I've got two external slave AX15s with different 4.0 bellhousings in the shop. It's academic, but I'm wondering if anyone knows more about these bellhousings other than the usual internal/external slave differences.
Trans P/N 52108047 for a 4.0 XJ 4x4 manual. It has a bellhousing with some external ribbing on top, the bellhousing has P/N 53008157 cast into it. It is of a complicated and unknown history - The transmission part number and transfer case clocking match an XJ, but the seller pulled it out of a YJ Wrangler. There are two different kinds of hardware store style bolts holding the bellhousing on to the transmission. I have no idea if the bellhousing is original to the transmission.
Trans P/N 52108048AB for a 1997 RWD XJ 4.0. I pulled it out myself. Factory style bolts with clean threads attach bellhousing P/N 52107552 to the trans. Pretty sure it was all original, down to the clutch and flywheel.
I know it's a nitpicky question but I was hoping someone could shed some light on this. My googling of the part numbers has not brought any clarity, or any pictures of another bellhousing with ribs on top.
I'm finally getting close to installing one of these bellhousings revisited this question because it's been bothering me.
Looking at the xjjeeps website, I sorted through the parts catalogs for 1988-1990, 1991-1993, 1994-1996, and 1997 to 1999 parts catalogs. I won't link them as I don't know if that's allowed, but a quick internet search should bring up the right site.
Overall transmission: The first reference to 52108047 is in 1994, which lines up with the changeover to the external style slave cylinder in that year. The RWD transmission code 52108048 also first appears here, but no revision codes (the AB suffix) are included in the 94-96 catalog that I saw. In the 1997-1999 catalog, no letter suffix correlates to a 1997 transmission. The -AB suffix covers 1998-1999 transmission. So, it would appear that 1994-1997 AX15s are identical. There was some sort of revision between 1997 and 1998 to both 4x4 and RWD varieties of AX15.
Note that the part number for the transmission DOES NOT include the bellhousing, which they refer to as a clutch housing.
Bellhousing/Clutch Housing: The 53008157 part number on the bellhousing with extra ribbing only shows up in 1994-1996 parts catalog. In 1997-1999 and the 2000 year catalogs, the 52107552 part number is used for both the 1997-1999 AX15 and the 2000+ NV3550 transmission.
So, I think my 4x4 transmission is likely from a 1994-1996 XJ, with a very small chance it came from a 1997 and had the early bellhousing swapped on for... some reason.
What I still don't know is why this change to the bellhousing was made. The bellhousings appear identical other than the ribbing, and it's common knowledge that they are interchangeable with no mention online of a difference, so what drove this change? Maybe cost and ease of casting? Is one ever so slightly stronger than the other? I have no idea.
Both transmissions are currently torn apart, only one will go back together. The 4x4 one was beat to crap inside, so I'll use as many parts from the RWD transmission as I can with the 4x4 output shaft and rear housing. I'll probably use the ribbed 1994-1996 bellhousing as well, since it's already been cleaned and the extra ribs would at least seem to make it stronger.
Hopefully they are made to original standards and not out of the crappy replacement parts you can buy to rebuild one. Because I'm having a GREAT time with that.
