D-9 gearing change

I'm not aware of any alternate gear ratios for a D9 19A, any changes of the larger tractors in its era were done through final drive ratios, but bear in mind, no matter what you do with a torque converter drive machine, you have very limited engine braking unless it was one fitted with a one-way clutch in the converter. I remember mention of them in the old service magazines and doubts about thir reliability, check in your parts book to see if a one-way clutch is fitted in it.

Don't believe you have any choice...all the torque converter models were geared that way. I don't show any options as attachments and that unique transmission pretty much put the limits on it.

Hi firpitch,
catsilver has it correct, there were issues with these freewheel clutches and they were removed as per a Service News Letter dated March 31 1962.
Sorry I do not have a copy.
Also the later edition of the machine Service Manual tells the mechanic to remove the unit when reco-ing it.
Hope this helps.
Cheers,
Eddie B.

A 17xxxx serial number would have had the roller clutch originally.....also shows a second attempt version of the clutch as a field installation....followed by a parts book insert showing the roller clutch components gone. Guess it do not work out as stated.

edb,
What is that diagram....sure doesn't look anything like the roller clutch???

Hi OM,
there is a lot of articles I could have posted, just as you mentioned on updates etc. That is the replacement for the freewheel unit.
All the ones I worked on, without the freewheel, re-used some of the original parts as fitted if they were re-usable. They simply re-used the cam and outer race but did not fit the rollers, springs etc.
The pic shows the full replacement unit if the cam and outer race were not re-usable. It was also what was fitted from the factory after it was decided to do away with the freewheel unit.
Attached is Product Bulletin June 28 1961, and a pic from the Serv Man of a partialy removed freewheel unit.
Hope this helps
Cheers,
Eddie B

Hi edb,
All good stuff....but I'm not seeing anything like that in 19A1 to 19A1818 part book😕 Am I missing something??

Roller clutch gone in second pic.

Also are we not talking two different events here?? I can see the roller clutch operating
the torque converter as a hydro-retarder to assist in engine braking but isn't the freewheeling feature just the opposite. Sorry if I'm being a PITA.

Thanks catsilver, edb, and Old Magnet for your replys. I didn't see anything in the parts book that would help me but if there was a fix I thought that You folks out there in the Cat world would know. This 19A with the 17XX serial is the latest version of the 19A's to have all the updates to the torque converter. Guess there is a reason for the air cooling on the brakes. I think it is a good idea to go slowly down hill inorder to provide more time for the heat to dissapate. Thanks for your input-- firpitch.

Hi Team,
the only info I have is for Powershift machines, I do not recall coming across a DD unit, I was under the impression that both PS and DD machines had the Freewheel units, BUT, I stand to be corrected, and learn something else in this trade.
OM, there certainly is not a Freewheel unit in your DD T/C pic, nor can I see where it may have been fitted.

Cheers,
Eddie B.

Hi edb,
Thanks for the response......all is not lost, both types are correct it's just that when the torque divider was added the location of the "freewheeling" clutch changed on both the D8 and D9.

I can certainly see where braking would be a problem with the 19A having a 4.1 mph 1st, 5.75 2nd, 7.8 3rd. etc. vs the 18A with 1.6mph 1st, 2.1 2nd, 2.9 3rd. etc.....and no hydro-retard effect to assist.

Sorry to bug you......gotta learn somehow and your one of the main sources😊 😊