'92 Diff Lock Light and button question (1 Viewer)

[Scota4570]

When I go into low range the diff lock light comes on, on the instrument cluster. I do not need to press the button. I do not want the diff locked all the time, even off road. The diff lock button does function in high range. I do not notice the heavy steering and wheels acting like it is really diff locked in low range. It seems to do fine off road as is. When I go back in to high range the light on the dash goes out.

Another thing I noticed recently is that the high low range lever is extremely hard to move.

Is something messed up?

 

[Marco Lau]

Actually that is not a diff lock, its called a center diff. lock. The CDL is automatically engaged in 4Lo. and it does not affect the heavy steering. CDL is not the same as diff. lock or lockers.

 

[CharlieS]

You can do the "pin 7 mod" to have full control over when the center differential locks.

 

[Scota4570]

Thanks for the information. So the light indicates proper 4WD on lockers. As long as it is working properly I will leave well enough alone.

What about the extremely stiff hi-lo range lever?

 

[NeverFinis]

Thanks for the information. So the light indicates proper 4WD on lockers. As long as it is working properly I will leave well enough alone.

What about the extremely stiff hi-lo range lever?

You will need to dissemble the lever, clean it, and regrease it.

 

[Scota4570]

Can I accomplish anything that helps from the top, through the hump, from the inside of the vehicle?

 

[ppc]

You can do the "pin 7 mod" to have full control over when the center differential locks.

@Scota4570 , There is no pin 7 mod available for 91-92 models with the A440 transmission. It's not electronically controlled like the A442F in 93-94 models.

What you need to do is to remove the 4LOW sensor switch connector on the rear extension of the transfer case. That will allow complete manual control of the CDL using the dash switch only.

 

[jonheld]

@Scota4570 , There is no pin 7 mod available for 91-92 models with the A440 transmission. It's not electronically controlled like the A442F in 93-94 models.

What you need to do is to remove the 4LOW sensor switch connector on the rear extension of the transfer case. That will allow complete manual control of the CDL using the dash switch only.

Technically, you can do the pin7 mod, as pin 7 on the CDL ECU does exist and will accomplish the same thing, less changing the shift points on the transmission.
However, it is far less invasive to simply unplug the low range switch on the transfer case.
I ran my 91 like that for many years.

Sit under the truck facing forward looking at the rear of the transfer case. The low range switch/connector is on top at the 1 o'clock position.

 

[Scota4570]

Based on this video, I think mine already has the 7-pin mod.


How about pulling the lever mechanism to clean and lube. Does it require special tools? Fairly easy?

I am not an enthusiastic home mechanic. I was once paid to be a mechanic on simple vehicles. I fix my own stuff to save money and because no shops in my area will work on old vehicles.

Thanks for the replies.
Scot

 

[CharlieS]

It is easy. Only requires basic hand tools and it isn't complex.

 

[Scota4570]

The pin that attaches the shift lever bell crank to the push rod is not easily accessible. The part that I am supposed to grab is facing up. I can barley see if from below. Grasping it is not an option. I might be able to wack it out with a long tool but I will not be able to put it back from underneath. Illustration AT6036 has the pin oriented 180* from mine. Is it OK to put it back by pushing it up from underneath?

Should I be accessing it form the top?

 

[NeverFinis]

Use long needle nose to grasp and rotate, then pin pull

 

[NeverFinis]

Never mind,

Looks like the pin is more accessible, on my 1996, if in low 4wd. It isn't rotable.

You can always pull the 4wd shift housing up into the interior a bit to access that pin

 

[Scota4570]

3 minutes ago

Success, all done, thanks everyone.

The grease was very dried out.

I would not say it was "easy" though. Maybe easy the 3rd time. I had to elevate the shift plate while holding the shift linkage with hay wire.

Regards,
Scot