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The Muncie Rebuild Page 

NOTICE!!  This Muncie Rebuild is now moved to a new domain:  www.SquidsFabShop.com  You'll have to go manually and type in the new address since GeeeeeOHCiteeeeez dot calm won't let me link out.

On the main page, there is a link to this muncie transmission rebuild guide.  It should have no problems with exceeding bandwidth, so it won't shut you off like this one might.  This geocities website will be taken down in the near future, so update your bookmarks.

This page is meant to help those considering a Muncie 4 speed rebuild who have never opened up a Muncie 4 speed before.  I was in this situation and found good information hard to find on the ‘net. Mainly a lack of good visual documentation.  Well, I think I know why; it's darn hard to do a rebuild AND take a bunch of good pictures AND put it on a webpage. Here's my attempt:

I picked up a 1967 Muncie at a swap meet.  I didn’t really know what to look for so I just checked for broken parts.  The info I found on the internet helped me ID what I was looking at during my search.  It was important to me to find a late 60’s tranny since it has the larger countershaft pin, correct spine count (to match my 67 vintage parts) and speedometer output on the driver side.

I paid $350 for it and yes, it was too much.  I ran into some old timers who said they remember buying Muncies at swapmeets for 25 bucks.  Sheesh.

To start:

Get a manual.  I simply have an old Chiltons manual which lays out the whole process in very basic steps.  It’s got a grainy exploded view so I found a nice exploded view here: www.autogear.net  Go to the literature section, scroll down and you can download a great PDF file of Muncie parts with an exploded view. Study this exploded view. As you look at it, it may not all make sense, but when you actually tear down the trans, it will all come together. Manual transmissions really are very cool mechanisms.

Some tools I found necessary: A small punch set, a brass drift set, and a “gorilla” class snap ring plier. A 2 jaw puller is needed, and of course various hand tools.

Someone recommended a supplier of muncie parts to me so I sent some emails and decided to go with them. Bob at www.fourgeartrans.com was very helpful.

Tear it down!

I didn’t follow any particular course of action, but just went carefully. Here are the main steps:

• Shift the transmission into two gears:  Twist the shifter shafts CCW (front shaft puts it into 4^th, back shaft puts it into 2^nd) This locks up the mainshaft so it won’t spin. Take the front bearing retainer off.
• Take off the “gland” nut, otherwise known as the input shaft nut. I had to chuck the blasted nut into my bench vise (not easy with a transmission attached) and turn the whole transmission by hand. I didn’t have the special wrench until later. Monkey wrench wouldn't grip it either.
• Shift the front fork shaft into neutral, (one click CW). Leave back fork shaft in second gear. This allows easy side cover removal.
• Remove side cover.
• Tap out the reverse gear shaft retaining pin with a punch. It’s on the side of the boss where the reverse lever enters the tail housing. Drive it out from the bottom up.
• Unbolt the tail housing. Pull out the reverse shifter fork shaft a little bit. Pull the tail housing off. Ya gotta be fancy to move it around the reverse gear inside.
• Take out the reverse idler gear and shaft. See figure 1

Figure1: Reverse Idler gear and shaft. Like the broken teeth?

• Remove the speedometer gear ring. I used a puller with homemade extensions to get the jaws to reach the ring. I also used heat (torch) because that speedo ring was TIGHT.
• Now you can slide off the big reverse gear.
• Pry off the midplate from the main case. All the gear works attached to the mainshaft will come out with it. Roller bearings will fall out of the input shaft inside the case.
• On the mainshaft, from the front, remove the front snapring. You’ll need to flex your gorilla arms to get this snapring off. Remove the slider/hub toward the front. I had to tap the hub off; it was a bit tight. Then remove 3^rd gear. See figure 2.

Figure 2. This is the midplate with 1st and 2nd gear and it’s syncro assembly (hub/slider/and brass rings). Reverse is hangin' off the back there. 3rd/4th synchro assembly and 3rd gear are already removed.

• From the back, remove the snapring just in back of the rear bearing. This is a gorilla class snapring too. See Figure 3.

Figure 3. Arrow shows back snap ring.

• I then brought the mainshaft-midplate-bearing-1^st-2^nd gear assembly to a machine shop to press everything off from the shaft. (bearing, 1^st gear bushing, and finally the synchronizer hub) One source on the ‘net said he just takes the assembly and smacks the tail of the mainshaft onto an aluminum plate on the floor a bunch of times to force off the parts. Seems violent, but it works. Since I had it done at a shop, everything came off at once.
• 2^nd gear can now be removed. You should have a bare mainshaft now.
• For the case, first, remove the reverse idler front gear and thrust washer. It’s hangin’ loose in there. Refer to your exploded view! You can now tap the input shaft into the case and take it out. Remove the bearing by tapping it out to the front using a drift from the inside. It shouldn’t be in there too tight.
• Now to remove the cluster gear (counter gear): Use a big brass drift and drive out the countergear pin from the front to back. After a few good hits it’ll slide right out. Lift the counter gear out. Lots and lots of needle bearing will pour outa there! Take out the bearings and spacers and thrust washers too.
• There may be a sheet metal “gear” riveted onto the front of the gear. It’s some sort of anti-rattle mechanism, but it’s been known to come apart and destroy the main case. It’s not needed anyway, so I drilled out the rivets and removed it. Figure 4.

