Joined: Oct 02, 2014 Posts: 2022 Location: South Carolina, Dorchester County
Posted: Fri Dec 20, 2024 12:57 pm Post subject:
HodakaguyTom wrote:
I ordered a Shift Tower rebuild kit that comes with the required small parts, except it's for the civilian model and doesn't include the gasket that goes on top of the M38 shift tower (specific to the M38). I used the gasket cutter to cut out a couple gaskets, I'll leave a couple extra in the parts drawer in case they are ever needed in the future.
And installed on the Shift Tower to test the fit.
Gorgeous work!
And perhaps the absolute best photography on the interweb!
Nice catch on the shift cane gasket!
I had to check, and yup, mine is missing.
Guess I'll have to make one the hard way (I don't have an old school gasket cutter like you do).
What are you using for gaskets on the 6 top cover bolts?
I need some of them too. ORD9 says they're copper.
Might be easier to find fiber washers at my local Ace Hardware.
Enjoying your progress!
Ditto on the G503 mirror! _________________ Ron D.
1951 M38 Unknown Serial Number
1951 M100 Dunbar Kapple 01169903 dod 5-51
“The only good sports car that America ever made was the Jeep."
--- Enzo Ferrari
Joined: Apr 25, 2024 Posts: 60 Location: Eastern WA State
Posted: Fri Dec 20, 2024 1:47 pm Post subject:
RonD2 wrote:
Gorgeous work!
And perhaps the absolute best photography on the interweb!
Nice catch on the shift cane gasket!
I had to check, and yup, mine is missing.
Guess I'll have to make one the hard way (I don't have an old school gasket cutter like you do).
What are you using for gaskets on the 6 top cover bolts?
I need some of them too. ORD9 says they're copper.
Might be easier to find fiber washers at my local Ace Hardware.
Enjoying your progress!
Ditto on the G503 mirror!
Thanks Mate. I'll send you a gasket if you would like, I cut a few extra. Just send me a message with the address you'd like it sent to. I believe the bolts holding the shift tower to the transmission case are just lock washers. I plan on sealing the threads with anaerobic sealant to prevent leaks.
The gasket was not normally available by itself. But it did come with the tranny seal kit. Ron F's kit stocks that gasket still. Oddly enough the TM 9-1804B parts illustration is incorrectly labeled. B is actually the spring seat washer WO# 635863 and D is the gasket WO# 801733 (ORD# 7374976). The illustration fig. 07-2 on page 185 in the ORD 9 SNL G-740 is the correct illustration. _________________ Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100
Joined: Apr 25, 2024 Posts: 60 Location: Eastern WA State
Posted: Fri Dec 20, 2024 2:09 pm Post subject:
wesk wrote:
The gasket was not normally available by itself. But it did come with the tranny seal kit. Ron F's kit stocks that gasket still. Oddly enough the TM 9-1804B parts illustration is incorrectly labeled. B is actually the spring seat washer WO# 635863 and D is the gasket WO# 801763 (ORD# 7374976). The illustration fig. 07-2 on page 185 in the ORD 9 SNL G-740 is the correct illustration.
That's great to know, thanks Wes. I imagine standard copper washers of the correct size would work?
3/32 ds is a bit thick for a standard copper solid washers. I would gues they are copper crush washers. EitherAN900- or MS29513- series. These are 3/32" thick. Since they are being used with a 5/16" dia. screw then the full parts number is AN900-5 or MS29513-5. Also do take note they are only used after engine serial MC74419 which is the switch to full fording kit engine. This was initially a test run during M38 porduction for jeeps MC51887 thru MC51988 Jan 1952 and full prodeuction with this new waterproof engine setup started with MC53262 Feb 52. If you have a 50 or 51 M38 it did not come with the copper gaskets. _________________ Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100
Joined: Apr 25, 2024 Posts: 60 Location: Eastern WA State
Posted: Fri Dec 20, 2024 11:30 pm Post subject:
wesk wrote:
3/32 ds is a bit thick for a standard copper solid washers. I would gues they are copper crush washers. EitherAN900- or MS29513- series. These are 3/32" thick. Since they are being used with a 5/16" dia. screw then the full parts number is AN900-5 or MS29513-5. Also do take note they are only used after engine serial MC74419 which is the switch to full fording kit engine. This was initially a test run during M38 porduction for jeeps MC51887 thru MC51988 Jan 1952 and full prodeuction with this new waterproof engine setup started with MC53262 Feb 52. If you have a 50 or 51 M38 it did not come with the copper gaskets.
