ZF FREEDOMLINE TRANSMISSION ISSUE

[SIVRTNGE2]

Hello All,
I'm trying to fix a transmission issue with my coach. I posted the problem on EI forum board, and was wondering if I could copy it here. If this isn't right, please forgive me and delete the post!!! If you're able to help correct this, please chime in!!!
Thanks in advance!!!
--
Bill


It’s been quite a while since I’ve given an update on Sadie. She’s running stronger than ever however, the transmission that was married to the ISX will not shift in auto mode. It is a Meritor ZF Freedomline 12 speed automatic unit.
The problem I’m having is this: the donor vehicle that this power plant came from had ABS. The transmission has an ABS “checks and balance” program in it that can’t be turned off or bypassed so I’m being told. Because I don’t have ABS on my coach, it will not shift in auto mode. I have talked to several people at different shops and online ABS forums that state the program in the transmission checks for speed sensor (tail shaft sensor), steer axle sensor(s), and drive axle sensor(s). The ABS module is in place, and Sonny told me that the light is on when he plugged it in so I’m thinking it’s looking for the wheel sensors that I don’t have.
I have looked at removing this transmission and replacing it with a B500 or HD4060 as a last resort. I have had Sonny to install a new clutch and fork kit for this unit therefore, I’d like to keep it and not blow more money by replacing it. I crunched some numbers and came up with trying to add ABS to the coach would be about $2300 less than R & R the transmission altogether.
To “all” of the talented folks we have on this forum, can someone please help me to get this figured out? I have always said “CANT” went away back in the early 70s.



rv_safetyman wrote:
Hi William

What a bummer! I did a bit of looking and found the following interesting information:


Quote:
The Freedomline transmission, from ZF-Meritor, first appeared in Peterbuilt 387's in 2001, and in T2000's and Volvo's in 2002. It a 2-pedal transmission with an air actuated clutch with a separate air tank. It is available in a 12-speed and handles up to 1650 lb-ft of torque. It has an aluminum transmission case, so it is lighter than the other automated transmissions. The shift console is typically mounted to the driver's seat and can swing up. The Freedomline will "skip shift" on its own - that is, if it detects a light load it will skip gears when upshifting. ZF-Meritor got into a series of lawsuits with Eaton and no longer sells transmissions in the United States market. If you are looking at a truck with a Freedomline consider that in the future it MAY be the case that knowledgeable service technicians and parts will be less available for a transmission that is no longer imported. Given an equal truck I'd probably not choose the Freedomline.


Since they no longer sell in the US, that will make getting technical information even tougher.

I have to wonder out loud if a person could set up a frequency generator to simulate the ABS sensors? It sounds like there are four wheel speed sensors. Can you locate them in the bundle? We would need to know if the transmission is only checking to see if all the wheels are going the same speed or if they are the correct ratio for the transmission pulse output. Next question would be: is the transmission looking for a pulse count (most likely) or a voltage?

As I think about it, I think a person (not me, but a good electronic designer) could design a fairly simple circuit to take the pulse output from the transmission, and convert it to a wheel speed pulse frequency.

Jim



SIVRTNGE2 wrote:

Hey Jim,
Thanks for the response. I did not know the transmissions were no longer available in the US. I do know that Volvo of Atlanta said if I ever needed anything, they could get it.

As for as the pulse generator thingy and the electricians are concerned, this is way over my head. I found this by doing some research:


Quote:

Gentelmen - Freedomline will not work in auto mode w/o ABS. This TCM compares Front wheel speed, rear wheel speed (of every wheel to check for tracktion) and output shaft speed (VSS). Only comparing all this data TCM may shift in auto mode.

So if you deisable ABS ore EBS (depending on trucks and year of make), ore one ore more wheel speed sensor will not work properly you will get J1939 no all data code in your transmission and you will shift manually.

Now pull all ABS codes, clear codes, do the test drive and pull all current and stored codes (MID 136 SID/PID/PSID/PPID FMI) and I will help you.
I need to know what brand is ABS unit, what P/N. Usually there are ABS-D ore ABS-E by Wabco (Poland make, Wroclaw plant) units, but It will not be a surprize for me if there is Bosch/KnorrBremse/Bendix unit ore something more exotic.

