Transfer Case Help

[Brian]

Hey all,

I am (was) really close to getting back on the trails. I’ve got a passenger drop NP241 transfer case out of an early 90's-ish model Chevy Blazer. It’s got your standard cable actuated shift lever for 2H-4H-N-4L. I tore it down and installed a SYE kit in it back in November. The install went well and I didn’t have any real troubles.

Fast forward to the last couple weeks. I finally got the shifter and cable rigged up and went to test drive it. All I have is 2H and 4H. I can’t get into N or 4L. I have plenty of cable travel left to get there, but there seems to be a mechanical issue holding me back. I went as far as hooking a ratchet strap to the shift lever (on the case) to it to see if it would budge with no luck.

Searching the web all I really found was troubles people had with it popping out of gear, nothing really about being stuck in particular gears. Any direction or things to consider before I drop it and crack it back open? Again, I don’t recall seeing any obvious signs of breakage, unusual wear or anything else abnormal when I had it apart.

Thanks!

[Spieg]

Sorry I'm not more knowledgeable about the 241... Is it possible to disconnect the cable and shift the TC by hand? This might help determine if the trouble is in the TC or the shifter/cable assembly.

[Brian]

I had the cable off and tried shifting it by hand but can only move it the same amount as when it's hooked up to the cable. That's also when I hooked a ratchet strap to it to get more leverage with no luck. I'm just out of ideas, but hate to drop it again. But it seems inevitable at this point.

[redneck23ms]

If it's the same as a 231. Sometimes you have to trim the shift rod to get to 4low. Take off the rear output housing and see if it will shift to blow then. Some sye don't have a cavity for the shift rail to go into the housing so you have to trim the shift rail

[dieseldoc]

I agree with Alex here sounds like the shift rail is the issue
but you may have to get deeper into it

[Jim]

No chance you have any part (outer lever plate or an internal rod) installed 180 degrees off? I don't know if it is possible - just toss'n the thought.

[FINOCJ]

I don't know anything about the NP TCs, but wondering if there are 2 shift rails like a lot of gear driven Dana TCs. Could you have the shift rods reversed somehow, or is there an interlock pin that goes between the shift rails or rods (the kind of thing that keeps the low range from being able to activate when still in 2wd). If its a little out of place, or rather not moving into the proper place (say because of a spring loaded poppet ball) then it might be blocking the shift rails.

[Brian]

No chance you have any part (outer lever plate or an internal rod) installed 180 degrees off? I don't know if it is possible - just toss'n the thought.

Good idea Jim, it's just that none of that had to be touched really during the SYE install. It's looking more like it's gonna be the Teflon type pads on the mode and range fork. If those are badly worn, or virtually gone, shifting problems occur. At least that's where I'm starting after I give it a final once over on the outside.

[Brian]

I don't know anything about the NP TCs, but wondering if there are 2 shift rails like a lot of gear driven Dana TCs. Could you have the shift rods reversed somehow, or is there an interlock pin that goes between the shift rails or rods (the kind of thing that keeps the low range from being able to activate when still in 2wd). If its a little out of place, or rather not moving into the proper place (say because of a spring loaded poppet ball) then it might be blocking the shift rails.

I hear ya about the Dana style. Not applicable on this one however. I'm inspecting the outside again tomorrow for any physical interference, but it's prolly coming out again and getting split open. And just after I had it sealed up tight! :bang:

[redneck23ms]

before you pull it look on the rear of the sye and see if there is a plug where the shift rail is. if so remove the plug and see if it will shift to 4low. if so you will need to remove the sye housing and trim the rail. if it was the teflon pad the shifter would move to low but it wouldn't actually be in low due to the shift fork moving but the ring wouldn't move quite far enough.

[Brian]

Finally had time to split the case back open. Found one of the mode synchro keys and one of the tension springs for it, stuck to the magnet at the bottom of the case! :eek: I can't believe the key made it all the way down there without getting chewed up or FUBARing any teeth. I can get a replacement spring set for about $12, so easy and cheap fix once the parts get here. Everything else looked good.

http://i119.photobucket.com/albums/o132/scout345/4x4/IMAG1422_zpsty3mdkyt.jpg (http://s119.photobucket.com/user/scout345/media/4x4/IMAG1422_zpsty3mdkyt.jpg.html)

http://i119.photobucket.com/albums/o132/scout345/4x4/IMAG1424_zpsjgqo3exf.jpg (http://s119.photobucket.com/user/scout345/media/4x4/IMAG1424_zpsjgqo3exf.jpg.html)

[Jim]

Nice find!

`hope it wraps up nicely for you.

[Brian]

Got the parts in, slapped it back together and it now has full range of motion. Discovered that the cross member I originally fabbed up will interfere with the front drive shaft. :bang: So, I saved up my paper money and got a pre fabbed one that just came in a couple days ago. So I'll be spending this weekend "unwelding" my old cross member brackets and trying to get this new one in before Monday. Sounds simple enough...

[Brucker]

Best of luck with the rework!

[dieseldoc]

Bummer....rework sucks.
Good find with the key and spring.....better go get a lotto ticket as it didn't chew any thing up.