How to diagnose your Eaton transmission air systems

In this video I go over the diagnostic procedure to check for problems with your Eaton fuller transmission air system.
I attribute my successes to god and give him the glory.
For a day in your courts is better than a thousand elsewhere. I would rather be a doorkeeper in the house of my god than dwell in the tents of wickedness. (psalms 84:10)
Here is a link to the larger troubleshooting manual with multiple transmissions:
assets.wellertruck.com/refere...
Here is a link to a list of transmission to chose your manual from:
truckmanualshub.com/eaton-ser...

[@arthurbarry2749]

You helped me out of a tough spot (stranded roadside) today Jason.

[@JasonTheMunicipalMechanic]

Glad I could help.

[@67aacosta]

Thank you Jason this is actually very helpful for me,

[@JasonTheMunicipalMechanic]

Glad I could help. There are service manual links in the description if you need one.

[@JasonTheMunicipalMechanic]

I put links to two service and troubleshooting manuals in the description for Eaton transmissions.

[@terrypayton8001]

While rectifying an air leak what problem should you look for in the shift bar housing

[@pateltruckdrivingschool3696]

Great video explained, Jason. I have Eaton 13 speed standard transmission on Volvo, in cool weather below 0 C, high range selector filp up/down but no movement in transmission. in this case move truck in warm shop for 1 or 1/2 hr. and works fine. I have notice high range line freezing up due to some water in. my question is how to clear water from transmission line ?

[@JasonTheMunicipalMechanic]

Other than removing the air lines and using the system to blow air through them to get the water out I don’t really know how to get it out. I would think it would work it’s way through when it was thawed eventually, but would recommend keeping the air tanks drained and making sure the air dryer is working and blowing off. There is an antifreeze you can put in the air system that should help keep it from freezing. I believe you can put it in after the dryer or directly in the air tanks and it should work it’s way through the rest of the system.

[@OldCrowsClassicCars]

Hey, how do you remove the piston to replace the O-ring? Do you just force loose the nut? Or is removal of the auxiliary required? Thanks again

[@JasonTheMunicipalMechanic]

I believe you just remove the nut.

[@IbrahimMohamed-dz1yi]

I have 13 speed I have oil coming up from a regulator to the splitter valve and I don’t know where the oil coming from. Can you tell me anything I can do?

[@stevennix3506]

Great video Jason. I’ve got a truck coming into the workshop tomorrow with an 18 speed RTLO fitted. Driver complaint is that the gearbox is neutralising/loses drive whilst in high range only but the gear shift lever does not slip out of gear. I am thinking that the range change cylinder is loosing air pressure and sliding out of range resulting in free revving, I wanted to get your opinion on this issue? I have yet to speak to the driver as to whether he needs to operate the high range switch or depress clutch to get high range to engage again. Thank you for your time.

[@JasonTheMunicipalMechanic]

I agree with what your thinking. I would think it’s an air pressure problem as well. I used to drive a truck about 10 years ago that did the same thing a few times but we didn’t figure it out because it stopped doing it. The trans would just go into neutral and when I pulled it out of gear it would shift to low range and wouldn’t shift to high range again getting stuck in low. We never figured it out but I would be interested in knowing what it is. I took it somewhere and they removed to line to the shift cylinder and sprayed some lubricant in there and it freed it up and it started shifting again. So it could be an issue with the piston being stuck. If you can get it while the fault is present I would check for pressure at the line going into the range cap and see if it’s the I want to say 60psi with high range selected. If it is I’d say it’s in the transmission if not I’d begin checking the air system. I have some manual links in the description of the video that might help but not of them says transmission going into neutral without moving the shifter could be 1 low air pressure and to check the regulator pressure. 2 internal transmission issue could be caused by and excessively worn or damaged sliding clutch or yolk. Hope this helps. The manuals have some troubleshooting sections in them too.

