Dana 20 won't engage 4H or 4L Most of the time

Dragnknights

New member
I have a 78 Scout with a 440 big chrysler backed with a torqueflite 727 and a d20 transfer case. I'm trying to get it trail ready but I can't get it into 4h sometimes and I can only rarely get it into 4l. I have a twin stick on it, and I've tried using different gear oils but nothing is really seeming to work with any constancy. I had the trans rebuilt recently and I asked the guy to take a look at the transfer case while he had it and he said everything looked in good condition. Any help would be great here. Thanks!
 
If you could describe how/what you are doing when you try to engage the front axle it would probably help us. I have a manual trans so my technique would probably differ than yours. I would make sure the front hubs are engaged, then at a very slow roll, or with your foot on the brake with the auto tranny in gear, push on the transfer case shifter as you let off the brake and try get the front axle engaged. You should not have to use excessive force on the shifter. I usually unlock the front hubs before I disengage the front axle, especially if I have been driving on rock or hard packed dirt.
 
The auto trans can make the process a bit fussier at times. For getting into low range, the gear selector needs to be in neutral and the vehicle stopped. High range is meant to be selected on the fly, but not while the rear wheels are slipping/spinning. That's not to say that it can't also be selected while completely stopped with trans in neutral in the same manner as low range. Coming out of low with the auto is often a two-handed approach. By that I mean, one hand will slowly cycle the gear selector back and forth between r-n-d positions while the other hand applies rearward pressure to the t-case lever. Once you get the lever out of low position and into neutral, if you encounter resistance going into 2h from neutral with the engine running, try shutting off the engine and waiting a beat. You should then be easily able to slip into 2hi and then re-fire your engine. These suggestions are intended for a single lever t-case. I don't know how much if any would apply to your twin stick setup.

T-case lube should only be sae 90 gl-1 mineral lube aka tractor lube, or straight 50wt racing motor oil. Nothing else.
 
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This is seriously great information. I haven't really been noting what I was doing or what gear I was in when she finally decided to engage 4h or 4l but I will try these out this weekend and let you know. Thank you so much. This is the only advie that I've received that made any sense. One last question, do you suggest locking my hubs before I try engaging the transfer case?
 
Just wanted to give a heads up. I took my Scout out for some testing today and got it into 4hi and 4low thanks to your guys' help. I had to do pretty much everything you guys mentioned or some kind of variant between all of them, but I did get it dialed in. Thank you!!!!
 
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