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D 21 Tranny ??

Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Farm Equipment
Forum Description: everything about Allis-Chalmers farm equipment
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=177385
Printed Date: 23 Sep 2024 at 5:27pm
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Topic: D 21 Tranny ??
Posted By: FREEDGUY
Subject: D 21 Tranny ??
Date Posted: 08 Jan 2021 at 5:49pm
The recent post about the '21 got me wondering about the drivetrain of the beast. Was the tranny/rear end a "beefed up" D series tranny, was it it's "own" animal" as far as the tranny ? Did it suffer the same ailment as the 190 as far as failures ?? There were not many '21's in our area, 210's and 220's though Wink. Thanks



Replies:
Posted By: Kansas99
Date Posted: 08 Jan 2021 at 8:40pm
Don't know about the tranny but the rearend was beefed up with heavier gears in the early ones.  The heavier gears included grinding out the cast to get them to fit is my understanding, I'm sure someone will be along to explain it right.


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"LET"S GO BRANDON!!"


Posted By: MACK
Date Posted: 08 Jan 2021 at 9:16pm
Transmission was strong, but bull pinion were weak.            MACK


Posted By: DSeries4
Date Posted: 08 Jan 2021 at 9:22pm
It is a hell of a lot bigger than the other D series transmissions!  They are both straight 4 speeds, so I am sure there are some similarities in design.  I have not heard of any jumping out of gear, but it doesn't mean it hasn't happened.  Remember:   Gear jumping was the result of operator abuse.
My local AC guru has been pulling with a D21 with the stock transmission and rear end for close to 40 years and has not had any problems.  That's with around 1000 hp in front of it!  Search "Killer Allis" on youtube.


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'49 G, '54 WD45, '55 CA, '56 WD45D, '57 WD45, '58 D14, '59 D14, '60 D14, '61 D15D, '66 D15II, '66 D21II, '67 D17IV, '67 D17IVD, '67 190XTD, '73 620, '76 185, '77 175, '84 8030, '85 6080


Posted By: DrAllis
Date Posted: 08 Jan 2021 at 9:43pm
The D-21 final drive was the weak link in the driveline. The bull gears had the inside axle bearing outside of the bull gear instead of on the inside like a D-19/190. The bull gears and bull pinion gears were too narrow for 127.75 PTO HP. They were probably OK for the original 103 HP without a turbo. The 210/220 addressed the final drive weakness by making things much bigger and locating that inner axle bearing on the inside of the bull gear. The transmission was never changed.


Posted By: SteveM C/IL
Date Posted: 08 Jan 2021 at 10:08pm
The trannys look just like a WD45 only BIGGER! Snap rings set brg play. D21-220 same trans.


Posted By: DrAllis
Date Posted: 09 Jan 2021 at 6:49am
The D-21 tranny was a change in design theory for A-C. First, it was located directly under the clutch/brake pedals and directly attached to the bellhousing, much like a WC, and was a stand-alone gearbox. It was 4-speeds that were closer ratio than anything they had made before. It coupled up to the rear-end, which had a wide-ratio two-speed range transmission. This allowed you to shift 1 thru 4 in low range and then shift to high range and start over with 1 thru 4. It was clearly different than anything they had built up to that time.


Posted By: tbran
Date Posted: 09 Jan 2021 at 9:04am
There was ability to update on the first bull gears, wider ones, required some grinding to make the bull gears fit in some cases.  The late Ernest Cook who worked for Johnson at Mayfield Ky related this info to us decades ago. He had some of the narrow gears in the back of his shop at Sharon Tn.  Also there was an early and late differential. 

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When told "it's not the money,it's the principle", remember, it's always the money..


Posted By: Calvin Schmidt
Date Posted: 09 Jan 2021 at 9:57am
The D21 transmission/rear end was the first one designed for independent live PTO.
Later D10/12's were a retrofit design. The killer on the final drives was too much torque, not horsepower. Friend had a D21 new and it was great without problems until it went back to the dealer after a few years and they discovered it was putting out 175hp. They had just been driving fast. Dealer turned it back to 135 hp and they had to drop a gear or two and then the final drive problems began. Wheel spin is what saves the final drives for pullers  


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Nothing is impossible if it is properly financed


Posted By: FREEDGUY
Date Posted: 09 Jan 2021 at 5:03pm
Thanks for all of the replies gentlemen, did the '21 have a PD like the previous D series/100 series ??


Posted By: DougG
Date Posted: 09 Jan 2021 at 7:00pm
No they they did not - all gear driven, 


Posted By: ncpackfan39
Date Posted: 11 Mar 2024 at 9:07am
Hello,

I’m looking for Allis Chalmers D21 PTO clutch Brake assembly parts. Pictures from the parts manual have the pieces circled that I'm specifically looking for. The parts are the brake assembly parts which are forward of the PTO clutch. If anyone has any of these, feel free to let me know at 919-273-6643. Thanks in advance for any info you might have.


Posted By: Calvin Schmidt
Date Posted: 15 Mar 2024 at 7:42am
Years ago now, my AC mechanic checked the PTO clutch on my D21. He commented that it was (or looked ) the same as a D series powered director clutch pack. The one side was locked to the main housing to serve as the PTO brake. Can anyone verify this ? 

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Nothing is impossible if it is properly financed


Posted By: DrAllis
Date Posted: 15 Mar 2024 at 7:48am
Similar design adapted to the D-21. The differences are the clutch housings depth to accommodate 7 discs on the power side and 2 discs on the brake side. A D-19/175 tractors had 4 discs in high and 5 discs in low for a total of nine driving discs.


Posted By: SteveM C/IL
Date Posted: 15 Mar 2024 at 8:25am
Calvin is spot on about torque being the killer. Deere mechanic told how when 30 series IIRC came out they were instructed by   corporate to NOT touch the fuel pumps! Later at a block meeting everyone was failing transmission parts except the dealer he worked for. The big guy ask my friend why everyone but them was having trouble. He smiled and said he didn't know.


Posted By: Calvin Schmidt
Date Posted: 15 Mar 2024 at 9:00am
Thanks for the PTO clutch info DR. Would this be the same for the 210/220 ?
OneNinety ? 


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Nothing is impossible if it is properly financed


Posted By: DrAllis
Date Posted: 15 Mar 2024 at 9:36am
No. All different design and hydraulic pressure applied clutch and brake.   180 thru 200 pretty much the same parts. 210-220 identical parts.


Posted By: ncpackfan39
Date Posted: 15 Mar 2024 at 10:25am
That is all good info. I appreciate the discussion. The part I’m looking for is the part that attaches to the inside of the rear housing that enable the PTO brake to do its job. I was curious if any other models used the same parts. Thanks for the discussion on that.



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