My first heavy truck xm215

[tburk49760]

I do have a tach, was spinning about 2300. It is governed to 2800 max. Definitely tight fit!

 

[Gunfreak25]

Sounds like she is slowly coming together, totally the way to do things. The 6V sounds really happy in there, looks like it really gets up and moves too. As you know, the #1 killer of Detroits is under revving. To the untrained ear, they sound like they're about to come apart. What's not to love about twice as many power strokes per revolution of the crankshaft. I don't know why they phased so many 2 strokes out, likely emissions. Your wheel cylinder post reminds me I have to replace two races/bearings in my rear hub. Pitted rollers!

 

[tburk49760]

Always something to fix... Slowly but surely she is coming together. Got the pneumatic transfercase sprag shifter operating so I can shift the transfercase manually to the reverse and forward mode. If only the trans had a reverse light switck, it could be automatic like the original... The brakes still need some love in the form of time and money but they are better... have fun with those bearings... how did you resolve the whole forward reverse transfercase shifter thingy?

 

[Gunfreak25]

Hey, Tim. The forward/reverse shift rod on the transfer is a common repower problem. The original Hydramatic shift tower/linkage worked so the transfer case was shifted in unison with the transmission. Obviously, with any new transmission you'd be hard pressed to modify the linkage to work the same way. So the best option as your previous owner was already well aware of, is to shift it manually. Not a big deal really, but if it bothers you or you really have no need for front wheel drive capabilities just remove the front driveshaft which will eliminate the need to shift the sprag transfer case.

Bada bing. As for the wheel bearings races...I use a large steel drift punch and a 5lb sledge to slowly drive them in. I use a digital micrometer (the side that measures depth) to make sure the race is seating uniformly. Another trick I read about when doing wheel bearing jobs is to overtorque the spindle nut which "seats" things. Then I back off and adjust the bearings as per the books specs.

 

[tburk49760]

Not have 6 wheel drive??? How dare you , sir! I just need to remind myself to flip the switch everytime I change directions. Not sure how zealous I need to be about that, as in , will backing 10 feet destroy the tcase if the sprag is in the forward mode, or does it only matter if traction is an issue??

 

[Gunfreak25]

Tim, I've honestly no idea how critical it is that the transfer be shifted in the direction of travel. I seem to recall a Memphis Equipment tech telling me it wouldn't take much to bind and break something inside. May I ask how the previous owner setup your reverse shifter rod? I am assuming he went with the typical lever type shift rod with a cutout to hold it in place for reverse since it is spring loaded.

If playing with that big lever is not your cup of tea, I fooled around with the idea of installing a pneumatic power piston (the "in/out" kind with a couple inches of travel) that could be simply operated via a dash switch. Would be a simple calculation as to how much power it takes to make the reverse shifter rod on the Tcase pop in and out of it's ball detent. The only downside is it would use the trucks service air supply, and if it were to fail it would leave you without power assisted brakes. I'll probably go the traditional shifter lever in the cab route .....

 

[tburk49760]

The po tried to set up a pneumatic cylinder and a switch that looked like it was supposed to actuate it when it contacted the shift lever when in reverse. 'twas not well done. Works fine now with a pull switch mounted on the dash and some minor reworking of the concept. Just gotta remember to pull and push the switch. A reverse switch on the trans would be totally automagic. Not much to fail actually. Seems pretty reliable and simple. Spring return and no air for forward mode, energize solenoid to add air for reverse mode.

 

[Section8]

Could you take pics of this set up?? I am realizing that I will have to come up with something like that as well.
Whether I stick with the manual 5 speed I have or get an automatic I will need to shift my transfer case. I didn't realize on these that the transfercase had a forward and reverse directional actuation.
Figured it would be as simple as just pulling a lever to lock a gear in to the pack to achieve having the front axle engage. Not a forward gear in the tranfer case then a reverse driven gear.
Either that or I am missing the whole what this discussion was about.

