear rag joint.

Rotate the drive shaft so the spirol pin in the transmission input yoke is in the vertical position.

Lower the tractor, using the jack that you have under the rear, until the drive shaft is LIGHTLY! resting on the jack stand. The jack stand MUST be right in front of the driveshaft output yoke. The driveshaft Must be supported well enough that when you drive the spirol pins out you cause no damage to the transmission input bearing.

Now, drive the spirol pin out of the transmission input yoke.

Now drive the spirol pin from the driveshaft output yoke. You may have to raise, rotate, lower to get that pin in an accessible position.

Once both pins are out, raise the tractor with the jack, enough to remove the jack stand.

Rotate the yokes and flex disc joint assembly about the shaft and move it forward.

Be aware; if you have a single rear rag joint there will be a ball bearing inside the transmission input yoke that aids in driveshaft centering, do not loose this.

Remove the bolts that attach the driveshaft input yoke to the front rag joint.

Remove the driveshaft from the machine.

Replace the fan. Inspect and if needed replace the front flex disc joint, and the rear flex disc joint and both front and rear ball bushings.

Cooling fan part # IH-547749-R1
Flex Disc joint part # 722-3000
Ball bushing part #941-3004
5/16” x 1 ¼” coiled spring pins. Mcmaster-carr #91598A526


Put it back together.

[twoton]

P.S. they are 1/4" spirol pins, not 5/16", my bad.

[MrRazz]

I ordered the fan and a pin punch. Just have to order the pins. I will give this a shot as soon as everything comes in the mail. I need to get my machine back in service asap, ive got lots of work to do on my property.