Nicholas Fluhart

July 20, 2009

Allis-Chalmers ACP 80 Lift Truck

The Allis-Chalmers ACP80 is a heavy-duty conventional type forklift. I’ve owned this one, a 1980 model, since 2007 (see the ACP80 project page here) and have been pleased with its performance and dependability. Below are the specs and information I’ve accumulated for the ACP80. I’ve also posted some pros and cons based on my experience with the machine.

1981 Allis-Chalmers ACP80 Forklift

  • Produced by AC’s Industrial Truck Division in Matteson Illinois
  • Model: ACP80
  • Fuel Type: LP
  • Engine: 6-cylinder Continental F245
  • Horsepower: 76
  • Transmission: Borg Warner Oil Clutch w/High and Low Range
  • Approximate Weight as Equipped: 12,322 lbs
  • Attachment: 42″ Forks
  • Load Tires: 8.25-15 14-Ply
  • Steer Tires: 7.50-10 12-Ply
  • Mast: 3-Stage
  • Lift Height: 182″ (Approx 15 feet)
  • Lift Capacity: 8,000 lbs
  • Mast Backtilt: 8 Degrees

-Industrial Truck Division

Allis-Chalmers first entered the material handling industry when it purchased the Buda Company in 1953. Buda was a manufacturer of engines and material handling equipment. I believe the main interest in the acquisition of Buda was so AC could produce their own diesel engines for their crawler tractor line, but it proved to be a two-fold blessing. Until that time, the diesels used in AC crawlers were GM diesels, also called Detroit diesels. The acquisition allowed AC the capability of controlling the manufacturing of their own diesel engines, which was a major plus, but their entrance into the material handling industry was also very profitable. Later, AC lift trucks were produced under the Industrial Truck Division of Allis-Chalmers. AC did well in the material handling industry for a number of years and despite financial hardships faced by many capital equipment manufacturers in the late 70’s/early 80’s, AC managed to hang on to their industrial truck division until 1986 when it was sold to AC Material Handling Corporation, a privately-held company.


I’ve found it very difficult to obtain information specifically for the ACP80 unit, so this part is basically from my experience and may or may not be completely accurate. To summarize the dissection of the model number, I believe the “AC” in ACP80 refers to Allis-Chalmers, the manufacturer. The “P” appears to refer to the model being pneumatic tire equipped. Some have said it refers to the fuel type, propane. This is likely derived from noting other models, such as the ACE which is electric. However, I have seen many ACP’s that were gasoline and diesel. If anyone has more detailed information, please feel free to post it. The “80” refers to the lift capacity which is 8,000 lbs. The smaller and more common sibling, the ACP60, is a 6,000 lb lift and the ACP40 is a 4,000 lb lift, and so on. AC also made conventional types even larger with the ACP 100, 120, and 140.

-Fuel Type

LP or LPG (liquid petroleum gas) is my preferred fuel type for lift trucks. It burns clean, which allows engines to last much longer. This also minimizes noxious exhaust gases which serves well in close quarters where forklifts are commonly used. However, I would have to say the main reason I like it is its convenience. The system is sealed and easy to deal with. I don’t always use my forklift regularly, and with the LP system, I don’t have to worry about the carburetor gumming up or the fuel going bad or perhaps accumulating moisture between uses. Another plus.


Continental engines are in a wide range of lift truck brands and applications as well as various types of industrial equipment. The Continental L-Head engines are old technology flat-head, points ignition type engines but are typically solid, bullet-proof power units. My ACP80 is equipped with a Continental F245 6-cylinder engine, which I believe produces 76 horsepower.


The Borg Warner oil clutch transmission, another common item in lift trucks, seems to be a solid unit. Borg Warner has long been a producer of industrial clutch and transmission related components. I’ve never had any trouble with mine. The ACP80 is equipped with a 2-speed unit that is handy when driving from point ‘A’ to point ‘B’, just shift it up in high range and it cruises at low RPM. When you get back to business, drop it down in low and it is responsive and powerful. At my place, I never really get into a position to use the high range. Low does pretty much everything I need, but the high range is a nice option to have when it is needed.