[@brentpew4853]

How do I fix oil leaking out the splitter valve blue line? Will a new k3331 kit fix it or is it an O-ring internal on the piston or the tube? Thanks

[@robertearl6363]

Have 10 speed eaton fuller automatic when I put it in park and cut the truck off I can here the gear move after a few seconds after I cut it off

[@OscarPerez-gu3yd]

Bro thank you so much for such an outstanding video and so well detailed, Bro I was wondering if you could share where you got that booklet with the diagrams

[@JasonTheMunicipalMechanic]

No problem. I printed the diagrams out from the service manual. In the description I believe I put a link to the Eaton service manuals. You just have to find your transmission in them. They are free on their website.

[@OldCrowsClassicCars]

Excellent video, by far the most complete. You mentioned that to select LO range there must be air applied whereas for HI range there's no air. This means that in the event of a air leak, the transmission would be stuck on HI range. I wonder if there's a way to change this. I much rather be stuck in LO than in HI....especilly if the dump truck is loaded. Also, it's unbeliaveble how a single O-ring can completely neutralize the transmission....

[@JasonTheMunicipalMechanic]

I know what you mean, being stranded because of a thin piece of rubber is hard to believe. I don’t know if there is a way to swap how the transmission selects the range. I think it would depend on the transmission and how it’s designed. I used to drive tractor trailers about 10 years ago and every once in a while the truck I drove would not shift to high range and would get stuck in low. I was lucky enough to be right near the garage so I just brought it back but it would be a problem 100 miles away.

[@OldCrowsClassicCars]

@@JasonTheMunicipalMechanic I'm sure there's a way to improve on that design. Can the range cylinder be removed easily, without removing the transmission? In other words, can the repair be done on the truck?

[@JasonTheMunicipalMechanic]

I believe it can be. I found this video that might help. kzbin.info/www/bejne/b6PZgImmdtx9qpo

[@robertshoemaker4868]

I have been stuck in high range in a loaded dump truck

[@ricardobonilla9101]

Hey Jason im getting alot of oil coming out of side exhaust port how can i troubleshoot my problem? Thanks

[@maxtindelahanty6340]

Hi great video by the way very informational… what I’m having trouble with is when I’m warming my truck up I have to shift my range selector up to check for air leaks. Once I do this I hear air leaking somewhere and then I shift it back down and air is also leaking so it seems the piston is stuck in the middle of high and low I have to wait a little bit until I hear a pop and then my range selector is good for the day. Just wondering if you think it could be the piston that’s what I’m thinking after this video I’ve replaced shifter knob. Acuator. And filter regulator so far and prob still there… Thanks for any input

[@JasonTheMunicipalMechanic]

I suppose it could be possible the piston is getting stuck. I would check the pressures along the system to find where it’s stopping. If you can find where the air is leaking from it might be the problem area. The slave valve controls the piston so it could be a problem if you haven’t changed it. I would verify that you have air tank pressure going into the regulator I think you need 90+ lbs, if you do I would next check the pressure at the range cylinder hose to verify you have the 58-63 lbs on the lines going into the range cylinder. If you have all of this and I would make sure you don’t have pressure on both range cylinder hoses at the same time. If it all checks out then your problem might be in the transmission. I would start there though I would try and find where the air is leaking from, it might just be the slave valve sticking.

[@maxtindelahanty6340]

Hi I just saw your comment reply this morning it happend again. I believe it’s my slave valve because air is pissing out of the the slave valve at the transmission so I’m assuming like you said I believe you called it the road runner valve is getting stuck so changing out slave valve this week hopefully solves problem

[@maxtindelahanty6340]

Quick question for you, so my dispatch let me keep it in there garage last night that’s heated and I didn’t have the problem with leaking air at all and my splitter worked completely fine any idea why it would only happen when it’s cold?

[@JasonTheMunicipalMechanic]

There could be water or oil in the air system

[@JHj-gy3ne]

Thanks!

[@JoseGonzalezMusic2022]

Hey Jason you have great content and I just wanted to see what were your thoughts with this. My slave valance is leaking from the breather . I’ve replaced the slave valance , air filter regulator , dryer and governor and it still Leaks, but it only does it at random times and does not let me move Foward or back. What would you suggest me to do ?