Joined: Apr 25, 2024 Posts: 60 Location: Eastern WA State
Posted: Fri Dec 20, 2024 11:30 pm Post subject:
Let the fun begin....reassembly time!
With NOS shift forks in hand it's time to assemble the Shift Tower. I had disassembled it again since my previous post so I could prep/paint the tower while I waited for the NOS shift fork to arrive.
A little wear on the old fork.
Getting ready to install the shift rails & forks.
Inserting the indent spring, there is one spring/ball per shift rail.
Then the indent ball goes in on top of the spring.
I used a small punch to compress the indent ball/spring while also pushing inward on the end of the shift rail, you need to compress the ball far enough to allow the shift rail to pass through into the shift tower.
Positioning the shafts so that the shift rail interlock will fall down and allow the 2nd shift rail to slide all the way into the tower.
Both shift rails, shift forks and retaining roll pins installed.
Starting to assemble the main shaft....NOS goodness.
Low/Reverse sliding gear, 2nd gear and synchronizer blocking ring on the main shaft. A liberal coat of assembly lube on the 2nd gear bushing and the blocking ring. You just want to place the blocking ring on lightly so it doesn't bind onto 2nd gear, it should spin freely.
Synchronizer assembly slid onto the shaft.
Installing the snap ring that holds the synchronizer assy onto the main shaft.
Assembled. Check that the blocking ring still spins freely.
Bagged to keep it clean until it's ready to go into the case.
Next up is assembling the needle bearings into the cluster gear.
I'm using a dummy/installation shaft made out of Delrin to assemble the needle bearings and spacers onto. I was going to build an installation shaft/tool myself but Sal at vintage Jeeper has these units already sized correctly and ready to go, so I just added to cart...bam . The bearings are assembled onto the installation shaft then the entire assembly is inserted into the cluster gear. The cluster gear is installed in the transmission case then later the actual shaft will be driven into the case and through the cluster gear, pushing the installation shaft out of the case in the process and keeping the bearings nicely in place on the actual shaft.
The original bearing spacer is placed on the installation shaft/tool along with a washer on either side.
Here I'm using some O-rings to hold the needle bearings in place as I assemble them onto the shaft. After the first row of needle bearings are all in place another washer is installed then another set of bearings and another washer. Two sets of bearings and three washers on each end.
Applying assembly lube on the needle bearings.
Sliding the shaft/bearing assembly into the cluster gear. Once the shaft/bearings are slid into the cluster gear up to the O-ring you cut/remove the O-ring and continued to slide the assembly into the gear, cutting and removing the O-rings as you get to them.
And assembled.
Last up for tonight was loosely installing the NOS reverse idler gear & shaft.
A quick trip through the ultrasonic cleaner to remove the oil/preservative
Joined: Apr 25, 2024 Posts: 60 Location: Eastern WA State
Posted: Wed Dec 25, 2024 8:09 am Post subject:
4x4M38 wrote:
Neat trick with the orings. I made my assembly dowels from wood. Pretty easy, if you can’t find the nylon jobbies.
This whole post needs to be a Sticky. It’s as good or better than Novak’s or the other tranny/transfer tear down and rebuild books. Fantastic detail and photos!
Thanks Mate, I'm glad your enjoying the pics. I enjoy the documentation process and always hope it will help others in their own projects.
Joined: Apr 25, 2024 Posts: 60 Location: Eastern WA State
Posted: Wed Dec 25, 2024 8:09 am Post subject:
One step back and several forward.
I got the cart ahead of the horse in my last post by assembling the cluster shaft needle bearings before I dry fit the cluster gear into the case to check for thrust clearance. It's a good idea to check for clearance before assembly, if the thrust washers have worn into the case and the clearance is excessive then the cluster gear can move back and forth which can contribute to 2nd gear jumping out. Now's the time to check to make sure the case is actually usable (actually that time would have been before paint lol) so I unloaded the bearings from the cluster gear, removed all the grease and dry fit the cluster gear into the case with the counter shaft.
