I've been fixing up a Terex 2566 for the past several months that I took off of someone's hands. It was sitting in a field with a load of dirt for several years and with tons of luck we were able to get it started, get it moving, dump the load, and get it on a trailer back home. That is when the fun started. Replaced starter that we burned up trying to get it fired up with very low compression. It had excessive blow-by and so we put in new pistons and sleeves and head gasket. We also rebuilt the turbo while we were at it. Radiator had to be pulled due to a pinhole leak and currently just patched up with JB radiator epoxy. New radiator is in the box waiting for overall truck to back in operational service. Here is the issue I could use some help with. After tons of work, we are now to the point of driving it around and it seems to have low drive power. For example, driving up a small incline with no load, we have to downshift all the way to 1st, keep engine rev'd high and it still struggles to make it up. It basically needs engine rev'd high to get going and maintain speed. On flat ground it will get up enough speed to get up to 3rd or 4th gear, but seems sluggish to get there and stay there. Aftermarket Deutz BF6M1013 engine with turbo Original??? ZF 6WG200 transmission Here is what I know about the transmission: Rewired everything from shifter to trans controller, getting proper 24V to proper solenoid controls. Drained oil and changed filter, put new engine oil back into transmission. Has a 4 solenoid controller box mounted on the side. These were originally stuck, all were pulled, put into cleaner, and exercised until functioning again. Currently has ~16bar pressure at the control port, it does require truck to be rev'd up, not sure if that is normal or not Currently has ~12bar pressure at each of the clutch ports Verified correct control pressure at correct clutch ports for each gear. After all that work it shifts F1-F6 and R1-R3 just fine Part of the problem is I don't know what "normal" is for any of the measurements. Should it have 16bar at idle? I'm pretty sure the truck doesn't have the torque it is supposed to, I don't think it would make it up a small incline with a load of dirt. When I unscrew pressure ports to check pressures, the oil seemed to have bubbles in it, which I don't think is normal. I don't think a brake is locked up as it seems to start rolling just fine. Appreciate any help I can get.
Hi Wits_end, please check the conversations folder. 12 bar at low idle is rather low, I'd say 14 bar/low idle is ok. However if pressure goes up to 16 bar at higher rpm, it is ok. No risk for slippage of clutches. Brakes: No residual pressures built up during drive? Not getting hot when driving? Brake pedal clear? No cabine mat touching pedal? Stall speed? Shift into 6th gear, wide open throttle, brakes applied, engine reaches which speed? Should be around 1800 to 1900 rpm. Oil level in tranny: around 50 to 70 mm below center output shaft, tranny warm, neutral, engine idling.
Thanks for the document and information, I finally got back around to testing so I could be a bit more specific about the numbers. Attached shows transmission oil pressures, I believe this is the control pressure as it is plumbed right next to the control pressure port on the controller as far as I can tell. Picture 1 is with the machine on, in neutral, at idle, about 13.5bar Picture 2 is in 1st gear, at idle, about 14.5bar Picture 3 is in 1st gear, with engine rev'd up to operating rpms, truck is moving, about 15.5bar The 12 bar I mentioned before is the pressure going out to the clutches, such as K1, K2, KR, etc, measured at the ports on the side of the controller. I read somewhere that there were supposed to be 12bar when the specific clutch was engaged by shift pattern. Brakes: Not sure how to tell if a brake is stuck or sticking? Picture showing pedal, all clear as far as I can tell. Applying the brake pedal stops the machine, so something is engaging, but still could be a stuck brake. Could a brake converter be bad? Not easy to lift machine and roll tires. Stall speed: RPM gauge is broken, will fix at some point, but don't know exact rpms. When in 6th gear, foot on brake, rev engine up, truck doesn't move, I would estimate 2-2.5x the idle speed. Again, no idea on exact rpm, but would guestimate 700 at idle and guess it is not far from 1800-1900. Oil level in tranny is at the top cutout in the dip stick when idling and at temp. Few pictures of brake pads, one is a bit shiny, but maybe it is the only one working?
