Oil Seal Cover Mystery - L4150

[yokoji]

Hi folks,

I am new to this forum and let me be very clear from the start - I am in no way experienced with mechanical endeavors and I'm learning as I go along. So please be patient and I appreciate any one who is willing to help!

We have a Kubota L4150DT and the right front axle has been causing us problems. First, the cap on the bottom of the axle case came off when the staking nut came loose and the 12T bevel gear dropped down. The axle has been worked on in the past so it is safe to assume that the nut had not been properly staked when put back together, although I can't be sure of this. I ordered a new collar, shim, nut and cap and put it all back together according to the workshop manual and filled the case with gear oil. Soon after, the front axle case nut came loose and came off with the cap on the end of the axle. Another nut ordered, put on, torqued, staked and a new cap put on. Another 2.9QT (or slightly less) of gear oil. Now, there is a small leak coming from the oil seal cover / mud guard plate. This is what I don't get.

According to the workshop manual for this tractor, there is an oil seal cover with a mud guard plate bolted to the front of it. If you look at the photos I've posted, you can see that there seems to be a single piece oil seal cover/mud guard plate as opposed to a plate bolted on top of the the oil seal cover. And at the bottom of this, on both front axles, there is a small hole. It is from this hole that the oil is leaking.

Does any one have an idea of what this hole is and why our tractor seems to deviate from that shown in the diagram in the workshop manual (parts 14 and 15 in the attached diagram)? I'm hoping there is something really obvious that I am overlooking here, and if so, please do point it out to me.

Thank you for your time.

 

[jnjpream]

Hi yokoji,

I'll tell you first that I don't know the L4150 tractor. But can offer a some thoughts from experience with other equipment.

That hole looks like a weep hole. It's job is to let water, or in this case oil, escape from the oil seal cover. Probably much like the weep hold on automotive water pumps, part of its job is to let you see that the seal is leaking and needs to be replaced.

As for the mud shield separating from the oil seal cover, I don't think I'd worry about it unless it causes a problem like interference when trying to remove the oil seal cover. It is quite possible that the mud guard was incorporated into the oil seal cover at some point instead of being a separate part. Another possibility may be that the mud guard is a press fit instead of a bolt on piece, but usually you can see the joint where the two pieces meet if this is the case (painted over maybe?). You may just have to call a kubota dealer parts dept and ask them about it.

It seems strange to me that the nut keeps coming off.. A staking nut, once installed usually gets hit with a punch and hammer on the top ring to indent it (into a groove or key-way on the shaft) to keep it from coming off (like a poor mans lock-nut). Did you "set" the nut (on both sides if applicable) when you installed it?

 

[yokoji]

I posted this thread in both the Kubota operating section and general repair - I updated the other one and forgot about this one. We had our mechanic over the yesterday and he too confirmed they were weep holes. I've ordered a new seal and sleeve for the leaking axle case. The oil seal cover looks like the one from the L5450 - as someone pointed out on the other thread - but the axle case is stamped with L4150DT, so I guess they just used a different cover. I did call our Kubota dealer - Al's Kubota in Hemet, CA - but the guy in the service departmant there is super rude and patronizing and pretty much flat out refused to help me. This is the second time he has spoken to me like this. I won't be going back!

When I put the new staking nuts on, I did stake them firmly with a punch - there was only one side to do on the bevel gear shaft, and two places to stake on the axle case nut. Hopefully they'll stay put now!

Thanks for the input, jnjpream.