Mule transmission stuck

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3rdCoast
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Mule transmission stuck

Post by 3rdCoast » Sat Apr 20, 2019 11:06 am

I have an A3 Mule that I have been working on for some time. The issue I am having now is that the transmission seems to be stuck in 2nd or 3rd gear. The mule will roll just fine when the Hi/Low is in neutral. I'm praying that I do not have to take the transmission apart too much or at all to fix this, as I know nothing about transmissions. Im to the point where I can finally do a test run, but this is the only thing holding me up. Has anyone had this issue before?

Thanks, Chris

markrdje
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Re: Mule transmission stuck

Post by markrdje » Sat Apr 20, 2019 12:25 pm

My 1st thought is transmission is full of gear lube? I am not a transmission man at anything, but I would start it up to see what happens.There are mule experts on this site it would be wise to listen to them I probably should have not said anything
change user name to mark

Chuck W.
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Re: Mule transmission stuck

Post by Chuck W. » Sat Apr 20, 2019 4:26 pm

Possibly shift detent ball issue, see viewtopic.php?f=148&t=265010
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muleman7
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Re: Mule transmission stuck

Post by muleman7 » Sat Apr 20, 2019 8:30 pm

Check the swing arm holding the shift rod near the gun opening it may be frozen not allowing the rod to move. Remove the cotter key and pin then try to shift the trans. When shifting if the bed moves where the bolt holding the swing arms are attached this is an indication that the arms are frozen or rusted solid.

Can you shift the trans into 1st or rev? Probably not if it's stuck in 2nd or 3rd because the lock out plug keeps 1st-rev in neutral and unable to move when in 2nd or 3rd.

One or more of the blocking plates in the synchronizer may have popped out and thus locking the sync sleeve from moving back to neutral.

If this is the case then tearing your transmission down is your only remedy.

Look through the post in Chuck W's post and you will see a reference to the difficulty of replacing the 2nd-3rd detent spring and ball on the M274 or A3 transmission.

If it is your synchronizer and you do not have the external 2nd-3rd poppet plug it is possible to remove the main shaft without pulling the 2nd-3rd shift shaft. You will need to remove the lock [set] screw from the 2nd-3rd fork and finesse the mainshaft out. Yes it is difficult to get the 1st-rev and 2nd-3rd forks to cooperate when removing and installing.

If you remove 2nd-3rd shift shaft then you must remove 1st-rev shift shaft and the lock out plug then install 2nd-3rd spring and ball. You will need to install a temp plug that will be pushed out when installing the 2nd-3rd shift shaft. Because 1st-rev shaft has to be installed before the mainshaft because you can not access the set screw and install the safety wire on the 1st-rev fork with the main shaft installed. To do this your trans must be level or with the mule on its side gas tank up to allow insertion of the spring, ball and lock out plug.

When replacing the mainshaft assy with a rebuilt synchronizer I use a rubber band on the synchro hub to retain the blocking plates because you must to move the synchro sleeve to engage with the fork and the plates could pop out.

I have replaced several synchronizers by turning the mule on its side gas tank down. Drain the fuel and engine oil.

This will be the most difficult build of your mule. The 2nd most difficult is setting up a ring and pinion gear properly.

When I pull my trans cover I leave the pinion and intermediate shaft attached to the cover and push against the main shaft only. You will need to remove the Low-High poppet plug, spring and ball. This leaves the 2 shafts undisturbed and attached to the cover and gives you room the remove the mainshaft.
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Chuck W.
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Re: Mule transmission stuck

Post by Chuck W. » Sun Apr 21, 2019 7:49 pm

North Alabama

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