Front Differntial failure L3940

[GarthH]

Hi all.

I just got bad news from my local dealer. Somehow almost all the gears and bearings on my front differential as destroyed. I don't how or why but suspicious on a 72" front blower and subframe that was sold to me by a dealer. I've had it about 4 years now and every year when I install it I say to myself "boy is that thing heavy for this tractor". Not sure though.

Does anyone have a good source of used parts? I'm looking the entire front differential off the L3940.

Thank you for your assitance.

Garth
306.717.2975

 

[K5lwq]

That is unfortunate and somewhat unusual. I would want to see what everything looks like. If the case is good, one would think you could rebuild that one cheaper and easier than finding a complete unit used. Also, I can’t imagine every gear is damaged beyond use.

 

[GarthH]

I agree. I might need to see it myself. I'm told that almost everything is damaged. On on side I'm told the knuckle, I don't know what connects to it but he tells me that it is unusable. I will ask for pictures.

Of course each front wheel is seen from the cab. I noticed some leaking on the right one during the winter and on the left one just in January. There are no other leaks. When I had the left wheel lockup, I changed the gear lube, I don't know how much came out but maybe 2 qts.

I had a seal leak on the right side back about 5 years ago and had the dealer fix it. He had no negative comments just a seal leaking. Obviously he filled it with fluid at that time.

I didn't check it as there were no leaks prior to last fall and now the winter.

They tell me a gear broke and the pieces were being ground up inside the housing.

Kubota Parts only sell pieces for the diff not the entire thing. Do you know if they might sell the entire diff in "whole good". I have bought tires like that from them, parts price for the tire is quite high but sales can sell the tire and rim together at a much better price.

Good questions

 

[jonsstihl]

Sounds like you are looking for a complete axle assembly. just to get the terminology right. you can search for a tractor scrap yard. my guess is the damage is more isolated to the outer assemblies (bevel gear cases) but hopefully the ground up metal is only in the outer assemblies and didn't get into the center section differential. lots of parts to replace in those outer assemblies and I'm not sure if the castings are still available. the 40 series is starting to get old.

 

[hodge]

I would doubt that it's the weight of the blower. A loader and its uses would put more load on the front axle than a blower, and the majority of owners have/use a loader- without axle damage. I believe that the failure is due to something else.

 

[GarthH]

Some pictures

 

[loggin]

Some pictures

That looks like some pretty sever damage. Wonder if the axle was low on fluid for some time..??

 

[jonsstihl]

that looks bad. Sorry for your loss. I did notice when I changed my front axle oil that the level dropped quite a bit after just running it a little so it is important to check the fluid level fairly often and keep an eye out for leaks. I didn't see any broken housings in the pictures so a good cleaning out and replacing the gears and bearings should get you back up and running but it will be expensive. just compare the cost of fixing to the cost of a new tractor. If the rest of the tractor is in good shape I would fix it. you don't mention how many hours are on the tractor but a 40 series without regen is worth a couple bucks. It may be cheaper to find an axle assembly from a tractor scrap yard.

 

[truckdiagnostics]

https://media.spicerparts.com/cfs/files/media/oQLkxMPRdFt3y2a9W/AXSM-0020.pdf?token=eyJhdXRoVG9rZW4iOiIifQ%3D%3D&store=original

About page 21 starts the failure analysis part. you should be able to look at the failed parts and come up with pretty close to what happens. Fatigue, overloading and low oil all look different when they fail.

 

[masscity]

I have a L3540 with the 6 ft snowblower and subframe. I've had it for 12 winters now and up to 40 hrs of use per winter.

I have the oversized FEL with the 6 ft heavy duty bucket, which puts much more weight on the front axle.

So far no problems, I change the front axle oil with 75w-90 Mobil 1 syn every 400 hrs. My front seals are leaking a little, but I make sure my axle oil level is ok.

I think I have around 850 hrs now and will change the oil again when I take the subframe off.