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33D Rear Axle Bearings

Anybody have any experience changing out the bearings in a rear axle?  I haven't been able to stop the transmission oil from leaking out around the new seal on that side.  I tried repositioning the seal but no help there.  Right axle is fine.  I determined that the outer bearing is shot, allowing the axle to "waller around" a good deal.  I've got the axle and axle housing off the tractor and removed an inner snap ring.  I'm trying to figure out how to remove the bearings.  I think I need to press the axle out of the housing.  Any hints would be appreciated.  Thanks.

Glenn
Glenn

RE:33D Rear Axle Bearings

Glenn -- The 101, 30, 33, 333, 44 and 444 all use the same rear axle bearing and seal setup.  You shoud be able to pull the axle without pulling the rear axle housing.  You must remove the large cotter pin that hold the large bull gear on the axle.  Remove the wheel and hub from the axle.  Remove bolts that hold the axle bearing cap onto the outside end of the axle housinf and pull / push the axle out.  The axle is not pressed in but may be stuck.  If you have the axle housing and axle off the tractor you should be able to push the axle out without a lot of force.  The outside bearing and bearing cup will sta;y on the end of the axle.  The inside bearing and cup will stay in the housing and is held in with a large snap ring.  The snap ring would need to be removed to inspect or replace the inner bearing.  The bearings are Timken or tapered bearings.  There should be a number of bearing cap shims on the bearing cap.  They may look like a metal gasket.  I think they come in .005", .010" and .020" thickness and usually will have a number of them on the bearing cap.  A common error is someone will add a gasket in an effort to stop any oil leak,but this effects the bearing clearnce or end play and causes the seal to leak.  If the bearing is good, the right number of shims will give you no end play but the axle will turn freely.  As the bearing wears or is replaced the bearing clearance needs to be adjusted.  The problem is finding new shims if you need them.  If the bearing is OK and just loose, you can remove some shims.  If you replace the bearing you need to check the bearing end play.  The outside rear bearings should be paked with grease before installing.  There should be a cup washer (Grese Retainer) that goes on the axle before the outside bearing goes on the axle, then the bearing and bearing cup.  Massey also used a felt washer on the outside of the seal to kept dirt out of the seal.  There is a grease fitting on the axle cap, as it may not always get transmission oil to the outside bearing. (as the land side wheel when plowing or if the trans / rear end oil is a little low)  Also make sure the bearing cups are seated before adding or removing shims.  The axle should not have any play but should turn free.

The same thing is true on the brake shafts  and seals.  The bearing are tapered and clearance is adjusted with shim.  However moving shims  left to right, or right to left side also adjusts Ring Gear and Pinion back lash.  It's best not to change the back lash as the gears have a wear pattern and unless there is a problem don't cchange it, but the bearing end play needs to be correct for the oil seals to work correctly.
Jerry B                

RE:33D Rear Axle Bearings

Jerry Thank you!  I did have to press the axle out of the housing.  Both bearings and cups were badly pitted and worn due to transmission filling up with water and sitting outside for a time at it's former home.   I've ordered all new bearings and seals with felt washers.  Also I'm wondering about the axle right where it rubs with the seal.  There's now a groove in the axle at that location.  Won't it continue leaking if the oil seal goes back in exactly the same location where the groove is worn?  What can be done about that?
Thanks for all your information.
Glenn
Glenn

RE:33D Rear Axle Bearings

Hi Glenn --  Yes the seal wear groove in the axle is a concern.  One way would be to get a different axle, which may not be that easy to find, and a used axle may have a seal wear groove also.  I would check if the new seal is just like the old seal, sometimes a repacement seal will move the sealing point in or out a little to try to use an unworn part of the shaft.  If it looks like the new seal will contact the shaft in the same/worn area I try to not drive the seal all the way in.  Usually an 1/8 " is about all that is needed.  It's important that the seal is square with the shaft and thats why a seal is usually driven in all the way.  If the seal is not square with the shaft part of the seal may run in the worn area and part of the seal will run in the not worn area.  It can pump oil out as it turns and also ware the seal fast  It's best if you have some kind of a spacer so the seal goes in square all the way to the spacer.  I've made spacers ouut of a circle of #9 wire.  I usually leave  piece of the wire heading into the center of the hole and you can pull the wire out after the seal is in.  If the groove is not very deep, new bearings and seal may fix the leak and you may not need to do this ???