Hi Wits_End, the pressures look pretty nice. Another idea: Does the Lock-up-clutch (LUC) engage? I doubt. Means you are driving permanently in converter mode. Pressure LUC: Page 59 port 67. LUC should engage as soon as turbine speed reaches around 1300 rpm. There is a small e-module installed somewhere counting turbine speed. Sensor page 45 pos. 7 faulty? plug/wires okay? Module will energize external solenoid for LUC located on rear side of control valve. Not sure whether LUC will already engage in 1st and/or 2nd? But must engage in 3rd up to 6th. Pressure around 12 to 13 bar.
Or what is more likely: There is an EST25 TCU box fitted for automated shifts, however result the same.
Sure do appreciate your time. I have the setup most like the one shown on page 71, with the A4 module. Only thing different is I only have 4 solenoid on the transmission controller for gear selection, not 5 as shown with Y1-Y5. I found an ohm measurement test for B2 speed sensor somewhere online and have previously checked it out to be within "good range". I have double checked the wiring too, but have not tested operation. The connector at the lockup clutch solenoid was broken long before but I repaired that and believe it is making good connection now. Just now this is what I checked: Lockup clutch pressure gauge never indicates any pressure, has not since I got it. I removed the gauge and put a pressure gauge on the hose, then I checked at idle, in 1st gear with brake on, and in 3rd gear with brake on and engine rev'd up as high as it would go. No pressure at all and doesn't look like fluid has been in the line recently. Reinstalled gauge and drove from 1st-4th and never got pressure on gauge. I removed the lockup clutch solenoid and it clicks with 24V applied using bench supply. I started machine with solenoid out and fluid gushed out of the hole. I reinstalled lockup clutch solenoid. I took off lockup clutch connector and put voltmeter on it and did the same above in 1st and 3rd and never got 24V. Waited for machine to reach air pressure to have brakes, took off driving with slight downhill and it seemed to go 1-4 just fine, not extremely agile, but moved. Got to bottom of slight incline and turned around, machine started struggling to turn and then to get going back up hill, had to shift all the way down to 1st and still struggled to get all the way back up. I would think if Lockup was engaged all the time, which I don't think is true, it would kill engine in 1st gear at idle? Next thing I can think is to remove all air pressure and see if maybe a brake controller is applying brakes? It does not have a parking brake at all, so no issue there. Not to jump onto another issue, but could be related, but we rebuilt air compressor and put new discharge line in and now we stay up around 150psi and about every 20seconds it pops overpressure valve to relieve overpressure. What regulates the air compressor to only maintain 120 or so psi?
Ok, 4 solenoids mean you got a really old baby. Almost 40 years old? LUC will only engage with tranny in gear AND turbine speed above 1300 rpm (and possibly from 3rd upwards, depending on setup). So, you need to drive to get turbine above 1300 rpm. And you should feel and hear the engine pulled down and truck being accelerated with engaging LUC. If you take off solenoid and start engine the pressure feed channel of LUC valve will spread oil. I'm still convinced the LUC doesn't shift. As long as the pressure gauge for LUC is not showing anything there is no signal from E-module. For a test: Energize LUC solenoid externally with 24 V when driving. You are right, at standstill with tranny in gear engine will be stalled with LUC engaged.
Yup, it was originally greenish color, someone oversprayed it white. I do not know the exact year, but I was guessing late 80s or early 90s. A41036 Thanks for that second image, I have searched everywhere for that and have been unable to find it. I took shifter and entire harness apart to draw up something like it. Oops, wasn't thinking straight, turbine would be output, not input, so machine needs to be moving to get rpm, got it. I'll give the LUC 24V while driving and see what happens.
Hi again, please see here two more copies out of a manual of 1984.
