Rebuilding NP241 or 241OR Transfer Case
Pre-work:
I have had some noise from what I thought was my rear axle, but actually was coming form my x-fer case. I posted a thread here on the issue. After running the Jeep on stands, there was alot of noise from the case. Not what I really wanted to do, but had to be done. I ordered a bearing and seal kit from Allstate Gear - NP241J. Here I will break down the process of overhauling a 241 x-fer case.
Any questions not answered here you can refer to the FSM found here: Jeep FSM Manuals
Items Needed:
Disassembly:
Once the case is out and on the bench, time to drain the oil. Remove the lower plug at rear of case, it is a 10mm allen. When I removed mine, hardly any oil cam out?! At one time i thought I checked it, but I digress.
Next come off the yokes. You will need a deep, thin wall 32mm to get the nuts off. The yokes should slide right off with the nuts removed.
I then started removing all of the 10mm bolts. I started with the rear flange cover and seal. Then I removed the 18 from the case halves. There is one 13mm on the top of the case. Take note of where it came from. The rear flange seal is pretty easy to get off, there are three tabs, just slowly pry with a screwdriver, and should pop off.
With the 18 bolts removed it is time to split the cases. Take your time and try not to damage the machined case halves getting them apart. The rear case half should slide away from the front case half half. In the rear case should also be the oil pump. DO NOT remove the bolts for the oil pump. This pump is aligned at the factory to the bearing race, and any movement will change alignment, rendering it useless.
This is how your case should look when removing the rear cover. (I forgot to take pictures, this is a reassembly picture) Remove the spring for the mode selector and set it to the side. Take a close look in the lower left of the case and note where the magnet is. It could be in either side of the case. Remove it from the case and set it aside. The front and rear sprocket assembly should be ready to pull out. Lift both sprockets out evenly from the case. They are heavy. Once lifted out the sprockets and chain can be separated. Also note when lifting out the sprocket, the mode fork will also come out. Try not to drop it and not loose any of nylon shims in the fork.
Here is what your sprocket assembly should look like when removed. Also is the mode fork in its position. There is no bearings or seals in this assembly, so all that is needed is a visual inspection of the mode fork and the three nylon bushings.
When I lifted out the sprocket assembly, I was greeted with a burned range fork. I did get this case used, and suspect that this happened with the previous owner. There were several flags I suspect this -
At this point you can remove the fork rod and flop the case around with the front facing you. Time to remove the remaining 12, 10mm bolts for the front side of the case to remove the planetary assembly.
When removing the assembly be careful as the ring gear may also slide out with the planetary set. If you have not done so already, remove the range gear from the planetary assembly.
This is the planetary flipped upside down and the ring gear is still on the planetary set. Also the range gear is resting in the planetary set.
The Planetary set is held in with a snap ring under the front seal. Dig out the seal on the input shaft, and there is a snap ring behind it. You will need a set of inside snap ring pliers to get the snap ring out. Pair I used is below which I got at O'reillys. With the snap ring out, the planetary should slid out from the bearing housing. On inside is the input bearing held in by a snap ring. The planetary is heavy, set it aside.
Below on the face of the planetary is a thrust washer. Remove old washer and install new thrust washer.
Rebuilding:
With the bearing housing upside down allows access to the input bearing. There is a snap ring holding the bearing in. Compress the snap ring and the bearing should slide out. Insert new BD-50-8 bearing along with snap ring. Seat bearing until snap ring expands in grove.
With new bearing installed it is time to reinstall the planetary set. Install planetary set and install snap ring to hold set into housing. Install the input seal, marked T-10. Carefully drive seal in evenly until flush with housing.
It is time to replace the output bearing for front driveshaft. With the main front housing on bench, remove the old seal from front output and using a socket and hammer, tap out the old bearing. Install the new #6207 bearing and drive in a new F4282 seal.
The rear housing has two bearings, a output bearing and a needle bearing set for the front output. The rear output replacement is the same as the front. Carefully drive out the old bearing, and side a new #6207 bearing in. The needle bearing is in a dead end, so it will take some creativity on your part to get it out. I first removed the inner cage and bearings, laving only the outer race. I then cut notches in the race to fit some washers inside to 'grab' the race and pull the bearing out. I setup a puller shown below to get the bearing out. Once out, I drove the new SCE 2416 needle bearing in.
New needle bearing:
There is just one seal left to remove and install, and that is on the rear output cover. Remove old seal and drive in the last F4284 seal.
Pre-work:
I have had some noise from what I thought was my rear axle, but actually was coming form my x-fer case. I posted a thread here on the issue. After running the Jeep on stands, there was alot of noise from the case. Not what I really wanted to do, but had to be done. I ordered a bearing and seal kit from Allstate Gear - NP241J. Here I will break down the process of overhauling a 241 x-fer case.
