B21 backhoe removal problem

wmarsden

New member

Equipment
B21
Oct 17, 2011
10
0
0
montreal, quebec
I'm trying to remove the backhoe on my B21. Problem is one of the two mounting levers appears to have seized. A hammer, lots of WD40 and a pipe extension lever will not budge the son-of-a-gun. I have not tried a blow torch, which strikes me as potentially dangerous. Does anybody out there have any suggestions. (Need to remove it so i can put chains on the back wheels before winter.) Haven't removed backhoe for ages. The other mounting level was also stuck but a few wacks with the hammer fixed the problem.
 

Teese

Member

Equipment
B20
Jul 19, 2013
39
1
8
Lynden, WA
You poor thing ... I had the same problem on my B20 ... the BH had NEVER been off until I dismounted it last year. Liberal doses of heat (I only have a propane torch), PB Blaster (um, while warm not at the same time as flame!) and a $20 Harbor Freight air chisel (with the blade cut off leaving a stub end) rat-a-tating on one end finally got the shaft to budge 1/16" in one direction. Incrementally inching it back and forth finally got it moving and ultimately sliding smoothly. I got the smell of the Blaster off me 3 weeks later.
 

Lil Foot

Well-known member
Lifetime Member

Equipment
1979 B7100DT Gear, Nissan Hanix N150-2 Excavator
May 19, 2011
7,259
2,200
113
Peoria, AZ
How about a pic of the offending mechanism? My first thought was to ditch the WD-40 & use PB Blaster.
I don't know if it would work for your situation, but I've recently had good luck with the "captain candle wax" method, heating the part & then melting parafin into the joint.
 

100 td

Active member

Equipment
B21TLB (B21, TL421 & BT751) Toyota SDK4 T116 Bobcat
Aug 29, 2015
1,776
8
38
ɹǝpunuʍop
I bought my B21 from a chicken farm, everything was seized solid with powdered chicken shit in every nook and cranny, corroding all the backhoe quick connections.
Although the lever may be seized, the pin wont be, so you can drive the roll pin out to allow the pin to slide out.
The other thing is to remove the spring on the hitch jaws and undo the bolts and remove the plate and then the jaws and then remove the hoe then get better access to it to start to move it. My jaws were frozen solid, as well as the lever, but the sliding pin can not seize up realistically. I used WD40 on the lever back and forwards after removing pin, and ended up getting it off, then emery taped shaft and centre and put it back with grease and slides beautifully. The jaws took about half hour of belting back and forwards with wedges behind to get off. Now all greased, hoe goes on and off in a flash. (One lever is bent compared to the other from belting it to unseize it!)
 
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wmarsden

New member

Equipment
B21
Oct 17, 2011
10
0
0
montreal, quebec
You poor thing ... I had the same problem on my B20 ... the BH had NEVER been off until I dismounted it last year. Liberal doses of heat (I only have a propane torch), PB Blaster (um, while warm not at the same time as flame!) and a $20 Harbor Freight air chisel (with the blade cut off leaving a stub end) rat-a-tating on one end finally got the shaft to budge 1/16" in one direction. Incrementally inching it back and forth finally got it moving and ultimately sliding smoothly. I got the smell of the Blaster off me 3 weeks later.
Thanks Teese for your suggestions. Never used BP Blaster but will give it a go. One question: when you used the torch, did it destroy the paint? Also, did you concentrate the flame on any particular area of the lever cylinder? Did you get the part red hot?
 

wmarsden

New member

Equipment
B21
Oct 17, 2011
10
0
0
montreal, quebec
I bought my B21 from a chicken farm, everything was seized solid with powdered chicken shit in every nook and cranny, corroding all the backhoe quick connections.
Although the lever may be seized, the pin wont be, so you can drive the roll pin out to allow the pin to slide out.
The other thing is to remove the spring on the hitch jaws and undo the bolts and remove the plate and then the jaws and then remove the hoe then get better access to it to start to move it. My jaws were frozen solid, as well as the lever, but the sliding pin can not seize up realistically. I used WD40 on the lever back and forwards after removing pin, and ended up getting it off, then emery taped shaft and centre and put it back with grease and slides beautifully. The jaws took about half hour of belting back and forwards with wedges behind to get off. Now all greased, hoe goes on and off in a flash. (One lever is bent compared to the other from belting it to unseize it!)
Thanks to everyone for your replies. 100 TD, i have one question. When you talk about the pin and the roll pin are you referring to the solid metal shaft encased in the spring that the lever has to force out of its pocket?
 

