Larger B series chassis/drivetrain the same?

[Verticaltrx]

After looking at a lot of these tractors I've begun to wonder how long Kubota has been using the same drivetrain and axles under its b-series tractors. I know the B3200 and B7800 use almost exactly the same drivetrain, but it really looks to me like the B2910, B3030, B21, B26, etc all use the same axles, rear housing, most of the transmission parts etc. Mostly just wondering out of curiosity, but also looking at possible parts interchangeability between the models, i.e. position control, etc.

Thanks for any info.

 

[Denwa]

After looking at a lot of these tractors I've begun to wonder how long Kubota has been using the same drivetrain and axles under its b-series tractors. I know the B3200 and B7800 use almost exactly the same drivetrain, but it really looks to me like the B2920, B3030, B21, B26, etc all use the same axles, rear housing, most of the transmission parts etc. Mostly just wondering out of curiosity, but also looking at possible parts interchangeability between the models, i.e. position control, etc.

Thanks for any info.

Me, I don't know, but will follow ur thread out of similar curiosity as I've got
a B20.

Also, I'd like to congratulate you on putting a question mark at the end of your post, as it is indeed a question. So many posts are questions masquerading as statements~ Sure helps to sort things out.

Standing by,
Dennis

 

[herringchoker]

Kubota's brochure of the day states that the B7800 "boasts the exact same powertrain, body, tires and implements as the B2910", the B7800 being the economy or standard version of the B2910. The B3030 replaced the B2910 and the B3200 replaces the B7800. I've not seen a B3200, but the B3030 is mechanically and frame-wise the same as the B2910/B7800, with some improvements (e.g. PTO clutch).

 

[Verticaltrx]

Thanks for the replies. Anyone know the drivetrain similarities between the B7800/B3200 and the B20/B21?

Its interesting to me how tractors that are basically identical strength wise have different ratings on the 3pt hitch and loader lift capacity. It seems like they decrease the lift capacities on the 'economy' models just as a selling point on the premium models.

 

[Verticaltrx]

I'm kinda surprised more of the Kubota guru's on here haven't chimed in on this. Regardless, I spent a couple hours with the parts manuals for a B2910, B7800, B3030, B3200, B21 and B26 and was surprised at how similar the 'Industrial' TLB's (B21/B26) are to the standard tractors.

The B21/B26 front axle is nearly identical to the B3030, and only differs from the B7800/B3200 by the center axle housing which has the mounts for the steering cylinder. Rear axles are the same throughout, rear diff are the same throughout, the HST is almost the same with only minor changes over the years.

What I was most interested in was the 3pt hitch cylinder/control assy. The B2910 and B7800 (B3200) use the same 3pt cylinder housing, and it looks as though the position control valve and associated linkages would swap over from the B2910 to the 7800/3200. I'm going to research this a bit more, and depending on the cost involved might try swapping position control over to my tractor once the warranty runs out.

I have always thought it was interesting on here how everyone says the B21/B26 is an 'Industrial' machine and will hold up better than the standard tractors under hard use. From what I have seen, the only thing that makes these tractors 'stronger' is the sturdier sub frame. The drivetrain is nearly identical.

 

[Ken45101]

I have always thought it was interesting on here how everyone says the B21/B26 is an 'Industrial' machine and will hold up better than the standard tractors under hard use. From what I have seen, the only thing that makes these tractors 'stronger' is the sturdier sub frame. The drivetrain is nearly identical.

Well a sturdier subframe would make a tremendous difference, IMO. The B21 is a relatively low power unit that is not going to tear itself apart. It quits working long before it's in danger of damaging itself (I have a B21 TLB). That's the beauty of hydraulics, the relief valves can be set to match the design capabilities.

I would also be cautious in looking at drawings, seeing similar dimensions and assuming equal strength. There could be stronger alloys or heat treating for the more powerful units.

Ken

 

[Verticaltrx]

Well a sturdier subframe would make a tremendous difference, IMO. The B21 is a relatively low power unit that is not going to tear itself apart. It quits working long before it's in danger of damaging itself (I have a B21 TLB). That's the beauty of hydraulics, the relief valves can be set to match the design capabilities.

I agree the sub frame makes an overall more rigid unit, but most of the failures I read about on here are over gear sets, ring and pinions, axles, diffs, etc.

I would also be cautious in looking at drawings, seeing similar dimensions and assuming equal strength. There could be stronger alloys or heat treating for the more powerful units.

I was comparing part number to part number, not drawings. :thumbsup:

 

[jim_wilson]

Sorry to resurrect an old thread - but did anybody ever figure out if the position control was in fact swappable into a B-series (like a B3200) - that comes with the 1/4 inching valve?

 

[art]

It is nearly the same back to the 2150.