I have a fleet of DD13 engines paired with Allison automatic, only one paired with DT12 and it has the same problem for the past two years. The problem started when the truck had around 500k miles. Basically, when the truck hit any bump or pothole, it would be out of any gear, and into Neutral. Right before it did that, the Hill Descent, both Re-gen, Start Blocked, and ABS lights would come on. I took it to local Freightliner dealer at least five times for the problem, they eventually lowered the trans and replaced PT Can, split-pin bushing, clutch, wiring harness, new filters, trans fluid, and other things. Now, the problem is that with a load and incline, all the dash lights that I mentioned before would came on, the truck would go into Neutral no matter what gear it was in, but if you let go with the accelerator pedal, the truck would go back into gear, but the cycle never stop, until the truck lost enough speed, and had to pull to roadside to re-start.
2018 Cascadia, when driving in town coming up to a light or stop sign, transmission will be very slow downshifting. Will start at 12 and usually gets hung up on 8. If I use the engine brake I can get it downshift to 6. Manual shifting up or down no issues. Issues are only in Auto. Usually at the light or stop sign I'll put it in neutral and then drive and it starts off in 3. Btw, I am having ABS issues as the light is on. Not sure if that's related. Also was told by the dealership according to my VIN that it does not have a filter.
Hi, great video. Have a question. When driving along and come to a stop, start to go again, it will go to manual mode, stop again and go to drive again, driver said it will do it in reverse as well. I'm assuming he means when truck is in reverse, and got to drive, it will switch to M mode. Need to stop truck everytime to d\go to drive. Driver says it does so also when truck is loaded. It will swith to M. Any advice will be greatly appreciated. No metal found in the oil, which is a relief hopefully.
How about the counter shaft brake? My DT12 revs up when shifting from even to odd gears. When I take off my feet from the accelerator pedal when it is about to shift, it will shift without a problem.
I have a DT12 in a 2016 and it will not pass transmission relearn but will pass clutch learn. It gives me the fault “minimum distance selector”. I just replaced the shift actuator and the split pin and the transmission wont go in neutral. The dash shows two dashes and the truck will start but wont move. Before this happened we had an issue where the transmission would get stuck in gear and keeps trying to pull forward even when you come to a complete stop. You would have to turn off the truck to stop it from moving. I was told it was the actuator or the split pin so I replaced both and reinstalled the software for the TCM. I dont know a whole lot about these transmissions so any help would be appreciated.
DT12 when pulling a loaded trailor 44k. I slow down to a stop light or brief stop (down shift). The truck accelerates from a brief stop. Truck jerks dives, stutters or sometimes stops especially up hill. The code "wont shift into gear" and " shift to neutral starter block", the codes rhen clear. Come to full stop shift into gear and drives fine. Only seems to happen when coming to a stop from a higher speed then accelerating like at a stop sign. The truck shifts fine when not loaded. Seems to happen with a heavy load so far.
I’ve got a DT12 that will not shift at all, I’ve done a clutch leak test, it’s passed I’ve relearned clutch Transmission will not re learn tho, I have a procedure fault stating the countershaft speed is too high
Hi steve. Hope help me find problem whit my transmission when driving show red scring transmission fault need repair service show F snd the gear but chang gear ok i stop truck turn off 5 seconds and turn on back snd the transmission Fault go off normaly do it when use engine break to often. Thanks
My dt 12 hesitate to shift to neutral after stop. What should I look for? Oh , secondary air tank drop fast , its randomly drop 10 psi within 5 seconds. Thank you
No throttle,truck shift to drive and neutral however will act as if it wants to move but will not move either direction drive nor reverse. i really don’t know what’s holding the truck to move. No codes only check engine light. Freight liner cascadia DD15 with DT 12 engine. Will appreciate your input. Thanks.
Hi,mine shift to 7 gear ,then when I accelerate it shows me 7 gear but truck not going,just down shift to 6 and it’s all good ,it happened few times what it can be? I got this truck 2 years ago,I have no chance to change fluid maybe I it’s fluid ?thank you
I haul chemicals with tank surge. Do you recommend getting a manual over the DT12 Automatics? It's hard finding a 3-4 year old truck that has a manual transmission.