Keep the info coming. Do you have that '84 manual? That is the Module we have in the dash. It has the pin numbers inside the module connector. I believe this was messed with in the past as the module was unplugged and on the dash when we first got the machine. I checked the wiring and it appeared to be wrong and missing the (+) wire to 24V. I originally did some testing with the red 24V wire, but that ended up being the (SM) wire, so not a good 24V source for engaging the solenoid. Guess in my past wiring checkout I assumed the module was right and likely didn't put attention to it since I didn't think I needed Lockup Clutch yet. First test I did what you said (no module), started driving, got to third gear and connected 24V to the (WK) wire, engaging the solenoid and bam we got good lockup pressure. The machine had more torque behind it in all gears above 3. As we got to the end of the test track, we did a circle turn to head back up the small incline, the machine had to be shifted down to 1st to get through the turn. For some reason in somewhat tight turns it really drags down. Another thing to look at. I applied 24V to the Lockup solenoid and it engaged in med-high rpms in 1st and 2nd and it seems to have more torque in those gears. Second test I reconnected the Module and it never engaged clutch in any gear or speed. I measured the inductive turbine speed sensor before with machine off and compared to this I found online somewhere: Speed Sensor is Good: 987ohms (Spec: 920-1120 ohms). Can't say this is 100% right, but did measure between something I found online. I measured the turbine speed sensor yesterday while driving and saw about 4k ohms at very lowest speed and mainly between 7.5k-12.5k while driving normal speeds, may have saw up to 14.5k at highest speed. Does this sound right? Should I have measured voltage or current? Seems like an inductive transmitter should be sending out a voltage pulse based on speed. Module Going to try to test module on a bench. From my picture attached, I gave hot 24V to (+) on pin 6 On pin 3, I measured 24V, looks like it is connected to some relay inside the controller. (IG) pin 4, Not sure of the exact output of the inductive transmitter (IG). Looks like the diodes need to be energize from right to left to flip those switches and engage WK. (SM) - When IG triggers WK, it looks like this signal gets grounded and flips a relay inside the controller. What is SM and what is it supposed to do? Not sure my module is working, but need to test IG first. Can you help with any tests for this? I don't see anything in circuit that limits WK to 3rd gear or higher? If IG is only based on output turbine speed than it should engage in any gear? I don't know what SM is doing? Would WK clutch potentially burn up if engaged in 1st while moving? Thanks!
Hi, yep, I got this manual, however this a really general manual including also the 4 speeds w/o LUC. The copies I sent is the entire stuff for LUC + 6 speed version. The SM port is a signal for gear shifter to avoid downshifts at too high speeds. (risk of overspeeding t/c and engine). SM (Sperrmagnet) locking device in shifter, locking shifter mechanically. W signal from shifter (wire 10) will switch off LUC during gearchanges. (During tests with external 24 V on LUC solenoid you should disengage when doing gearchanges as shifts with LUC on are harsh.) Tight turns: Are you sure difflock (between front and rear axles) is disengaged? Speed sensor: should throw a voltage between 0.5 and 6 volts. Test: tranny neutral, engine reving up, turbine will spin and sensor should give voltage. Some LUC E-modules got a signal from shifter not to engage LUC in low gears. Simply shift comfort reasons. There is no reason for burning LUC or something else in 1st or 2nd. This feature is not shown in this general manual.
Checked IG with machine on and in neutral using standard DC voltmeter. 0.0V at idle 1.5V at nearly full throttle Not sure of the exact circuit, but wouldn't this be a pulsed output, probably can't read without an oscope? I tried testing the Module by giving 24V and then a 0 to 6V input, but never got a 24V output at the WK pin. Maybe due to the IG signal needing to be pulsed at some rate? Without exact details of the control switch circuit, either the switch clicks at a certain voltage or there is filtering to switch when the RPM or pulses get to a certain frequency. Waiting on new retention spade connectors to finish rewire and try module in machine again. Per page 71 of the 6WG200 document, starting at the voltage source F1, I don't have a wire giving 24V to pin5, which is the DR E3 at the A2 module. I also don't have the output wire W(+). I measured pin 7 on the A2-X2 connector and get nothing. So I am currently wiring it up with 24V into pin6 (+) just like it shows. So that means my circuit will not disengage WK during shifting. On that image above I see the (wire 10) but do not see where it goes? Can't tell if diff is locked or not. I have tested the air circuit before when I replaced the diff lock switch and do not believe it is getting air pressure when switch is off. Maybe I can try to jack the rear end and drive, Ill get to that at some point.
