Another option if the encoder for the transfer case go's out

malkavian · Post by **malkavian** » Tue Jan 17, 2006 6:32 am

I still need to find some more info on this but I was hopeing HJ or some of you other guys might have some info on parts to use for this.

I was reading peterson's off road and a guy wrote in about his blazer and asking about alternatives to buying a new encoder motor becasue his was stuck in 4hi. They replied saying that in a pinch you can remove the encoder motor from the side of the t-case and manually engage four low or high to get you back to a good road. Then he went on to say that you could put a manual shifter on the t-case and have the lever on the floor like a normal 4wd. The only problem is they did not go into detail about what shift linkage off of what thransfer case would work. So I am going to try to find some info on what trucks had our transfer case with a manual shifter. Oh yeah this was on a newer s-seris also.

malkavian · Post by **malkavian** » Wed Jan 18, 2006 2:30 am

ok so far I have found out you have to replace the selector shaft that the motor turns to engage the transfer case. Then just about any lever assy that gives you the clearence you need will work.

Come on HJ chime in here LOL .

Post by **HenryJ** » Wed Jan 18, 2006 5:19 am

I don't know enough about it.

There is a thread going about the swap over on ZR2.com and I have seen a discussion on it somewhere else.

malkavian · Post by **malkavian** » Wed Jan 18, 2006 8:21 am

OK thanks Hj . I was hoping you might have some sugestions. Ill check on zr2.com also.

Blaze One · Post by **Blaze One** » Wed Jan 18, 2006 2:20 pm

I maybe completly wrong about this , but could you use a Posi Lok thingy ?
http://www.4x4posi-lok.ca/

Dunno if that is at all related to your idea . But thought i would throw it out there anyway .

Post by **HenryJ** » Wed Jan 18, 2006 5:56 pm

Blaze One wrote:I maybe completly wrong about this , but could you use a Posi Lok thingy ?
http://www.4x4posi-lok.ca/

Dunno if that is at all related to your idea . But thought i would throw it out there anyway .

That just actuates the front axle eliminating the vacuum actuator.
From the sounds of things the posi-loc is not a good product and has some issues.
If I get some time this weekend perhaps I'll link the information that I have seen.

Post by **HenryJ** » Wed Jan 18, 2006 7:06 pm

Found a little time

GM Transfer Case info

muslhed wrote:http://4oemparts.com/transmissions/tcgmt.html

Apparently GM stopped using the manually shifted NP-231 in 1997, with all newer models using either the electroniclly shifted NP-233 or NP-236. It also seems that not all Chevrolet NP 231's are created equal! The earlier models have direct linkage that shifts the X-case...while the newer 231's have a cable that shifts it....I believe. If I am correct, this will make for a MUCH easier swap than I had previously thought!

(cut & pasted from internet)
New Venture Gear T-case terminology: In a separate conversation with me, Sankar K. Mohan of New Venture Gear defined what the numbers on their T-cases mean:

The first number is the number of speeds:

"1" = one speed (high range). Example – the NV 136.
"2" = two speeds (high range and low range). Example – the NV 241.

The second number is the strength:

The NV 241 is designated "4" in strength – tougher than the NV 231, but not as heavy duty as their largest T-cases, which go up to a "7" (eg, NV 273, for vehicles with a GVW of 17,500 lb).

The third number designates the type of T-case:

"1" = part-time 4WD
"2" = full-time 4WD with an open center differential plus lockable part-time option – like the Selec-Trac NV 242 of the Jeep Cherokee and Dodge Durango, or the Hummer’s NV 242HD AMG.
"3" = electrically shifted.
"4" = not currently used.
"5" = Torsen-type differential.
"6" = computer controlled multi-plate wet clutch, like GM’s AutoTrac NV 246.
"7" = GeroDisc – like the Grand Cherokee’s Quadra-Trac II NV 247.
"8" = not currently used.
"9" = viscous coupling.

An even more in depth explanation here:

http://www.bc4x4.com/faqs/yj.cfm?cat=6&faqid=162#faqtop

muslhed wrote:I got the opportunity to look at Tom's (95whtZR2) 1995 ZR2 truck closely. I discovered that he had the manual X-case shifter in the floor....and it did not move with the rest of the drivetrain due to a broken motor mount! This told me that the shifter was not physically connected to the tranny, like the 1st Gen S-10's NP231 is. I crawled under his truck (while checking out his freshly beat up driveshaft) and saw first hand that it is in fact manually engaged by a shifter cable......not linkage!

So, what does this mean? There were 2 different NP231's made: 1 for the 1st Gen with manual linkage, and a different one that is engaged by a cable. This obviously makes the swap very simple! If one wanted to completely swap out their electronicly shifted NP233 or Autotrac NP236, all they need is a NP231 off of a 95-97 S-10 (instead of one off of a 1st Gen). There is one small hole to be drilled in the floorboard for the shifter cable to go through, and I'm sure you could order the lil grommet from GM to keep water out.

Here's a few pics:

http://photobucket.com/albums/b240/Musl ... er%20pics/

Now, I would like to know how some of you are swapping in a fixed yoke off of a old 1st Gen NP231 onto your NP233's. To me, it would make a lot more sense to swap that yoke onto the newer version of the NP231 that is engaged via a shifter cable vs. electronics. The newer version of the NP231 still has the CV joint prop shaft.