A lot of weight is required to move heavy objects with stability. The ACP80 is a very weighty machine. I stuck mine the first day I used it. Even on a very hard packed dirt surface you have to be careful if you drive back through your tracks. The weight is concentrated on four narrow tires and you can literally feel the ground moving under you when operating the machine off-road. Even on concrete floors you need to take note of the slab depth; this thing will break concrete. Some models came with dual wheels on the load axle which would serve well off-road. My machine was intended to be used in tighter quarters and has the single drive wheels for better maneuverability.

– Attachment

The forks on this machine are heavy, 5 inches wide and 2 inches thick. The factory equipped forks are approximately 3.5 feet in length. The forks on my machine appear to be closer to 4 feet. Overall, they are adequate for this unit. In fact it could easily handle longer forks. I recently installed fork extenders on mine, making the length 5 feet.

– Tires

The data plate shows the factory equipped tires to be 12 ply. The load tires (drive tires) on my machine are 14 ply wide-walls. The wide wall design is to protect the wheel rims. Forklifts are often operated in tight areas and the rims can get scraped and bent. This is especially true on machines like mine that utilize Dayton wheels. The lugs tend to extend out a little bit further than rims with center lugs.

– Mast

A strong 3-stage mast is a great asset on any forklift. My ACP80 has a very heavily built but relatively short mast. The shortness makes it ideal for operating in a shop or warehouse where the unit may travel through doorways or under low ceilings, but to make up for the short height it has three stages. The overall lift height is about 15 feet. The lift capacity is 8,000 lbs, so it will handle quite a load. The mast tilts forward and backward but does not have side-shift, which wasn’t really common until later.

Unloading Two Paper Rolls Weighing 900 lbs Each

Transporting 900 lbs Paper Roll

– Pros

This is one of the most dependable machines I’ve owned. The great thing about the LP gas is it can set up for long periods of time and still fire right up when I need to use it, no matter if the weather is hot or cold. Another plus is the pneumatic tires. It can easily negotiate gravel and other hard surfaces in addition to paved surfaces. The ACP80 is actually considered an “all-terrain” forklift, not to be confused with “rough-terrain” forklifts which have much larger tires and are typically not of the conventional lift truck design. The transmission is smooth and the high and low range is nice. The 3-stage mast with tilt adds to the capability in service, especially when the machine can lift 8,000 lbs. Overall, very capable.

– Cons

For a conventional type forklift, it is somewhat large. You have to plan ahead because, compared to smaller units, it takes much more space for maneuvering than you might think. Also, it’s very heavy so you have to be careful where you operate it. If you get it stuck you’ll need something substantial to get it out. The tilting mast is great, but it was built before side-shift was common so you’ll have to be a good driver. One of the main drawbacks of having such a large mast is it severely limits visibility. It’s very difficult to see exactly where your forks are, so you need to have a good feel of the machine because you won’t be able to see everything.

Loading Scrap on 1979 Ford F-600 4x4

You’ll probably be seeing this forklift in the background of many other posts. At some point I’ll post some videos of it in action.

You may also be interested in the ACP80 project post here.



  1. I have a ACP 80 and the low side of the trans only grind’s when I try to shift it in , would you have any ideas where I might find a trans. or parts if I get the nerve to tear it down . I sure would be greatful for any help . Thanks Dennis

    Comment by Dennis Bays — March 13, 2011 @ 12:09 pm | Reply

    • Dennis,

      That’s not good…low range is used the most. If you haven’t already, check the shift linkage. I had a minor issue with the linkage on mine, but there was no grinding involved. Fortunately, I haven’t had to search for transmission parts, but for rebuild kits and such, you can do a google search and come up with a lot of parts suppliers. You may also find a complete used trans from a forklift repair shop in your area. There were recently some complete new old stock transmissions on eBay for $1500 OBO. If you build up the motivation to tackle the project, these are good machines.