Pulled rear drive shaft, no change in machine really bogging down on turns, requires downshift to 1st. Checked IG with an o-scope, voltage looks good per your numbers as I go from idle to max rpm. At Idle it is only showing 237hz at an engine rpm around 800rpm. While I expect the torque converter to be slipping, not sure what a good turbine speed would be doing in neutral. At Full throttle, approximately 2000rpm, the turbine speed sensor frequency can only ever get up to 1100hz, which would never trip that 1300 rpm number stated earlier. Again, tranny in neutral, so minimal drag on the output I would assume. I can't test driving, but wouldn't a load on the output of the tranny cause more "slippage" and higher difference.
Hi again, heavy load during turns w/o rear output shaft: Either brake coming on or limited slip diff dragging too much. Ususally it was a 25% limited slip diff fitted at that time. Possibly an oil change in diff might improve friction coefficient. frequency speed sensor: Tranny in neutral I'd assume already at low idle turbine spinning with alsmost engine speed, at higher speed even higher than engine as only input gear train spinning. Did you even open E-module and check components? Did you check speed sensor for mechanical damage? Also see conversation.
Thanks for your continued help, it is greatly appreciated. In digging more into torque converters, looks like turbine speed will always be below input pump, which is what creates the torque, until you lock it up and then they are equal. I am obviously seeing that, but can't tell if too much slippage or not. Your previous torque converter test in 6th gear seemed to indicate torque converter is good. Ordered a pulse generator so I can test the Electronic Module, I can't say if the module is good or not because it never gets the input it needs from transmission transducer. Checked turbine transmitter wires again and all looked good. Next step is to pull and check out.
I'll give an update of where I am at. Drove the machine up and down rock road, a very gentle steady slope up in one direction. It made it back and forth about 5 times. Still struggling to get rpms up and torque up while going up the slope, ran fine on the way down. I installed a switch to engage WK just to try it out in different scenarios, it helps, but still something off. Without RPM gauge on engine and I can't find a sensor in the timing cover which is where it potentially should be. Anyway, kept thinking engine seems sluggish and maybe that is why I cant get the driving torque I need. Checked pressurized intake system for leaks and found several around intake manifold and the turbo hose. Tearing that apart today and going to fix boost leaks and then go drive again. No boost sensor or boost gauge on the machine, so no way of knowing. I plan to add some kind of gauge in.
Fixed a few small turbo leaks and larger one at the intake gasket, went ahead and replaced the gasket. Fixed RPM gauge, missing power, ground, and signal from alternator W port. Showing 600rpm idle and getting up to about 2300 at full throttle. Had to play with the selector switch on the back for # of cylinders, no idea which one it is on, just kept spinning til good rpm. Previous radiator had a pinhole leak that was epoxy fixed, but we went ahead and replaced radiator with a brand new one. Started testing WK Module with signal generator and was able to get the SM signal to switch with about 1200Hz signal into IG, but the WK was not switching to 24V. Took Module apart and could not feel electromechanical switch clicking. Started doing some measuring and the input signal from the high pass frequency circuit was not getting there. Didn't want to spend more time or damage anything so I put a jumper from the input signal that was working to the one that wasnt and now we get beautiful 24V when 1200+ hz signal is input on IG. Truck is running better, feels to have more power, and now the WK is engaging at the correct RPMs and making it drive much better. Time to start moving some dirt.