[@JoseGonzalezMusic2022]

Valve**

[@JasonTheMunicipalMechanic]

If you already replaced the slave valve it could be an Internal leak in the range cylinder. You can go to this link on page 11 and it references a leak from the exhaust port of the slave valve and the possible causes. assets.wellertruck.com/reference-materials/troubleshooting-manuals/eaton-fuller-air-system-trouble-shooting-guide-trts0920en-us_0615-2015.pdf I believe you can replace the range cylinder piston without removing the trans. It should be behind a cover and a nut on the shaft that holds the piston on. There might be some dirt or debris in there that is jamming up the piston and letting air by the seals too which might be why it’s not all the time and if it’s mid shift it would explain why it won’t drive too. It’s where I would look next if it was me.

[@JoseGonzalezMusic2022]

I appreciate it Jason, thanks for the reply👍🏽

[@truckininspired8702]

I’m in need of some advice, I have an Eaton 8ll. When I flip the switch to high range and go to neutral it makes a grind sound for 1/2 a second. And doesn’t do that from high to low any thoughts?

[@JasonTheMunicipalMechanic]

If I were to guess I’d say one of a few things could be happening. The change from high to low happens by an air piston being moved to move a shift fork that slides a sliding clutch back and forth that will engage in the gear and transfer the drive through it. My guess is the sliding clutch is grinding on the one set of gears probably the high range gear. It probably meshes easier into low that’s why it doesn’t grind. Why it grinding could be clutch fitment issue into the gear, A sticking clutch fork piston, or low air flow delaying the shift. Could also be a insert valve sticking depending on the design of the transmission. I included service manual links in the description if you’d like to look into it more.

[@truckininspired8702]

@@JasonTheMunicipalMechanic Thanks for the information! This truck is full of gremlins. This one was the one that showed its ugly head today

[@quranical-lyspeaking9019]

Great video and loved the Bible verse in the description! Can you briefly explain what deep-reduction is/does?

[@JasonTheMunicipalMechanic]

Thank you. I have a verse in every video. Without god I wouldn’t be able to do what I do so I like to acknowledge it for him. Deep reduction is basically like a really low first and reverse gear. It adds another gear in and cuts the first and reverse get in half. You get almost no speed out of them, they are made to move heavy loads around where you need a lot of torque. I’d use them off road where it’s harder to get the truck rolling. You have a lo gear and in deep reduction it goes to lo-lo

[@quranical-lyspeaking9019]

@@JasonTheMunicipalMechanic That’s really cool especially in today’s society where disbelieving in God is encouraged! And oooooh okay cool thanks makes sense I work on trucks and the only trucks we have are Eaton 10 or 9 speed so I haven’t come across any lo-lo. Thanks a bunch, I subbed and God bless!

[@JasonTheMunicipalMechanic]

The transmission in this video is an 8LL so it has the double lo. I’m not sure if it’s called deep reduction in the other transmissions but the feature would be used as the splitter with the little blue switch on the shifter.

[@slabbinwithsean9089]

I have a 13 speed and about two miles from my delivery she wouldn’t go to the high side of my transmission 5-8 low or high splitting it would go in gear but just rev I fixed a fitting on the splitter that was leaking air and it started working again for about 60 miles but then two miles away from pick up she wouldn’t go to the high side

[@JasonTheMunicipalMechanic]

Go into the description of this video select the first link to the manual and the troubleshooting for this is on page 18 it is no or slow shift into high range. If the deep reduction splitter doesn’t work either I would look to the air supply to the shifter or regulator if it’s just the high low your going to need to diagnose it with the troubleshooting steps.

[@stratefacts9075]

@@JasonTheMunicipalMechanic I have a 10 speed eaton fuller....truck goes into high range but will not go into low range....replaced the slave valve n still having this problem??

[@poopmissile69]

I have that same trans i believe. What would cause air to mix with the oil making it white? Looks similar to when water mixes with it. Mine is not a water cooled trans.

