Adding PTO to 420U--Help!

So I have a few questions:
It's got a 5 speed trans, appears to take the shaft for a continuous running pto and the tractor SN is 132115.

What do I tell the guys at the salvage yards when I ask about availability? Should they be able to get me the right one with the info above, or is more info needed?

Is adding a PTO as simple as I thought it should be if I can find the right part? Am I going to need a lot more stuff than a shaft & shield?

Please help me out on this.

Dick Scott

The tractor does have the engaging lever & when I move it I can feel and hear a little "clunk" like it is engaging something. Also, a salvage guy sold me a PTO from a JD 40, thinking it would fit and when I slid it in, it felt like it engaged some gears. Unfortunately, the shaft was too long to bolt into place & I had to take it back.

Also, the operator's manual says "When using equipment which requires the standard power shaft (560 rpm), the lower cover can be removed from the transmission case and the standard power shaft attachment installed. This attachment (optional equipment)..." There is also an upper cover for a high speed drive.

So as I see it, if I had the right shaft, it should work, unless I am missing something else here, since I know little about tractors.

So, how do I know for sure, which shaft it should take?

Can I put any faith in the fact that the case or housing behind the clutch housing matches exactly the one shown in both the shop manual and the operator's manual as the one for the live PTO? The clutch pedal matches as well, while both are different for the non-live PTO. Steamer suggests I can't, but I didn't tell you guys all the particulars, such as the engaging lever being present.

Can a person tell when looking at a PTO shaft on the shelf whether it is for a live or non-live setup?

What else do I have to know?

I appreciate the answers you guys have given so far--I see I should have given you more info.

Dick Scott

Now, you can tell if you happen to have a live PTO setup before you get the output shaft. Run the tractor forward and depress the clutch just far enough to lose drive power to the wheels. While holding the clutch pedal in this position, move the PTO engagement lever. If you hear and feel some gears clashing, you have live PTO. If it goes in, or hangs up going in, without hearing a lot of clashing, you do not have live PTO.

The live PTO works by allowing the inner clutch to disengage (pedal 1/2 way down) the drive to the transmission input shaft (and to the rear wheels if it's in gear) without losing power to the PTO shaft. If you put the pedal the rest of the way down, you'll disengage the outer clutch and shaft and lose power to the PTO along with power to the wheels.

Non-live PTO only has one clutch and shaft, so when you lose power to the wheels, you also lose power to the PTO. This is why the test I described eariler will tell you which PTO you have. I suspect that it isn't live, since that was a special order option on most sub models (which you didn't mention, so I'm presuming it's a standard). As far as I can recall, only the Row-Crop Utility (W sub model) came with the live PTO as standard.

Also, if you have a direction reverser option, you can't have live PTO. The reverser replaced the center frame with a mechanism that allows reverse travel in any forward gear by selecting forward or reverse rotation of the transmission input shaft. This means that there was no room for a second clutch and power shaft for a live PTO. It also means that the PTO direction would reverse whenever the machine was backing up!

I mention this option because 420/430/440 machines that had the reverser installed were shipped with the PTO output missing due to the thought that these machines would be used with loaders or dozers and not to power PTO implements. I always thought it was really due to that reversing PTO shaft feature. If you have a reverser, you really need to know about this before you find out the hard way!

My 420C crawler/dozer has a reverser on it and I have to disengage the PTO lever prior to backing it up when I'm using the bush hog on it (or I'll make a mess out of the bush hog gearbox and maybe my reverser internals!).

Thanks for the comprehensive & informative reply. Now all I have to do is finish my 12 volt conversion so I can get it running & try your test. You provided just the info I need.

Thanks again.

Dick Scott

Here's a radical idea that may be more practical. Instead of changing the entire transmission and clutch, why not couple a 10 or 15 gpm hydraulic pump to the crankshaft of the engine, then run the PTO implements with hydraulic power. With a reservoir and a valve or two you can have live hydraulics and live PTO and no PTO shaft to mangle or get tangled in.

Gerald J.

In this case, what you'll get is the standard (non-live) PTO drive, which is geared off the main input shaft. If you have the engagement lever in place on the top of the transmission case near the shift lever, you'll have all the internal PTO driveline installed inside the main housing. Now, all you need is the PTO output shaft assembly for the 5-speed that goes in place of that cover you're looking at.

Most machines were built with the PTO drive parts, so that the dealer could add the PTO later. But this was not always true. Sometimes a 'fleet order' would come in for several hundred tractors for a large customer with specific use for the tractor (i.e. The US Air Force used them to push and pull jet planes around an airbase). Many times these would be contracted to leave out or add on specific items. It is possible to find 5-speed transmissions without any PTO drive at all for this reason.

How to tell? If you don't have the PTO engagement lever on the main tranny housing, then you're missing all the internal driveline parts for the PTO along with the output part you already know you don't have. This would mean tearing apart the machine and replacing the transmission (or adding in the missing bits) to get a PTO..... .