M1123 Shifter Problems

[Archangel_Hk]

Morning Boys,

So I got in my HMMWV yesterday morning at the ass crack of dawn, fired it up, put it in gear and took off. It slid into gear as smooth as it should. Drove 40 miles to work and when I got there, I went to put it into reverse, the shift lever was harder to move. It went into gear just fine, just stiff shifter. When I left work 12 hours later, it was back to normal. Then I get home 40 miles later and the shift lever was stiff again. Any help would be greatly appreciated.

 

[HoveringHMMWV]

Fluid level check ok?

 

[Archangel_Hk]

Fluid level check ok?

Yeah, all the fluid is at the right levels and amazingly, all look clean.

 

[Mogman]

Yeah, all the fluid is at the right levels and amazingly, all look clean.

Look clean? you mean you have not changed all the fluids and filters?

 

[Archangel_Hk]

Look clean? you mean you have not changed all the fluids and filters?

That was the first trip. Engine oil, hub oil, trans fluid.

 

[Mogman]

40 miles with unknown fluids?

 

[Archangel_Hk]

40 miles with unknown fluids?

Negative. That was after the initial fluid change. Had the vehicle delivered didn't want to drive it before all that was accomplished

 

[Retiredwarhorses]

Fluids have nothing do with a shifter assy and hard shifting…unless something is restricting the shaft, I’d be looking at the shift linkage or the shifter I’ve replaced quite a few gummed up shifters.

 

[DREDnot]

Yeah almost as important as the fluid changes is removing the shifter assembly completely and emptying that bag full of dirt that surrounds it. Never seen one that wasnt nastier than a shopvac.

While its out on your bench you should be able to find the reason for your problem.

If you are going to be installing reverse lights this would be the time to install the reverse light switch.

After alot of detailed cleaning and light lube where appropriate you should be able to reinstall a perfectly smooth shifter.

 

[Archangel_Hk]

Fluids have nothing do with a shifter assy and hard shifting…unless something is restricting the shaft, I’d be looking at the shift linkage or the shifter I’ve replaced quite a few gummed up shifters.

That's what I was thinking. It still goes into gear properly, but the shift lever gets stiff after a while.

 

[Archangel_Hk]

Yeah almost as important as the fluid changes is removing the shifter assembly completely and emptying that bag full of dirt that surrounds it. Never seen one that wasnt nastier than a shopvac.

While its out on your bench you should be able to find the reason for your problem.

If you are going to be installing reverse lights this would be the time to install the reverse light switch.

After alot of detailed cleaning and light lube where appropriate you should be able to reinstall a perfectly smooth shifter.

View attachment 946755

Looks like it's going to the shop. Unsure how to do that exactly. Don't want to jack it up. Unless you have some pointers.

 

[DREDnot]

Looks like it's going to the shop. Unsure how to do that exactly. Don't want to jack it up. Unless you have some pointers.

You dont need to jack it up.
You do need a helper though.
There is plenty of ground clearance to slide underneath.

CHOCK YOUR WHEELS!

Helper in the cab to hold/turn the 4 screws that attach the shifter assembly. Remove the two cotter pins to detach the shift linkages. Disconnect the wires(3?) that pass through the boot . Lift out. Its no harder than working on a lawn mower or something

 

[DREDnot]

Shifter assembly is simple as well. These pics are from my M998 when I was adding reverse light switch. 4 speed shifter is basically the same.