I measured the thrust with both a dial indicator and a feeler gauge, ended up being about .010", slightly on the snug side but plenty usable....I'm good with that clearance.
Played with taking the thrust reading between the thrust plates and between the gear & thrust washer.
Loading the bearings back up on the installation shaft and inserting them back into the cluster gear using o-rings like last time.
Assembly lube on the steel thrust washer.
And stuck in position in the case.
The small brass plated thrust washer goes on the end of the cluster gear, the two tabs on the back go into the notches on the end of the cluster gear.
The large thrust washer had a slight conical bend to it out of the package, when placed up against the case the edges of the washer were slightly elevated. This would cause uneven contact/wear on the bearing so I used a seal driver and a socket to lightly tap the washer flat and take out the bend. Test fit in the case and it's now sitting nice and square.
Cluster gear and thrust bearings sitting in the bottom of the case. This assembly will stay there until the final steps of assembly when the counter shaft will be installed.
Reverse gear installed.
Time to build up the input shaft.
The oil slinger will go onto the shaft first, the raised portion goes towards the bearing. This raised lip provides clearance for oil to reach the bearings if you are running a open face bearing. I'll be installing a sealed bearing.
Bearing pressed onto the shaft and snap ring installed.
Next up I'm plugging the oil return hole in the case. The original design uses an open face bearing on the input shaft, oil would flow through the bearing and into the bearing retainer where it would then drain back into the case through the oil return hole. Oil was stopped from traveling out along the input shaft by a single felt seal that didn't work very well so you would end up with leaks dripping out of the bell housing. By running a sealed bearing you won't have oil entering the bearing retainer so you don't need the oil return hole, plugging this keeps any oil in the case where it belongs. I'll be keeping both seals in place on the bearing to minimize oil leaks. Sealed bearings will run a Loooooong time and the bearing grease will remain uncontaminated from any debris circulating in the transmission.
A silicone plug with a coating of shellac will keep it in place. Install the plug from the outside and press it in tight, then use a razor blade to cut the plug off flush. A light coat of shellac on the inside will seal it up nicely.
Installing the input shaft/bearing into the case. I coated the outer circumference of the bearing with a light coat of Aviation Permatex to keep any oil from seeping around the bearing and into the bearing retainer.
After installation I went to test fit the bearing retainer and found that the snap ring was to large, it was interfering with the bolt holes as well as preventing the bearing retainer from sitting flush onto the case. There is a recessed area on the back side of the bearing retainer where the snap ring fits into, this snap ring was to large to fit into the recess by .029". I used a high speed rotary file to carefully remove some material from the inner diameter of the snap ring until the snap ring fit fully into the groove and provided the necessary clearance.
I'm also installing bolts with copper washers to eliminate the oil collector. With the sealed bearing the collector is no longer necessary, the input shaft needle bearings will get plenty of lubrication from oil carried up by the gears themselves. I applied a good amount of Anaerobic sealant to the bolts and washers to seal up the holes in the case where the oil collector was mounted.
Installing the needle bearings with a healthy dose of assembly lube into the input shaft.
Prepping the main shaft. Applying assembly lube on the needle bearing surface as well as the forward blocking ring.
And into the case.
Installing the rear bearing adapter, this is a snug fit and is tapped into place.
Sliding the bearing spacer onto the shaft.
Bearing installed on the shaft.
At this point the transmission is turned upside down and the cluster gear will fall into position, allowing the counter shaft to be pushed in, pushing the installation shaft out in the process and keeping all the needle bearings where they should be in the cluster gear.
Before fully seating the counter shafts I test fit the locking tab on the case. The tab was to wide and would have caused issues when mating the transmission up to the transfer case. I trimmed down the lock tab for proper clearance, test fit one last time using the gasket as a template and then fully seated the counter shafts/lock tab into position.
I picked up a NOS made in the USA bearing retainer but upon assembly noticed I could feel bind as I rotated the input shaft. I believe the small snap ring on the input shaft is contacting the retainer. Comparing the NOS unit with my old one I noticed the old one has a deeper machined recess than the NOS unit, allowing more clearance. I test fit the old unit and the binding is gone. Hmmm...I'll have to address this.