[@poopmissile69]

No pressure on the trans when i loosen the fill up plug

[@JasonTheMunicipalMechanic]

I’m not sure what would cause that. There are some links to the service manuals in the description. They have a trouble shooting section in them that might help.

[@poopmissile69]

Thanks for the reply. I've looked through them several times before i came here. Can't find anything anywhere that mentions my issue. I can't hear any leaks in high or low

[@frankieortiz4519]

- I have a 8ll when I split it to high “even when parked” my slave valve starts leaking air what can it be?

[@JasonTheMunicipalMechanic]

The slave valve is the valve on the side of the transmission. I just want to make sure that is the valve you are talking about. The troubleshooting section says it can be an internal leak in the slave valve or an internal leak in the range cylinder. The troubleshooting procedure is In the first link I provided in the description on page 11

[@dannyleger6621]

I have a 89 GMC C7000 with a Eaton RT-610 10 speed transmission. It has a 19470 range valve. It has a strong air leak all the time at the range valve. Could that cause the truck not to move at all? Is it possible to manually put it into low or high without the valve? It is only a yard truck. The clutch pedal feels good, transmission goes in and out of gear and the gear movement can be felt thru the shifter but no power to the driveshaft. This started when the pto cover was open and someone moved the truck 10 foot and some oil leaked out. Not sure if it is a coincidence and the air range valve is the issue.

[@JasonTheMunicipalMechanic]

I don’t believe moving it 10 feet is what damaged it. I would repair the air leak at the shifter. I’m under the impression that the transmission should normally be in either high or low by supplying air the the shift piston on the rod side and when you move the lever on the shifter it will select the other range by applying pressure to the side of the piston without the rod creating more force because of the larger surface area. The selector shaft could be stuck between the ranges. I would repair the air leak at the shifter to try and repair it but if you want to manually selected one range you need to take air coming from the air regulator and feed it directly to one of the lines going into the range cylinder assembly and disconnect the feed to the slave valve and possibly remove the second line from the range cylinder to vent it so the air can escape. It can be done but it would probably be easier to repair the air system if that is what the problem is. There are some diagrams in the service manuals I put in the description that should help and there are troubleshooting procedures in the manuals as well. You can pull the range cylinder cap off and see if the piston is stuck which could be a problem as well. But there is no mechanical way to lock it in a specific range it is air controlled. Unless you push the range cylinder forward and put a spring or something inside then put the cap on to keep it forward, I think that would lock it in high though.

[@dannyleger6621]

@@JasonTheMunicipalMechanic awesome, thanks so much for your reply. I will download that manual and check it out. I'm in south Louisiana. Where are you located?Have a blessed evening.

[@JasonTheMunicipalMechanic]

Massachusetts. I wish you good blessings as well.

[@OldCrowsClassicCars]

@@JasonTheMunicipalMechanic Just what I was looking for.

[@gerardonajar8196]

What is the tiny hole at the bottom of the air regulator for?? Is it supposed to be leaking air through there??

[@JasonTheMunicipalMechanic]

I don’t believe so. I think it’s to vent out the pressure if the diaphragm starts leaking.

[@breyp6982]

Don’t have any air when I flip my splitter on the high range. what should I check for first? (13 speed)

[@JasonTheMunicipalMechanic]

If you look in the description of the video there are service manuals. assets.wellertruck.com/reference-materials/troubleshooting-manuals/eaton-fuller-air-system-trouble-shooting-guide-trts0920en-us_0615-2015.pdf Go to the first manual, on page 80 of the manual there is a photo of the air system you can follow to see where your air is getting stopped. You should have air to the road ranger valve on the shifter on the s line at all times. If you don’t you will need to trace it back and if you do you will need to verify it’s being sent to the slave valve when you flip the lever

[@stratefacts9075]

I'm having trouble with my truck...goes into high range but will not go into low range...replaced slave valve n still having the same problem

[@JasonTheMunicipalMechanic]

Go to the link above and it should be on page 14 called no or slow range shift into low. It will give you possible causes and troubleshooting steps.

