NP 246 4 Lo not working

[Big T]

Replaced the NBSS and that did not get me 4 Low. That leaves the TCCM.

 

[Big T]

Installed the replacement Transfer Case Control Module and…..no 4 low.

I am down to the second encoder motor after the mechanic could not get the new AC Delco unit to shift out of neutral (returned for refund). Now I am down to a new Dorman Encoder motor unit.

How hard is it to remove and install these encoder motors? Do I have to pull the front drive shaft?

 

[RI Chevy Silveradoman]

In my truck you pull the front drive shaft then remove the three bolts and unclip wire harness for encoder motor removal. Pretty easy. I think may have a Genuine GM encoder motor if you are interested. I bought the wrong one. And they would not take it back.

 

[Big T]

In my truck you pull the front drive shaft then remove the three bolts and unclip wire harness for encoder motor removal. Pretty easy. I think may have a Genuine GM encoder motor if you are interested. I bought the wrong one. And they would not take it back.

What year is your truck?
I just replaced the NBSS and the instructions said to pull the front drive shaft to create the needed clearance to remove it. I could not get the front portion past the u-joint and it looked like I needed to pull the the crossover pipe which was causing the clearance problem. I was able to create enough clearance between the drive shaft and the NBSS to remove and replace it. But it’s sounding like I need to pull the crossover pipe, then the front drive shaft. I talked to the mechanic and he could not remember if he had to pull the crossover pipe.

 

[RI Chevy Silveradoman]

2006. But it's a Duramax 2500 HD

 

[Big T]

I crawled under for a look and I have to pull the driveshaft out of the transfer case. Which means I need to pull the crossover pipe so the front of the drive shaft can clear it’s attachment to the differential. This makes it a longer job that will have to wait until there is no fishing.

 

[RI Chevy Silveradoman]

Well that sucks...

 

[MrMarty51]

I crawled under for a look and I have to pull the driveshaft out of the transfer case. Which means I need to pull the crossover pipe so the front of the drive shaft can clear it’s attachment to the differential. This makes it a longer job that will have to wait until there is no fishing.

And fishing is mighty important too.

 

[Big T]

Two things on this truck that have not worked for years: 1) ABS, and 2) 4 low.

The ABS has been inoperable almost since the time I've owned it. The PO had it unplugged. I got it working for a brief period and it went out. Tried replacind ABS unit and the sensors at the hubs, but no go. I just gave up. With the GMT 800 front brakes on it, the braking is more than good.

4 low went out a couple years into owning it. Several threads here with no resolution. The next encoder motor is the final attempt to get this corrected. If not, I just live with 2hi, 4hi, and AWD. Such BS when it's a new transfer case in there.

Really getting frustrated with these trucks. My wife's 4Runner does not suffer any issues like these trucks and its got 300K miles vs 233K on mine. I can see why people pay a premium for a Toyota. The American trucks are just repair hogs.

 

[dbrannon79]

are there any options to make it manual rather than electronic engagement?

 

[Will L.]

Yeah- going over differences of trucks with a guy at work. If you can’t afford an $80,000 truck that is trouble free- ya get a $8,000 truck and deal with stuff not working. Or put $10,000 into it and it makes it far better. Still doesn’t make it same as a new truck.

Having a GM, Ford, Dodge means it can really handle abuse and still be on the road after 250,000 miles. Usually more comfortable to drive, especially long trips or towing/ hauling big boy weight.

We have a 4 door Tacoma and FJ Cruiser right now. Neither gets better mpg than our 6.0 LS Suburban or Escalade did. Oil changes are SUPER crucial in the Toyota engines vs the LS we ran 30,000 miles on each oil change. Never did transmission oil changes- and because we almost never towed heavy - those trans are good for 250,000-300,000 miles like that. Try that with a Toyota that tows a single axle camper and you will be eating engines/ transmissions.

Idk if your wife’s rig gets worked out off road, but Toyota transfer cases are NEVER the ones off roaders choose to put in a dedicated off road rig. Anyone getting serious with offroading in Toyota or anything else either gets Atlas or New Process.

On older trucks like these, it only makes sense to me for everything possible to be mechanical. Having the front axle & transfer case shift manual seems the only way to go.
our 01 suburban had the button push transfer case including auto 4wd- convenient for my wife when it snowed on occasion- other than that I planned on replacing it with cable shift when the fancypants version failed. Having done many classic car restorations, all the electrical stuff and vacuum stuff is almost always junk at 30 years. Things like reactive solenoids (that xfer case and diff lock shifter) also fall into that category. And trying to fix them piecemeal is almost always a disaster. Its like rebuilding part of your engine now and another part later. You never end up with new and perfect, always a mostly working unit.

 

[Big T]

Yeah- going over differences of trucks with a guy at work. If you can’t afford an $80,000 truck that is trouble free- ya get a $8,000 truck and deal with stuff not working. Or put $10,000 into it and it makes it far better. Still doesn’t make it same as a new truck.

Having a GM, Ford, Dodge means it can really handle abuse and still be on the road after 250,000 miles. Usually more comfortable to drive, especially long trips or towing/ hauling big boy weight.

We have a 4 door Tacoma and FJ Cruiser right now. Neither gets better mpg than our 6.0 LS Suburban or Escalade did. Oil changes are SUPER crucial in the Toyota engines vs the LS we ran 30,000 miles on each oil change. Never did transmission oil changes- and because we almost never towed heavy - those trans are good for 250,000-300,000 miles like that. Try that with a Toyota that tows a single axle camper and you will be eating engines/ transmissions.

Idk if your wife’s rig gets worked out off road, but Toyota transfer cases are NEVER the ones off roaders choose to put in a dedicated off road rig. Anyone getting serious with offroading in Toyota or anything else either gets Atlas or New Process.

On older trucks like these, it only makes sense to me for everything possible to be mechanical. Having the front axle & transfer case shift manual seems the only way to go.
our 01 suburban had the button push transfer case including auto 4wd- convenient for my wife when it snowed on occasion- other than that I planned on replacing it with cable shift when the fancypants version failed. Having done many classic car restorations, all the electrical stuff and vacuum stuff is almost always junk at 30 years. Things like reactive solenoids (that xfer case and diff lock shifter) also fall into that category. And trying to fix them piecemeal is almost always a disaster. Its like rebuilding part of your engine now and another part later. You never end up with new and perfect, always a mostly working unit.

That was helpful.