Converting an automatic t-case to manual

snoranger said:

Yes you can, but you need to use some of the internal parts from a manual shift case. So why bother, just install the manual case!

Seriously, You can mod a front housing to accept the manual shift parts. They arent machined to just accept them. You can even mod a 1354e to accept 13-50m parts. I've done it and we named it a "13-52".


So here's your concrete answer:
Yes it can be converted. Is it worth it? Not unless you have the internal parts sitting around.

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snoranger said:

I built this case about 5 years ago, so I'm going by memory. Go easy on me, I'll probably miss something and have to add to it later.

To build a 13-52 you need:

13-54e front case
13-50m rear case(no mods needed) or mod a 13-54e rear case
Either 13-50 or 13-54 adapter plate and input shaft(more on this later)

Completely disassemble and clean both cases.

The 13-54e front case will have a part of a hole where it needs to be drilled to accept the shift shaft. Drill that hole all the way through. I dont remember the size, but it has to be drilled undersized and reamed to the size of the shift shaft. It MUST be reamed to the final size, the bore must be smooth seal. The shift shaft has an o-ring to seal this hole.

You will not be able to do this next mod on all 13-54's , but there is a way to make it work anyway. Install the shift shaft and internal linkage from the 13-50 into the new hole in the 13-54. You will see that the 13-54 case is thicker where the shaft goes through the case. measure the difference in thickness (you need to be very accurate with this measurment).

1) Some cases have more material then others. If you can, The easiest way is to grind down the case (90° to the new hole you just drilled and reamed), by the amount you just measured.

2) If there isnt enough material, install the shaft and internal linkage. Put the external shifter arm on ( in the correct orientation) and tack weld in place. Be sure its in the right spot, before you weld it.

The last hole that needs to be drilled in the front case half is for the detent and spring. This can be done 1 of 2 ways:

1) Drill from the top down. The manual case has a sensor to illuminate the 4x4 lights. You can drill the case for this sensor, then drill farther down into the case for the detent and spring. (this will make sense when you have the cases apart).

2) drill the case from the bottom up. Drill the detent hole all the way through on the manual case. This will show you where to drill on the electric case. Drill the hole in the same place as the manual case. Tap the hole about 1/2" deep to 1/8" pipe. This will allow you to install the detent and spring form the bottom and hold it and seal it with a 1/8" pipe plug.

I chose #2. I dont need a sensor to tell me when I put the shifter into 4x4 or low, and it was easier that way.

Now, we have the front case half modified. Next we have to make a few choices. Did the 13-54 have a 6 gear or 4 gear planetary setup?
If your answer is 6 gear, use it. Its a little stronger. You must use the front adapter plate, planet gear/ input shaft, shift fork, and gear from either the 6 or 4 gear setup. If I remember correctly, they have to be kept as a set.

The 13-50 has an aluminum 2/4wheel shift fork, the 13-54 has a plastic one. They are interchangeable. I chose to use the 13-50's aluminum one, I believe its stronger.

Now that you know this case inside and out, use your new found knowledge and reassemble it and hope it works! Sounds easy right?

STEEV--- Its your T-case, you got anything to add?

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country0001 said:

Dude, you should really add pics and submit this as a tech article.

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BONES said:

Sounds a lot better than the making it manual shift from the back of the case on the e-shift motor hole.

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snoranger said:

I dont have any pics. When i did this, I hadnt planned on writing anything up on it. I just did it because it had to be done. If i make another one, I'll do a full write-up. The only pics I know of were taken after it was installed. I cant take any pics, because the owner moved to Michigan. But if he's reading this, he can pull the case out and take it apart for some pics.

If someone gives me a 13-50m and a 13-54e, I'll make another. I dont want to cut up the 2 STX cases I have.

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kevinsranger said:

I got that 4405 you can play with

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snoranger said:

Drop it off. I havent had one of them apart yet.

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snoranger said:

I dont have any pics. When i did this, I hadnt planned on writing anything up on it. I just did it because it had to be done. If i make another one, I'll do a full write-up. The only pics I know of were taken after it was installed. I cant take any pics, because the owner moved to Michigan. But if he's reading this, he can pull the case out and take it apart for some pics.

If someone gives me a 13-50m and a 13-54e, I'll make another. I dont want to cut up the 2 STX cases I have.

Click to expand...