Print Page | Close Window

powershift gear selection

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=137681
Printed Date: 08 Nov 2025 at 7:55pm
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com


Topic: powershift gear selection
Posted By: grinder220
Subject: powershift gear selection
Date Posted: 23 Apr 2017 at 9:55am
Which is the better choice for the power train for doing tillage work with a 7040,high rang 2nd gear or low range 6th gear? Both are nearly identical for ground speed.



Replies:
Posted By: Orange Blood
Date Posted: 23 Apr 2017 at 10:20am
I personally like keeping the transmission shafts turning a fast as possible for the desired ground speed selection for heavy tillage, and shock loads.  higher speed = less torque for the same work.

Let the two speed and the rear make and take the torque, not the lighter gears of the front.

That being said 6th gear does use the A1 & A2, of which A1 clutch which has the fewest discs and plates of any in that trans, but that is because the torque is less at higher shaft speed (engine speed).  On the other hand, 2nd uses C1 and B1, C1 being one of the clutches with the most plates and discs, B1, right behind it with only one less disc and plate.

6th will have the trans operating slightly more efficiently, as the front clutch pack is engaged directly to the input shaft rather than a planetary assembly adding heat.


-------------
Still in use:
HD7 WC C CA WD 2-WD45 WD45LP WD45D D14 3-D17 D17LP 2-D19D D19LP 190XTD 190XTLP 720 D21 220 7020 7030 7040 7045 3-7060
Projects: 3-U UC 2-G 2-B 2-C CA 7-WC RC WDLP WF D14 D21 210 7045 N7


Posted By: grinder220
Date Posted: 23 Apr 2017 at 11:54am
That's what I wanted to know, thanks


Posted By: DrAllis
Date Posted: 23 Apr 2017 at 1:22pm
You will have more available drawbar HP in 2nd gear. Hook the tractor to a dyno and check HP in each of the six speed selections and you'll find 5th and 6th are the least efficient HP wise. 1st and 2nd gears are actually more efficient than a P.D. transmission.


Posted By: wekracer
Date Posted: 24 Apr 2017 at 6:04am
What are you pulling that you can run that fast. That's over 7mph. My 8050 with 18' disk likes 5th low. That's 5.5 mph and if I hit a wet spot I need to shift down to 4th sometimes. I have to admit that I've never tried in high range but then I would have no gear to shift down to.


Posted By: LeonR2013
Date Posted: 24 Apr 2017 at 6:45am
Running to tall a gear for the work you're doing will cause the governor to add more fuel, so you can use more fuel to get the job done. Might be a little or might be a lot.


Posted By: DrAllis
Date Posted: 24 Apr 2017 at 7:26am
My advice on running 2nd HIGH is the job should be light enough so there is no need to be shifting down to 1st gear at any time and then shifting back up to 2nd high. Reason?? because the shift from 1st to 2nd is very rough and I personally would try and avoid that under load. 2nd HIGH on a field cultivator works well if the load isn't too great.


Posted By: grinder220
Date Posted: 24 Apr 2017 at 12:24pm
Im pulling a 19ft Krause disc with it with no power issues,in fact I'm only running 2/3 throttle and I'm in clay hills. She handles it just fine.


Posted By: DrAllis
Date Posted: 24 Apr 2017 at 12:27pm
Life is good.


Posted By: automaticdave
Date Posted: 24 Apr 2017 at 1:39pm
I use low range then if I need to back up I don't need to shift from hi to low.



Print Page | Close Window

Forum Software by Web Wiz Forums® version 11.10 - http://www.webwizforums.com
Copyright ©2001-2017 Web Wiz Ltd. - https://www.webwiz.net