The Do's and Don't's of shifting btw 2H, 4H and 4L (1 Viewer)

[Crimsoncruiser]

I have heard several things about locked hubs and shifting into and out of 4WD in a stock FJ40/43. Hoping I can get clarification.

I understand it is good to drive somewhat regularly in 4WD to keep everything turning and oiled. Makes sense. It is also occasionally a good idea to lock the hubs and drive if you aren't getting into an 4WD situation (wet or snowy roads or gravel). I assume this is correct.

I am primarily curious about shifting into and out of 2H, 4H and 4L. Is it OK to shift from 2H to 4H (assuming the hubs are locked) on the fly? Perhaps in neutral but with the wheels turning, say on a highway or road where there may be occasional ice and snow? I was driving through Oregon and was told to keep the hubs locked and to shift in and out of 4H as needed.

I believe it is a must to be stopped and in neutral to shift into or out of 4L.

Thank you for corrections and confirmations.

 

[B y r o n]

You don't have syncro's in the transfer case so all shifting will be done while stopped.

2WD for normal around town or light off-road on say forest roads.

Lock the hubs and 4WD Hi for looser off-road conditions or snow on paved roads.

Lock the hubs and 4WD Lo for rougher or steeper off-roading.

Once you're done with 4WD put it in reverse and back up a short distance or rock it. It will make getting back into 2WD a lot easier. Don't forget to unlock your hubs.

If you've been driving around in 2WD for a long time and want to spin up some fluids in the front end, lock the hubs and it will get the axles turning. Your gas mileage will drop so don't forget the hubs are locked and unlock after a short drive.

 

[CruisinGA]

When driving in a straight line, if the hubs are already locked (or using drive plates), you can shift 2WD/4WD on the fly. I do it all the time.

 

[Living in the Past]

When driving in a straight line, if the hubs are already locked (or using drive plates), you can shift 2WD/4WD on the fly. I do it all the time.

I also keep my foot off the accelerator. Vacuum just pull 4WD knob. Manual I slowly pull the lever back and let it slip in not forced.

 

[Brew40]

Are there certain years for vacuum assist?
My 40 has been sitting in a garage for over 30 years. I’m getting closer to running status but have not been able to move the transfer stick with the engine not running yet.
I have a 12/1978. Thanks for any insight-

 

[POPO AGIE]

I live in Wyoming and when mine was my daily driver the hubs were most likely locked from Fall to Spring. When the hubs are locked you can shift on the fly and did it all the time if I saw a snowy or icy spot ahead on the highway. Just get off the throttle before you pull the lever to 4H and the same when going back to 2H.

I also was able to shift from 4H to 4L on the fly, but had to switch gears with the transmission first. If I was in 1st gear I had to switch to 3rd gear or if in 2nd gear I needed to switch to 4th gear because my 4 speed transfer case had a 1.9:1 gear ratio in the low range.

I will have to figure out how to shift from 4H to 4L with the new H55F and split transfer case that has a 3:1 gear ratio for low range on the fly. Looking forward to learn how.

 

[Malleus]

I still get a kick out of locking hubs...anyone ever see a four wheel drive tractor or construction vehicle with locking hubs?

 

[POPO AGIE]

I am not going to put them back on when I rebuild my front axle. I have a set of Diamond Drive flanges for the rear axle and will use them on the front axle.

 

[Crimsoncruiser]

I live in Wyoming and when mine was my daily driver the hubs were most likely locked from Fall to Spring. When the hubs are locked you can shift on the fly and did it all the time if I saw a snowy or icy spot ahead on the highway. Just get off the throttle before you pull the lever to 4H and the same when going back to 2H.

I also was able to shift from 4H to 4L on the fly, but had to switch gears with the transmission first. If I was in 1st gear I had to switch to 3rd gear or if in 2nd gear I needed to switch to 4th gear because my 4 speed transfer case had a 1.9:1 gear ratio in the low range.

I will have to figure out how to shift from 4H to 4L with the new H55F and split transfer case that has a 3:1 gear ratio for low range on the fly. Looking forward to learn how.

Thank you so much for your inout

 

[B y r o n]

I still get a kick out of locking hubs...anyone ever see a four wheel drive tractor or construction vehicle with locking hubs?

How many 4WD tractors or construction vehicles have you seen that had to navigate metropolitan areas or worried about gas mileage?

 

[Living in the Past]

I live in Wyoming and when mine was my daily driver the hubs were most likely locked from Fall to Spring. When the hubs are locked you can shift on the fly and did it all the time if I saw a snowy or icy spot ahead on the highway. Just get off the throttle before you pull the lever to 4H and the same when going back to 2H.

I also was able to shift from 4H to 4L on the fly, but had to switch gears with the transmission first. If I was in 1st gear I had to switch to 3rd gear or if in 2nd gear I needed to switch to 4th gear because my 4 speed transfer case had a 1.9:1 gear ratio in the low range.

I will have to figure out how to shift from 4H to 4L with the new H55F and split transfer case that has a 3:1 gear ratio for low range on the fly. Looking forward to learn how.

Back in 1974 was able to pull off the 4H to 4L climbing a steep hill. Stock running gear in my 68. That was three on the tree and under dash transfer shifter. It was able to stall in high ranch and was able to double clutch and get it I to 4L. It bucked when I let the clutch out with it in low range. Nothing broke, engine didn't stall and made it up the hill. Trying to pull off a first to third on the column shift at the same time wasn't going to happen. This was shortly after I bought the 40 and few trips like this is what made me realize the Land Cruiser stock was tougher than anything else I seen at the time. Have a H55F waiting on parts to put in a later FJ40. I don't run twin stick so the throw from four high to four low across neutral in the middle along with shifting a five up would be a challenge. The idea of shifting three times lower in a 5:1 first gear would just be asking to break something. Never made a habit of shifting between 4H and 4L on the fly. If I think I'll need low range ahead with stop and shift ahead of time. Have newer Toyota's SUVs with automatic transmissions. Those the transmission must be in neutral to shift between ranges.

 

[POPO AGIE]

I have not had good experience with 3 on the tree transmissions and don't ever want one again. The 3 speed in my Broco was wore out and would fall out of second gear going down hill. I had to back up to get it out of 4H and unlock the hubs.

I agree about not shifting on the fly with H55F in low gear from HR to LR would not be a good idea with a 3:1 LR. I am not sure if the ratios would even work shift from 4H to 4L would even work.

It is all theoretical now since I don't have the H55F and transfer case yet, but should have them in about 3 weeks, or the R2.8 yet. I have a lot of work in front of me on the front and rear axles first.

 

[Malleus]

How many 4WD tractors or construction vehicles have you seen that had to navigate metropolitan areas or worried about gas mileage?

You know, I wrote that just to see how long it would take you to write that.