Figure 4. Rattle gear taken off. Notice rivet on top after being punched out. Spring underneath is removed too.

Now the main case should be bare.

Take a look at all the itty bitty parts. Time to wash ‘em and the case too. Time to determine what you need to do a good rebuild. My gears were in good shape, although the engagement teeth on third gear were a bit rounded off. The engagement teeth are the little “nubs” on the sides where the cone shape is. See Figure 5. The sliders grab these teeth when the gear is engaged. If they’re rounded off too much, the gear will push the slider off and back into neutral. Reverse gear has no synchro, hence no little engagement teeth.

Figure 5. Black arrows show the engagement teeth. These are in good shape. Brass synchro (otherwise known as the blocking ring) is installed over the cone portion of the gear.

I didn’t want new gears so I talked to the Fourgeartrans guy and he recommended Torque loc sliders. These help keep your gears engaged especially if your gear’s engagement teeth are a bit worn. Normal sliders are straight splined. Note the Torq-loc splines. On the left is the destroyed original, and on the right is the Torq-Loc. See figure 6.

Figure 6. The original was in pretty bad shape (left). Torq-Loc slider on the right.

I sandblasted all the case parts since they were really stained and dirty. I tried chemicals, but the finish was still stained and ugly. I used fine Olivine blasting sand. Lot's of work but it looks good.

I repaired a stripped hole in the tailhousing with helicoil, and also fixed a hole in the tailhousing from a long bolt used on the shifter mounting plate. I used JB Weld epoxy to seal it up. This is good stuff!

Figure 7. Blasted case on the left, pencil showing hole in tailhousing on right. Nothing a little judicious use of JB Weld won't take care of.

So get your rebuild kit and let’s get started on the….

Rebuild!

• Assemble your synchronizers. The synchro hubs have a flat side and an extended side. The extended side will face front for both 3^rd/4^th assembly, and 1^st/2^nd assembly. The slider (i.e. sleeve, i.e. clutch) for the 3^rd/4^th set is slipped over the hub so the tapered side faces front. The 1^st/2^nd slider in slipped over it’s hub so the the taper faces the rear. Figure 8a and 8b.

Figure 8a. Synchronizer assemblies. 3^rd/4^th is to the left, 1^st/2^nd is to the right. Hubs are already inside the sliders. Finger points to hub extension. The analogy used frequently is the assemblies stacked together look like “a hamburger bun” as you look at it.

Figure 8b. This detail shows the spring holding the key in place. The spring holds all three keys in. It is the same on the other side. Note the orientation of the keys.

• Put some oil on the main shaft and slide on second gear with a synchro. Cone side toward rear. See figure 9a.
• Slide on the synchronizer assembly (the one to the right in figure 8) with the hub extension toward the front. I used a brass drift and tapped it on. Make sure the brass blocking ring is aligned so the 3 wide gaps fit over the keys in the synchro assembly. Also, careful you don't knock the synchro assembly apart. See figure 9b.

Figure 9a and 9b. Correct orientation of synchro assembly to be installed.

• Now you can place the 1st gear bushing on. This will need to be pressed. I used a 2 foot length of 1-5/8 I.D. steel pipe. See figure 10a and 10b.

Figure 10a. In the foreground we find on the left: 1st gear sleeve, to the right one beating shalilly, and in the middle one steel pipe. Figure 10b is the pipe pressing the sleeve down to the hub. Make sure you tap it down all the way.

• With the shaft tail sticking up in the air, install a brass blocking ring into the synchronizer assembly, being careful to align the notches with the keys, then lube up the I.D. of first gear and slip it onto the bushing. See figure 11.

Figure 11. Blocking ring is in the synchro assembly (align the 3 notches in the blocking ring with the keys in the synchro), and first gear is about to settle in.

• Time to press the rear bearing into the midplate (rear bearing retainer). Put in the bearing snapring first, expand the snapring and press the bearing into place. Press it in until the snapring snaps into place. Tapping may be necessary. See figure 12.

Figure 12. Snapring locates bearing. Make sure the bearing is facing the right way or it'll be sticking out of the midplate.

• Place the midplate onto the mainshaft and press the bearing down until it hits the first gear bushing. Again, you may need the help of a hammer and pipe. See figure 13.