      Comment by nfluhart — April 5, 2011 @ 9:55 am | Reply






    Comment by RW ONEAL — December 28, 2011 @ 11:11 pm | Reply

    • The ACP 100 is rated to lift 10,000 lbs. The serial number should be located on a tag on the front of the steering column, or at least that’s where most of them are located for the ACP models. There you should find load and tire capacities as well as other specs. Once you obtain the serial number you can contact the former ‘Kalmar AC’ distributor (Kalmar ended up with the AC Industrial Truck distribution before it was eventually changed again to something else). Their website is gone, but I believe the company is still operating in Covington, GA under a different brand name. Their phone number is 800 311 8452. If they are still around, they can supply year model, information, manuals, parts, etc. Otherwise, you’ll have to rely on a local forklift service company or Google for manuals, etc. I’ve also found knowledgeable people on various internet forums, such as and others. Good luck with your machine!

      Comment by nfluhart — December 29, 2011 @ 2:35 pm | Reply

  3. i have a ACP 70 D with a borg warner T 11 in it. the forklift would not move in reverse. i removed the transmission and started looking at parts and air tested port holes and passages. my front clutch pack engages with ease but my reverse does not. got to looking at the reverse piston and it has to holes in it that look machined. is there suppose to be a ball or something blocking these passages so the oil would not escape or what could my problem be? thanks

    Comment by Brian — February 18, 2012 @ 9:53 pm | Reply

    • I couldn’t say for sure on whether it requires a ball to block the passage. Assuming the shift linkage was operating correctly (I had a linkage issue with mine, but mine is an oil clutch manual transmission) you may want to check the fluid you drained to see if something is in it. Otherwise, the best recommendation I could give would be to find a diagram of the components. I’ve located a relatively simple diagram of the valve body here: However, I have been unsuccessful in locating any other T11 diagrams online, so you may want to look into getting a parts or service manual, both will have diagrams. I reviewed my manuals, but unfortunately they do not cover the T11 or any of the automatics.

      Comment by nfluhart — February 24, 2012 @ 1:21 pm | Reply

  4. inserted a 7/32″ ball in one of the holes in the piston according to a parts diagram that i found and it fixed my problem thanks again

    Comment by Brian — March 1, 2012 @ 7:56 pm | Reply

    • Cool…glad you got it figured out.

      Comment by nfluhart — March 12, 2012 @ 12:53 pm | Reply

  5. I have a acp80l pssngl serial#adp 100431 can you tell me what is the recamended trans fluid also the year thanksjim

    Comment by jim — November 26, 2012 @ 7:44 pm | Reply

    • Unfortunately, I don’t have a serial number index, but if the numbering system is the same as mine I’d say you have a much newer model. I posted an inquiry in the Allis-Chalmers forum at Yesterday’s Tractor and found someone who gave me some serial number info; you might try over there: If it has a Borg Warner oil clutch transmission with high and low range, it likely takes automatic transmission fluid, as does mine.

      Comment by nfluhart — January 12, 2013 @ 6:44 pm | Reply

  6. My ACP 60 mast stops at the first stage, is there a trick?

    Comment by Barney Auman — March 12, 2013 @ 7:08 am | Reply

    • I assume you mean it stops at first mast as you are raising it? (Mine would stop as it lowered…see the post on hydraulic repairs part 1). No trick that I’m aware of. Inspect the mast as you raise it. If it’s a mechanical bind in the mast linkage, you should hear/feel the hydraulics and/or engine bog down as it encounters the problem. If it’s a hydraulic problem it could be the second stage cylinder or something causing the fluid to essentially bypass the cylinder back to the reservoir, in which case it probably wouldn’t bog the engine.

      Comment by nfluhart — March 12, 2013 @ 3:37 pm | Reply

      • This is going to seam like a no brainer but two of the mask section have been disconnected. The mask leaked so they by passed it. I have no idea how the hoses are supposed to go. There is a fitting at the top and bottom of the rear mask cylinder but no hose. Thanks for your quick response.

        Comment by Barney Auman — March 12, 2013 @ 4:05 pm

      • I think I can clarify…The fitting at the bottom of the rear cylinder goes to the hydraulic valve. The fitting at the top of the rear cylinder goes to the bottom of the short cylinder. It’s just a hard line that links the two cylinders; it does not require a hose reel. View the photos from my hydraulic repair posts on my ACP 80. Hope this helps.