If you install new bearings and cups it's important to check that bearing clearance.  When you bolt the end cap to the axle housing, it pushes the outside bear cup into the bearing, the snap ring holds the inside cup from moving out.  If there are not enough shims on the end cap the bearing will be too tight and will lock the shaft or make it turn hard.  Too many shims and the bearings are too loose. (will have end play and with tapered bearings the weight of the tractor will push the shaft up and out of the center of the seal.)   Somwtimes the number of old shims is just right.

Water can enter the transmission because of a bad rubber boot on the gear shift lever.  If the boot has been replaced and seals good then the transmission needs to breath or when the transmission gets hot it builds pressure and pushes oil out the seals.  I think that the breather on a 33 is under the steering shaft support where it bolts to the transmission.         Good Luck !!!    Jerry B  

RE:33D Rear Axle Bearings

Hey Jerry B 
Thanks for all the great info about this topic.  I've reinstalled the new bearings and have the axle and housing attached to the transmission.  Now I'm ready for the seal.  I've taken note of all your pointers.  So, I also have a concern about if there is a right orientation of the seal.  Does it have to go in one way only, or can it go either way.  On one side, the rubber is sealed to the metal.  The other side is more open and you can see the steel spring inside surrounding the circumference.  Does it matter which side is in or out?
Thanks!
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Glenn

RE:33D Rear Axle Bearings

Hi Glenn --  Yes, the seal should only be installed one way -- there are many different seals but the way you describe your seal the more open side with the spring around the rubber (which makes the dimeter smaller) goes to the inside or where the oil is that you are trying to seal in, this lip holds the oil in.  Some seals have a double lip -  the outside one tries to seal out dirt but the lip with the spring around it should go toward the oil.
     Before you install the seal is the time to install the axle cap, this pushes the outer bearing cup in and you check the end play or if the axle is locked up or hard to turn. (It will turn a little hard because you are turning all the gears.  (can be checked easier when the axle housing is off the tractor)  Remove axle cap to install seal into it..
      Next is to install the axle cap with the seal in it.   This must be done very carefully.  It is  easy to damage the seal lip. (most seals are installed and then the shaft or pulley is installed from the outside in, but on these axles you are trying to install the axle cap with the seal onto the axle shaft, so it is very easy to damage the seal lip.  I understand Massey had a tool to help install the axle cap and seal. (I've never seen one -- only pictures)  On the standard model tractors the axle size increases in a step, from the axle wheel taper to the axle -- the problem is getting the seal lip onto the axle without damaging it.  On the row crop the axle is the same size all the way so it is a problem getting the seal started on the axle shaft, but the bigger problem is that the axle has about eight grooves cut into the axle (for a snap ring to keep the wheel from sliding out on the axle.)  as you are installing the axle cap with the seal in it, the lip of the seal drops into these grooves.  If you force it on you may damage the seal.  I've tried a number of different ways like using thin, narrow tape lenght wise to cover these grooves.  The axle must be clean and dry so the tape will stick, but you need to use a lot of lub on the outside of the tape, axle and seal lip so that the cap and seal will slide on.  You may need to work it up and down and turning the cap gently to help it slide on.
        Good Luck                Jerry B  

RE:33D Rear Axle Bearings

Jerry B! 
Thanks so much!  You provided a lot to "chew on".  You also answered my question.  I'll try to be very careful installing the seal over all those grooves on the axle.

Thanks again. 

Glenn