SYE install: Remove transfer case or not?

[DuncLJ]

I'm installing an Advance Adapters SYE and CV driveshaft in my np231 this weekend. I am aware that the SYE can be installed with the TC either in or out. I just would like a consensus or opinions as to which might be the better option.
Thanks

 

[LJGreg]

Easiest part of the entire install for me was dropping the TC. It probably took me 20 minutes. I borrowed a friends motorcycle jack which made it dead simple. Pretty sure it would be a real pain in the ass trying to do it while it is still attached.

 

[Jerry Bransford]

Absolutely no need to drop the tcase. It's easier and faster to just leave it bolted to the transmission.

 

[mrblaine]

Easiest part of the entire install for me was dropping the TC. It probably took me 20 minutes. I borrowed a friends motorcycle jack which made it dead simple. Pretty sure it would be a real pain in the ass trying to do it while it is still attached.

Borrow or buy a pair of drive-on ramps, pull the back tires up on them, go to town with the t-case still in place. Far easier than chasing it around on the bench to get some of the snap and lock rings off, plus the trans acts like another set of hands to hold stuff in place for you. Super easy to do if you can sit up under the rig. I've done them both ways, much prefer under the rig.

 

[Jerry Bransford]

Under my Jeep with the rear wheels up on ramps is how we did mine when Blaine came over nearly 20 years ago to show me how to do it. I was prepared to remove the tcase before he arrived, I'm glad we didn't!

 

[LJGreg]

Borrow or buy a pair of drive-on ramps, pull the back tires up on them, go to town with the t-case still in place. Far easier than chasing it around on the bench to get some of the snap and lock rings off, plus the trans acts like another set of hands to hold stuff in place for you. Super easy to do if you can sit up under the rig. I've done them both ways, much prefer under the rig.

To be fair, I did screw up my install and put my synchronizer assembly in upside down. I didn't notice until I had it all bolted in place. So maybe I'm not the best person to give advice on this one.

 

[DuncLJ]

Thank you gentlemen. I shall procede with the TC installed and the back on ramps.

 

[tworley]

I did mine with the tcase installed.

 

[T Crawford]

I did my np 242 on the bench with a new shaft, but that was my opinion

 

[EzPeezy]

It's easy enough to take the transfer case out and reinstall it, and that's what I did when I did mine. If you haven't had it out before it's a good opportunity to clean up the tub a little bit.

 

[crackedcornish]

I've done it both way, and I think it all depends on where you plan to do it

if you have a good, solid level surface to work on then leave it in and work under the Jeep, otherwise take it out and work on it where your safe

 

[ballpark]

Quick question, how do you get the dust cover off of the output spline? Thanks!

 

[Jerry Bransford]

Quick question, how do you get the dust cover off of the output spline? Thanks!

Just cut it off, you won't be needing it once the SYE is installed.

 

[JKLNHYD]

I took mine out to do it, mainly because I wanted to clean the tcase up as much as possible and I don't like being restricted in a space to do something as extensive as a SYE. I also would not be comfortable sitting under there dropping crap in my face or into the open case and not being able to control that.

 

[mrblaine]

I took mine out to do it, mainly because I wanted to clean the tcase up as much as possible and I don't like being restricted in a space to do something as extensive as a SYE. I also would not be comfortable sitting under there dropping crap in my face or into the open case and not being able to control that.

If you can sit up, you aren't dropping anything in your face because it is eye level to back of the case.

 

[ac_]

I have done it both ways also. I found it easier to get the case cover back on on the bench, but doing it under the car wasn't much worse. When I did mine under the car, I did it on jack stands on my back. Probably much easier in the car if you had a proper lift, but again I didn't, and it went fine.

Just make sure you drain it completely first either way, and take your time. It is really straight forward. Also another suggestion at least replace your shift shaft seal while you are in there. It is much easier with the case apart.

 

[JKLNHYD]

If you can sit up, you aren't dropping anything in your face because it is eye level to back of the case.

I didn't have any ramps so I would have been working off of jack stands and didn't think I'd get it high enough with what I had to be able to sit up fully.

 

[Midtenn]

If you are replacing the chain while you are in there, does it change the suggestion?

 

[ac_]

If you are replacing the chain while you are in there, does it change the suggestion?

Nope because you have to remove that either way.

 

[freedom_in_4low]

I started off leaving mine in. One of the threaded bosses snapped off the front housing so I ended up having to pull it off after all and did the install in another case before putting it back in.

I don't know if all the transmissions are like this, but access sucks butt for the nuts that hold the transfer case on to the AX15. There's not enough space for a ratchet and socket, and if you use a regular wrench you get a few degrees per turn at best so it's incredibly annoying. I would consider a ratcheting wrench to be a mandatory tool if you decide to remove the case.

I would definitely leave it in the Jeep doing it again. And I would clean and lubricate the exposed threads on the case half bolts before removing them. The one that broke was for the 12pt bolt at the top, and it has like an inch of excess length for some reason.