8550 and 4M305 drivetrain
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=177193
Printed Date: 21 Aug 2025 at 2:19pm
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: 8550 and 4M305 drivetrain
Posted By: victoryallis
Subject: 8550 and 4M305 drivetrain
Date Posted: 01 Jan 2021 at 8:41am
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Allis Hunters post here and on Agtalk got me thinking. It’s no secret Allis drivetrain struggle to handle high horsepower. My 7580 has had multiple issues with the Cummins another fella on here dads 7080 couldn’t withstand the Cummins either. I’ve seen a few 7580’s without low range. When Allis made the 8550 or 305 did they use a more stout drivetrain?
------------- 8030 and 8050MFWD, 7580, 3 6080's, 160, 7060, 175, heirloom D17, Deere 8760 |
Replies:
Posted By: DrAllis
Date Posted: 01 Jan 2021 at 9:39am
| 7580/4W-220 transmission came from the 7040/7060 tractors. Four-wheel drive transmissions (like FWA) have much less slippage/more traction, therefore there are times the transmission is loaded heavier than a 2-wheel drive tractor. The 8550/4W-305 is a much heavier/beefier transmission and Power Director clutch assembly. I believe the dropbox is the same between all the four-wheel drive tractors. I know of 8550's that were over 400 HP instead of 305 and in time had driveline troubles. |
Posted By: DougG
Date Posted: 01 Jan 2021 at 10:18am
| In my opinion, Allis built the drivelines for standard horse power that they tested for- and the u joints and configuration they designed weren't the best as reading of some problems on here- BUT all the rage of those times/ years was - turn more fuel, or turn them up! More smoke! In tractor pulling it's 300 ft- all day in the field at 100% load will take it's toll |
Posted By: LB0442
Date Posted: 01 Jan 2021 at 11:17am
This is some paperwork I found in my books a while ago. I doesn't really answer the original question but it is interesting info on the differences of 7580/8550 to 4W-220/305.  |
Posted By: ajl
Date Posted: 01 Jan 2021 at 2:06pm
| Just wonder what the source is of those notes LB? I have been trying to find output specs for a 305. It would seem that according to those notes it would have a hydraulic pump output of around 38-40 gpm compared to the 23 gpm rating of my 8070. The main job we do with these tractors is running an air drill with a hydraulic driven fan which taxes the capacity of the hydraulic system on these older tractors. Sometimes a 305 comes up around here and it would be nice to know for certain that they have more hydraulic capacity than my current tractor. |
Posted By: DrAllis
Date Posted: 01 Jan 2021 at 3:14pm
| Main hydraulic pump is driven off of the rear axle/PTO drive and was never larger than 23 GPM. Had Allis continued, a 40 GPM pump was certainly in order for the times. |
Posted By: LB0442
Date Posted: 01 Jan 2021 at 4:02pm
This is out of a factory book for the updated 8000 series. It is called "qualified service training 1982-83 tractor". You can see the date of 12-81 in the corner of the pages. Here are the next 4 pages.    This is the book.  It is full of these over detailed blueprints of all of the driveline and the controls, this is a picture of the articulated frame. They are too large to go on my scanner, this is just a partial page.  |
Posted By: LB0442
Date Posted: 01 Jan 2021 at 4:36pm
| Obviously they are listing combined flows of all the pumps on that page. So if you have 23 to remotes, 17 to steering, that would leave 14 for lube?? That would be for the 4W-305, 54gpm. |