Any questions not answered here you can refer to the FSM found here: Jeep FSM Manuals
Items Needed:
- NP241 Bearing Kit - Allstate Gear
- Mopar ATF +4 Fluid - 2 Quarts
- Permatex Anaerobic Gasket Maker #51813
- 32mm Deep Impact Socket
- Snap Ring Pliers
- 10mm, 13mm socket and ratchet
- 10mm Allen wrench or socket
- 3/8" and 1/2" torque wrench
- Two 6207 bearings
- One BD-50-8 bearing
- One SCE2416 needle bearing
- One SCE2110 needle bearing
- Two F4284 seals
- One T-10 seal
- One thrust washer
- One C-572 seal
- Misc. washers and O-rings
Disassembly:
Once the case is out and on the bench, time to drain the oil. Remove the lower plug at rear of case, it is a 10mm allen. When I removed mine, hardly any oil cam out?! At one time i thought I checked it, but I digress.
Next come off the yokes. You will need a deep, thin wall 32mm to get the nuts off. The yokes should slide right off with the nuts removed.
I then started removing all of the 10mm bolts. I started with the rear flange cover and seal. Then I removed the 18 from the case halves. There is one 13mm on the top of the case. Take note of where it came from. The rear flange seal is pretty easy to get off, there are three tabs, just slowly pry with a screwdriver, and should pop off.
With the 18 bolts removed it is time to split the cases. Take your time and try not to damage the machined case halves getting them apart. The rear case half should slide away from the front case half half. In the rear case should also be the oil pump. DO NOT remove the bolts for the oil pump. This pump is aligned at the factory to the bearing race, and any movement will change alignment, rendering it useless.
This is how your case should look when removing the rear cover. (I forgot to take pictures, this is a reassembly picture) Remove the spring for the mode selector and set it to the side. Take a close look in the lower left of the case and note where the magnet is. It could be in either side of the case. Remove it from the case and set it aside. The front and rear sprocket assembly should be ready to pull out. Lift both sprockets out evenly from the case. They are heavy. Once lifted out the sprockets and chain can be separated. Also note when lifting out the sprocket, the mode fork will also come out. Try not to drop it and not loose any of nylon shims in the fork.
Here is what your sprocket assembly should look like when removed. Also is the mode fork in its position. There is no bearings or seals in this assembly, so all that is needed is a visual inspection of the mode fork and the three nylon bushings.
When I lifted out the sprocket assembly, I was greeted with a burned range fork. I did get this case used, and suspect that this happened with the previous owner. There were several flags I suspect this -
- It was split to install a Teraflex 2 - low kit. They used black RTV instead of an anaerobic sealant for the case. If you look at the rear seal cover shows all of the excess RTV on the inside. I am assuming that it could have blocked the drain back somewhat.
- There was more excess sealant on the split cases. The screen for the oil pump was half blocked, the magnet was covered also. If they were this careless, I am sure they were careless about the adjustment of their shifter upon re-installation, hence the burned range fork.
At this point you can remove the fork rod and flop the case around with the front facing you. Time to remove the remaining 12, 10mm bolts for the front side of the case to remove the planetary assembly.
When removing the assembly be careful as the ring gear may also slide out with the planetary set. If you have not done so already, remove the range gear from the planetary assembly.
This is the planetary flipped upside down and the ring gear is still on the planetary set. Also the range gear is resting in the planetary set.
The Planetary set is held in with a snap ring under the front seal. Dig out the seal on the input shaft, and there is a snap ring behind it. You will need a set of inside snap ring pliers to get the snap ring out. Pair I used is below which I got at O'reillys. With the snap ring out, the planetary should slid out from the bearing housing. On inside is the input bearing held in by a snap ring. The planetary is heavy, set it aside.
Below on the face of the planetary is a thrust washer. Remove old washer and install new thrust washer.
Rebuilding:
With the bearing housing upside down allows access to the input bearing. There is a snap ring holding the bearing in. Compress the snap ring and the bearing should slide out. Insert new BD-50-8 bearing along with snap ring. Seat bearing until snap ring expands in grove.
With new bearing installed it is time to reinstall the planetary set. Install planetary set and install snap ring to hold set into housing. Install the input seal, marked T-10. Carefully drive seal in evenly until flush with housing.
It is time to replace the output bearing for front driveshaft. With the main front housing on bench, remove the old seal from front output and using a socket and hammer, tap out the old bearing. Install the new #6207 bearing and drive in a new F4282 seal.
The rear housing has two bearings, a output bearing and a needle bearing set for the front output. The rear output replacement is the same as the front. Carefully drive out the old bearing, and side a new #6207 bearing in. The needle bearing is in a dead end, so it will take some creativity on your part to get it out. I first removed the inner cage and bearings, laving only the outer race. I then cut notches in the race to fit some washers inside to 'grab' the race and pull the bearing out. I setup a puller shown below to get the bearing out. Once out, I drove the new SCE 2416 needle bearing in.
New needle bearing:
There is just one seal left to remove and install, and that is on the rear output cover. Remove old seal and drive in the last F4284 seal.