Hey Steve, I have a DT12 on a 2017 cascadia evo I have started having a issue similar to what you are explaining on the video my dt12 recently started going into neutral while up shifting from 11-12 and more often while down shifting on low gears. When I arrive to a stop or red light it tends won’t go into gear just stay on neutral and I’ll have to switch to drive or reverse and neutral on the handle while it’s on neutral and trying to go into gear it’s making shifting hissing noise like it’s trying to enter but won’t enter gear at some point it’ll go into gear and on handle I’ll switch to drive or reverse depending what I’m trying to do at the moment , can that be related to the relearn ? I’ve added over 100k miles and haven’t done a relearn while doing pm service.. any thoughts on what it might be ?
I know this is probably a stupid question but there's no question stupid not the one that's not asked does the transmission do I have to do any programming to the transmission before I install it
Hey Steve, my ABS light is coming on whenever I push the brake paddle It will be quick for a few seconds and then goes back off. It just happens when I have a trailer any recommendation thank you
To address that code you will want to check the connector at the TCM X1 ( transmission computer ). Look for damaged or loose pins. If you cannot see any pin damage then you have to remove the transmission computer to inspect for water intrusion. If there is water intrusion then you have to replace the computer. If theres no evidence of water intrusion, shift your attention to the automated the shift controller which is bolted to the side of the transmission and inspect for damage
My truck has 650,000 miles. I recently replaced that stupid split-pin and had the mechanic inspect the clutch, he tells me clutch is fine. This is the original clutch (I bought it new) what's up with that? Do they last that long?
Did you tell your mechanic you had the truck all that time and didnt replace the clutch! If yes, look for another mechanic for your transmission issues! Clutches have a minimum 300,000 replacement for long overhaul or sooner for short overhauls! In other words change your Clutch!
@@am.b5688 Yes I did and he says computer or the solenoids float gears most of the time barely touching the clutch. His words. Truck shifts fine, zero transmission issues (knock on 🪵) so I have no complaint. The reason for the transmission work was the splitter pin refused to put a gear so since they're going through the area I requested for clutch inspection in that case I could safe some money on labor
I have a 2017 DT12... When I'm loaded, if I have my foot to the floor, there will be slipping in 10th 11th and 12th.... Usually at the lower RPM range of those gears, it'll slip for a second and then come back and grab and maybe slip some more, maybe not. But if I'm easy on it, it may not slip as much. It's hard to get it to do it bobtail. But it does still do it, if my foot's to the floor in 12th gear...... If I shift manually, and run the gears a little bit tighter, higher RPM, without my foot to the floor, and I shift into the next gear, the RPMs don't drop as low into the next gear, and I can avoid the slippage. Any thoughts?
Had the same problem. 2020 Cascadia with 525k miles. Spent 3 month in/out of the shop. Did every testknown, sent the data to Daimler , no luck. Finally changed the clutch and solved the problem.
F$&K Speedco - They wanted $150.00 shop labor and several hours of wait time with only 1 guy working the lube side for changing out the fluid - I skipped it and got it done in about an hour $50.00 shop labor in Wilmington CA - And FYI DD12 fuid ain't cheap ! Paid $93.00 a gallon from Freightliner for 4 gallons
Shift-N-Shift, if not an air leak, is likely a failed Split Pin Bushing. This is a known issue with a detroit bulletin
I have a fleet of DD13 engines paired with Allison automatic, only one paired with DT12 and it has the same problem for the past two years. The problem started when the truck had around 500k miles. Basically, when the truck hit any bump or pothole, it would be out of any gear, and into Neutral. Right before it did that, the Hill Descent, both Re-gen, Start Blocked, and ABS lights would come on. I took it to local Freightliner dealer at least five times for the problem, they eventually lowered the trans and replaced PT Can, split-pin bushing, clutch, wiring harness, new filters, trans fluid, and other things. Now, the problem is that with a load and incline, all the dash lights that I mentioned before would came on, the truck would go into Neutral no matter what gear it was in, but if you let go with the accelerator pedal, the truck would go back into gear, but the cycle never stop, until the truck lost enough speed, and had to pull to roadside to re-start.
Have you figured out the problem
Much appreciative of the break down on the dt12 … especially for the people like my self who works on there own truck
2018 Cascadia, when driving in town coming up to a light or stop sign, transmission will be very slow downshifting. Will start at 12 and usually gets hung up on 8. If I use the engine brake I can get it downshift to 6. Manual shifting up or down no issues. Issues are only in Auto. Usually at the light or stop sign I'll put it in neutral and then drive and it starts off in 3. Btw, I am having ABS issues as the light is on. Not sure if that's related. Also was told by the dealership according to my VIN that it does not have a filter.
