D-14 Tranny Overhaul

[onetotaltoolman]

Nearing the end of a D14 complete overhaul. Last to-do's are a leaking PTO lever O-ring, which predicated the removal of the tranny housing.
At first glance, the gears, to me, looked ok. However, after a close inspection, looks like I'm not so lucky. The engagement teeth of the infamous 3rd. gear on the pinion shaft are pretty torn up. AGCO parts book says to replace that gear and the reverse gear located next to it as a set. Crap - $450.00 for the pair. Let this be a lesson to those who think the A/C's have automatic transmissions. My question is this - I'm not a tranny guy. Once i start to pull the gears out for the replacements to go back in, is there anything else i should auto replace while the tranny is off of the machine. I've replaced about every seal on the tractor, so i'd just as soon do it that way and 50 years from now let someone else do the same thing again. Thanks for tips.

 

[DrAllis]

Don't do ANYTHING until you KNOW it jumps out of third gear going downhill with a push behind it. You haven't even driven it to know, right ??? That's all I'm going to say.

 

[onetotaltoolman]

no, i have started it (once) after a ton of engine work. This is a perplexing deal. Pulling the tranny requires some work-hours, and i am already pulling it now to replace that darn pto lever o-ring. Both PTO seals were completely shot, and i'm hauling the pto shaft to the machine shop to fill in the grooves formed by years of turing in the seal itself. There is no question, after close exam that the 3rd. gear (pinion shaft) engagement teeth are chewed up and rounded off. The agco book now says to replace the pinion gear with a new reverse gear mated up next to it. My luck is usually no luck, (unless counting my beautiful wife and 5 kids!)so if i put this entire thing back together, seal it up to roll, drop the clutch and see if it skips, then i'm back to tearing down again. I heed your advice on everything, but in this example, i'm budgeting the parts against the time and additional labor to make this thing ready.

 

[DrAllis]

(quoted from post at 05:33:29 07/21/23) no, i have started it (once) after a ton of engine work. This is a perplexing deal. Pulling the tranny requires some work-hours, and i am already pulling it now to replace that darn pto lever o-ring. Both PTO seals were completely shot, and i'm hauling the pto shaft to the machine shop to fill in the grooves formed by years of turing in the seal itself. There is no question, after close exam that the 3rd. gear (pinion shaft) engagement teeth are chewed up and rounded off. The agco book now says to replace the pinion gear with a new reverse gear mated up next to it. My luck is usually no luck, (unless counting my beautiful wife and 5 kids!)so if i put this entire thing back together, seal it up to roll, drop the clutch and see if it skips, then i'm back to tearing down again. I heed your advice on everything, but in this example, i'm budgeting the parts against the time and additional labor to make this thing ready.

Dumping the clutch proves nothing. The jumpout situation is always a downhill PUSH. Third gear isn't the only gear in the transmission. Don't know how you intend to use it, but second gear does a lot of things.

 

[rustred]

looks pretty darn good to me them gears. thats what happens when your grinding gears instead of giving it 2 seconds before u shift. them gears will out last you and the next guy, if yu dont grind em. as they say if u cant find em grind em, then rubber gears next year.

 

[4wdtom]

The gears look good because they don't engage and disengage. It is the sliding collars that connect the gears to the shaft to engage different gears. The CA is a constant mesh transmission which means all the gears stay engaged all the time for all the gears (except reverse which is the straight cut gears). The collars which slide with the shift forks have teeth or splines on the inside which engage the shaft they slide on and when the collar is half on the shaft and half on the gear it is slid to it will lock that gear to the shaft and transmit power. The gears just idle or turn on their shaft until engaged with the collars. It is these teeth on the inside of the collars and the teeth on the hub of the gears that wear from grinding them. A constant mesh transmission works this way as opposed to a sliding gear transmission in which the gears actually do slide and their teeth do have to engage and disengage and will wear from grinding. Dr. Allis is wish to say to try it before going to the trouble and expense to fix. There may not be a problem or you might find you can live with it.

 

[onetotaltoolman]

4wdtom - i have never rebuilt a transmission. Your point above is pretty much what i figured out after closely examining the gear sets. At first 5-second glance, i'm thinking finally some luck here because they looked ok. Then, while i'm sliding the gears and realize how the trany actually works, i see the chewed up engagement tabs on 3rd, and think oh-oh, trouble. This d14 was a salvage-save, which means i have never driven it. Dr. allis has a very good point- drive first to see if the gears work fine. My counter balance to that is how much time i have (before my lovely wife makes me start living in the outbuilding) to tear this down again. RIght now, the tranny is resting on my welding table. I opted to replace third (on the pinion shaft), which the AGCO parts book says use 3rd. with a new reverse which is butted up against it. No perfect world here, but i had to pull the tranny anyway to replace the PTO o-ring. In my opinion, even though both those gears cost a ton, it was easier to replace them now and get a better shot of not having to pull the tranny apart again. Every thing in front of the tranny and behind the tranny has now been rebuilt, so i'm hoping this thing runs, then the last step will be to do some mild dissasembly for the paint booth. We shall see.,,,,,,. Thank you for a great explanation on the gear-driven transmission.