        Comment by nfluhart — March 23, 2013 @ 7:36 pm

  7. I have an ACC80 2PS ( two cyl mast) am looking for seal kit for second stage cyl . seal & wiper in gland nut , seal 3″ OD 2 5/8 ID . every place I have called want me to find out the kit # . can you help ?

    Comment by Roy — June 25, 2014 @ 2:57 pm | Reply

    • As seen in this post, I rebuilt my cylinders a while back. I did a quick google search and found At that time, they had an online catalog. Not sure if they still do, but I just measured my seals and they had an Allis-Chalmers kit that matched the dimensions. May be worth contacting them.

      Comment by nfluhart — June 25, 2014 @ 3:27 pm | Reply

      • Thanks very helpful link . found the seal kit I needed . State Seal of AZ has been looking all week . & the lift equipment place where we found a kit for the primary cyl , said “the old guy that knew this stuff died”

        Comment by Roy — June 25, 2014 @ 9:02 pm

  8. Your question about the acp, the p stands for Pneumatic,ACC the lastC stands for Cusion (Cuskion tire) the ACE model E stands for ELECTRIC MODEL THE 80 designation stands for 8,000 lbs which is the capacity of its lift capabilities. So for example An ACC40 would be Cusion tire 4,000 lb capacity. I worked at the Matteson ITD of ALLIS-CHALMERS as an assembler there for several years and yes they were a well designed machine. hope this helps

    Comment by Steve — October 6, 2014 @ 10:16 am | Reply

    • Thanks for your comment. It’s hard to find people with knowledge of these old lifts. There’s lots of info on the farm equipment…much less on the ITD.

      Comment by nfluhart — October 6, 2014 @ 12:38 pm | Reply

  9. Good morning Mr Fluhart. I have a AC-P80 truck lifter. Engine is broken and I am trying to fix it. It has been hard get the replace parts. I am wondering if there is a service manual or parts catalog somewhere and how to get it. Engine is a D436 Allis but some parts have a WAUKESHA brand name engraved on it. Thanks for your help

    Comment by Arnold Pinto — August 7, 2015 @ 11:59 am | Reply

    • Yes, there are manuals available from Kalmar-AC. I ordered some a few years ago for my 1981 ACP 80 when I was rebuilding the lift cylinders. Unfortunately, the mast isn’t covered in the manuals so they were of no help for that project. As for engines, my manuals only cover the D262 for some reason. I have a Continental F245 engine, so they’re not much help there either. I wasn’t offered an engine choice when I bought the books, so I figured all the engines offered in the ACP 80 in 1981 would be covered. They are not. However, they seem to cover the rest of the machine so I’m sure they’ll be helpful when I have to replace an oil seal on the front axle which I plan to do shortly. Anyway, you might check with them and see if you can order a book specifically for your engine.

      Comment by nfluhart — August 26, 2015 @ 9:54 am | Reply

  10. Hello Mr. Fluhart, I have a ACP-80 that needs a new master brake cylinder, brake wheel cylinders and brake shoes. Can you recommend a supplier for these parts? I thought perhaps NAPA?

    Comment by Dan Staehle — March 10, 2016 @ 9:44 pm | Reply

    • Sorry, I must have missed your inquiry. The master cylinder is fairly common, I’ve seen them on eBay. I’m not sure about the wheel cylinders (I’ve got one leaking on mine as well) but I think would be a possible source. I used to get a lot of forklift and power unit parts at NAPA and Crow Burlingame, so if you’ve got some good stores near you I’d start with that. The stores here had some old guys that were extremely knowledgeable. Unfortunately, they have all retired and now they hire people off the street just like O’Reilly and Auto Zone, so I rely on the internet for most of my parts.

      Comment by nfluhart — July 13, 2016 @ 9:32 am | Reply

  11. Hello, I have recently purchased an ACP 80 forklift with the dual front tires and the steer axle is in need of replacment or rebuild. Every place I call wants the model #, but I’ve looked high and low and cant find an ID plate anywhere. The lift is one that has a full cab with doors and windows, it is LP fueled. Any help would be greatly appreciated.