Assembled. Holding the rear bearing in position and spinning the input shaft resulted in smooth operation in all gears. Getting closer!
Joined: Apr 25, 2024 Posts: 60 Location: Eastern WA State
Posted: Sat Dec 28, 2024 9:33 am Post subject:
Moving onto the Transfer Case
Started by assembling the front bearing retainer.
Paper gasket is installed ahead of the seal.
A light coat of Aviation Permatex to seal the outer edge of the seal against the case. This helps prevent leaks from going around the seal. I'll be installing a sealed bearing here so this step really wasn't necessary.
Using a seal driver to seat the seal. You can use a socket ect but if the socket is any to small or not wide enough you'll bend the metal housing of the seal during installation which will take pressure off the internal spring and cause leaks.
I'm installing a sealed bearing in the front retainer to help in preventing oil leaks. You can keep both seals installed or remove the inner seal so that the bearing is lubricated by the gear oil in the case. I'll be keeping both seals installed. This bearing is rated at 11,000 rpm and will live an easy life in this application. The grease inside the bearing stays clean/uncontaminated and will provide a long service life, think of sealed wheel bearings in a car...200 - 300k miles is common. Here I'm carefully popping off one of the seals to verify the bearing has proper grease, which it did! I've seen some sealed bearings with almost no grease so I always like to check before installation. After checking the grease I pressed/snapped the seal back into place and it's ready for installation.
Again using Aviation Permatex to ensure oil doesn't leak around the outer edge of the bearing.
Installing the bearing into the case.
Installing the snap ring to retain the bearing in the case.
Love these rechargeable magnetic lights from Harbor Freight....soooo handy.
Installing the lip seals for the shift rails.
Packed the seal with grease before installation.
Carefully selected a socket that covers to the outer edge, you don't want to bend the seal during installation with a socket that's to small.
Now to assemble the rest of the bits.
Installing the front output clutch shaft into the bearing. This is easily tapped into place with a hard rubber mallet.
Assembling the front wheel drive shift fork.
Applying assembly lube to the output shaft clutch gear then installing the assembly on the shift fork.
Carefully inserting the shift rail through the seal. The seal will hang up on both the front edge of the shaft and the rear edge of the shift lever cut out. Use a small pick to carefully work the lip of the seal over the shaft so you don't damage the seal.
Assembling the under drive shift fork and safety wiring it into the case.
Time to assemble the rear output shaft.
This shows where the thrust washer will go while the shaft is out of the case, you're not assembling this washer at this point. The washer only goes on one way.
I'm using a NOS output shaft that came with a pre-installed busing. If your re-using your old output shaft you will want to inspect this bushing and change it out if it's worn. Removing this bushing is a pain, you'll also need to ream the new bushing once installed for proper clearance.
I tried to order NOS made in USA parts for everything I could, a few items I had to go new on. Sal at Vintage Jeeper checks hardness on all the new parts to ensure they were properly heat treated and will hold up over time. Nice!
New bearing installed on the rear side of the rear output shaft.
Applying some assembly lube and mating up the output shaft sliding gear and output shaft gear.
installing the assembled gears onto the shift fork
Inserting the rear output shaft into the case and through the gears
Installing the thrust washer onto the rear output shaft
And the snap ring
Installing the bearing onto the front of the rear output shaft. I used a piece of pipe that only contacts the inner race of the bearing to drift the bearing into place. I braced the rear of the output shaft against my leg while drifting the bearing into place.
Installing the front outer bearing race. This race is installed flush with the case, the front bearing housing will fully seat the race to the proper depth.
Using a hammer on alternating sides of the bearing shell can and often does result in uneccessary wear on the opening. Much better to drive the bearing race squarely with a round adapter or even a piece of pipe or large socket. _________________ Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100
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. The bearings are assembled onto the installation shaft then the entire assembly is inserted into the cluster gear. The cluster gear is installed in the transmission case then later the actual shaft will be driven into the case and through the cluster gear, pushing the installation shaft out of the case in the process and keeping the bearings nicely in place on the actual shaft.