Hi, great video. Have a question. When driving along and come to a stop, start to go again, it will go to manual mode, stop again and go to drive again, driver said it will do it in reverse as well. I'm assuming he means when truck is in reverse, and got to drive, it will switch to M mode. Need to stop truck everytime to d\go to drive. Driver says it does so also when truck is loaded. It will swith to M. Any advice will be greatly appreciated. No metal found in the oil, which is a relief hopefully.
Great video! This helps me pinpoint the issue I am dealing with. What is the name of the part you are describing at 4:08? Can you provide that? Thanks
What if we are park and it won’t go in to Reverse or 1st gear?
Thank you very much for making this video learned a lot.
How about the counter shaft brake? My DT12 revs up when shifting from even to odd gears. When I take off my feet from the accelerator pedal when it is about to shift, it will shift without a problem.
Thanks best explanation
I have a DT12 in a 2016 and it will not pass transmission relearn but will pass clutch learn. It gives me the fault “minimum distance selector”. I just replaced the shift actuator and the split pin and the transmission wont go in neutral. The dash shows two dashes and the truck will start but wont move. Before this happened we had an issue where the transmission would get stuck in gear and keeps trying to pull forward even when you come to a complete stop. You would have to turn off the truck to stop it from moving. I was told it was the actuator or the split pin so I replaced both and reinstalled the software for the TCM. I dont know a whole lot about these transmissions so any help would be appreciated.
Did you figure out what the issue was im having a similar issue
Did you figure out what the issue was ?
Have you figured anything out
I'm keeping my 10 manual Eaton
My dt12 goes 1 to 6 just fine then when it time to go to 7th it has a hard going into 7 when the truck is cold
DT12 when pulling a loaded trailor 44k. I slow down to a stop light or brief stop (down shift). The truck accelerates from a brief stop. Truck jerks dives, stutters or sometimes stops especially up hill. The code "wont shift into gear" and " shift to neutral starter block", the codes rhen clear. Come to full stop shift into gear and drives fine. Only seems to happen when coming to a stop from a higher speed then accelerating like at a stop sign. The truck shifts fine when not loaded. Seems to happen with a heavy load so far.
Sir, did ever find out what was the cause , I’m dealing with that exact problem? Thanks!
Hi I have same problem with my 2019 Freightliner’s Cascadia, specially when it’s cold weather, what would be the problem thanks
Hi I have same issue did you find out what is the problem?! Thanks
2019 Cascadia with DT12 660 k miles, also noticed will not shift at colder weather, from the and starts kinda of little jerky while driving
I’ve got a DT12 that will not shift at all,
I’ve done a clutch leak test, it’s passed
I’ve relearned clutch
Transmission will not re learn tho, I have a procedure fault stating the countershaft speed is too high
I like it , thank you brother
Hi steve. Hope help me find problem whit my transmission when driving show red scring transmission fault need repair service show F snd the gear but chang gear ok i stop truck turn off 5 seconds and turn on back snd the transmission Fault go off normaly do it when use engine break to often. Thanks
My DT 12 revs up on up shift what would cause this just repleced clutch flywheel and actuator about a year doing something again
Cascadia 2020 what means light came on says..clutch under heavy strain ??
My dt 12 hesitate to shift to neutral after stop. What should I look for? Oh , secondary air tank drop fast , its randomly drop 10 psi within 5 seconds. Thank you
No throttle,truck shift to drive and neutral however will act as if it wants to move but will not move either direction drive nor reverse.
i really don’t know what’s holding the truck to move. No codes only check engine light. Freight liner cascadia DD15 with DT 12 engine.
Will appreciate your input.
Thanks.
Shifter paddle
How do you attach a PTO?
Hi,mine shift to 7 gear ,then when I accelerate it shows me 7 gear but truck not going,just down shift to 6 and it’s all good ,it happened few times what it can be?
I got this truck 2 years ago,I have no chance to change fluid maybe I it’s fluid ?thank you
What causes a shudder at little or light acceleration
I haul chemicals with tank surge. Do you recommend getting a manual over the DT12 Automatics? It's hard finding a 3-4 year old truck that has a manual transmission.
Is there a possibility of an internal air leak in DT 12 looks like I have this problem.?