    Comment by Aaron — July 12, 2016 @ 4:04 pm | Reply

    • The data plate on most of them is on the front of the steering column. It may be hard to see if it’s got a cab.

      Comment by nfluhart — July 12, 2016 @ 4:58 pm | Reply

  12. I just bought the same lift truck ACP 80 D 2PS S it looks like the one shown above I would like to know some overall maintenance questions how do you go from hight and low range what fluids go in it (Tranny, hydraulics, engine, etc) and where mine is the diesel with one ram up front and all 3 rams are leaking where is the best source to get rebuild kits please advise the thing runs like a top but acts sluggish maybe in high gear don’t really know.

    Comment by Gene — April 4, 2017 @ 2:26 pm | Reply

    • Without seeing your lift I’m not positive, but mine has two shifters on the steering column. The one on the right is hi/low range…hi is pushed forward and low is pulled back. Best source I have found for seals is at I got mine there a few years back and they were good to work with. Service manuals may be a good idea. The only place I could find manuals (at least when I bought mine a few years ago) was at this link: Part number for the manuals is AK0130070. As for fluids, the types and weights are in the manuals if I remember right. It’s all pretty standard. Front diff is an Eaton and takes gear oil. Hydraulics take standard hydraulic fluid, transmission is a Borg Warner and takes ATF, and if you’ve got a diesel engine I’d run Rotella 15w40.

      Comment by Nicholas Fluhart — April 5, 2017 @ 9:22 am | Reply

  13. Excellent project, and very kind with your responses to the deluge of questions. I have a mid-80s diesel Toyota 8K, 1990 Clark Electric, and a LPG 1940s (Hyster I think.) I am working the Toyota too hard to restore it right now, looking forward to winter when I have more time. The Clark electric was bought for an inside-the-shop back saver. Has a few minor issues that I will work through this winter too. The old Hyster has been parked outside for 8 years, and I worry that I may have let that one go too long. Thanks for your posts about restoring your AC. It is a good inspiration!

    Comment by Mike — September 5, 2017 @ 2:05 pm | Reply


    Comment by jim matteucci — March 8, 2018 @ 1:09 pm | Reply

    • The parking brake is adjusted by turning the brake handle after the set screw is loosened (it tightens or loosens the cable). The main brakes are hydraulic and self adjusting, so if they don’t work you could potentially have a number of issues.

      Comment by Nicholas Fluhart — May 17, 2018 @ 11:11 am | Reply

  15. Hello, I have a 1961 APC – 60 fuel type is Propane. The engine has 2 dip sticks with filters side by side .
    I am trying to figure out which one is for oil and which one is for the transmission. There is no fluid in either one. Thanks advance, Dennis Proksa

    Comment by Dennis Proksa — May 17, 2018 @ 10:36 am | Reply

    • I guess one could also be for the hydraulic oil? At any rate, you’ll want to trace the dip stick tubes to their destination. One will go to the engine block and the other will either go to the transmission case or the hydraulic reservoir OR pump housing on the front of the engine. Hope this helps.

      Comment by Nicholas Fluhart — May 17, 2018 @ 11:08 am | Reply

  16. I just boutght this lift.It is a ACP 80 and it will barely go up a hill. So I guess this has a 2 speed transmission but I don’t see where to shift it into low. I don’t have a manual. Can you shed some light and maybe a picture of your shifting mechanism?

    Comment by Daniel Neubert — October 9, 2020 @ 10:06 am | Reply

    • If it has low range, the shifter is on the right side of the steering column opposite the forward/reverse lever. If you think the lever is missing, you can pull the floorboard and see the linkage for the forward/reverse and high/low on the transmission. Some of the smaller units may not have high/low but most of the ACP80’s I’ve seen do.

      Comment by Nicholas Fluhart — October 9, 2020 @ 1:00 pm | Reply

  17. Just snagged one for $700 and it likely needs a clutch. “ran when parked” as they say. The company I work for used it up until it was red tagged. The yard guy would shut it off, put it in gear and start it up again and away they’d go. Somewhere along the line they decided that wasn’t the best thing to do. So, I’d like to get my hands on the service manual and the clutch parts.

