'46 CJ2A T-90 Side (Column) Shift

Item resolutions:

1) Oil Slinger (aka "Oil Retaining Washer" by Willys):

While not 100% conclusive, I am convinced that the oil slinger WAS used on all CJ2A transmissions, for these reasons:

a) The original illustrations below did not depict an oil slinger, so I questioned its use.  I then found another illustration, from the same '45 Maintenence Manual, which DOES show the slinger.  The clutch assembly cross-section:

So I am assuming that the illustrations in Figs. 1 & 2 are in error.

b) My transmission DID have this slinger (very early '46 CJ2A S/N 16279)

c) Nobody responding to my requests had ever seen a transmission without one.

2) Main Shaft Oil Seal:

a) It WAS used on transmissions prior to s/n 24196.

The answer is in the manuals, but it's not obvious, intuitive or well documented.  More sleuthing uncovered these passages (quoted from Willys manuals):

The Service manual says: "Effective with Model CJ2A S/N 24196 and all other models listed, oil circulation is provided between the transmission and transfer case by the addition of drilled passages between the two units."  And it goes on to detail the changes.  With cross circulation, there was no further need for a seal, and it was subsequently eliminated.

The Parts Manual lists: 3 different transmission "assemblies" for column shifts:

• 640122 used up to S/N 24196
• 641730 used from S/N 24196 up to 38221
• 644317 used after S/N 38221
  

A comment after the 640122 assembly says to "use 1 each, A-15428"

Looking that up:

• A-15428 is an "oil seal, transmission main shaft, up to S/N 24196".  It just isn't shown in any parts manual illustration.

And from the '45 manual: "Place the oil seal, no. 27, in position in the main shaft bearing adapter or plate, no. 28, with oil seal lip facing forward.  Install the bearing adapter and seal assembly over the end of the main shaft and in the case"

b) My transmission DID have one.

I could not remember if it had one or not, as it has been 6+ years since I disassembled the transmission.  But after inspecting my rear bearing spacer, it was clear that it did have one.  The wear patterns from the original felt seal are quite evident in these photos:

     

I have found a modern replacement seal:  Chicago Rawhide # 17310  (or Nation Seal # 43071s)

Photos show the seal w/the spacer in place.

      

3) Front (Bearing Retainer) Gasket:

The full coverage front gasket is a carry-over from WW-II military vehicles.  As with many other parts, Willys had excess inventory at wars end, and used these parts on CJs until they were depleted, when they changed to the retainer only circular gasket.  Either type can be used.

I got this info from old-timer, who's been in the Jeep business for 30+ years, mostly as a motor pool mechanic in the Air Force.  Apparently there was (and still is for some) a requirement that military vehicles have a water-tight seal between transmission and bellhousing.   They wanted to keep as much water out of the bellhousing as possible.  This doesn't make much sense, since there are still far larger openings in the bellhousing for water to get in, but it's the only explaination I've got so far..

The difference in position of the input shaft WRT the clutch disk is inconsequential, and Willys subsequently eliminated the full flange gasket on CJs.

Original issues:

Fig. 1 (from the '45 CJ2A Maintenance Manual)	Fig. 2 (from the '45 CJ2A Maintenance Manual)
Fig. 3 (from the '49 CJ2A/CJ3A Parts Manual)	Fig. 4 (from the '49 CJ2A/CJ3A Parts Manual)
Fig. 5 (from the '65 Jeep "Universal" Service Manual)	Fig. 6 (from the '65 Jeep "Universal" Service Manual)

1. Main Drive Gear (Input Shaft) Oil Slinger:  Fig.1 shows no oil slinger behind the main drive gear bearing.  Figs. 3-6 all DO show an oil slinger.  Figs. 1 & 3 are supposed to be the same transmission.  Fig. 2 is a cross section of the transmission in Fig. 1.  It does NOT depict an oil slinger either.
2. Main Shaft Oil Seal:  Figs. 1 & 2 show an oil seal on the main shaft spacer between the transmission and transfer case.  Fig. 3 depicts the same item, but calls it a "bearing spacer - later type".  Figs. 4-6 do not show this seal/spacer.  In the Fig. 2 cross section, it is clearly a seal, looks like felt.  The '45 Maintenance Manual reassembly instructions includes a paragraph describing correct installation of this seal.
3. Front (Bearing Retainer) Gasket:  Figs. 1, 3 & 4 show a full flange gasket, which encompasses the entire transmission to bellhousing mating surface.  Figs. 5 & 6 show a circular gasket that would fit only the bearing retainer. leaving the transmission to bellhousing a metal-to-metal mating.

• Oil Slinger:  If it's installed when it shouldn't be, it would shift the drive gear rearward, possibly causing hard shifts/grinding between 2nd. & 3rd. gear?  If it's NOT installed when it should be, there would be a wider gap for the syncro to fill, possibly contributing to 2nd. gear popping out?
• Oil Seal:  if it's not installed, there's an open channel for transfer case oil to migrate into the transmission, through the bearing.  Many people seem to be experiencing this.  Could this be part of the problem?  The '65 Service Manual states that after SN 24196, transmission & transfer cases were drilled through to allow oil circulation between the 2 cases.  In these cases, an oil seal serves no purpose.  Prior to SN 24196 the cases were isolated from each other, and apparently require this seal.
• Front Gasket:  without this gasket, the input shaft would seat just that much deeper into the clutch disk.  I haven't measured anything to see where it all fits together, but this might be cause for those instances of clutch dragging?  The gasket thickness is minimal, but it might make a difference.

• I've not heard of a T-90 transmission w/out the oil slinger, but I have questioned it's neccessity.  The bearing is already shielded on this side, so what benefit would an added slinger provide? Did the earlier side-shifts not have them?
• I did NOT get a rear oil seal in my transmission rebuild gasket kit.  I don't remember if an oil seal was present when I disassembled it (years ago), but I want to use one. Does anyone know of a new oil seal part number to properly fit the rear bearing adapter?
• I also don't remember if a full front gasket was present when I disassembled it.  I wonder why Willys changed it?  Should a full-flange front gasket be used on an early side-shift?