WHY:
My rear TC output shaft seal let go recently and my transmission output shaft seal has been leaking for a while, so I needed to pull the TC and make some repairs. The FSM for the '94 does not include any information regarding the removal of the TC. It assumes it is out and on your bench. I think there is a separate service manual for the transmission that includes removing the TC, but I don't have it??? Also, there are several threads discussing conversion of the TC to part time, but none detail removing the TC, or at least I could not find one. If you are replacing only the rear output shaft seal, the TC does not need to be removed. Just the output shaft can be removed from the TC. So, thought I would post this up. It is not that difficult, but without any info in the FSM, it is nice to have a write up and photos to explain the process. Also, I called a local shop and was told that the TC can only be removed with the transmission, which is very wrong.
TOOLS: socket set 3/8" & 1/2"
socket universals 3/8" & 1/2" & extensions
open/box end wrenches
pliers
lead/sledge hammer
impact gun, 1/2"
breaker bars
rags
wood blocks
floor jack, 2x is best
transmission cradle or homemade cradle
good lighting under the 80
PROCEDURE:
Drain the gear oil. I guess you could do this once it is out, but think it is easiest to just drain while still bolted in. Remove the front and rear drive shafts from the TC using a 14mm socket/wrench. If they don't compress enough, you may have to remove from diff as well.
There are six bolts that hold the TC to the transmission. #1-3 and #6 are easy to get at (these face and are accessed from the rear of the truck) and #4-5 (these face the front and are accessed from the front of the truck) are a little difficult but not bad.
Start at the front of the truck below the TC front output shaft. Disconnect the hi/lo/n shift linkage by pulling the cotter pin and disconnect the electrical connector from the front output shaft. Remove bolts #4-5 which are 17mm. #4 is easy with an extension and impact gun. #5 is a little difficult because the hook on the transmission makes access difficult and puts a large angle on the socket extension. If you have a swivel-socket this works the best. I used a 3/8" swivel socket w/extension and breaker bar and got it free pretty easily.
Move to the back of the truck and disconnect the ground wire, breather lines, speedo sensor cable and the two other position sensor electrical connectors and the diff lock motor electrical connector. If you can't reach all the connections, they can be disconnected once you lower the TC a little which provides better access. Just make sure the wiring harness has plenty of slack.
Remove bolts #1-3. These are very easy with an impact gun. I replaced #2-3 finger tight so the TC would not drop out unexpectedly once I got #6 free. To get at #6 you need to lower the transmission about 2-inches. To do this, remove the transmission protective guard and block the transmission oil pan with wood and support the transmission/TC with a floor jack. Once the transmission is supported, remove the transmission cross support from between the frame. Then lower the transmission/TC about 2-inches. In this position you can get at #6 easily. You can't see it, but will have plenty room to get a socket on it and remove the bolt. All six bolts are 17mm. At this point, the TC is ready to be pulled off, but first I lifted the transmission back up to level it out. The transmission cross member needs to stay removed to drop the TC so the front output shaft does not hit it when lowering. My pictures incorrectly show the cross-member in place, but I was not able to lower the TC without removing it.
Using your second floor jack and cradle, position it under the TC and strap it in tight with a tie-down, chain, etc. The TC is heavy, so don't try to support it with just a floor jack base. If it falls off the jack, you will either damage the TC or injure yourself. I did not have a "true" transmission jack, so I took a plate of steel, bolted it to my floor jack and welded a plate to the side to support the TC. I'm sure the same thing could be made out of wood as an alternate. This worked excellent as cradle to support and remove the TC and to move it to my shop once removed.
My rear TC output shaft seal let go recently and my transmission output shaft seal has been leaking for a while, so I needed to pull the TC and make some repairs. The FSM for the '94 does not include any information regarding the removal of the TC. It assumes it is out and on your bench. I think there is a separate service manual for the transmission that includes removing the TC, but I don't have it??? Also, there are several threads discussing conversion of the TC to part time, but none detail removing the TC, or at least I could not find one. If you are replacing only the rear output shaft seal, the TC does not need to be removed. Just the output shaft can be removed from the TC. So, thought I would post this up. It is not that difficult, but without any info in the FSM, it is nice to have a write up and photos to explain the process. Also, I called a local shop and was told that the TC can only be removed with the transmission, which is very wrong.
TOOLS: socket set 3/8" & 1/2"
socket universals 3/8" & 1/2" & extensions
open/box end wrenches
pliers
lead/sledge hammer
impact gun, 1/2"
breaker bars
rags
wood blocks
floor jack, 2x is best
transmission cradle or homemade cradle
good lighting under the 80
PROCEDURE:
Drain the gear oil. I guess you could do this once it is out, but think it is easiest to just drain while still bolted in. Remove the front and rear drive shafts from the TC using a 14mm socket/wrench. If they don't compress enough, you may have to remove from diff as well.
There are six bolts that hold the TC to the transmission. #1-3 and #6 are easy to get at (these face and are accessed from the rear of the truck) and #4-5 (these face the front and are accessed from the front of the truck) are a little difficult but not bad.
Start at the front of the truck below the TC front output shaft. Disconnect the hi/lo/n shift linkage by pulling the cotter pin and disconnect the electrical connector from the front output shaft. Remove bolts #4-5 which are 17mm. #4 is easy with an extension and impact gun. #5 is a little difficult because the hook on the transmission makes access difficult and puts a large angle on the socket extension. If you have a swivel-socket this works the best. I used a 3/8" swivel socket w/extension and breaker bar and got it free pretty easily.
Move to the back of the truck and disconnect the ground wire, breather lines, speedo sensor cable and the two other position sensor electrical connectors and the diff lock motor electrical connector. If you can't reach all the connections, they can be disconnected once you lower the TC a little which provides better access. Just make sure the wiring harness has plenty of slack.
Remove bolts #1-3. These are very easy with an impact gun. I replaced #2-3 finger tight so the TC would not drop out unexpectedly once I got #6 free. To get at #6 you need to lower the transmission about 2-inches. To do this, remove the transmission protective guard and block the transmission oil pan with wood and support the transmission/TC with a floor jack. Once the transmission is supported, remove the transmission cross support from between the frame. Then lower the transmission/TC about 2-inches. In this position you can get at #6 easily. You can't see it, but will have plenty room to get a socket on it and remove the bolt. All six bolts are 17mm. At this point, the TC is ready to be pulled off, but first I lifted the transmission back up to level it out. The transmission cross member needs to stay removed to drop the TC so the front output shaft does not hit it when lowering. My pictures incorrectly show the cross-member in place, but I was not able to lower the TC without removing it.
Using your second floor jack and cradle, position it under the TC and strap it in tight with a tie-down, chain, etc. The TC is heavy, so don't try to support it with just a floor jack base. If it falls off the jack, you will either damage the TC or injure yourself. I did not have a "true" transmission jack, so I took a plate of steel, bolted it to my floor jack and welded a plate to the side to support the TC. I'm sure the same thing could be made out of wood as an alternate. This worked excellent as cradle to support and remove the TC and to move it to my shop once removed.
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