No 4 low on transfer case

[Turbo Terry]

1999. 161 k. Transfer case fluid changed every 50 k as per book. I use 4 high all the time winter roads here is Alaska but maybe only put it in 4 low twice in the last 20 years. Now I notice it won’t go in. I tried the neutral slow roll etc. just grinds and won’t engage. What’s the problem?

 

[GrantP]

I used to have to shut down the engine with the trans in neutral to get 4 low in my 97 without any grinding. Annoying but it worked, give it a try. I bought the 97 with about 40k on it and it behaved that way from day one, it may just be the nature of the 241 DLD case? Never had a problem going to 4 HI.

 

[Road Dog]

Neutral and stopped always works for me. I had to adjust the linkage after I bought the truck to get it to properly engage.

 

[petersonj]

I tried the neutral slow roll etc. just grinds and won’t engage. What’s the problem?

Neutral on the transfer case, or neutral on a manual transmission? If it is neutral on the manual transmission, you may have a transmission output shaft that won't stop spinning. One cause could be wrong oil in transmission or a very cold morning. This could cause the transmission counter shaft to keep rotating while the transmission is in neutral.

Try putting the transmission in a gear and leave the clutch pedal depressed with engine running. Now the transmission output shaft will have come to a stop. Try shifting the transfer case into 4 low. It should not grind - but it might not go into gear because two gears hit head on. If that happens, just momentarily engage the clutch to reposition the transmission output shaft.

- John

 

[KATOOM]

Transmission in neutral and rolling VERY slowly should be all it needs to shift into 4 lo. Its never a smooth shift but grinding is not right...

The only reason I can think of is, because you have a CAD front axle, the transfer case has a syncro ring to allow "shift on the fly" which simply means that ring engages like the syncro in a transmission whereby the front driveshaft must spool up to reach the road speed of the rear driveshaft in order to engage 4wd. With this type of transfer case, if you shift into 4wd at speeds above 10 mph as normal driving characteristics then you'll wear out that syncro ring and cause the transfer case to grind when switching ranges.

Shifting into 4wd should always be done at slow speeds unless you have a full time non-CAD 4wd system.

 

[JMcCoy]

4L does not engage like 4H.

1) Stop
2) Put the transmission in neutral
3)Shove it in 4L without stopping in neutral (transfer case).

When I say shove, I mean SHOVE IT! Don't go easy on it.

Stopping the transfer case shifter in neutral will only make it harder.

There are no sincros in 4L, so don't roll.

Let us know how it works out.

 

[KATOOM]

4L does not engage like 4H.

There are no sincros in 4L, so don't roll.

Actually it does, and yes there are... The synchro ring is located on the main shaft and is there to assure the driveshaft speed is aligned with the main shaft speed during selection. If the transmission output shaft is trying to turn the transfer case input shaft then even if the truck is not moving it will still allow grinding.

 

[JMcCoy]

I stand corrected on the sincro. The procedure for engaging 4L remains the same.