Front tranny leak

[Carls_jeep]

Yes, it's a solid spacing. The two shafts are trapped by the bearings and the spacing is fixed as to how much you set in it.

I think you will need to have the second gear and synchro assy you will use mounted on the shaft to set the clearance. It's been two years since I built my tranny but I think the clearance is related to the input shaft, synchro assy and second gear. Difference in machine tolerances could cause issues.

I used toe clamps from my milling machine to hold the bearing against the case. A bolt, and a flat bar with holes drilled in them will do the job. What you want is for the shaft to be able to slide in the bearing so you can measure the end play with a dial indicator on the end of the output shaft. Pull hard on the shaft to be sure it comes all the way back and push hard forward to be sure your measuring the full clearance.

[bretto]

I found the parts in the mailbox today.  Now to find the time.  
There is a little bit is machining burrs I need file down but they look great.  And the spacing on the cones of the input shaft and 2nd gear looks almost to be 3/32"  I didn't take a real measurement, just put em up to them to take a quick glance and there is significance difference compared to the old ones.

[Carls_jeep]

Well, those are NOS for sure. It's a good idea to clean everything up and make sure the collar slides on the hub. Mine had some tight spots that I dressed off with a fine file and some mold dressing stones. I bought a pair of NOS blocking rings from Peter DeBella last spring just in case.

[calvinhunt]

Any tips on holding the bearing and adapter to the housing other then mating the tranny to the transfer case?

I messed with a couple of C clamps and got pretty good satisfaction in holding the rear bearing in place while getting a feeler gauge down in between the aft end of the output shaft and the rear bearing spacer. �Then I found that it was just about as effective to have someone firmly push on the honed out set up rear bearing while taking the end play measurement. �The real test comes when you bolt the TC to the tranny with gasket and any sealant/permatex in place.

[bretto]

FYI
If someone in the future runs across this posting, and looking for rings. �The part# on these are 243-14F. �This may be a manufactures part #, I dont know. �The manual shows the rings part # to be 640397. �I did some searching an found that there a few NOS rings out there now for sale. �If you go looking specifically for rings for Jeep, Willys, etc or the 640397 part # , you mostly end up with results�that look to be overseas repo stuff.

[bretto]

Calvin, I got your VM last night.  Our team won the basketball game by the way.
I appreciate again you sending those shims and I will return what I don't use, maybe all.
I got to digging at this a little more.  What we are really going after here as an end result is getting the spacing of the gears, hub, and rings in tolerance.

I came across a Willys sevice bulletin from July 21, 1947 concerning transmission jumping out of 2nd.  It has some info that is related to this job.

This is just the tail end of it.

5. Check fit of second speed, gear to shaft.  If loose, new bushing, Part
No. 640400 or second, speed gear, Part No. 640396, should be installed.
There should, be .003 to .014 end play between rear face of gear and
shoulder on shaft when gear is pressed, toward front of transmission,
so that clutch hub is against snap ring.
6. The clutch sleeve must engage second speed gear to a depth of 1/8"
beyond the chamfered edge of teeth.  If less, new spacer, Part No.
643621, or a .030 shim should be installed betweem spacer and shoulder
on shaft for CJ2A, CJ3A, end 4WD.  On the 2WD the .030 should be
installed between the rear bearing and shoulder of shaft.

[Carls_jeep]

I believe you still have to clamp the rear bearing against the back of the tranny case to measure that clearance and have the output shaft pulled all the way to the rear if the bearing slides on the shaft. If the bearing is pressed on the shaft then clamp the bearing in the case and measure the gap as described in the service bulletin.

[bretto]

Ok, I took some measurements.
I am getting .020-.022 movement with the rear gear and nut off.
I put the gear and nut on and I figure this lets me measure the play in the bearing itself and I get �about .008-.009 movement.
So with that, does that mean that my overall spacing would be in the .012-.013 ball park? �Once the gear is bolts on, the only movement you get is the bearing slop.

I also measure .012 clearance between the rear of 2nd and the shoulder of the shaft so that looks good.

[Carls_jeep]

If you put the gear and nut on and clamp the bearing to the rear face of the case you shouldn't have any movement in the shaft to speak of. The ball bearing may have a few thousandths movement in the balls and races but that's all. Maybe that is what your measuring and getting .008-.009".

After reading the part of the service bulletin you posted I am starting to understand why you want the .012" to .016" end play in the rear output shaft. Since Willys mentions that second gear should be at least 1/8" into the shift collar that's the reason Jeep Parts tells us to measure the end play and limit it to .012" to .016". When you do that you will have second gear into the shift collar as far as it will go and still have some clearance between the input and output shafts.

I think you should leave the nut and gear off and set the end play as Jeep Parts describes.

