B7100 PTO Repair

[Christianbenzon1]

Hi there,
New to the page.
I’ve got a 1979 B7100 geared tractor that I’ve had a couple years.
PTO does not work and the guy I bought it from had opened tractor up and found the one-way clutch broken.
He removed the broken parts and put back together.

I’ve now split the tractor and ordered a one way clutch (H6670-14380) off Ebay.

My tractor has 18 splines on the transmission side and 28 splines on the PTO shaft side.

The part sent to me has 28 splines on both sides of the one-way clutch.

Am I missing something? Did I get the wrong part?
When I split tractor there was a broken piece remaining that has clearly been worked on. I can’t figure out what it is and it doesn’t show in the service manual.
Some sort of adaptor from 28 to 18 spline that’s been broken?

 

[JosephGozo]

may i suggest contacting these guys? They have plenty of stock for both grey and regular compact tractors even older models.. I have dealt with them twice in the past.

https://www.trakter.com/ (greece)
https://www.stavros-savva-co-ltd.com.cy/ (Cyrus)

cannot help much with the splines. Mine is a b7100 which comes without the overrun clutch you speak of. (i wish it had it!) but i installed a slip clutch on the output end so it should prevent damage.

Joseph

 

[Christianbenzon1]

What year is your B7100? It seems there may be a serial number split.
I’m wondering if my tractor also doesn’t have a clutch. Maybe the broken part is some sort of coupler from 18 spline to 28?

Have you opened yours up?

may i suggest contacting these guys? They have plenty of stock for both grey and regular compact tractors even older models.. I have dealt with them twice in the past.

https://www.trakter.com/ (greece)
https://www.stavros-savva-co-ltd.com.cy/ (Cyrus)

cannot help much with the splines. Mine is a b7100 which comes without the overrun clutch you speak of. (i wish it had it!) but i installed a slip clutch on the output end so it should prevent damage.

Joseph

 

[Big Kahuna]

I believe you need 66706-14380 also 66611-14370 Boss spline. Kubota was having failures with their splines and started making adapters for the earlier models, I think pre 1980, don't hold me to it. I have a b6100 with a crank adapter to run the new style front pto clutch, the finer splines of the early models just did not hold up. I good dealer should be able to help you.

 

[Christianbenzon1]

That

I believe you need 66706-14380 also 66611-14370 Boss spline. Kubota was having failures with their splines and started making adapters for the earlier models, I think pre 1980, don't hold me to it. I have a b6100 with a crank adapter to run the new style front pto clutch, the finer splines of the early models just did not hold up. I good dealer should be able to help you.

That is great information. The boss spline is some sort of adaptor then? Are there reliability issues with this or is this to correct that?

 

[Big Kahuna]

It was a correction of there problem, you should be good to go once you get the right parts. It was put back together without repairing I would say no one knew what was going on at the time. Dealers 40 years is what made Kubota. They could turn around, pick a part off the shelf and you were good to go.

 

[Deuce]

How difficult would you say this task has been thus far? I have a '77 B7100 that also doesn't have the factory over run clutch (think it is before they installed them) and have been considering installing it when I do a light overhaul this spring (going to replace the rear axle shafts anyway)

 

[Christianbenzon1]

It was a correction of there problem, you should be good to go once you get the right parts. It was put back together without repairing I would say no one knew what was going on at the time. Dealers 40 years is what made Kubota. They could turn around, pick a part off the shelf and you were good to go.

My serial number is B7001-61783, does this change anything.
Will the boss spline still adapt the clutch to fit?
I appreciate your help, I’ll head to the local dealer tomorrow to see if they can locate parts.

 

[Christianbenzon1]

How difficult would you say this task has been thus far? I have a '77 B7100 that also doesn't have the factory over run clutch (think it is before they installed them) and have been considering installing it when I do a light overhaul this spring (going to replace the rear axle shafts anyway)

It’s been doable, I’d assume I’m 4 hours to get it torn down to this point. I am no master mechanic so take that into account if you can do it faster than I did.

 

[North Idaho Wolfman]

Based on the serial number you gave you shouldn't have needed the boss spline, but odder things have happened with these.
And you never know what the past owners have done to it.
More picture of that parts you have might help sort it out.

 

[North Idaho Wolfman]

Looked into it deeper, it appears that you have an older style output shaft than didn't have a one way clutch, and that has a different spline count than the newer shafts.

I think this is the shaft you need:

OEM 66706-14310 Original Gearbox Shaft 3th B7100, B6100 | Stavros Savva & Son Ltd

OEM 66706-14310 Original Gearbox Shaft 3th - Suitable for Kubota Tractor Models B7100, B6100

www.stavros-savva-co-ltd.com.cy

I take it the PTO shaft was not connected at all right now?