Figure 13. The midplate isn't pressed on yet here, but you can see the locating lip of the midplate is facing down. This will register it with the maincase when the time comes....

• Install a snapring in the groove directly behind the rear bearing. The rebuild kit should have several thicknesses. Pick one so it's as small a gap as possible when installed. Place it so the ends are behind splines. I don't know why, but they want you to. See figure 14.

Figure 14. Still not fun trying to wrestle this sucker on even with the right tool.

• Install the reverse gear with the flange facing toward the end of the shaft. Install the speedometer ring. I used the old input shaft nut as a washer in between the pipe and speedo ring so I wouldn't bugger the speedo ring. See figure 15.
• Test fit the tailhousing onto the midplate and look to verify the speedo ring is lined up in the middle of the speedo cable hole.

Figure 15. Notice the old input shaft nut as a washer for banging on the speedo ring.

• Time to install the 3rd and 4th gears onto the front of the mainshaft. First, oil up the I.D. of 3rd gear and slip it onto the mainshaft with the cone facing forward. See figure 16a.
• Install the synchro assembly with the hub extension facing forward also. This may need to be tapped on with some slight persuasion too. See figure 16b.

Figure 16a. 3rd gear is being slipped on. Cone toward the front. Figure 16b. Now the synchro assembly is being placed on. Make sure to tap it on all the way.

• Now the front snapring can be placed on. Orient the snapring so the ends are behind a spline. See figure 17a.

Figure 17a. Here is the front snapring installed. Notice that it says T-10 on the slider. T-10s and Muncies share many common parts. Figure 17b. Your assembly should look like this!

• Time to get to the maincase and cluster gear. Get your jar of grease ready. Study your exploded view for the sequence of parts.
• Pack some grease into the cluster gear center and place the long spacer inside. Place a single thin washer in, then smear grease around the inside. Start packing in the roller bearings. Pack as many as will fit. Place another thin washer on top and press the works inside. Smear more grease around the inside, then pack more roller bearings (as many as will fit). Place yet another thin washer on top and press it flush with the end of the counter gear.
• Go to the other side of the counter gear and put a thin washer in there, smear some grease, pack in roller bearings, another thin washer, more bearings, then the last thin washer. Figure 18b shows the roller bearings inside.

Figure 18a. Case and countergear. Figure 18b. You can see from the edge on down: thin washer, roller bearings, thin washer, roller bearings, thin washer, and yep, the big long spacer is in there. Same for the other side.

• Apply grease to the back side of a thrust washer. These have a tab which fits inside the notch in the case. Squash them into place on each end of the case. See figure 19a and 19b.
• There seems to be many methods to do this next part. I found it to be very easy for some reason. Many have said it takes many tries, but it was so easy, I was surprised. Here's what I did:
• Place the main case so the front end is on the bench top.
• Manuever the counter gear into position with care. Ensure that the thrust washers stay in place. Use a screwdriver or your fingers to put the thrust washers into postion.
• Take the countershaft pin, flat end first and push it down into the countershaft hole. Wiggle the countergear to help it along. The pin should go all the way except for the last half inch or so.
• While holding the countergear with one hand, tip the case on its' side and use a finger to align the front thrust washer and guide the pin to the front hole in the case. Once it finds the hole, it will need to be pressed the rest of the way. BEFORE YOU DO: Make sure the pin is aligned correctly. On the rear part of the case, the raised part of the pin is up and as you look at it from the rear. It should aligned to the 8:00 o'clock and 2:00 o'clock positions. Figure 20b.
• Tap the pin in until the notched part of the pin is flush with the case.

Figure 19a and 19 b. Thrust washer being installed on front of case.

Figure 20. Note the orientation of the pin notch.

• Now place the case on its' side and install the front reverse idler gear thrust washer. It also has a tab which mates with a notch in the case.
• Install the front reverse idler gear. It will be loose for now. Figure 20.

Figure 20. Front reverse idler thrust washer and gear (not installed yet in photo). They'll be loose until the rest of the guts are insalled.

• Load the input shaft bearing cage with their roller bearings. They are installed from the outside. Grease will hold them in.

• Load up the input shaft roller bearing area with grease and slip the cage and roller bearings inside. see Figure 21.

Figure 21. The input shaft is ready to have the bearing cage and roller bearings place inside.

• Place the last blocking ring into the 3rd/4th synchro. Make sure the notches line up with the keys. Place the input shaft assembly onto the mainshaft. The insider roller bearings will slip over the mainshaft tip. See figure 22.

Figure 22. This is the whole shebang. The 3rd 4th synchro is slipped over to engage the mainshaft (4th gear position) to help hold the input shaft on for the next step.

