Daniel Kant

Hi!

Has anyone here had any issue with the 6th gear "popping out" to neutral ?

Ive experianced this behavior today now and then when driving thru Germany on my way to Croatia with the family. Just putting my hand on the gear stick (No force needed) when in 6th gear prevents it from popping out but ofcourse this should not be needed.

All the other gears work great and the can is performing as it should except for this behavior in sixth gear.

Any thoughts on this?

ADias

Gear lever adjustment?

Iceter

Gear pop-out is most often caused by bad or misaligned shift linkages. ALso, worn transmission/engine mounts can allow the transmission to move excessively and this movement can cause the linkage to be misaligned and the gear lever to pop out. I assume this is less common with cable linkages but it still happens.

Internally, worn bearings can allow the gears to move relative to each other and disengage. This is most evident when you are applying or reducing torque (accelerating or decelerating).

But, the most common cause for this is just sloppy shifting. When I am distracted, I will (rarely) not fully engage the next gear, then the transmission will pop out when I go back on the accelerator. If this is a one-time occurrence and you can't duplicate it, it may not be something to worry about.

Daniel Kant

Thanks for your informative reply!

Fahrer

It can very well be a worn synchronizer. Syncros not only match the speed of gears when shifting but also keep the gears in place. The can happen more often in lower gears ( e.g. 2nd) as gear speed matching is more challenging but resting one's hand on the gear shift lever while cruising can cause premature wear of the top gear sycnhronizer.

Petza914

Check that the cables underneath the car are properly latched into their holders - they'r known to pop out. Once you put them back into their proper holders, you can wire tie them in that position to keep them from coming out again.

Iceter

I have always been told that gear pop-out is caused by a bad synchro, but in my admittedly limited knowledge of how a manual transmission works, I can't figure that one out. The synchro doesn't hold the helical gears together. In most manuals, the gears are held together by the shafts they ride on and sometimes by fairly weak springs once you're in gear. Once a gear is selected, the synchro is out of play. It's usually play in the bearings that hold the shafts that allows movement of the shaft(s) and that allows the gears to pop out.

I can only assume that the synchro idea comes from the fact that once the shaft bearings are worn and allowing movement, the synchros are probably pretty worn out, too.

I'm just thinking out loud here. Again, I'm not a transmission expert. I've rebuilt a couple of Toploaders but replacing the guts of a '60's transmission with all new parts is very different from being able to diagnose issues with a modern transmission. I would be interested in knowing how worn synchros could cause gear pop out because I've heard that for years but can't get my head around how it actually happens.

Iceter

So, for clarification, Daniel, can you tell us how often this happens and under what circumstances?

Does it happen a lot or only when you're distracted?

Does it happen immediately after shifting or does it happen after you've been in gear for a few (or several) minutes?

Does it happen only when you accelerate or decelerate, or does it happen when you're cruising at a steady speed?

These questions can help get to the bottom of the issue.

Daniel Kant

At first i thought it was me being sloppy with putting the gear in correctly but this is not the case, it has happened even if i really make sure its in the 6th gear.

It happens at cruising speed on highway doing around 80 mph, sometimes just after shifting in to 6th but sometimes it would stay in gear for a longer period 20 minutes or so. Accel or slowing down doesnt seem to have an impact.

I get the feeling that its more prone to pop out when the car is warmed up and only happens in 6th gear. I once noticed how the gearstick kind of "wobbled/shaked" before poping out.

Thanks for taking time

Iceter

Hmm, I'd definitely start with Petza's suggestions. Maybe the cables are loose and if you hit a bump or the speed and rpms are just right, there is enough movement to pull the lever out of gear?

Daniel Kant

yes, i will have a look st that as soon as i get back from my trip, Thanks.

Daniel Kant

Back from my trip to Croatia and made some observations during my trip home. The 6th gear will not pop-out to neutral if i keep the throttle will little (just keeping speed) pressure. If i apply pressure to the throttle and accelerate it will almost always pop-out, and i can see the gear stick move towards the center (neutral position), just as if there are to much "play room" for it to move when under accel.

It only happens in 6th gear position.

Petza914

If you've pursued the other suggestions, this sounds like it might be an issue internal to the transmission for that 1 gear (6th). Haven't seen this issue before.

Daniel Kant

Nops not yet, booked on monday august 7th. Is it a costly thing to change the syncro for 6th gear (if that should be the source of error)?

Petza914

Not 100% certain, but am guessing the trans has to deinstalled, opened up, repaired, and reinstalled, so could be rather costly