336D Front Axle Guru's Needed...

[Gypsyman]

I'm in the process of doing a complete front axle rebuild on the 336D due to the previous owner running it dry.

What I'm finding inside is a lot of sealed bearings where there should be open type oil bath bearings. These are all being replaced with the correct bearings.

The question comes with the top bearing on the outboard gear housings.

This bearing is above the axle oil fill level, however, I can see that there is an oil drain slot on the outer edge of the housing. This indicates to me that there should be an open bearing in this position. I assume that the action of the upper gears meshing causes oil to be "pumped" up to the bearing.

One dealer that I spoke with says that he uses a sealed bearing in this position but it appears that the factory design is for an open unit in this position. Maybe this was a known failure point that I am not aware of. I haven't found any information that would lead me to believe this though.

I'm not new to axles or gearboxes but this is my first run thru a 336D front axle. For those of you that have done a 336D front axle rebuild, did you use an open or sealed bearing for the outboard upper position?

 

[winston1]

Haven't been there done that. This is the sealed bearing Hoye is showing for it. Yanmar Tractor Parts: BEARING _ After further looking, they are showing sealed bearings on all the radial bearings. Curiosity killed the cat. Don't have a 336 parts manual but do have a ym2002d parts manual. Input the Yanmar parts number for upper and lower bearings. Both came back from more than one parts dealer as double sealed bearings. I have concluded sealed bearings were the original supplied bearings. May be wrong, won't be the first time.

 

[Domush]

This bearing is above the axle oil fill level

This part confuses me, as I have an oil fill on the axle itself (left, towards center pivot) and all bearings are well below this fill point. Since many of the bearings (all of them so far) on mine are open, this allows the oil to seep into the spindle assemblies, which essentially makes the remote oil fill holes obsolete unless you are in a hurry to use and can't wait the 6 hours for the oil to seep in on its own.

Having said all of that, I'd much rather have sealed bearings in mine, as it'd be one less thing to worry about!

 

[grainger12002]

mine has the sealed on top and thats what I replaced with. Look closely at the caged bearings in gthe middle,mine where in tough shape,I replace all the bearings and seals,are you going to sleeve the tower and use the oversize seal from Hoye ?

 

[Gypsyman]

Haven't been there done that. This is the sealed bearing Hoye is showing for it. Yanmar Tractor Parts: BEARING _ After further looking, they are showing sealed bearings on all the radial bearings. Curiosity killed the cat. Don't have a 336 parts manual but do have a ym2002d parts manual. Input the Yanmar parts number for upper and lower bearings. Both came back from more than one parts dealer as double sealed bearings. I have concluded sealed bearings were the original supplied bearings. May be wrong, won't be the first time.

I've confirmed that all of the original bearings were of the open type as I had at first suspected. I have no idea why the aftermarket bearings are being supplied as sealed units.

This part confuses me, as I have an oil fill on the axle itself (left, towards center pivot) and all bearings are well below this fill point. Since many of the bearings (all of them so far) on mine are open, this allows the oil to seep into the spindle assemblies, which essentially makes the remote oil fill holes obsolete unless you are in a hurry to use and can't wait the 6 hours for the oil to seep in on its own.

Having said all of that, I'd much rather have sealed bearings in mine, as it'd be one less thing to worry about!

The upper bearing in the spindle housing is actually above the oil fill level and relies on splash from the upper gears to lubricate it. I will still use the remote fill points. After looking at the close tolerances of the lower needle bearings and shaft it wouldn't surprise me if it took quite some time for oil to make it's way past them to the outer gear case.

mine has the sealed on top and thats what I replaced with. Look closely at the caged bearings in gthe middle,mine where in tough shape,I replace all the bearings and seals,are you going to sleeve the tower and use the oversize seal from Hoye ?

I'm replacing all of the bearings including the lower needle bearings.

I have the repair kit from Hoye here but after looking at how it must be installed I'm going to try the undersized seals from Jamiesons first and save the Hoye parts for a worst case scenario.

After another great discussion with Gary Jamieson (who is an absolute WEALTH of knowledge on the Yanmars) I understand why sealed bearings are being used in the upper spindle housing location. It would appear that the upper bearing was a trouble point so he started using the sealed bearings in this location which was my original plan. I popped the seals out of the bearings and properly packed them with EP grease. It's amazing how little grease is in a sealed bearing from the manufacturer.

Should be good to go when it all comes back together.