[@staceyjordan7612]

Did you figure out your problem? Because I'm having the same issue

[@twillight888gf5]

How to get a remedy of eaton fuller transmission 13 speed,when 2nd low and hi gear,exit when they were engage

[@twillight888gf5]

What will we do sir,hope you will reply my questions..thank you

[@JasonTheMunicipalMechanic]

Is this a problem that is only in second gear? Is the shift lever physically moving out of gear into neutral? Is it doing it in low and high gear?

[@shoryadogra8388]

I have a eaton 13 speed transmission. I am getting problem while up shifting from low to high gears (when using splitter). The truck wont take gears and when i acclerate it . It gets into the gear with a jerk and loud sound (thats fuckin scary). Rest of the gears are ok . Only problem is in splitting gears from low to high. It could be a air leak or some mechanical fault?

[@JasonTheMunicipalMechanic]

I believe the splitter uses a insert valve to switch it. There should be a troubleshooting section for it in one of the manuals I have in the description.

[@whackythunder3692]

So if the air filter/Pressure regulator supplies too much pressure, will that cause air leakage in the control valve?

[@JasonTheMunicipalMechanic]

If you are talking about the shift lever controls then I would imagine too much pressure could cause a leak, but the manual refers to the leaking at the shifter control as an internal leak in the slave valve, an internal leak in the insert valve, an internal leak in the control valve, or the wrong air lines connected. There should be a link in the description with the troubleshooting procedure for this. I think it’s in the larger manual on page 34

[@whackythunder3692]

@@JasonTheMunicipalMechanic thank you.

[@whackythunder3692]

Found it...It was a cracked piston low high in the tranny the area of air regulator.

[@JasonTheMunicipalMechanic]

Glad you were able to find it. How was it to change?

[@whackythunder3692]

@@JasonTheMunicipalMechanic#1 Remove plate/cover..#2 loosen nut...#3 put air to back of piston through air line..#4 remove nut...#5 remove piston. Easy.

[@randyschwehr1464]

I have an Eaton super 10. 5/6 gear are where 1/2 should be then i have 7/8. & 9/10 in 3/4 5/6 as well as where they are supposed to be. Reverse is faster than it should be. Would this be a range problem? Splitter seam to work correctly. Basically im missing 1-4 and reverse is very fast.

[@JasonTheMunicipalMechanic]

It sounds like you not shifting into the lower range. Some transmissions are set naturally in the high range and need the air switching to shift it to low range and some are naturally in low and the air shifts it to high. If your splitter is working then I would assume you have air to the transmission and up to the range selector. If you flip the range selector up and down do you get the burst of air out of the handle? I would go to the hose that goes into the shift fork piston at the rear of the transmission and remove it and switch the range on the shifter and see if you get air coming out of the hose. You should have about 60 lbs I think. If you do your problem will be in the transmission, if you don’t it will be the road ranger valve on the shifter or the slave valve. It should have air in one position and not in the other. Also there will be a constant air applied to the back side of the shift piston (which is the side facing the engine) that keeps it in either the high or low range and when you apply air to the face of the piston the extra surface area because the shaft is not there overcomes the air on the back side and shifts the fork. If your missing the constant source then it could be the air regulator. There are manuals in the description for Eaton transmissions that can help you troubleshoot this further. This is how I would start on the transmission we have. Im not sure how yours is set op so some things may be different than this. Eaton has troubleshooting manuals on there website for I think all there transmissions. I think one of the links I posted is to a page to select your transmission from a list of them.

[@randyschwehr1464]

@@JasonTheMunicipalMechanic i changed transmissions (used) and it has exactly the same problem.

[@randyschwehr1464]

@@JasonTheMunicipalMechanic thank you for your help

[@randyschwehr1464]

I took the air regulator apart and the range piston part attached to it and evidently the super 10 automatically shift between high and low range depending on what position the gear shift is in.if i move it side to side i can now hear it work. It worked for about 3 days. Then it changed its attitude and now i have 2 4 6 8 10. It shifts between high and low range but splitter quit working. It used to be loud like the range valve. But now i can barely hear it. Does this sound like the road ranger valve problem on shifter? Ive since changed the preasure regulator and cleaned the splitter piston.