 

[Christianbenzon1]

Looked into it deeper, it appears that you have an older style output shaft than didn't have a one way clutch, and that has a different spline count than the newer shafts.

I think this is the shaft you need:

OEM 66706-14310 Original Gearbox Shaft 3th B7100, B6100 | Stavros Savva & Son Ltd

OEM 66706-14310 Original Gearbox Shaft 3th - Suitable for Kubota Tractor Models B7100, B6100

www.stavros-savva-co-ltd.com.cy

I take it the PTO shaft was not connected at all right now?

Correct, my PTO shaft was not hooked up.
The PTO would spin from the friction of touching the end of the 3rd shaft but if you grabbed it with your hand it would immediately stop spinning.
How would it have originally been hooked up with the 18splines on the 3rd shaft and the 28splines on the PTO shaft?
The 3rd shaft that is in my tractor has a snap ring on it to keep the one way clutch from going on too far.
I can’t find diagrams showing this.
Has my 3rd shaft maybe been replaced with something from a different tractor?

 

[Deuce]

Looked into it deeper, it appears that you have an older style output shaft than didn't have a one way clutch, and that has a different spline count than the newer shafts.

I'm pretty sure I'm in the same boat parts wise with my '77 7100 which doesn't pass the tests for having a factory over run clutch.

How many parts and how deep (split tractor?) would it be to "upgrade" to a factory over run setup? I know it's not cost effective but I'm never parting with it...

 

[JosephGozo]

I am not sure what year is mine and it is a B7001 sorry*.

I did open the box several times. last year i tore a tooth off the 1st PTO gear when tilling and catching a tree stump. (taking it out required a full strip) but the pto shaft job is easy through the rear plate (don't mess with this shims). I also did try adjust them due to new bearings and cracked gearbox case at the dowel hole .

Mine has a splined bush that connects the two shafts. I think since it is spring loaded and has sliding parts you would need a different layshaft to drive the PTO. As indicated above.

I installed this slip clutch on mine. cost me 90(Euros of british pounds). I had to shorted all the shafts as i did not wish to extend the length of the 3point hitch arms. Tractor is a tight fit on the trailer with certain implements.

I thought a slip clutch is better but needs to be checked and torqued to prevent it rusting solid. the over run clutch in the box is ideal when using things like a drum mower which keeps driving your tractor. I got used to quickly depressing the clutch and putting the PTO on neutral when mowing and if i need to move without the mower working. The over run clutch in the box in the case of implement lock up (tiller catching a stone it is of not much help. (if i am correct)

PS and i am pretty sure that over run adaptor clutches can be bought and added to the PTO shaft end. (might be cheaper ?)

 

[Christianbenzon1]

I believe I’ve solved my conundrum....

Tractor did not originally have one way clutch (H6670-14380). It instead had the 66611-14370 Boss Spline.

Original Boss Spline and original PTO shaft 66611-1451-5 would have failed/broken on previous owner.

I assume previous owner ordered updated PTO shaft 5 66706-14510 that has the 28 splines instead of the original shaft 5 66611-14515 that has 18 splines.

He then split tractor and found shaft 3 66611-14310 has 18 splines and his new shaft 5 had 28 splines and put it back together.

To have a working PTO:
-I can either order boss spline and a 18 spline shaft 5 and have a working PTO but no clutch
-Or.... purchase shaft 3 66706-14310 with 28 splines and upgrade to clutch.

I hope this detail helps someone in the future.

 

[Christianbenzon1]

Image

 

[Christianbenzon1]

Looked into it deeper, it appears that you have an older style output shaft than didn't have a one way clutch, and that has a different spline count than the newer shafts.

I think this is the shaft you need:

OEM 66706-14310 Original Gearbox Shaft 3th B7100, B6100 | Stavros Savva & Son Ltd

OEM 66706-14310 Original Gearbox Shaft 3th - Suitable for Kubota Tractor Models B7100, B6100

www.stavros-savva-co-ltd.com.cy

I take it the PTO shaft was not connected at all right now?

I got this 3rd shaft picked up from my dealer today.
Do you know if I need to pull 1st and 2nd shafts to swap? Or am I able to sneak 3rd shaft out by itself?

 

[North Idaho Wolfman]

Yikes, it's been a long time since I was in one of those.
I've worked on a bunch of HST buy only a handful of geared.
I'm sorry I can't remember the sequence off the top of my head.
If you get into it and get stuck ask specifics and maybe my tired brain will remember.