b7100 4x4 problem

[badbowtie]

I have a older b7100 4x4 that is gear drive and I was out moving snow yesterday for acouple hours. I was in high side using 4th and reverese in high side. I want to back up one time and it made a weird noise from the front end. I clutched it real quick and just went forward instead. I made one more push forward about 400 feet to the pile and went to back up and it did it again. Like a popping noise if you back up and you can watch the front tire jurk like at a certain spot during the revolution. I tried reverse in low side and same thing. I had one more push and know it is doing it in forward also in low side and high side. If I put it in 2wd it will not do it at all but 2wd is pretty much usless around here I always have to use 4wd. I need to see what you guys think happened so I can start to tear something apart and see what I did.

 

[Thomas]

Can you grib the drive shaft see if theres play...turn also push/pull.

 

[carpenter383]

If it's just one front tire that "jerks" It sounds like it may be a bad u-joint at that wheel.

 

[badbowtie]

I will check the driveshaft in about a hour but I just moved and it and it is also doing it in 2wd so I guessing that it would have to be something like a ujoint. I think it is only the right wheel sitting in the seat. Is their a way to check for a bad u-joint but what is weird is I set the front end loader on the ground and raised the front wheels and they seem to spin fine.

 

[badbowtie]

It really doesn't look like there are u joints, it looks like knuckles. With the front tires off the ground, I removed the front drive shaft completely, and if you spin 1 wheel at a time, it is fine. If you spin both at the same time, it hits a real hard spot. If you hold 1 front wheel and spin the other, it will do the same thing with the hard spot. I marked the outside of the tire, and the hard spot is in the same spot. Any ideas from where to go from here?

 

[carpenter383]

It really doesn't look like there are u joints, it looks like knuckles. With the front tires off the ground, I removed the front drive shaft completely, and if you spin 1 wheel at a time, it is fine. If you spin both at the same time, it hits a real hard spot. If you hold 1 front wheel and spin the other, it will do the same thing with the hard spot. I marked the outside of the tire, and the hard spot is in the same spot. Any ideas from where to go from here?

Did you try this on both sides? If so it sounds to me like the problem is either the teeth on the ring and pinion or the bearings that support the pinion and or the carrier
If you reach down and grab the end of the pinion where the front driveshaft bolts to does it have any slop in it?
Does the front axle leak oil?

When you spin one wheel at a time (with both off the ground) it's just turning the spider gears, the other side should spin in the opposite direction. when you hold one wheel or turn them both in the same direction you're turning the whole carrier/ring gear and pinion.

 

[badbowtie]

Yes is it does it on both sides the same. Correct about spinning one and not holding the other side. Were the drive shaft slips in and the boot goes over the housing that holds the tube the splined shaft is in. That piece that is in the the housing that is splinned in side is loose it has about a quarter inch play all around. So It looks like I can maybe unbolt it their and see what I have.

 

[badbowtie]

Nevermind about the spot where the drive shaft goes in about being loose, I took the 3 bolts out and there is a universal in there. I removed the universal off the spline, which I would the pinion, that bearing is not loose. It seems like the clunk is worse when you are spinning the tires in reverse than forward. I guess next it to pull the front light cotter pin that is on the pivot bolt, but how do you get that bolt out to get the front end to be sitting on the work bench. Just looking for a quick how to get the front differential out.

 

[carpenter383]

Are you talking about removing the whole front axle or just the center section?
I don't have any experience with your particular tractor, so I can't give you an accurate answer about removing the pivot pin. BFH? LOL
It sounds like you're gonna need a service manual because you need to know torque specs, proper shimming methods, etc.

 

[BotaBigot]

From your description, sounds like ring/pinion gear, or possibly carrier bearing. Based on what you were doing when it started, my money's on ring/pinion. Had similar experience with a B6000 pushing FEL into spoils pile. Chipped ring gear...

You'll need a shop manual and maybe a used parts source...

 

[badbowtie]

I have a manual around some were with torque specs but it is not the easiest to read I will try to find it tonight. I just looked and found the part number for the ring and pinion and it is like 329.00 I will have to find a good place to find used parts. It looks like the 7 inches of snow coming will have to melt on its own I can't move it. I am going to remove the front end tonight and tare it apart to see what I got for sure. I hope for a bearing or something cheaper but I will see.

 

[NIdaho]

If you are looking for some parts for B7100D 4x4. Check this Craig's List ad -- Kubota B7100 4x4 Parts Tractor
The manual transmission went out on me and I decided it was time to upgrade. This guy bought the tractor from me with the intent of fixing it up (he is a diesel mechanic) but it sounds like the cost of the parts was too much.

Engine ran great, almost new tires on the fronts. new seat

I would still be using it if the tranny hadn't of bitten the dust. But then again, I sure love my B3200 !!

 

[badbowtie]

Okay I pulled the front apart tonight and need a new pinion and ring gear. Like you guys said everything else is good I will have to call that guy tomorrow and ask what he wants for them. I am also trying to find anywere else I can get them cheaper than 329.00

 

[BotaBigot]

Rather than looking for a ring and pinion, which you will have to set up, think about a complete used front axle...bolt in and go...

Do a search here and "google" for used (Kubota) parts.

 

[badbowtie]

I thought about that to but did not remove the whole thing. I guess I have to pull the motor up so I can pull the pin to drop it down. I just looked at a part break down and looks like their is not different shims. So do you not have backlash like you do on cars. Am I missing something or do I have to lift the motor to pull that pin out.

 

[carpenter383]

I'm guessing b7100's all used the same gear ratio, but you should still check and make sure your replacment gears are the same ratio. Just count the teeth on the ring gear and divide by the number of teeth on the pinion gear.
If you go with a used axle you can check the ratio by holding one front wheel and turning the other exactly two revolutions while counting how many times the pinion gear turns.
If you change the ring and pinion, when setting the backlash on your new gears start with the origional shim from the old pinion gear. The one between the pressed on bearing and the pinion gear, this will normally get you real close on pinion depth, then you just have to worry about shimming the carrier and setting pinion bearing preload.
You can take the old pinion bearing and hone the center out so you don't have to press it on and off incase you need to change the shim. Then after you find the correct shim (likley the origional from the old pinion) use it and press the new bearing on the pinion.
Hopefully I didn't confuse you too bad Good luck!

 

[BotaBigot]

Still have my old B6000 manual, and YES there are backlash settings...now, having said that, my instinct tells me that since tractors are low-tech low-speed machines, settings likely aren't as critical as road vehicles.

Don't know how axle held in for 7100, but on 6000, there was a pivot pin with a hairpin lock on backside which allowed you to drop complete axle.

Oh yes...Western Kentucky Salvage was where I got my ring and pinion...

 

[badbowtie]

Okay I have the pin and the nut off and then the pin would have to drive out towards the rear but it only moves about .5 inches and then hits the oil pan.

 

[carpenter383]

Still have my old B6000 manual, and YES there are backlash settings...now, having said that, my instinct tells me that since tractors are low-tech low-speed machines, settings likely aren't as critical as road vehicles.

Don't know how axle held in for 7100, but on 6000, there was a pivot pin with a hairpin lock on backside which allowed you to drop complete axle.

Oh yes...Western Kentucky Salvage was where I got my ring and pinion...

I agree backlash setting would be less critical with a low speed tractor ring and pinion.

 

[carpenter383]

Okay I have the pin and the nut off and then the pin would have to drive out towards the rear but it only moves about .5 inches and then hits the oil pan.

That sucks So you gotta take the oil pan off to remove the axle?