 

[Gunfreak25]

Just to clarify, the front axle engagement is done automatically. It kicks power to the front axle when any rear wheel begins to slip 6% faster than the front. The sprag which controls this action just needs to be told which way to deliver the power to the front axle. This is done via the "reverse shifter rod" on the front of the transfer. As said above, it is spring loaded and requires a decent amount of force to pull outwards out of it's ball detent. Out for "reverse" and in for "forward". With no linkage hooked up it is automatically retracted inwards via an internal spring.

Tburk, that is quite amusing that the previous owner used the idea I had. Tis a small world. I completely forgot, you are correct in that "forward" mode there's no need for air pressure. So it would be safe as well. I can only imagine how he hooked it up. It looks like a simple setup, atleast in my mind. Any chance of pictures, or a model number/make for the air cylinder? It would save me a lot of shopping and crunching numbers for power specs....

I love the idea of rigging the electricals to the Reverse gear on the transmission. It will be easy for me since Reverse is at the very top of the shift pattern. Park being utterly useless, it will not be used. Time to buy wheel chocks.

 

[tburk49760]

Some pics.
Sorry, no part numbers on the cylinder...

 

[topo]

The first transfer case I had in my m211 did not shift in to 6 wheel drive when put in reverse like it should .When I tryed to ajust it I found it needed more travel then the shifting linkage would allow . I changed transfer cases . If I ever need to use that older transfer case I would mount a air cylinder on it to get the extra travel .

 

[Gunfreak25]

Previous owner retained the crossmember linkage as I had envisioned, excellent pictures and many thanks for posting! I will be replicating the setup on my own truck. Any pneumatic cylinder capable of 30lbs pulling force should be enough. Most are likely well above that range.


Topo, you are correct. There is a "sweet spot" that reverse shifter rod likes pulled out to, for proper function of the front axle engagement. GMC was smart to use all threaded linkage to adjust for wear with age. I will be doing the same and testing with the truck on 6 jack stands.

 

[tburk49760]

Road trip for a cargo bed and a better hood!

 

[m1010plowboy]

Somebody went shopping!

That hood is missing the big crease across the middle. Great find, looks pretty straight.

When are you painting it and did you nail down a color yet?

What's the story, how did you find 60 year old truck parts laying around Washington?

 

[Gunfreak25]

Come on, Dave. If he told you that, he'd have to kill you....

 

[tburk49760]

For some reason, when somebody finds something broke and green. they call me... If I told you, my wife would beat it out of you then kill them Most likely going to go with ww2 olive drab. My diesel powered samurai is hat color and I like it... The new hood has a weird modified gate hinge thingy on the front edge that looks like it was meant to heep the hood from flying up in the event a GI forgot to latch the hood... seems original based on the paint clues... hmmm think I'll keep it... pics soon... Got the hood mounted and started torching the ugly rusted wrong current bed off... Paint goal is 45 days from now... lets hope i can keep that dream alive...

 

[butch atkins]

The hood you have is a late model hood ,the hinge thingy should have a rod on it that hooks to the bottom of the brush guard .if you can go back to the truck where you got the hood you should look for the rest of the parts that are attached to the drivers side of the front windshield .All of this works together to keep the hood open when you work on the truck.You may be able to take the telescoping hood hinges off of the early hood and swap them to the new hood.Dont know this for sure.Please post pics of this if you can.Good luck on your project

 

[Gunfreak25]

Your doing it man, your doing it....great progress.

 

[tburk49760]

Several things are motivating me to get after this one is my own attention span equivalent to that of a gnat. Second is that I really want to drive the thing to work pretty soon and buy pretty soon I mean in the next 60 or 90 days. That means painting and everything more or less motor pool restored in that timeframe. Plenty of stuff to do between now and then. Thanks for the encouragement guys...

 

[Section8]

Wow!! Ambitious!!!
Git R done!!!
Awesome score on the hood and cargo bed! Looks like it should take minimal prep work to clean it up and prep for new green!!!
Keep the posts comin!