FinallyGotaZ wrote:got a quote on the shifter mechanism and cable linkage, etc, off a 94 non-z sittin at the junkyard. He wanted $50 for all the lever and linkage so I wasn't too sure. I didn't have everything I needed to pull it anyways. But I checked at the dealer just to see what the whole assembly would be new. $126.

malkavian · Post by **malkavian** » Thu Jan 19, 2006 6:45 am

HJ you are the man. I didnt get a chance to check out zr2.com had to get ready for work. Thanks for takeing the time to post that though. Im doing some salvage yard serches this weekend. Hopefully Ill find something I can use.

On the posi loc. I used one on my 91 xj untill I replaced the stock dana 30 axles with some from moser. After reading Hj's post on the posi lock for the s-10 months back I think I would stay away from it.

Thanks again Hj. Ill report back my findings this weekend .

malkavian · Post by **malkavian** » Thu Jan 19, 2006 9:21 pm

I called around after I got up for work and found 3 s-10s with the lever actuated transfer cases. I can get the whole assy for about $30 . If I get off work early enough sat. morning Im going to pick up the one of the cable assys and one lever assy. Then hopefully next weekend I will have off and try this mod out.

Post by **HenryJ** » Fri Jan 20, 2006 6:11 am

You may need to be checking fullsize trucks too?
There are plenty of S-series that are running floor shifters, but they may mostly be using "hard" linkage not the cable.
The linkage shift would be pretty tough to adapt.

malkavian · Post by **malkavian** » Fri Jan 20, 2006 7:28 am

ok thanks for that bit of advice didnt even check on the full size trucks.

Blaze One · Post by **Blaze One** » Fri Jan 20, 2006 5:58 pm

This is a great mod if it works out , I spent $1400 on repairs to my 4wd because it got stuck in 4 lo once , and it wouldn't engage either . If i had known about this , I could have saved my self lotsa $$$ .

And ended up with a more reliable transfercase in the end , since my 4wd is acting up and not disengaging complete ( i think ) .

Post by **HenryJ** » Fri Jan 20, 2006 6:25 pm

It is not a "done deal" yet. I have a feeling the lever at the transfercase may not be a simple bolt-on mod. There may also be some BCM issues when shifting to low range?

Like I said, I don't know enough about it to be of much assistance.

malkavian · Post by **malkavian** » Sat Jan 21, 2006 2:41 pm

Hj maybe right. I didnt get off work in time to get to the salvage yard but Ill get a chance next saturday. Im not even sure it will work. I am pretty sure the mechanical part will be simple to work out but I have no Idea about bcm issues yet.

Miles · Post by **Miles** » Tue Jan 24, 2006 4:25 pm

malkavian wrote:
HJ you are the man.

Naw man.....I'm the man!

J/K HJ!!

As you can see from my post from ZR2.com, I've done a HUGE amount of research on this subject. My thread over there is now going on 3 pages of compiled information about GM Transfer Cases for the S-10. The NP231's that came in 2nd Gen S-10's, were cable shifted versus the old style NP231 that was linkage shifted. That would be drastically easier to swap in than the manual linkage. Here is some pics of the cable shifted 231:

http://photobucket.com/albums/b240/Musl ... ct%20pics/

Currently, I've got the Autotrac X-case (4-button) in my Blazer, and I plan to swap it out for a 2nd Gen NP231-HD that has the cable linkage. My plan is to also swap out the front slip yoke of the 2nd Gen NP231, for the front fixed yoke from the earlier 1st Gen NP231. After that, I plan to use the JB Conversions SYE kit for the rear slip yoke. The end result will net me a manually shifted X-case via shifter cable, with fixed yokes front & rear. Much more reliable that either the electronic 233 or 236.

BTW, the second Gen Posi-Lok cable works fine. Drastically better than the 1st Gen. Please refer to my write up on this subject here:

http://64.177.211.114/Midwest/html/txfo ... wtopic=561

HenryJ,

I started a separate thread here, with this same info inside, if you'd like to sticky it. I worked pretty hard to compile that information, and would like to share it with as many S-series owners that would find it beneficial.

malkavian · Post by **malkavian** » Wed Jan 25, 2006 3:03 am

Muslhed... Can you post a link to your thread about this manual shift mod. I think you might save me a lot of leg work saturday if I am off work.

Post by **HenryJ** » Wed Jan 25, 2006 5:17 am

Look up

malkavian · Post by **malkavian** » Wed Jan 25, 2006 9:38 am

LOL I thought he ment there was more info. ok just go ahead and kick me.

Miles · Post by **Miles** » Wed Jan 25, 2006 6:47 pm

As I stated above, there is 3 more pages worth of information about this on ZR2.com.....but ya can't look at it right now!

malkavian · Post by **malkavian** » Sun Jan 29, 2006 3:23 am

Sorry I have not had a chance at all this weekend to get to the salvage yards. My dog is in the animal hospital and I had to work all weekend . I have to have a weekend off soon LOL or IM going to go nuts.

Miles · Post by **Miles** » Sun Jan 29, 2006 9:18 am

malkavian wrote:Muslhed... Can you post a link to your thread about this manual shift mod. I think you might save me a lot of leg work saturday if I am off work.

Now that ZR2.com is back up &running, here's that link:

clicky

Post by **HenryJ** » Sun Jan 29, 2006 9:22 am

Muslhed wrote:...here's that link:
clicky

HenryJ wrote: GM Transfer Case info

Like I said...look up it has been there all this time.