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ZF Transmission Problems

HATCHEQUIP

Senior Member
Joined
Oct 19, 2011
Messages
1,147
Location
VILLANOW GEORGIA
First time here MAYBE ANSWER SOME QUESTIONS

Answers to SOME of the questions here
1st case problem: Just had one come thru the shop no 1st or 2nd just 3rd and 4th sound stupid that they let you have the high gears but not the low ones but your problem is that wire #i think it was 25 and letter has no power the power goes thru the parking brake switch and thru the declutch switch and the declutch pedal and thru the 2 brake preasure switches then to the computer behind the seat. We found the problem to be low brake preasure not letting current thru the preasure switches.blown oring on the spool in the brake accumalator valve and 1 accumalator that was not holding preasure.

2nd samsung problem: We had a jcb come thru with sometime no direction control in forward and found it to be a micro switch in the controler. On some units that have a rubber boot you can pull it back and listen for a click when tou shift it back and forth maybe spray a little contact cleaner in there to get to working or pull controler off and drill out 2 rivets and you can get to the switches to replace or just give them a good cleaning and then force a little dielectric grease past the plunger into the guts of the switch and use screws or rivets to put back together. The shifter only comes as a complete assembly and is pretty pricey. Hope this helps some one as im getting cramps from all this typing. Havent done this much since highschool alooong time ago. Yall take care.
 

dingo

Active Member
Joined
Sep 18, 2010
Messages
43
Location
nth qld, australia
Occupation
diesel fitter
zf transmission in a komatsu wheel loader

Gents im having issues with a low oil pressure fault on a komatsu wheel loader. im going to change the pressure switch on top of the control valve and then recheck pressures. My question is can mains transmission pressure be adjusted ie. relief valve. i have read and re-read our service manual but cant find whether it can be. Also ive heard these traniies are good when they are working but a mongrel to repair.
 

spanner

Well-Known Member
Joined
Sep 2, 2011
Messages
55
Location
Sunshine Coast Queensland Australia
Occupation
Heavy Equipment Fitter
Answers to SOME of the questions here
1st case problem: Just had one come thru the shop no 1st or 2nd just 3rd and 4th sound stupid that they let you have the high gears but not the low ones but your problem is that wire #i think it was 25 and letter has no power the power goes thru the parking brake switch and thru the declutch switch and the declutch pedal and thru the 2 brake preasure switches then to the computer behind the seat. We found the problem to be low brake preasure not letting current thru the preasure switches.blown oring on the spool in the brake accumalator valve and 1 accumalator that was not holding preasure.

2nd samsung problem: We had a jcb come thru with sometime no direction control in forward and found it to be a micro switch in the controler. On some units that have a rubber boot you can pull it back and listen for a click when tou shift it back and forth maybe spray a little contact cleaner in there to get to working or pull controler off and drill out 2 rivets and you can get to the switches to replace or just give them a good cleaning and then force a little dielectric grease past the plunger into the guts of the switch and use screws or rivets to put back together. The shifter only comes as a complete assembly and is pretty pricey. Hope this helps some one as im getting cramps from all this typing. Havent done this much since highschool alooong time ago. Yall take care.


Hatchequip. I had exactly the same issues. 621B no 1st or 2nd. After much poking around phoned Case dealer who said check brake accumulator pressure. Sure enough one circuit was low. Accumulator control valve is behind a plastic plug just at back of the right rear wheel. Tried adjusting but made no difference . Replaced valve and instantly fixed the problem. Apparently this is their idea of a brake failure sfety control. No 1st or second renders the machine almost useless but still moveable. This machine also had erratic selection of fwd /rev. Swapped out controller with a sister machine and away it went. I didn't try to fix it though just got a new one.
Just on that accumulator control valve, don't try and adjust it without gauges and numbers.
 

DShepard

Member
Joined
Apr 20, 2012
Messages
6
Location
Mass.
I'm working on am SL150 that won't shift into either forward or reverse. We've tried a new shifter, and read out the resistance on the solenoids. When it works, it's fine, but will just stop completely with no warning. Totally dead now. Any advice would be appreciated. Thanks.
 

