Braking and transfer case questions???

[Speddmon]

Hello all,

I've been reading a lot of posts preparing to do my recovery in Sparta, WI here in a few weeks. I've read through the -10 TM and read, then read more, and finally read even more posts about the deuce. I've done a lot of searching but there are 2 nagging questions in the back of my mind I'm not 100% sure of the answers.

I've read a lot about the differences between the sprag and the airshift transfer cases. I'm about 80 to 90% sure mine has the airshift case. My question is pretty simple and the TM doesn't cover it well, if it did I missed it.

Can the front axle of the deuce be shifted "on the fly" like a lot of 4x4's, or should it be done while stopped. Can it be done while in gear with the clutch depressed or should the main transmission be in neutral? I'm also planning on installing lockout hubs down the road. I'm curious about going in and out of 6x6, some manual hubs on 4x4's, you need to back up a few feet after disengaging the front hubs to make sure they fully disengaged. Is this the case with the ones used on the deuce?

Now to the braking question. It seems to me that there are a lot of posts dealing with bleeding the brakes and working on master cylinders, air packs and wheel cylinders.

Are the deuce brakes really that much of an unreliable PITA all the time or is it just a few unlucky souls who seem to have a lot of trouble with their brakes? I would really hate to have to bleed the brakes or worry about them failing every time I go to take her out for a drive.

I'm sure these are stupid newbie questions but I can't seen to find definite answers by searching so it's time to ask the pro's. Thanks in advance guys.

 

[jwaller]

you can probably shift the front diff in on the fly and I've done it at speeds below 10mph but I've got no reason to try it at full speed.

our lockout hubs do not require backing up.

 

[LanceRobson]

Starting with the last question;

These trucks can be more than 55 years old and the vast majority of deuces have single circuit brakes due to the single cylinder master cylinder. That tends to account for many of us being anal about brake preventative maintenance.

Any big air pockets mean you have weak brakes and any big fluid leaks mean you have no brakes at all.

The air pack can be an issue but the trucks have air assisted brakes and in the event of a loss of air or an air pack failure the full brake capacity is still there, it just takes about eight or ten times the pedal pressure to get the normal stopping power. Unless you have a leg like an elephant and are on a mission worth somebody dying for, any driving with an inoperative air assist should be limited to low speed operation needed to get the truck out of harm's way.

A "positive lock-up air shifted transfer case" (the official GI term) equipped truck will have a lever and function light on a small panel under the dash. It's normally under the instrument panel.

The best way to function check the system in the shop is, with air pressure built up, the master switch "ON" and the truck engine not running, jack up a front wheel.

With the air assist switch in the "OUT" position, the wheel should turn. Flip the lever to "IN". You should hear a soft "thunk" from under the center of the cab floor and the function light should come on. Try to turn the front wheel. It should turn no further than the few degrees of lash in the front end. Flip the lever to "OUT" and the light should go out accompanied by the "hiss" of air releasing from the system. The wheel should turn again.

It can be shifted at any time but try to avoid shifting when the rear axles are slipping, especially if the front axle is on solid ground. The differentials will send the torque to whatever wheels are getting traction and that means all the torque suddenly goes to the front axle and things can break quickly. I always back off the power before flipping the switch.

Get back into 4x6 as soon as you don't have to use 6x6 to drive. If the front and rear tires are not closely matched for height it puts a lot of strain on the drive line because any difference in tire circumference must be made up by tires scrubbing and the front axle is not as robust as the rears.

Enjoy the truck. It's good to see you asking questions before things break.

Lance

 

[jasonjc]

The BIG thing about the brake bleeding is that some of these truck have sat for years with no use. And this is the main reson for the need to bleed them , it's not a every day thing. And also keep in mind that most of these truck are 30+ years old so there is alot of crap built up in the master and wheel cyc. I had a truck that drove and stoped just fine but was leaking a small amount from one rear wheel cyc. When I went to fix it I found a ton of crap in it. So I replaced all of them and flush out all the lines.

 

[2Deuces wild]

I agree, Any truck that sits for years will have issues. Its a good idea to be sure very thing works and maintenance is done before any long trips. Most trouble is axle leaks cogged fuel filters leaks etc.

 

[GoHot229]

I have the Air Shift and I'v shifted on the fly several times last winter, and if I recal was going around 25 at an easy pace, not under acceleration throtle. It shifted with no drama at all. Another time I was in the dirt, muddy dirt mabe 3-4 inches of muck and shifted on the fly and under a small amount of throtle, I didn't like that one, it seemed to make a thud, small but just the same a noise. I'd dont know how fast you can be going and ingage it but I'd say at lower speeds around 25 off the throtle it would be fine. No guarentees though and again it was the air shift type. Mabe some member knows how fast you can be going while ingageing it?

 

[Speddmon]

Thanks for the replies guys, I'm really getting anxious to make this recovery. I have it set up for the 22nd at 0700. I talked to Mike at McCoy and he said the truck came in around January and was driven in, so it's not been sitting for an excessively long time. I'm hoping that the brakes will not be an issue until I get her home and can go over everything really good.

A "positive lock-up air shifted transfer case" (the official GI term) equipped truck will have a lever and function light on a small panel under the dash. It's normally under the instrument panel.

My truck has the lever and light below the dash but you know as well as I do, until you see it with your own eyes and verify it, that doesn't mean it actually has the airshift transfer case.

Get back into 4x6 as soon as you don't have to use 6x6 to drive. If the front and rear tires are not closely matched for height it puts a lot of strain on the drive line because any difference in tire circumference must be made up by tires scrubbing and the front axle is not as robust as the rears.

Enjoy the truck. It's good to see you asking questions before things break.

Do you happen to know if these trucks are set up similar to your standard 4x4 with a slightly "faster" gear ratio in the front axle? IE...4:10 rear end with a 4:09 up front so the front wheels actually "pull" just a little??

In all the years I've had my 4x4 pick-up I've only had the need to shift on the fly one time, and that was in about 16 inches of snow. I'm hoping to never have to do that with a deuce but I always want to know how my equipment operates before I need to operate it. I don't know about a lot of other people, but I work hard for my money and the toys I buy I want to stay in tip-top condition...that means learning how to use them properly and then learning some more. After that, you learn a little more about them, and the next thing you know, you'll learn even more. I am a firm believer that you are never too old to learn something new, and that everybody has something new to bring to the ballgame, you just need to find out what it is!

Thanks again

 

[jasonjc]

6.72 front and back

 

[m16ty]

Most of the trucks come from GL needing attention in the brake department. After you get the truck and go over the system and replacing what's needed they are pretty trouble free. On any vehicle this old it's a good idea to check the brake system often because the old designs don't have much in the way of safety features if something does go wrong. I check my MC level and look under my truck for leaks just about every time I drive it. I haven't had any problems but I like to stay on top of it.