Anyway I will help you to fix your ABS


This guy is in Uganda or somewhere and I haven't been able to get in touch with him.




rv_safetyman wrote:

William, that is a good starting point. I have downloaded the service manual to see if anything jumps out at me.
I am going to start a new thread so that we don't clobber up your project page.

Jim



   

rv_safetyman wrote:

William, as noted, we are making a bit of headway here. I downloaded the Maintenance Manual and I am picking away at that manual. Your note from the tech helps a lot in that he clarifies that the transmission speed sensor output is compared to the output of the speed sensors. That is a big piece of information.

I have been looking at the wiring diagram and it does not have any wheel sensor input locations which leads me to believe that that the transmission ECM gets the wheel speed transmission speed information from the ABS ECU unit. Do you have that unit? If so, we need to see what inputs it has to the box.

One of the main things we need to deal with is what fault codes you have. From the manual, it looks like you would have an Fault 231 FM 14 error. That is the fault that says the ABS ECU is not communicating with the transmission computer.

Not sure how this fits, but here is the quote on the transmission sensor:


Quote:
Output shaft speed sensor #2
is a four wiring harness that plugs
into the transmission wiring harness
(the same one that is connected
to the voltage doubler and ZMTEC).
It is protected with convoluted
tubing. Automatic mode is
available, there are no system
restrictions.


Jim

 

SIVRTNGE2 wrote:
 
Hey Jim,
I'm sorry to say this but here we go!!! I'm a truck driver with expertise in the the transport field  . What you just said to me is like speaking Dutch. Sonny still has Sadie in his possession. He did tell me that the transmission has "SM" on the display. He also said when he hooked up the ABS, the idiot light came on. That's all I know.

Maybe Sonny will see this thread shortly and tell the rest of you geniuses what he has tried!!!
--
Bill
 
 

[Busted Knuckle]

Could the ABS system be fooled by using 1 wheel sensor (on just 1 wheel or even the transmission?)

Trust me I'm the last one you want fooling with electronics issues, but just a suggestion!
  BK 

[SIVRTNGE2]

Thanks BK,

I appreciate someone even responding. I haven't been on this site in so long...I thought everyone might have forgotten me lol. I think Sonnie has already tried to do this.
--
Bill

[George Todd]

Can I make a suggestion in the form of a question?

What does the ABS do when it is satisfied that everything is turning at the right speed?  The answer might be that it sends a DC signal on one wire to the TCM, allowing it to upshift, or shift automatically.

Look at the harness between the ABS and the TCM and see if the wire functions are described.
HTH,
G

[luvrbus]

Check MCI Tech Support they used the ZF in some of their models just don't say Eagle lol sorry but I never heard of anybody getting one to shift automatic with out the ABS

[TomC]

Freightliner also offered the Freedom 12spd ZF transmission for a short time.  We bought all the specialized tools to work on the transmission-but later finding out the transmission is so complicated, we never worked on them-just R & R'd them with a factory replacement unit.  I haven't seen a ZF in a truck for a long time-yet it was 2002 & 2003 when they were offered.  When they work, they're nice, but when they need work, they're very expensive to work on.  I would suggest you change over to the Allison 4000 series since the ZF Freedom is not available in the US anymore.  Trying to setup your bus with ABS is just going to be a big headache.  With the sensors, having the wire looms made (you can't just cut an ABS wire to length and hope it works), programming a computer (if you in fact even have the proper computer for ABS to read).  I would just cut my losses with the Freedom transmission and switch to the nearly dirt reliable Allison transmission-you'll love the performance difference-and if you drive it right, the fuel mileage will be about the same.  Good Luck, TomC

[luvrbus]

They have a plant in Greenville SC to build the ZF for trucks ZF won the law suit against Eaton and the truck manufactures

good luck

[SIVRTNGE2]

Well, I just want to say thanks to each and everyone of you for the replies. I have decided to try 1 or 2 more options before I throw the towel in. Any and all other suggestions would also be greatly appreciated!!!
--
Bill