Hey everyone. I've got to replace the encoder moter on the `01 Olds with the NP 136 TC. From my research, it looks like the driveshaft would need to be removed to complete this project. Am I crazy to entertain this idea? I have never removed a driveshaft before. It looks faily easy to remove--I guess my main concern is putting it all back together. Also, is the shift motor easy to remove/install. I will take it to a shop if this is not a project recommended for a DIYer

 

Don't know about the Olds for sure, BUT.....

I just did that on my '04 blazer, and in the blazer's case I had to remove the front drive shaft..... Four bolts at the front differential u-joint and a gentle pry to get the u-joint out of the yoke, and a gentle tap on the driveshaft "hub" at the transfer case end, and it slid right off the splined output shaft of the transfer case.. Recommend you put indexing marks with chalk or felt tip marker so the driveshaft / yoke gets put back the same as it was removed... also if the u-joint caps are the least bit loose, run some tape around the u joint so you don't waste time looking for all the little needle bearings on the ground......

 

Thanks. The Olds is just like all the rest of the s10s, with the addition of SmartTrak. The physical layout is the same. What is the likelihood that I get the driveshaft off and and can't get it back together? I really don't want to end up with a 2 ton brick in my garage. Do you guys buy these shift motors from the dealership or go with any other brand? I like to be frugal but don't like to buy junk to save money. I was thinking a remanufactured? Thanks for your time.

 

RockAuto is were you want to get your part from. Best prices and if you need someone to talk to when making sure your getting the correct part they have live understanding people.
The job is well within the DIY scope.

Just use caution, jack stands, no milk crates, spackle buckets...etc...........

 

My Drivshaft slid right on the output shaft by hand.... no coaxing needed... I don't know if the motor portion of your encoder is working, but I posted this a few days ago:

Encoder repair on Wife's '04 Blazer.... pictures at: www.rlfarms.com/blazer/

Four button pinout info at RLFARMS.com/blazer/4button/


Blazer's 4x4 has been flakey for several years, but on the ranch in central California it never snows so, 2-hi and 4-low worked fine.... But we moved to Reno, Nv. and winter is comming (it snowed a few days ago at Lake Tahoe, so it's comming here in a couple of months). Reading through the GM shop manual, only 2-hi and 4-low IS a FAILURE mode the TCCM control module) goes into when it can't properly "read" the encoder signals. To see DTCs (diagnostic trouble codes) for the 4x4 system, ground pin 13 of the ALDL (assembly line data link) connector (under the dash near the ), turn ignition key to "on", observe the DTCs on the 4x4 push button's LEDs. Hers had a DTC of 002 (bad encoder or connections). I've cleared the codes before (by unplugging the TCCM for a while so the capacitors could discharge) and it would shift fine for several shifts, then revert to only 2-hi and 4-low again. So, time to fix it (before it snows). I unplugged the connector from encoder/motor and checked the "channels" with a voltmeter (turn ign key to "on" and measure the channel pins to ground, should be 5.0 volts +/- 0.4) OK. I removed the Encoder / Motor assembly (after removing the front driveshaft), and took the unit into the operating room (aka the kitchen table). I removed the three security torx screws and seperated the encoder from the motor / . SEALED.....DANG.... so I tested the Encoder "switch" for channel "A"... WOW, while SLOWLY rotating the encoder, the ohmmeter jumped from 0.9 ohms to 40.0 ohms to 300.0 ohms (very flakey), then open, then back to ground at the other end of travel. I figured if one channel is bad, odds are the other channels are bad too. Well, it's only core value now, so nothing ventured....... I took my pin vise with a SMALL drill bit and drilled two SMALL holes just on the inside of the "O" ring (see web pics). Introduced some contact cleaner into the with a syringe (the wife is a nurse, she gives me some very handy tools!!!). I rotated the encoder "switch" through its range of travel several times (like 30) and retested the "channel" pins to the ground pin. Very low resistance and steady, either ground or open for A, B and C, depending upon position, no more high resistance. Channel P is a "pulse" to ground while the encoder is rotating. Reattached the encoder to the motor assembly and reinstalled it into the truck. Cleared the DTC by unplugging the TCCM for several minutes. Tested the truck on and offroad, shifted just fine!!!! many many times... FIXED, at least for now... Later I thought that I should have put a drop of silicone seal or black tape over the holes....... oh well.....

Additional, tried in and out of 4x4 (both ranges) offroad for the last 2 days, still shifting like it's supposed to.....

 

Thanks for all of the knowledgeable advice. I successfully replaced the t.c. shift motor and the AWD is now working properly. I am very happy. The AWD system had been on the fritz for over a year; for a number of months, the AWD would work intermittently--although, more recently, the system had been completely non-functional. One local shop tried and failed to fix the issue. In the end, I found this task easier (and less time consuming) than replacing the plugs and wires.