When I rebuilt my tranny I put the original spacer between the shaft shoulder and bearing and measured the end play. I think it was about .040" or a little less. I then made a new spacer the right thickness to get the end play I wanted. That way I didn't have to use shims, which I would have had to make anyway.� �

[bretto]

Ok, I took some measurements.
I am getting .020-.022 movement with the rear gear and nut off.
I put the gear and nut on and I figure this lets me measure the play in the bearing itself and I get �about .008-.009 movement.
So with that, does that mean that my overall spacing would be in the .012-.013 ball park? �Once the gear is bolts on, the only movement you get is the bearing slop.

I also measure .012 clearance between the rear of 2nd and the shoulder of the shaft so that looks good.

Yes, the .008 was the bearing slop or movement in the bearing itself.  This is the older honed out one used as a slip fit.  I also put on the new one to compare and it measured in at .005.
Anyway, I thought I should measure that movement to see where it was in comparison the movement of the shaft itself.
Now I'm wondering do you take that bearing movement out of the equation or is its part of the overall end measurement?  Reason I ask this because if its part of the sum of the space, there is a difference of .003 between the old and new bearing.
With the older bearing with no nut or gear on the end of the shaft, I get .020-.022 of movement in the shaft.   Now logic would tell me, the newer bearing, if it was a slip fit, it would measure in at .017-.019.  Then adjust from there.

[calvinhunt]

Reason I ask this because if its part of the sum of the space, there is a difference of .003 between the old and new bearing. With the older bearing with no nut or gear on the end of the shaft, I get .020-.022 of movement in the shaft. � Now logic would tell me, the newer bearing, if it was a slip fit, it would measure in at .017-.019. �Then adjust from there.

I believe I'm following your procedure, and if I am, I agree...adjust from there. �You're looking for .012 - .016. �I sent you shims of .003, .010, and thicker. �The .003 would take you down to .014 - .016 theoretically. �I would take it. �Final torquing of the TC to the tranny may give a slightly different, but most accurate reading.
George at Army Jeep Parts had me do my final check at the rear end of the splines on the output shaft (main shaft) between the end of the splines and the case (or whatever the splines end up fitting against--its been a long time) with the output shaft being loaded to the front in order to provide a gap at the rear.

[Carls_jeep]

Calvin, after reading your post I began to think, so I went to the barn and got my old shaft and bearing. I measured the movement in the bearing races and found the bearing to have .012" end play. I suspect a new bearing may have at least .005" .006" because these are low class bearings and would not be good enough to use in a lathe or mill spindle. Those applications require a tighter fit.

Your reasoning sounds good to me too. Now that I have measured my old bearing I feel better about the clearance that I left in my rebuild. I have been concerned I may have set it to tight but now I think it's just fine. A plus is, as time goes by wear enters the equation and the clearance increases.

I'm understanding this more now and I think if you measure the play in the bearing your using to set the clearance and the play in the new bearing and enter that into the equation you will end up with a good fit.

However, if you had the bearing clamped to the rear of the case tight, then putting the transfer case on the back should not change anything. One thing I did was to measure the protrusion of the rear bearing out of the rear of the tranny case and then measured the recess in the transfer case. I found what thickness gasket I needed to put between the cases so the bearing would clamp up tight and still seal the two cases. The rebuild gasket kit I bought had three different thickness gaskets to use. If you use to thick a gasket you will end up will excess end play. If you use to thin a gasket you can end up with a leak or a broken ear on the tranny which mine had when I tore it down.

Aren't these Jeeps fun to work on and get right. �;D :-/ �

[bretto]

The guy I bought the synchro unit from has listed some more.  He must have a bunch.  It would be nice to be able to buy another to have on hand.
http://www.ebay.com/itm/55-56-57-58-Ford-Transmission-Sychronizer-Gear-T86-T90-/220775742951?pt=Motors_Car_Truck_Parts_Accessories&hash=item3367427de7&vxp=mtr

[Carls_jeep]

Today I spent some time searching for how many vehicles the T90 was used in and didn't have much luck. I never have been good at picking the right combination of words to do a good search. Does anyone know all the applications of the T90 tranny?

[calvinhunt]

Carl,
 ï¿½The eBay ad says it's for Ford cars 55 through 58, 6 or 8 cyl. �That kind of surprises me. �Like you, I'd like to know how widely the T-90 tranny was used.

Brett,
 ï¿½Thanks for sharing the info with us. �Man, am I tempted to just purchase those NOS parts to have around. �I hope that I never need to replace the ones I'm now running, and don't expect to so I hesitate. �If I ever do need them I'm going to be real sad if I don't buy them now while they are available. �I'm going to have to dust of my crystal ball and take a look into it.