100 td

Active member

Equipment
B21TLB (B21, TL421 & BT751) Toyota SDK4 T116 Bobcat
Aug 29, 2015
1,776
8
38
ɹǝpunuʍop
Thanks to everyone for your replies. 100 TD, i have one question. When you talk about the pin and the roll pin are you referring to the solid metal shaft encased in the spring that the lever has to force out of its pocket?
Yes.
But realistically I think it would be quicker and easier to just remove the 2 bolts holding the plate on which holds the quick hitch pawls(jaws), and remove them and take the hoe off and then work on getting the leavers free after pulling the circlips and then clean the shaft up and grease it.

Something to check as you may have forgotten (since it's so long since removing the hoe), make sure you have taken the load off the hoe quick hitch before trying to release the leavers, as the pin will have load on it. So push out the dipper a little and then boom down to lift the rear of the tractor "slightly" then try to release the leavers, as this will take the load off the pin before trying to mover the levers.
If no good, then remove the plate and jaws as per above.
You will need the load off the jaws to do this as well.
Don't forget about safety, and the possibility of the movement/pushing/pulling/falling of components and complete backhoe when doing this.
 
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Teese

Member

Equipment
B20
Jul 19, 2013
39
1
8
Lynden, WA
Just to be clear ... on my B20 the BH's beveled retention pins (the combination of beveling and a pushing spring would appear to prevent any play between the tractor-mounted pegs and the BH's pin cradles) were frozen in place and the cam levers that slide them were free (at least they were ready and willing to do their assigned tasks). The stubborn retention pins slide in a 2" long bushing, and that's a lot of metal-to-metal contact just inviting corrosion; it's difficult to understand why these bushings never deserved a grease zerk.
The propane torch generated insufficient heat to get things red hot, and I'm not even sure the paint succumbed to what heat I did have. One thing I did was to wrap thin strips of cloth on the pin at the edge of the bushing and soaked them with PB Blaster ... I like to think that the cooling parts enhanced the wicking action that drew the ready supply of PB Blaster further into the bushing.
 

100 td

Active member

Equipment
B21TLB (B21, TL421 & BT751) Toyota SDK4 T116 Bobcat
Aug 29, 2015
1,776
8
38
ɹǝpunuʍop
Hi Teese,
Not sure if they changed the design from the 20 to the 21, but on my 21 the pins only slide thru a 3/8 plate, not thru a tube. The other thing is that there is load on the other end of the pin (square metal block) from the jaws of the hitch, and I'm hoping that wmarsden has forgotten to unload this when trying to remove the hoe. The problem with mine was that I couldn't move the levers because the lever pivot tube was frozen solid. No zerk on them either, but the pin had no restriction to moving.
 
Last edited:

Teese

Member

Equipment
B20
Jul 19, 2013
39
1
8
Lynden, WA
100 td
That would explain a lot ... I was thinking the hoes were identical and we were on different planets. Mine is a BT750. To the rear the pin merely passes through a hole in a plate, but to the front near the cradle & peg it passes through the bushing I mentioned. I've [tried to] attach a page from my WSM with an arrow pointing to the offending bushing.
 

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100 td

Active member

Equipment
B21TLB (B21, TL421 & BT751) Toyota SDK4 T116 Bobcat
Aug 29, 2015
1,776
8
38
ɹǝpunuʍop
Hi Teese,
Mate, I could be flying under the radar, so I could be on a whole different wavelength!
The offending item is the lever (150) which rotates around it's pin (3/4 the way up the red line to the plate). Mine was locked solid. This lever pushes on the roll pin (090), which protrudes each side of the lock/release pin (060 PIN SET). The lock/release pin is only captured in the hole in the 3/8 plate and the opposite end, with the thick square plate, just floats in-between the main frame and the plate with 2 bolts (100 COMP PLATE HOLDER). IIRC, the square block (not tapered) doesn't wedge tightly between the pawls (030 HOLDER MOUNT), it just stops them from opening, but does get pressure on it by the weight of the hoe pushing against the pawls. The locking/release pin (PIN SET) could be slid out of the way if the roll pin is pulled out, I think I belted mine thru a bit to loosen, then wedged it back with a screw driver to have some protruding to get a pair of visegrips on to remove.
One other thing I just noticed, mine doesn't have the locking pin (080) thru the main pin (060 PIN SET).
If wmarsden does have this locking pin, he would have to remove it first to be able to move the lever! So I'm guessing either he hasn't taken the load off by lifting the rear of the machine, or he still has the locking pin in, or it's frozen solid with chook shit!
Parts list here http://www.kubotabooks.com/AutoIndex/index.php?dir=Backhoes/&file=BT751 Backhoe.pdf
 

