My stick shift pops out of 5th gear

mercury
milan

#1

While I was on the freeway all of a sudden my car pops out of 5th. so I got off the freeway drove around some back roads shifting it to 5th and found it only pops out when I get close to or am at 3000 rpms. So what could cause that?


#2

It is a i4 2006 mercury milan premier stick shift.


#3

It’s not a good sign when a manual transmission pops out of gear.

It usually points to something worn in the transmission.

A bungee cord connected to the shift lever and dash while in fifth gear will buy time until you find a replacement transmission/vehicle.

Tester


#4

Excessive end play in a gearshaft and/or excessive wear in the synchronizer hub and/or shift fork more than likely.

You need to think for a minute and ask yourself if you have a tendency sometime to drive with your hand resting on the gearshift lever. That can cause excessive wear problems.
I agree; it’s going to require internal transmission work or transmission replacement.


#5

Check your motor mounts. At 3,000 rpm in 5th the engine is maxing out torque and that may be swinging the engine enough to pull the linkage to OD.


#6

edit. At what mph does the rpm reach 3,000 in 5th gear? And are you attempting to accelerate when 5th drops out?

You may have a weak engine mount and at 3,000 rpm with the throttle down to accelerate the engine is swinging and putting tension on the shift linkage causing the problem.


#7

you reach 3000 rpms at about 70 I was accelerating not real hard just a little.


#8

Could a torque mount cause the same thing?


#9

Yes it could


#10

Yes. A torque mount will cause the problem.


#11

The part of your transmission (I can’t remember the name of the part) that holds the car in gear is worn out.

Your choices are to get the transmission rebuilt, replace the transmission with a new or rebuilt one, or live with it. Back in the day, some drivers would rig a bungee cord to hold the shifter in gear when they had this problem. If I were you, I’d rig a bungee cord to hold it in gear on the highway, and hold it in manually on shorter trips.

A potential cause of this is resting your hand on the shifter while the transmission is in gear. If you’re doing that, stop doing that.


#12

I replaced the torque mount and it hasn’t slipped out of gear so far.


#13

Well here’s a tentative congratulations @Quinn_Desilets


#14

Long ago I worked at a used car lot as one of my summer jobs. (Three part-time, and one 7 day a week.) They sold very used pickup trucks. One old Dodge from the early fifties had a rubber band cut from an inner tube and screwed to the metal dash board. It held the floor shifter in third ( Four speed with a grannie gear.)


#15

I had a Datsun 620 five speed pickup truck a long time ago. After some high mileage, the gear shift lever would start to move back and forth when driving and coasting. It turned out to be a ring nut that backed off the end of the output shaft that held 5th gear in position. The engine torque on the helical cut teeth would move that gear, and the shift fork in one direction while driving and another direction while coasting.
I had to replace it twice and the third time, I ordered a Datsun 720 transmission shaft which had a left hand thread for that ring nut. Also, and just as importantly, the needle bearing inner race for the fifth gear was a press fit on the shaft instead of a slide fit. Fixed the problem.


#16

That’s hilarious.


#17

Hey, thanks.