• Slip the front midplate gasket into position. I used a thin bead of silicone to keep it in place.
• Apply a bead of slicone to the back of the maincase.
• Lift the gear assembly into position at the rear of the main case. Put your hand inside and guide the gears into the case. Keep going until the midplate is against the main case. Align the dowel pin and then tap the midplate until it is seated. Since I was taking my time and I wouldn't get to the tail housing until later, I used some bolts to snug it all down to "seat" the beads of silicone. I let it sit overnight to cure. See Figure 23.
• Slip the reverse idler pin into a liberally oiled reverse idler gear. Slip it into the case and manueuver the front idler gear so the splines engage. Be careful to make sure the tabbed thrust washer stays in place inside the main case. Figure 23b.

Figure 23a. The midplate has been tapped on. Figure 23b. Bolt the whole thing on to seat the silicone. Also note the reverse idler has been installed. It'll still be a bit loose until the rear of the pin is seated in the tail housing.

• Time to install the front bearing. Place the snap ring onto the bearing. Place it over the input shaft and press or tap it down until it seats in the main case.
• Lock the transmission into two gears. This will keep the mainshaft/input shaft from turning.
• Install the left hand input shaft nut. Tighten it up. I bought the correct wrench, even though it was a bit pricey. I don't want to monkey with a monkey wrench for this one. Use loctite, and/or stake the nut to the mainshaft.
• Install the gasket on the bearing retainer. I used slicone on the gasket. Align the retainer so the oil drain path is correct then bolt it on. Use sealer on the bolts!
• Tail housing time: Press or hammer out the yoke bushing. I used a 1-1/4 inch socket which fit perfectly. Install the new bushing. I used a piece of hard wood to start it, then as it went below the outer seal lip, I used big washers to hammer on. Drive it in until it is flush.
• Install the rear seal.
• Install the seal for the reverse lever shaft. A 3/4 socket is perfectly sized to tap it in.
• Install the spring and ball bearing into the hole for the reverse lever.
• Install the reverse lever as far as it will go. The lever must be pressed in so the ball is bearing against the detents on the shift arm:
• This gets tricky: How do you press the spring and ball down and push the reverse lever in all the way? I used a piece of shim from a feeler guage set to use it like a shoe horn. It worked very nicely, but the shim was slightly mangled. (When is the next time I'll need an 0.008" feeler guage anyway?) See figure 24.

Figure 24. The shim is being used to shoe horn the lever past the spring loaded ball bearing. Shown here, the reverse lever shaft still needs to be pushed toward the outside of the case about 3/8 of an inch.

• Rotate the reverse shifter arm forward so the ball bearing is pressing on the bottom detent. This is the engaged position for reverse gear.
• Now pull the reverse lever shaft out of the case as far as possible. Be very careful not to let the ball bearing spring out past the lever. The lever needs to be in this position to allow the tail housing to slip onto the main case and reverse gear while you install the tail housing.
• Place the reverse shifter fork (forklet?) into the reverse shifter arm. Align it so its' slot is vertical

• Slip the gasket onto the midplate.
• Move the reverse gear out to the rear of the splines it rides on (reverse gear disengaged).
• Manueuver the tail housing over the tailshaft and line up the fork over the reverse gear flange. Once the fork is on the flange, align the reverse idler shaft into the tail housing and then push the tail housing on all the way. Tap the tailhousing the last bit if needed, but don't force it.
• Push the reverse shifter shaft into the case now so you can see clear through the hole the tapered retaining pin goes into.
• Make sure the 1/2 and 3/4 synchros are in nuetral, and then rotate the input shaft and see if it is indeed in reverse.
• With pliers, rotate the reverse shifter shaft CW. This disengages reverse and you should now be in true nuetral.
• Install the tapered pin to lock the reverse shifter shaft into position.

Figure 25. Tailhousing installed.

• Time to assemble the shifter cover plate. Install the seals in the shifter plate. A 3/4 socket works nicely.
• Install the detent levers.
• Install the spring.
• Install the shifter shafts with forks. Pull the detent levers up to push the forks in all the way. Leave the 1st/2nd lever rotated toward the left, or 2nd gear position.

Figure 26. Here is a detail of the shifter forks installed in the shifter plate.

• Place the shifter cover gasket in position and manuever the cover on. Install all the bolts and torque them on.
• Install the speedo driven gear housing.
• You are done, but, DON'T FORGET TO FILL IT WITH OIL BEFORE YOU FIRE IT UP!

The finished product. Kinda ugly isn't it? I am going to do a final scrubdown and maybe clear coat it.

This was a very rewarding project and it really isn't that hard.

This is my first cut at putting down the whole procedure so if you see anything amiss, I'd appreciate any feedback. See my About page to get my email address.

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Dave Miles

October 10, 2004