Ok here’s the story...

Just bought this 92 blazer with HO package. The 4x4 wasn’t working when I bought this truck, the 2 button lights would flash once on start but after that nothing. Anyhow this isn’t about trying to fix the stock button option, rather I want to know if a stock floor shifter can be bolted on the TC that I have now or do I need to replace the TC with a floor shifter.

 

it is possible to convert it to the manual floor shift. but....you know.......it's a hell of a lot easier to just fix/replace the TCCM, than it is to remove the encoder motor, cut the hole in the floor, find a donor truck for the shifter/linkage/shifter boot/etc.





have you even tried to fix the issue? it may only be a bad/corroded connection.

 

use search.
there was a cat that cut a hole and ran a long wrnch down to this TC for "manual shifting"

 

Yes, I have been trying to fix the problem. As mentioned the 2 button switch would only flash once at start and then go dark. So I pulled the connector from the encoder assembly and cleaned that and now the button flashes several times and I hear the clicking from the tccm. But after several flashes the 2 button switch goes dark again and the 4 wheel isn’t engaging. When I get the time and weather I’ll pull the tccm and check the connections there but after that .... who knows.

I have been reading all the posts on this issue and have a feeling it might be the encoder. The cheapest I can find new is about 150 bucks - I don’t know if replacing it with a used one is the best solution. I haven’t completely abandoned the idea of fixing the fly button but I saw 2 floor shifters at the u-pull it today and started to think it might be easier as a long term solution to convert to the floor shifter. The only drawback right now is the two floor consoles I saw are a different color from my interior. If I did the floor shifter I would make the axe cable manual also to get completely out of any future problems with the 4x4.

 

i highly doubt it's the encoder. hit the TCCM first, it's the more faulty of the two (in my experience).

but if you have a truck(s) that are sitting there complete, then it might be a good idea to line up the parts, just incase there is a major electrical issue going on with your truck. see if the guy @ the wreckers will set it aside for you (for a bit) f you pull everything off the truck.

and make sure you get everything from it. a friend of mine forgot to get the support bracket for the linkage arm, and his truck was always a PITA to shift if the frame was loaded up o one corner only (ie; frame twist).

don't really know why you'd want to do the posi-cable lock to your truck, unless you've had diaphram issues in the past.

personally, with all of the 4WD S series i've owned, i've only ever changed one diaphram-and it wasn't even on my truck! my youngest brother's Jimmy had the diaphram split on the bottom side 'cause the vacuum switch on the t-case leaked fluid into it.


which reminds me i need to change that too.

 

I figure if I do the floor shifter I would need to find another way to activate the axle cable since the vacuum switch at the TC wouldn’t be working with the encoder assembly gone. But as I think about this there must be a vacuum switch on the floor shifter option. I guess the vacuum switch on the TC works either way, with or without the encoder. I did see a guy using a electric solenoid and switch to activate the vacuum to the diaphragm. I also saw another guy using an universal locking cable mounted under the dash to pull the axle cable - sorry this method seems a little redneck to me.

I was wondering if the floor shifter assembly bolts to the (3) hole pattern the encoder assembly uses?

Oh that reminds, today I saw a blazer with the passenger side dash ripped out. There were 2 silver component boxes, piggy backed, one with 40 wires going to it and the other was half the size with about 20 wires. Is the tccm the smaller of the two?

 

yes, it bolts to the same location.

 

Time to revisit this project. Today I looked at a 91 with manual floor shift and there was something different. The 91 had a center bolt that held the linkage to the TC, rather than the 3 that hold the encoder on mine and the shifting shaft is threaded for a nut. The counter guy did some key tapping and found out that 92, seems just 92 has it own manual shifting linkage for the 4x4. Can anyone conform this?

 

Next question, is the shift pattern the same for both the electronic and manual TC?
So, it appears if I want a manual shift for the 4x4 I either need to swap out the TC -or- franken-slash and hack my own linkage and shifting TC mount. Now this sounds like a project~ Pretty much have the whole conversion worked out in me head, just need to see the selector shaft on the 233. I think it's the same size and shape as the 231, just need to know if there is a bolt hole in the 233 compared to the threaded shaft on the 231. In the morning I am going to check the TCCM for any bad connections and if it still doesn't work I am going to take the encoder motor off and start the layout for this conversion. As I see, the mounting plate on the encoder motor is going to become the bracket mount for the pivot bolt on the shifting stick. :::in progress:::

 

Well, I got some good news and some bad news. First off, i want say whomever designed the encoder motor and its placement is retarded. Having to pull the front driveline is bad enough, but yanking the yoke is lame. I pulled the yoke and fluid started running out. WTF is this, the fill hole is slightly below the yoke so there shouldn't much fluid pouring out. Come to find out the TC was over full buy 2 1/2 liters, that's all it's spose to hold, roughly. SO where does this leave me, sitting there wondering how there could be so much fluid in the TC, there are a couple of ways I can think of, someone filled the dam thing up passed the fill plug and quickly put the plug back - doubt it. Or, there is tranny fluid leaking into the TC.

After getting the encoder off, I tested the input shaft on the TC and it was in 2H but wouldn't move. I had to wrench the crap out of the selector shaft to get it move one click, and the front yoke did lock. After several back and forth from gear to gear, it moved another click. There was noway that little encoder motor was ever going to get that thing to shift. So now I got 4H and 4L both working but still seem rather hard to engage.

This is just a guess but I have a feeling being over-full the TC could have locked up in 2H and the encoder motor just couldn't move the selector. The guy that owned it before me must have thought his tranny was using fluid over the years not knowing it was going into the TC. And one day the 4X4 stops working so that's why he told me he thought it was the encoder motor.

So, I went demo on the encoder assembly and have worked a solution for a (bolt-up) manual shifter solution. Not sure if anything like this has been done, I know guys weld wrenches and all kinds of stuff to shaft but i am going to make this like Chevy should have done in the first place. I am not sure of the status of this TC but I know in low speed tests the yoke for the front is turning without any howls, growls or grinds. I still need to install the front driveline for a load test but as luck would have, removing the front driveline, I found out that I have a blown U-joint so need to get that replaced.