    Comment by Richard McElligott — December 29, 2020 @ 1:29 am | Reply

    • The closest thing I’ve found for a service manual I got from a company called Kalmar. It’s not got my particular engine (Continental F245) or mast in the manual for some reason. Might google Kalmar or Kalmar AC and see what you come up with. As for the transmission, mine’s got a Borg Warner with an oil clutch. You may be able to find something online.

      Comment by Nicholas Fluhart — April 3, 2022 @ 2:36 pm | Reply

  18. Mr. Fluhart, great web page on the ACP 80! I was a young manager of manufacturing engineering back in the 1970’s when I worked for Allis Chalmers Industrial Trucks Division in both the Matteson, Illinois plant and the Lexington, South Carolina plant. We built the gas & LP trucks in Matteson. Lexington was were we built the electric fork lift trucks. I remember it well. Looking at the pictures reminds me of the all the trouble it took to set up the paint booths, the weld bays, the assembly lines, the store rooms, the shipping & receiving areas, and more. The best part was driving the trucks out of the Shipping area onto the transport trucks. I’m reminded that I have extensive documentation on a cutting-edge program we created back then called the “Manufacturing Engineering Certification Program”. This corporate Allis Chalmers program was an early precursor to the many quality assurance & manufacturing control programs that followed in the 1980’s at many other companies. I plan to make some of that material available through my current web site. Good luck to you and all the ACP owners.

    Comment by Larry Gary — July 15, 2021 @ 5:40 pm | Reply

    • Hello Larry. That’s awesome. Thanks for the message and the info.

      Comment by Nicholas Fluhart — April 3, 2022 @ 2:25 pm | Reply

  19. Hello, I read about you rebuilding the long cylinder on your ACP80 and I have the same machine with the same leak. Would you possibly still have the part number or numbers for the packing kit to repair it? Any info would be greatly appreciated
    Thank you, Aaron Riggs

    Comment by Aaron Riggs — August 16, 2021 @ 1:32 pm | Reply

    • Unfortunately, I don’t have a part number or an active link to the kit. However, I bought it from Contact them and they may be able to help.

      Comment by Nicholas Fluhart — April 3, 2022 @ 2:27 pm | Reply

      • Hi all! I am new but I have a few questions. I have a ACP80 and it has a problem with the power steering. Tracing the lines it seems to be getting the fluid from the hydro pump that runs off the rear of the truck. the lift works great but no power steering. Any info on what could be the problem or any manuals would be great also.
        Thanks Duane

        Comment by D Smith — April 30, 2022 @ 6:50 pm

      • Hello Duane. On mine, both power steering cylinder lines are hooked to the steering box on the end of the steering shaft. The cylinder should not be hooked to the hydraulic pump directly (I don’t think). Unfortunately, I don’t have a line on a manual that would include the hydraulics. I got a manual for mine from Kalmar, but it does not included the hydraulics.

        Comment by Nicholas Fluhart — May 1, 2022 @ 12:17 pm

      • Why are you blocking my comments?

        Comment by Mike Murray — May 2, 2022 @ 8:45 am

      • I’m not. There’s a delay on posting for moderation due to crazies on the internet.

        Comment by Nicholas Fluhart — May 2, 2022 @ 1:47 pm

  20. My ACP80 has a steering link power steering system, rather than oil to the box itself. My steering link has a valve built into the end of the link that when “asked” to move by the steering box, actuates a valve in the end of the link. With mine the link receives oil from the pump directly. My Tyrone pump has a second section dedicated to the steering. Which system do you have Duane?

    Comment by Mike Murray — May 2, 2022 @ 8:25 am | Reply

  21. The Buda engine repair manual.




    Comment by Mike Murray — May 2, 2022 @ 8:31 am | Reply

    • Thanks for the info.

      Comment by Nicholas Fluhart — May 2, 2022 @ 1:45 pm | Reply

RSS feed for comments on this post. TrackBack URI

Leave a Reply to Nicholas Fluhart Cancel reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

Blog at

%d bloggers like this: