Has anyone else ever heard of this problem?

I have a manual 2004 Mazda 3 with about 40,000 mi. When I get on the highway for 30+ min, 5th gear on the shifter slowly slides down and eventually pops into neutral. Once it starts, it doesn't stop until I stop driving, popping into neutral every 5-15 secs or so, although it seems to go through lulls. The only things I can do to prevent sliding into neutral are holding my hand on the shifter and taking my foot off the gas, which seems to make **** fall back to where it should be in 5th.

There are no noises or otherwise, except when I rev the engine high after it pops into neutral.

I talked to the dealership, and they told me they didn't know but they would guess that it's a synchronizer. Needless to say, I don't want to have someone take my tranny apart for 1500 on a guess.

Any chance it could be a bushing on the shifter or something else outside of the transmission?

Any insight from the smart people on this forum would be appreciated! Thanks.

 

Hello,

I have this similar problem, the 5th gear pops into neutral every now and then, I have to shift it to neutral then shift it back to 5th gear and it will stay there for a long time or sometime it pops back to neutral and I have to repeat this process. I am curious if you have a fix/cure for this?
Thanks

 

If my experience means anything to you, it's bad news.

Everyone I talked to said probably the synchronizer -- no one knew. The issue stopped happening for a while. I even took it to a few repair places, but they were unable to recreate the issue by driving in 5th for extended periods.

Anyway, time passed, and I was moving about 1000 miles away. Not having any other option, I drove the car to my new city (my first time driving over 100 miles since the issue arose). It was fine until 2/3 of the way there, at which time it soon became impossible to even engage 5th -- every attempt only brought major grinding.

The next day, all gears produced a loud, constant grinding noise. I let it sit for a week, and the lower gears worked again with no noise but 5th just ground like a feeble whimper (maybe like the synchronizer had ground down to nothing by that point?).

I eventually got a "new" salvaged transmission and replaced the clutch at the same time. I would've sold the whole thing, but with value of the car depreciated to almost nothing given the required work, I just didn't have a choice.

No more problems 9 months and lots of $$$ later.

Sorry...I hope this doesn't happen to you. If you're still in warranty, you might want to start harassing Mazda.

Still pretty bitter about the transmission falling apart after 5 years of relatively light driving. For what it's worth, I'm relatively experienced driving manuals and could probably count on one hand the number of times I ever screwed up and carelessly ground a gear a bit -- and never 5th (I think one of the mazda people I talked to asked if I grind the gears).

 

Hello, Thanks for your feedback and realized what your resolution was. I am also an experienced manul transmission driver as I have a Volvo 740 with well over 450,000km on it with the ORIGINAL clutch and transmission, the transmission/gear shift had minor problem around 400,000km but given it was the origianl equipment, I was just happy that it lasted this long. The Mazda Protege that I am having this problem is only about 110,000km on it with original transmission. Now I have to save some money for this major repair. Thanks again for your feedback.

 

Ok.

I will share my experience.

I have a 2007 Mazda "3". 2.3. 5 speed manual transmission.

I started to get the "slip" a little.
But it went downhill quickly.


The biggest issue was when I put it in cruise control.
When the car was driving on flat or "up hill", and there was a "load" on the engine, it did not slip.
When I was in cruise control and I went over a small (or big) hill and started "down", when the "load on the engine" stopped, the gear would slip out like clock work.
Very very annoying.

I had to start driving in (up to) 4th gear only.

So I did internet searches. To see how I might fix it. (or if it was lost cause or a "big job" (aka, taking the transmission out of the car).


So after internet researching, I thankfully found out that "getting to" the the parts that were probably the culprit was fairly easy.
You can get to the "butt end" of the transmission by taking off the front drivers wheel.
And removing some of the plastic "mud guards".
And removing the thin metal "pan" on the butt end of the transmission.


There are 2 videos I found.

......

The "in general" mazda issue video:

Find:

Does Your Mazda Pop Out of 5th Gear? Heres How To Fix It Without Pulling The Transmission!
by "I Do Cars"

Contrary to the above video, the shift fork (for the 2007 Mazda 3) was available for new purchase (under $100).

.......

The next video was a "jackpot" video for disassembly of the butt end of the transmission. (Note, the focus of the video is "swapping gears" and I was not "changing the gears". I think because of the alternate "primary topic" it was finding this video was a little obscure)

"Replacing 5th Gear & Synchro Ring on a 04-09 Mazda 3"

by "madmatt2024"

............


Ok. Now I will add my tidbits to the above videos what I encountered.


If you car is "5th gear slipping"... the "shift fork" is a very likely culprit.
It seems to be aluminum (softer metal).


Now, the part of the shift fork that "wears out"... is on the "inner side" (aka, toward the engine) of the shift-fork. Therefore you need to take out the shift-fork to inspect it.

It is not that hard. You remove a big 32mm nut, and there is a "pin" you take out at the bottom of the shift-fork. And it will come out.
Take some pictures before disassembly. I would also "yellow crayon" mark (or some paint or something) on the outside of the "gears" that come out .. so you can but it back together without reversing the gears.

After you take it off, look at the "inner side" of the fork.

Mine was obviously worn...and its probably like 2mm or something like that.. but it is enough to cause the slippage.

So obviously the repair here is to "replace the bad shift-fork with a new one".

..

Now the more important part (IMHO) that you might not pay attention to.

So when you take off the "pan" on the butt end of the transmission, you will lose some transmission gear oil fluid.

EVEN IF YOU ARE GOING TO "re-use" your gear-oil, I HIGHLY SUGGEST to drain the gear oil into a pan. And "empty" the transmission.
Why?
Because of the way you refill the gear oil (you take out the upper plug (where the lower plug is the one on the very bottom to drain))..and you "put in gear oil until it starts dripping out". While this refill method "kinda works".. I think it can give you false positives when you think the gear box has enough gear oil.

So.. by completely draining the existing gear oil, and then refilling, you are able to PAY ATTENTION to how much is going back in. This sounds like overkill, but I'm trying to convey, because of how the refill process "leaks", you may not really be filling up the gear box with enough gear oil.

And now a second important part. Get the CORRECT WEIGHT gear oil. Don't do a "close enough" gear oil WEIGHT (which is probably what you found at the local auto store)... plan ahead and get the correct weight. (I'll let you research and find that one).

Then, as you refill the tranmission, catch any "drippings". But by counting the oil you put in and the oil that leaks from the upper plug, you can have some confidence that you put in the correct amount. I think it is 3.1 quarts (?? do your own research here).
So I bought 4 quarts. And I poured out 3.5 quarts into the funnel...and about .4 quarts "dripped" into my catch pan.

Why is this important?
I think there is a direct correlation between the wear of the shift fork and not having enough gear oil (of the correct weight).
The person who owned the car before me.. took very good care of it.
And perhaps too good of care.. what I mean is.. I think the previous owner did ALL of the "maintenance items" including doing a gear oil change...and I think the person who did the gearoil change... didn't put enough back in .. not maliciously.. but because of the "false positive" with how you think you have put enough in.

(Oh yeah, when I did a full drain of mine, I only had about 2 quarts of gear oil..that is when I started putting the puzzle together).


Ok... so the shift fork damage (wear and tear) was very obvious.
I decided that "while I was in there", to change the brass-like material "synchronizer ring". Maybe I didn't have to change this, but maybe I did (??)
The new one and old synchronizer was close (as far as noticeable damage on the old one), but at the same time, it was $50 or so...and the older I get, this was a small price to pay for not having to open it up again.

So below are the part numbers I ordered.
If nothing else, if you find the mazda online parts catalog images, you can find the part on the image to figure out how to find the part(s) for your model.
The "internal transmission" diagrams are a little confusing on which inner transmission parts "go where?".


GC0317265 Ring, Synchronizer.
G50217406C Shift Fork.
F52017628 Nut, Lock.

I got all of those for under $200 IIRC.

The "nut", you may be able to re-use your existing. But you may damage the nut when you "un-indention" it to allow it to turn. (It is exactly like a CV axle "nut" where you "dimple/intent" the nut on installation.

Obviously, when you take apart your shift fork assembly, you may want to visually inspect everything. But the parts seem to be made up of 3 materials.
The aluminum (?) shift fork. The brass (?) synchronizer ring. And the super hard steel (?) gears. And the aluminum and brass seem to be the primary maintenance parts.


My advice: If your money is more important than your time, if there is damage to the shift-fork, just replace that.
If your time is more important than your money (again, we're talking < $200 for all the soft metal parts)...then get all 3.


One more piece of advice. I did an online order for the parts on Sunday night.
I got an email on Tuesday afternoon that "2 items are back ordered". GAAA!!!!
So even when you find a good price mazda genuine online parts vendor... call them before ordering online to make sure they have them within a decent amount of time.
The next place, I called them and there were like "we have 2 of them on the shelf, and I can get the third in 1 day, thus the parts will shift in 3 days". That was acceptable for me. But keep in mind, this is not a "next day" type of situation.


I'm 2 weeks into the "after repair".
My 5th gear does not slip. In cruise control too.
The one thing I was more aware of is not to "agressively push hard" when I put in 5th gear.
And to keep my knee off of the shifter.

And the lower gears shift more smoothly. I think my correction of the low-level-gear-oil is the reason for the more smooth shifting.


So in a nutshell.

Remove and inspect the shift-fork.
Drain the existing gear oil. Pay very very close attention to refilling the transmission.
Make sure you get the correct amount of gear oil back in.
While you're 'in there', highly consider replacing the synchronizer ring.

 

So the pink/fuscia arrows show the wear and tear on the shift fork. The wear and tear goes all the way around the half circle.
YOu can see the "shininess" of the wear.

The round brass object is the synchronizer ring .

 

i'll not popping out of fifth gear thing. I had the same problem with my maja. Protege, it's real simple on those the fifth and reverse or on that outer small cover. You can pop it off and make sure the gears are torqued down correctly and the nuts are locked into place and make sure your synchro and everything is fitting right in where it's post you. Sometimes it's just a lot of wear on that slighter that slides in between or wear on their shipwork, not shifting it all the way into gear check that out. They have some videos on YouTube. You can watch that's a reverse slider.