PORC SYE for NP231

Hey there, I have a potentially stupid question...

I just purchased and attempted to install the PORC sye for a NP21 (not that it being from PORC makes any difference). Anywho, when I yanked out the main shaft, it was different from the shorter main shaft they sent me. On mine, the speedo gear was all funky and the main gear pack wouldn't fit onto the new shaft. The bearings looked very close, but wouldn't quite work...needless to say, I ground down the yoke in the mean time, but is there a fix for this other than buying a new gear set and a different model speedo set up?

TIA

Michael

Hmmm....can't find an edit button, so let me elaborate....once I realized that the gear pack wouldn't work on the new shaft, I reassembled the old mainshaft assembly and put it back together, I inserted some washers to work as a temporary t-case drop, and reinstalled the old slip yoke DS. Unfortunately, even with my my T-case dropped, the DS was still binding at the slip yoke, so I ground away some metal so the DS could accomodate the steeper angle.

Anywho, I heard someone say something about older cherokees having a different type of speed sensor, I was curious if those also had slightyly modified main shafts. Unlike the 231 on my YJ, this didn't have the little plastic gear for the speedo...instead, the gear was actually on the shaft itself.

I'm a little baffled and would love to get this fixed. I checked my build sheet, it just says "DHNS - Command-Trac Part Time 4WD System". I looked at the tag on the case and it says New Process Model 231 Version J....anyone know of this oddball t-case?....or am I just a one in a million schmuck?

What year XJ is this going in? I put a PORC SYE in my `95 with no major problems a week ago. The only part of the install that they do not explain well is the need to press the needle bearings off of the drive sprocket. However, this is easy enough to figure out with any mechanical knowledge.

On mine, the speedo gear was all funky and the main gear pack wouldn't fit onto the new shaft.

Click to expand...

The PORC speedo gear needs to be secured on the new mainshaft with the supplied snap rings. I didn't have any issues with it.

The bearings looked very close, but wouldn't quite work...needless to say, I ground down the yoke in the mean time

Click to expand...

Which bearings are you talking about? The needle bearings on the drive sprocket might need to get pressed out, depending on the year.

You ground down the yoke? I have NO clue what you mean here.

Edit: I get what you meant about grinding the yoke now.

Anywho, I heard someone say something about older cherokees having a different type of speed sensor, I was curious if those also had slightyly modified main shafts. Unlike the 231 on my YJ, this didn't have the little plastic gear for the speedo...instead, the gear was actually on the shaft itself.

Click to expand...

On my stock mainshaft, the speedo gear is formed as an integral part of the shaft. On the PORC shaft, you need to slide on the supplied plastic speedo gear, and secure it with snaprings.

Yeah, I'm talking about the needle bearings....if you press those out, are there supposed to be other bearings to insert?

Or is it just supposed to spin on the two machined surfaces on the new shaft...no bearings at all?

When I did the sye on my YJ they supplied another set of needle bearings, however all the parts did a complete swap with no effort or modification....the YJ was a '93, the XJ is a '94

and to be honest, as soon as their directions said to remove the T-case from the vehicle, I threw them back in the box and went from memory =(. But like I said, no bearing removal or change was required on the YJ.

BTW, thanx heaps for the replies....was thinking I was gonna have to completely rebuild this thing

No new bearings are to be installed on the mainshaft. Once the bearings get pressed out of the drive sprocket, it goes on perfectly. I also wondered about the no bearing setup, but since no one has been complaining about noises or breakage, I'm assuming there's no big issue.

Ironically, the 231 in my XJ is out of a `94. I swapped it in to replace a broken 242.

Here's a write up I did that shows what to do with your bearings, etc...

http://naxja.org/forum/showthread.php?t=74749&highlight=porc+pictorial

Very nice write up! Wish I saw that before I started the endeavor.

Anywho, how exactly did you get the bearings out without scarring the wall of the gear? Just a punch, hammer, and a lot of precision or what?

What I did to remove the bearings was use an arbor press and a 1-1/2" socket. The socket was about 0.030 less than the OD of the needle bearing cage. It didn't take much pressure at all for the bearings to slide right out.

I guess if you didn't have access to a press you could hammer the bearings out. Although any machine shop could press them out for you pretty cheap. If you're not comfortable hammering on them and running the risk of scarring the shaft, I'd have a shop take care of this step.