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Bill725

Small BGB Gears NLA

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Bill725

According to the local dealer, the small BGB gears, used in the FDT's, are no longer in production, there are no parts in the warehouse and the only new ones are at dealers. From a previous post, we know both driven cross shafts are NLA. The input shaft used in the 700 & 725 models is NLA and I suspect later input shaft is next.

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Chris727

Good to know, but realistically we were probably lucky they were available as long as they were. I'm having trouble with parts for tractors less than 10 years old. 

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Brettw

I have a set with a small chip in one spline on one gear.  Was going to toss them some time back, but realized they were likely still a very serviceable set, and they weren't easy to find at the time.  Now they are like hens teeth. They might not be a set for long term heavy work load, (although I think they would prolly be fine)  but they will work for the garage queen or show tractor.

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Chris727

Seems like I run into more issues with the gears wearing on the inside where they contact the shaft and the woodruff keyway, than I do with the teeth themsevles wearing. Possibly inadequate torque or lack of loc-tite on the bolt during a previous reassembly. 

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wwbragg
9 hours ago, Brettw said:

I have a set with a small chip in one spline

Hit that chip with a spot of weld and file it smooth.  I did that with the tranny input shaft on my 65 Mustang when I was in college - - - ran fine.

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wwbragg
7 hours ago, Chris727 said:

gears wearing on the inside where they contact the shaft

Ream out the bearing and insert a bushing.  All things are possible to him that believeth (or has access to a good machinist).

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Tom45

The problem I find (in gearboxes that have oil in them) is the keyways wallowing out along with some wear of the shaft / bore.  I have filed larger keys to fit worn keyways but that is not the best solution.  I also have the same problem in transmissions and axles.  The rear axle shafts are often cracked in one of the keyways.  

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Bill725
6 hours ago, wwbragg said:

Hit that chip with a spot of weld and file it smooth.

 

5 hours ago, wwbragg said:

Ream out the bearing and insert a bushing.

WWBragg,

Please provide address and I will send several BGBs for repairs.

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MrSteele

I had a problem with an input shaft last year. No new available from the parts stores, had one made and hardened. Bored the front of the BGB and had a hard bushing shrunk in for the needle to bear/wear on. Had an awful problem with a factory incorrectly cut input gear. I have another Landlord that I am going to rebuild the BGB with bearings and seals store away for posterity. The 23D off that one has been built and sits patiently waiting for a machine to be dropped into

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TimJr

BGB = Bevel Gear Box as used on the large frame garden tractors from the model 700 up through the last 18hp Sovereign.  It is the gearbox that sits just ahead of the seat.  Driveshaft from the engine powers the gearbox.  The RH output runs the trans drive belt and the LH output runs the mid/rear PTO.

Early tractors/FDT (foot dragger tractors) up through the 3300? series used a smaller diameter input shaft and different internal gears.  I didn't look it up, just going by memory that the 3300 still had the old style mid pto and early style BGB?

Later tractors with a cone clutch for the mid/rear PTO used a larger input shaft and matching gears.

I would consider the BGB a little bit of a weak spot, but no tractor is perfect.  As mentioned above, they have been know to chuck out the key/keyway for the cross shaft, wobble out the I.D. of the cross shaft gear along with wearing into the O.D. of the cross shaft.  If they get run low on oil, the input shaft front needle bearing will pretty quickly start eating into the input shaft.

If the RH trans drive pulley ends up coming loose at all, the cross shaft end play gets out of whack and will mess things up.

On the cone clutch tractors, the PTO clutch cover can come loose and will wobble out the key and/or the O.D. of the cross shaft.

I haven't seen actual gear failures, but have heard of them.  I think a lot of the failures are ones that were not maintained with good oil or if a pulley came loose, no one caught it until it was too late and damage done.

 

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MrSteele
On 2/12/2020 at 7:50 PM, TimJr said:

I haven't seen actual gear failures, but have heard of them.  I think a lot of the failures are ones that were not maintained with good oil or if a pulley came loose, no one caught it until it was too late and damage done.

Yep, mine came apart in about a minute, when the bolt came out of the gear retainer and let the driven gear walk away from the input gear. When it went back together, there was plenty of Loc-Tite on that bolt. Applied, ran the bolt in, immediately removed, reapplied, then installed and torqued the bolt. The second dose was to make certain the first dose covered all threads

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