Trans popping out of gear

[Wheelhorse#1 1,975]

Hello all !  

I have a commando 8 with the 4speed manual 5053 trans.

Problem is it will pop out of third gear when under load, all others no issues.

.

 

Any experience on what will cause that? I’ve never taken on of these trans apart but this is a great reason to do and learn .

I flushed and changed the oil recently.

Thanks for your time /Knowledge 

[squonk 47,979]

3RD gear is worn out. Very common. Wheelhorsepartsandmore sells new ones.

 

https://wheelhorsepartsandmore.com/product/3523-3rd-gear/

[Wheelhorse#1 1,975]

4 minutes ago, squonk said:

3RD gear is worn out. Very common. Wheelhorsepartsandmore sells new ones.

 

https://wheelhorsepartsandmore.com/product/3523-3rd-gear/

Thanks Squonk 

Though it might have been something along those lines.

[ri702bill 12,894]

But wait! There's more! Also figure on a new shift boot, 2 qts of 90 weight gear oil,  and case gasket. IF any of the 4 oil seals are even questionable, that is the time to change them.

Ahead of time - see if the hitch pin will come out! It must be removed to be able to split the case.

Once the Unidrive is apart, other pieces inside may be worn  - particularly bearings - that is where it runs into money...

[Achto 32,441]

 

If I have to split a tranny apart, I order a complete bearing and seal kit right away. Buy once, cry once. Figure do it once, do it right. 

 

https://wheelhorsepartsandmore.com/product/base-kit-1-for-manual-transmission/

[wallfish 20,547]

Those 3rd gears get worn from grinding of the gears. Once it's worn enough it will cause that pop out of gear issue. Replacing it is the only fix now.

Somewhere along the line it was being shifted into gear when the clutch wasn't working properly, so it ground down the edges of that gear. 3rd gear barely engages into the other gear which drives it and you will easily see why it will grind down so quickly if you open it up to change it.

[squonk 47,979]

9 minutes ago, Achto said:

 

If I have to split a tranny apart, I order a complete bearing and seal kit right away. Buy once, cry once. Figure do it once, do it right. 

 

https://wheelhorsepartsandmore.com/product/base-kit-1-for-manual-transmission/

And if you don't use all of the parts, save them for the next one or someone else may need them.

[rjg854 13,329]

Mike and I have rebuilt 2 maybe a couple of years ago.  And they can get pricey, depending on what they need. Well worth it though, cause it will last longer than you 

It's really not as difficult as you might think. The worse part is the cleaning.

[WHX?? 57,877]

2 hours ago, wallfish said:

grinding of the gears.

Can't find em grind em...

I'll take a pound...

2 hours ago, rjg854 said:

the worse part is the cleaning

Got that right ...  

Edited Saturday at 11:45 PM by WHX??

[ineedanother 2,835]

17 minutes ago, WHX?? said:

Can't find em grind em...

I'll take a pound...

Got that right ...  

That'll buff out 

[WHX?? 57,877]

12 hours ago, ineedanother said:

That'll buff out 

Not too far from the truth ... was picking rust boogers for a week tho ..  

Edited yesterday at 12:36 PM by WHX??

[953 nut 68,735]

16 hours ago, rjg854 said:

cause it will last longer than you 

Randy, I know I'm old but you don't have to remind me.                  

[squonk 47,979]

3 hours ago, WHX?? said:

 

 

 

The good ol' Hospital pan used by HVAC Engineers to catch leaks until we "have time to fix it " There's probably a few hundred in the ceilings at the hospital I worked at! They used to be pink but the vendors decided the gray blends in better with concrete block and ceiling tiles! 

[Handy Don 17,370]

1 hour ago, squonk said:

hey used to be pink but the vendors decided the gray blends in better

The ones in our collection are all a sort of puppy-s**t brown!

[Wheelhorse#1 1,975]

19 hours ago, squonk said:

The good ol' Hospital pan used by HVAC Engineers to catch leaks until we "have time to fix it " There's probably a few hundred in the ceilings at the hospital I worked at! They used to be pink but the vendors decided the gray blends in better with concrete block and ceiling tiles! 

That’s funny cause we use to use a similar pan at a university I used to work at.

Condensation leaks everywhere above the tiles  ,was supposed to be a temporary fix but often wound up being permanent 😆 

 

Thanks for all the suggestions.Sounds pretty costly this may be a good reason to buy another, decent shape parts tractor but I’m running out of room ! 

[WHX?? 57,877]

On 9/19/2026 at 2:45 PM, Wheelhorse#1 said:

taken on of these trans apart but this is a great reason to do and learn .

True and we can coach you thru it. @Racinbob says shim the input shaft too. 

The worse part 'side of cleaning as Randy says is the ouch to buy a replacement gear. 

 

1 hour ago, Wheelhorse#1 said:

Condensation leaks everywhere above the tiles

Been there done that ...  Missus used to bring those pans home by the gross from the hospital before she retired. I'm finally out of them and can't talk her into going back to work. 

Edited 6 hours ago by WHX??

[Racinbob 13,115]

1 hour ago, WHX?? said:

True and we can coach you thru it. @Racinbob says shim the input shaft too. 

 

Only if it needs it. With the engine off and put the shifter in 3rd gear. Do not hold the shifter and try to move the input shaft in and out (side to side). You want absolutely zero play. Any play translates to the 3523 gear separating that amount from the 3522 input gear. If there's any play at all slide the appropriate shim on the input shaft before you put in through the case.