DShepard

Member
Joined
Apr 20, 2012
Messages
6
Location
Mass.
Yes, there is. It appears to be working. The (P) lights up on the dash, and the relay behind the seat closes when you engage the brake. The way the machine just stops responding acts like it would if you engaged the parking brake, oryou had the declutch switch for the left brake peddle engaged. Dealer is at least 3 weeks out on service. This machine has been very reliable, and still has a lot of life left in it. Too bad the support is no longer available.
 

alrman

Senior Member
Joined
Jun 20, 2009
Messages
3,303
Location
QLD Australia
Occupation
Diesel Fitter;Small Business Owner;Cleaner
Air brakes or power brakes? - check switches
Charge pressure req to release power brakes? - check sender & actual pressure.
 

DShepard

Member
Joined
Apr 20, 2012
Messages
6
Location
Mass.
Air brakes. Machine would always move even if air pressure wasn't up. Technical info is almost non existent. We do have a wiring diagram, but it is very poor.
 

alrman

Senior Member
Joined
Jun 20, 2009
Messages
3,303
Location
QLD Australia
Occupation
Diesel Fitter;Small Business Owner;Cleaner
Does it have a declutch option switch on dash for LH brake pedal?
Is power getting to FNR lever?
Does backup alarm sound when reverse is selected?
Look for all grounding wire points - under dash & around trans & give them a good clean.
 
Last edited:

DShepard

Member
Joined
Apr 20, 2012
Messages
6
Location
Mass.
Yes, it has the declutch switch, which does work, when it moves. The blue light goes on and off when the switch is moved. The relays behind the seat close when the FNR is moved. I can feel different relays closing depending on which direction I select. Backup alarm sounds in reverse. Sometimes strongly, sometimes weakly, or not at all. It's done that for years, however. I will check for good grounds.

This problem started this spring after the machine sat all winter. At first, it was sporadic, but now it's stopped all together. Is there a main power feed to the trans solenoids? When it will shift, I can hear the solenoids working (engine off) but now I only hear the relays.

Thanks for all the help.
 

Alberto Krohn

Member
Joined
Nov 23, 2011
Messages
10
Location
Venezuela
Hello, we have a Terex TA30 articulated truck, on the display appears the error code EE, according to the manual it means that there is no communication from the TCU to the display, and the transmission stays in neutral, it does not move forward and backward. According to the manual we have to check the wiring between the TCU and the display, we have checked it several times and it is OK, we bought a new TCU and the problem continues, I do not know what else to do.
Do you have any suggestion?
Thanks
 

oldseabee

Senior Member
Joined
Jan 23, 2010
Messages
529
Location
Milner, Ga.
Occupation
Retired
Have you checked all the shift solenoids and the lockup valve solenoid? Also check the lockup valve and input speed sensor.
 

IAFarmer

New Member
Joined
Oct 2, 2012
Messages
2
Location
Iowa
Hi-

I have a Case 821B with 8000 hours that keeps blowing the transmission coils/soleniods. We have replaced the FNR shifter, replaced transmission filter, replaced all the soleniods at least twice (at $500 each) replaced a wiring harness, rebuilt a wiring harness that had high resistance, tested the TCU (which had been replaced previously). All of this work and probably more was done by our area Case dealer's technicians. This last time, our $3000 in repairs got us 5 hours of operating time. Then it wouldn't move. After letting it sit overnight, we were able to get it to go in 3rd & 4th. This has been going on for years, according to the previous owner. I feel like we are treating the symptoms, not the causes of the issue. There must be something that the techs are not considering. Anyone have any ideas?

Thank you
 

quackattak

Well-Known Member
Joined
Jan 30, 2010
Messages
188
Location
Oregon
need to physically track down your ground for the coils, I went through same thing with a 621b. Once I grounded the solenoid harness to the transmission had no more problems. Ask your techs what is inside the coil and what would cause it to fail, start tracking down your problem one coil at a time. If there not grounded properly there is no way to control voltage. The computer is very delicate, any wiring trouble the computer will shut itself off.
 

IAFarmer

New Member
Joined
Oct 2, 2012
Messages
2
Location
Iowa
re:

need to physically track down your ground for the coils, I went through same thing with a 621b. Once I grounded the solenoid harness to the transmission had no more problems. Ask your techs what is inside the coil and what would cause it to fail, start tracking down your problem one coil at a time. If there not grounded properly there is no way to control voltage. The computer is very delicate, any wiring trouble the computer will shut itself off.

I think you may be right about the ground. When he was hooking the battery up yesterday, Dad said that he could feel an electrical tingle when he leaned against the frame. If it is trying to ground through him, then the regular ground must not be 100%. I will definately have the tech check that out. Thanks!
 
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