[@JasonTheMunicipalMechanic]

@@randyschwehr1464 do you have the transmission number off the tag on the transmission. I’m not familiar with your transmission and I don’t want to give you bad information. The video I saw showed using an air lever on the side of the shifter to switch between 1and 2 and so on. I didn’t see anything about a second selector so I’d like to try and find the exact manual before I give you any more advice. There is also a top2 version that shifts between 9and10 on its own which has some electronic control to it. It should default into a regular super shift mode if there is a problem it says but it seems to interrupt the air signal so if it has a physical problem it might not be helping so there are a lot of variables and I’m not sure what you have exactly and I’d like to see the air flow chart to know how it is supplied.

[@billyjoebreweriiillc2663]

Why would oil or tranny fluid end up in air limes to HIGH LOW SPLITTER? bad o rings? Or bad air filter ?

[@JasonTheMunicipalMechanic]

Oil can get into the air lines from the compressor I don’t know how much oil you have coming out but I would check the air tank drains. Some tanks are split into two tanks in one but look like one tank so check both ends for a drain. You might be able to get gear oil from the trans up at the splitter switch from that piston leaking by and oil getting through the exhaust of the valve. Is the splitter cover vent clogged and forcing air up through the splitter switch. There should be a short blast of air, is there a longer higher volume of air at the splitter switch than normal? It’s hard to tell how much oil your talking about or if it’s just a few drops in the line. There isn’t a lot connected to the splitter and I’m really just looking for a scenario that might be possible here. I’ve seen some older trucks get oil in the air lines over time from the air compressor and it will make its way through everything.

[@billyjoebreweriiillc2663]

@@JasonTheMunicipalMechanic thanks for your reply Jason I really appreciate it. I think it's just coming through the Piston or I should say I'm hoping it's coming to the Piston. I'm going to try and change out the splitter and see if that helps

[@stratefacts9075]

I have the same issue...changed the slave valve n my truck still won't go into low range..but goes into high range just fine....it's very frustrating trying to figure this out....

[@Kingsr92]

I Have a code on my dash saying Gear Pos. Sensor Problem Detected Shifts Inhibited 2015 automatic Frieghtliner cascadia Which it’s not allowing me to go into to gear once I go into gear it just Beep I had water in my air tanks I had to drain out It started to work but next day Same thing happened Fault code spn 521485 fmi 2

[@JasonTheMunicipalMechanic]

I found this on a google search of the code. www.justanswer.com/medium-and-heavy-truck/dowqs-freightliner-cascadia-automatic-transmission-spn-521485-fmi.html

[@JasonTheMunicipalMechanic]

Also here is a service bulletin for that code as well. static.nhtsa.gov/odi/tsbs/2017/MC-10189089-9999.pdf

[@Bigola]

Losing air in lo range what should I do

[@JasonTheMunicipalMechanic]

Where is the air leaking from?

[@Bigola]

@@JasonTheMunicipalMechanic thanks for your reply. If I stop at a stop light the transmission will not shift to 3rd gear not until the rmp gets to 2000. And a buzzer horn comes on for low air. What do you think is the problem

[@JasonTheMunicipalMechanic]

Can you hear air leaking? Is the transmission staying in high gear until it shifts? What transmission do you have?

[@Bigola]

@@JasonTheMunicipalMechanic EATON FULLER TRANSMISSION. It SHIFT fine in high gear, it only happens when I stopped at a light or traffic. It will not shift to 3rd

[@Bigola]

@@JasonTheMunicipalMechanic I can't hear air leak but when I stop is always hard to shift to 3rd gear. Please I need help

[@Bonnyiceman]

It would have been more helpful if you touched the line you were referring to than pointing in the general direction of four or five lines with the corner of a sheet of paper. Thank you.

[@JasonTheMunicipalMechanic]

The service manual links are in the description. You can download them and get the diagrams I was using. The manuals will have more troubleshooting info as well.