M818 Transfer case questions

[citizensoldier]

My M818 will not go into or has no Low range. At first I thought maybe the linkage was out of wack but I unhooked the linkage and used a big pry bar on the shaft. It is out as far as it will go. When I put it in gear it will not move and feels like it wants to grab but will not engage. I see some type of access hole on the side where the High/Low shaft enters the case. I have many manuals but nothing shows a blow up of how that shaft works or what is in that section. I am just wondering if its something simple like maybe a keyway is sheared or broken shaft? Or is my T case toast and time to swap it out. Ughh.. 800lbs of fun in the shop..Is that adjustable some how inside the case?

 

[73m819]

my xcase would not go into low, when I changed it out, I used a pry bar to put it in low, the xcase immediately locked up, took a bar in the inspection hole to free it, just had it out doing the trail at the first GA. rally, all the time trying to force into low, I am sure glade it did not go in, a locked up 819 would not have fun on the trail

 

[citizensoldier]

What caused it? Did you tear down your old one? Whats that shaft moving? High range is just fine.

 

[73m819]

acted like it locked in both high and low ??, never took it apart, the shift rod had full travel, would come out of high but not go into low, forced the shift rod past normal travel, it locked things up ??????

 

[citizensoldier]

Hmmm.. I really would like to understand how and what that rod does exactly before I pull that mother of a boat anchor out. I am just trying to figure out if something is not adjusted right or could be remedied from the access point or if the low range is no longer working for some reason.
I did a search but found nothing about this only a rebuild of the upper bearing.

 

[jasonjc]

The shift rod move a sift fork. The fork is lock to the shaft by a set screw. This set screw is to be lock wired in place. If not it can and will losen up then the case will not shift. Does yours shift out of high? The cover you are looking at is to get to the set screw. I'd check that frist.

 

[augiedoggy]

I split open my bad transfer case, and as I recall the input shaft has a shift fork and the 2 gears with synchros just like any transmission, only Way bigger.
I'm sure you know that the T-case holds very little gear oil and it must be driven to get the gear oil up to the input shaft.
I started checking into replacement parts to fix mine and quickly found that a used case was, by far, cheaper.

Oh yeah, it does have that bolt which locks the shift fork to the shift shaft (under the side cover) which should be saftey wired into place. Make sure that didn't back out.
oh just what jasonjc said above

Best wishes and don't try to bench press that case outa there! lol

 

[citizensoldier]

Thanks guys I am going to pull that cover now that I know something "could" have loosened up. It will not shift out of high and when I move the shaft to low it sounds like it wants to shift.. Yea I know they take little lube for the size of that thing and it all sits way down low.
I have a rebuilt T case I just don't want to pull that big sucker out only to find that a set screw backed out... It is huge but seems very simple as far as T cases go. Thanks again this is just what I was needing to know. I have searched and searched to find a blow up of that area and nothing so far. Or a rebuild manual for that case??? Anyone?

 

[73m819]

CS, look in the -20p, -24p, and the -34p, ( named them all, forgot which on) for blowup pics of inside of the case and how things go