AGAIN 16X16 FORD NH TRANSMISSION

[JULESB]

Hello from a new member.
I have a 1993 Ford 6640 SLE tractor (5 000 hours) with the famous 16x16 transmission. It's a 3 levers transmission with the nearest stick being a shutlte that has to be moved in forward or reverse to engage the transmission. Lately when I move the shuttle stick to select forward or reverse, no gear engaged. The tractor has been checked by 2 different NH dealers without any result. The only way I have found to keep moving the tractor is the following procedure : before shifting the shuttle stick, I quickly depress the foot throttle pedal to increase the motor RPM and as soon I release it, I smoothly shift the shuttle. I'ld really like to find another to keep my tractor moving!
Our comments will be appreciated.

 

[slowzuki]

You need to get a better NH mechanic. There's a lot of owners of this model or the 7740, 7840 etc at Machinery - British Farming Forum and they may be able to help. Accumulators go flat, wiring issues etc on these are pretty well known by the guys on there.

 

[whodat526]

Hello from a new member.
I have a 1993 Ford 6640 SLE tractor (5 000 hours) with the famous 16x16 transmission. It's a 3 levers transmission with the nearest stick being a shutlte that has to be moved in forward or reverse to engage the transmission. Lately when I move the shuttle stick to select forward or reverse, no gear engaged. The tractor has been checked by 2 different NH dealers without any result. The only way I have found to keep moving the tractor is the following procedure : before shifting the shuttle stick, I quickly depress the foot throttle pedal to increase the motor RPM and as soon I release it, I smoothly shift the shuttle. I'ld really like to find another to keep my tractor moving!
Our comments will be appreciated.

i believe you have a electrical problem i delt with this on a ts100 and there was a foward and reverse soleniod on the side of the trans that was shorting out

 

[RickB]

Shuttling between forward and reverse involves mechanically shifting a single synchronizer through its three positions (F, N, R) via a cable and moving a dump valve spool which releases oil from the clutchpacks allowing the direction change. Checking the cable connection involves removing the floor mat and floor panel as a start.
The dump valve is either cable controlled (early) or solenoid controlled (late) dependent on whether your forward/reverse lever has a dump valve button on the knob.

 

[flyingcow]

+1 RickB. used to use this type of tranny on snowtrail groomers. TS110's I think. Especially in cold weather, guys would break the cables. Unless you had a new cable, they were finicky to shift. Keep in mind we had guys that were abusive when they shifted.

 

[Harry in Ky]

On the early models, the cable on the clutch pedal is connected to an interlock to prevent the shuttle lever from shifting out of neutral unless the pedal is depressed. The clutch packs are controlled electrically by switches and the clutch pedal potentiometer, by way of the trans. controller. If the controller senses a problem with a switch, coil circuit, or pressure switch, it may not engage the clutches you,ve selected, but it should show an error code on the dash. This may appear with a warning light in the form of a hand pointing to a book. It may appear in different spot on the dash,depending on the cluster, digital or analog. I think the trans codes are mainly limited to E10 thru E29 but I'm not positive. If your tractor won't move in your selected gear and there are no error codes, you may have a problem with a status switch or related circuit. Remember the controller needs to know what gear and speed range its in to calibrate shifting charactistics. A bad signal from a status switch tells it that your'e in neutral in that range, so it will not engage any clutches. Another possibility of course, is the controller itself, but you go there when all else fails. There is a firm in Canada that can repair some of the problems, but they charge $275 to test and diagnose. Hope you don't have to go there.
The later tractors came with the Quad Mod version which had the dump valve button on the shuttle lever knob for clutchless shuttle shifting. When looking for parts or info on your trans, you need to specify what trans, inst. cluster, EDC or not, etc. Wiring diagrams for these tractors are very complex with all the different versions to sort through.

 

[Kevc]

Hey julesb
When you shuttle forward or reverse and release clutch pedal without going through your routine can you clutch packs engaging or does synchro grate and shuttle lever kick? Or does tractor just sit there without making any attempt to engage drive? Would like to hear back have stripped countless number of these trans v popular here in Ireland

 

[whodat526]

Shuttling between forward and reverse involves mechanically shifting a single synchronizer through its three positions (F, N, R) via a cable and moving a dump valve spool which releases oil from the clutchpacks allowing the direction change. Checking the cable connection involves removing the floor mat and floor panel as a start.
The dump valve is either cable controlled (early) or solenoid controlled (late) dependent on whether your forward/reverse lever has a dump valve button on the knob.

isn't that on the sl and not the sle trans like he has

 

[JULESB]

Hey julesb
When you shuttle forward or reverse and release clutch pedal without going through your routine can you clutch packs engaging or does synchro grate and shuttle lever kick? Or does tractor just sit there without making any attempt to engage drive? Would like to hear back have stripped countless number of these trans v popular here in Ireland

Kevc,

The tractor just doesn't move. Before I've found the routine explained in my post, I had to play with the shuttle lever many, many times and usually the tractor starts to move for a few feet and stops moving again. Then I have to shift the shuttle forward and reverse many times before the gears engage. After that the shuttle can be shifted without problem for the rest of the day if I'm lucky.
I should have specified that the tractor is a SLE, year 1993, white roof top and the shuttle is a rod model (the cables models came after). Also to code error is displayed on the instrument panel, except the dreaded orange book with the letters ''CP''.

Thanks to all of you for your generous comments.

 

[Kevc]

Julesb,
From your description I think prob lies wit clutch cable/dump valve adjustment which has the result of causing a conflict between clutch potentiometer and pressure switches and pwm solenoid and tcm thus no drive, tractor moves couple of feet drive lost or cp on dash. To adjust cable remove return spring on dump valve lever( on trans side cover inside accumulator) then loosen lock nuts on clutch cable and with 31.5mm spacer against bulkhead depress clutch pedal to touch spacer. Then pull outer casing of cable down until inner cable is taut, with cable still held taut thread lower nut up against bracket to hold tension. Lock cable in this position using upper nut. Reattach return spring to lever and all is hopefully ok!!!!! Other possible causes are dump valve retaining bracket cracked on inside of trans control valve similar symptoms to cable adjustment ( seen on tractor last week after trans had 23000hrs on clock) or problem with 5volt line reference from tcm(pwm solenoid amps incorrect voltage ok) v common on tractors with electro link
Kevc