Author Topic: Any Muncie 4 speed experts out there?  (Read 13592 times)

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Offline 72vet

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Any Muncie 4 speed experts out there?
« on: December 18, 2010, 04:38:47 PM »



Recieved this from a new member to the club


While manoeuvring into my garage and shifting from first to reverse gear, my shift linkages have stuck in the reverse plane, however I can't grab any gears.  What's worse, is that when you try to let the clutch out it bogs down like its stuck in first and reverse at the same time.??  I've again got my baby up on stands and have been tugging on the various linkages based on the assumption that it's still stick in first gear and reverse gear.  A friend told me that it was a common problem in old Aussie 4-speed boxes if you shifted between the planes too quickly and that I just have to shift one of the gears back into neutral state, however I'm struggling to move any of the linkages (being behind the exhaust system and the cross member doesn't make it any easier....).  If I knew what the "neutral position was for all of the levers going into my gearbox, I could at least be able to see which one are in the wrong position.  I'm sure that this is a somewhat common problem.  Is there anyone in the club that can give me some directions?

Any help would be appreciated.  Mathew
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Offline Camo

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Any Muncie 4 speed experts out there?
« Reply #1 on: December 18, 2010, 06:00:01 PM »
This may help.....




The 4-Speed transmission gearshift linkage utilizes three shift rods and levers. A simple gauge block will aid in making the proper adjustments. The adjustments can be made without the gauge block by having an assistant hold the manual shift lever in the neutral positions. Remove transmission gearshift lever seal from the floor pan.

Place transmission in neutral (Click the side cover levers to the center position {Center of three possible locations} and set the reverse linkage to the neutral position. Reverse has only two positions engaged or disengaged {reverse lever should be forward for the neutral position}) and install gauge block in position as shown in illustration.
Remove the cotter pin, anti-rattle washer and clevis pin at each shift lever.
On each shift rod, adjust the threaded clevis to permit free entry on the clevis pin into the hole in the transmission shift lever.
Reconnect the clevises to the shift levers.
Remove the gauge block and check the shifts. If any roughness still exists, one of the clevises may require adjustment of approximately one-half turn. Determine the rod and clevis requiring adjustment by sighting along the slot where the gauge block was used in step 2.
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Offline sirfixalot

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Any Muncie 4 speed experts out there?
« Reply #2 on: December 19, 2010, 07:02:06 AM »
Some aftermarket shifters have about a 1/4" hole drilled thru the shift levers use same adjustment procedure place a drill bit thru holes to align

Offline Matt G

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Any Muncie 4 speed experts out there?
« Reply #3 on: December 19, 2010, 12:48:32 PM »
Thank you everyone for the replies.  It turns out that this problem was pretty easy to fix.  Lessons for all are:
- 1/2 and 3/4 linkages into your box are vertical when in neutral.  This should give you a base/known position to work from.  Reverse gear only shifts one way, and it's pretty easy to see.
- It is absolutely possible to grab 1st and Reverse gears at the same time (shifting very quickly between these two gears is not advised...).
- Your gearbox will shift easily by hand (by pulling on the linkage bars between your shifter and the gearbox linkage), however if it doesn't it's because your driveline is in tension - which needs to be relieved.  I think this is similar to shifting into "Park" on an automatic and then letting your car roll to a "gearbox stop" before pulling on the park brake.
- To relieve your gearbox tension, simply slip the clutch in and shift in and out of whatever gears you can grab.

After I relieved all of the driveline tension, I shifted my car out of 1st gear with so much ease that I was in disbelief that it was that simple.  

Thank you everyone for your assistance.  This process has connected me to the forum which I think is a great resource. I'll look to participate a little more in the future!!
Cheers

Matt

Offline Reklaw

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Any Muncie 4 speed experts out there?
« Reply #4 on: December 20, 2010, 08:17:20 AM »
Hi Matt, I've had a similar thing happen to me with a Saginaw box (which is much similar to a Muncie). I have found that the adjustment technique is critical, one turn out on the selecting rods and lockup can occur. You're lucky that you could relieve the driveline tension by releasing the clutch. In my experiences, I've had to jack the rear of the car up, getting both wheels of the ground, because the tension preventing the release of the lockup situatiion was at the rear of the box, not the front.
Bob
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Offline Matt G

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Any Muncie 4 speed experts out there?
« Reply #5 on: December 27, 2010, 01:11:01 PM »
Good point Bob, I'll check my linkage adjustments next time i'm underneath.  
I was speaking with a massive holden lover recently who gave me another tip.  If you're out for a drive when this occurs and you only have your standard jack in the car, you can normally get the car home by pulling it out of reverse gear and driving it home in 1st (remember that it's stuck in 1st gear in the gearbox, however in the reverse plane on the shifter).  The tip was to give it a real boot full in 1st then slip the clutch and coast until your slow down, then give it another boot full of juice again.  Can't be real good for your car, however there's no way you'll catch me getting under my vette with only the jack holding it up...
Again, thanks everyone for your help.