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wmarsden

New member

Equipment
B21
Oct 17, 2011
10
0
0
montreal, quebec
Thanks again. Much appreciated.
I had dipped the boom to take the load off the quick hitch. It was the first thing I did. (The other mounting level slides perfectly.) So the load is not a problem. I soaked the stuck lever mounting tube (bushing affair) with PB Blaster and later doused it with boiling hot water but to no avail. I'm going to try a blow torch. If that doesn't work, I will have to remove the plates, as you suggested. I'm pretty sure that my problem is the same as yours, a frozen mounting lever tube (or bushing). And you are right, it should have had a grease zerk. I think that's a design flaw.
I take it that the two screws you are talking about are the two large ones on each side of the spring? When I remove them, what can I expect to happen? I don't want any negative surprises.
 

100 td

Active member

Equipment
B21TLB (B21, TL421 & BT751) Toyota SDK4 T116 Bobcat
Aug 29, 2015
1,776
8
38
ɹǝpunuʍop
If wmarsden does have this locking pin, he would have to remove it first to be able to move the lever! So I'm guessing either he hasn't taken the load off by lifting the rear of the machine, or he still has the locking pin in, or it's frozen solid with chook shit!
Thanks again. Much appreciated.
I had dipped the boom to take the load off the quick hitch. I'm pretty sure that my problem is the same as yours, a frozen mounting lever tube (or bushing). And you are right, it should have had a grease zerk. I think that's a design flaw.
Right, so chook shit it is!

I take it that the two screws you are talking about are the two large ones on each side of the spring? When I remove them, what can I expect to happen? I don't want any negative surprises.
No surprises, the hitch is made up of very few parts, nothing to fly out or be lost. The 2 small bolts with the spring between them simply hold the jaws open when off, the jaws are held in by the plate with 2 big bolts. I just went and had a look at mine, I'm not sure if there is enough room for the plate to slip off in-situ or not, you would have to try, only 4 bolts to undo, give it a go. Otherwise pull the roll pin out of the locking pin and push it rearwards, then take the hoe off.
Once the lever shaft and tube are cleaned then greased, I doubt it would ever seize again, I expect they left the factory dry, or with only a little oil on them. Once greased, I doubt anything could overcome/push the grease out and reduce the lubrication enough to seize it again in the next 10 years!
 
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wmarsden

New member

Equipment
B21
Oct 17, 2011
10
0
0
montreal, quebec
Sorry i took so long to get back to your guys. I finally used a blow torch to heat the lever cylinder and an extension of pipe to work the lever. Although it took some time, it did the trick. Now to install a grease zerk.
 

100 td

Active member

Equipment
B21TLB (B21, TL421 & BT751) Toyota SDK4 T116 Bobcat
Aug 29, 2015
1,776
8
38
ɹǝpunuʍop
Once the lever shaft and tube are cleaned then greased, I doubt it would ever seize again, I expect they left the factory dry, or with only a little oil on them. Once greased, I doubt anything could overcome/push the grease out and reduce the lubrication enough to seize it again in the next 10 years!
I wouldn't worry about a zerk if you pull the circlip and emery tape the pin and tube.
 

ath42

New member

Equipment
B21
Jan 13, 2020
2
1
3
Lancaster PA
Resurrecting an old thread to add my experience for any future searchers of the internet.
I had the same issue with a B21/BT751 that I bought. Tried a big cheater pipe but that just bent the handle (150). Soaked it in PB Blaster, WD40, ATF+acetone (not all at the same time :), didn't help. Tried heat (though I only have a little plumbing propane torch) without result.
I did manage to get the roll pin (090) out, but that didn't help because the "ears" on the handle (150) keep the pin (060) from moving because the big square piece on the end of the pin hits the ears. Doh.
I ended up just sawing the ears off the handle. Sawzall on the outer ear and air chisel on the inner one (couldn't reach it with the sawzall). So I have destroyed the handle, but now I can get the backhoe on/off by moving the pin (060) with a screwdriver. If I am ever so motivated, I will try to chisel the handle completely off and replace it.
 
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L35

Active member

Equipment
L35/TL720/BT900/York rake/Valby chipper
Jun 13, 2010
403
232
43
CT
I went through this when I got my L35, (same mechanism). I don’t think the the backhoe ever came off. I got it at 10 years old. Fought it tooth and nail finally got them free took them all apart sanded them and lubed them and they have been smooth as butter since.