Hey Steve, I have a DT12 on a 2017 cascadia evo I have started having a issue similar to what you are explaining on the video my dt12 recently started going into neutral while up shifting from 11-12 and more often while down shifting on low gears. When I arrive to a stop or red light it tends won’t go into gear just stay on neutral and I’ll have to switch to drive or reverse and neutral on the handle while it’s on neutral and trying to go into gear it’s making shifting hissing noise like it’s trying to enter but won’t enter gear at some point it’ll go into gear and on handle I’ll switch to drive or reverse depending what I’m trying to do at the moment , can that be related to the relearn ? I’ve added over 100k miles and haven’t done a relearn while doing pm service.. any thoughts on what it might be ?
I know this is probably a stupid question but there's no question stupid not the one that's not asked does the transmission do I have to do any programming to the transmission before I install it
Yea
Hey Steve, my ABS light is coming on whenever I push the brake paddle It will be quick for a few seconds and then goes back off. It just happens when I have a trailer any recommendation thank you
Mine too, please share if you find out
@@namelessless9055is that a trailer abs light or trucktor one
@@suldaan87trailer abs light
What the clutch life on dt12
And what the system when it going to bad and there’s any way to check ?
300,000 or sooner for city driving only!
Man I think I fuked up buying this rig....😅
Are there any grease fittings on this transmission?
Is it safe to change the fluid if it's at 500,000 miles?
Should change its oil with Detroit AT-12 approved transmission fluid every 300,000 miles
I want to repair my truck's automatic transmission. My truck is in Richmond CA area. Do yoy have any branch in this area?
spn 521485 fmi 2, can you tell me where the gear position sensor is? Thank you
To address that code you will want to check the connector at the TCM X1 ( transmission computer ). Look for damaged or loose pins. If you cannot see any pin damage then you have to remove the transmission computer to inspect for water intrusion. If there is water intrusion then you have to replace the computer. If theres no evidence of water intrusion, shift your attention to the automated the shift controller which is bolted to the side of the transmission and inspect for damage
@@LRMLeasing thank you sir, I will give that a look
Buen video go USA thanks
My truck has 650,000 miles. I recently replaced that stupid split-pin and had the mechanic inspect the clutch, he tells me clutch is fine. This is the original clutch (I bought it new) what's up with that? Do they last that long?
Did you tell your mechanic you had the truck all that time and didnt replace the clutch! If yes, look for another mechanic for your transmission issues! Clutches have a minimum 300,000 replacement for long overhaul or sooner for short overhauls! In other words change your Clutch!
@@am.b5688 Yes I did and he says computer or the solenoids float gears most of the time barely touching the clutch. His words. Truck shifts fine, zero transmission issues (knock on 🪵) so I have no complaint. The reason for the transmission work was the splitter pin refused to put a gear so since they're going through the area I requested for clutch inspection in that case I could safe some money on labor
l am viet nam love semi trucks united startes.
❤❤❤
I have a 2017 DT12... When I'm loaded, if I have my foot to the floor, there will be slipping in 10th 11th and 12th.... Usually at the lower RPM range of those gears, it'll slip for a second and then come back and grab and maybe slip some more, maybe not. But if I'm easy on it, it may not slip as much. It's hard to get it to do it bobtail. But it does still do it, if my foot's to the floor in 12th gear...... If I shift manually, and run the gears a little bit tighter, higher RPM, without my foot to the floor, and I shift into the next gear, the RPMs don't drop as low into the next gear, and I can avoid the slippage. Any thoughts?
Had the same problem. 2020 Cascadia with 525k miles. Spent 3 month in/out of the shop. Did every testknown, sent the data to Daimler , no luck. Finally changed the clutch and solved the problem.
Didn’t you smell clutch?
Would you able to find out the problem?
F$&K Speedco - They wanted $150.00 shop labor and several hours of wait time with only 1 guy working the lube side for changing out the fluid - I skipped it and got it done in about an hour $50.00 shop labor in Wilmington CA - And FYI DD12 fuid ain't cheap ! Paid $93.00 a gallon from Freightliner for 4 gallons
If you are conblaiving about fluids, you dont have a problem!
Can you install a PTO on this dt12
Where do you find a pot for it
Any luck??? On PTO DT12
Yes it mounts on the rear plate on the right side of the driveline
Dt12 and truck quit pulling and has a hot brakes smell,no codes what’s your opinion? Bad hot smell around the flywheel area