RoToR23

This just started today, the car is a 2004 with 12k miles. My gears dont grind or clunk or anything but when i redline in first or get close to and and try too shift quick, i hit like a wall in second gear and have to wait for the revs to drop before i can get it into gear. 2nd gear is the only gear i have trouble with although i never redline in 2nd gear and try to shift into third. This will happen even when i do not redline and my RPMS are above 5k. It really annoying and kind of bothers me cuz sometimes ill notice i hit a walll in other gears without grindining or clunking.

rotary.enthusiast

An 04 with only 12k miles? Wow...

Anyway, it sounds like your synchros aren't synchronizing the speed of the collar with the speed of the gear you're shifting into. A properly functioning synchro will prevent the dog-teeth from making contact with the gear until they are synchronized (which is why you don't hear grinding). Make sure when you're shifting that you have the clutch pedal fully depressed as partial clutch engagement will cause your synchros to have to change the momentum of the engine in addition to the clutch/input shaft which will not only destroy your synchros very quickly, but will also slow the synchronization down, which in turn will prevent you from actually shifting.

The next time you hit a "wall" when shifting, return the shifter to neutral, release the clutch pedal, then fully depress it and try shifting again. Not an ideal "fix," but it should get you by without destroying your transmission.

You might also check your transmission fluid, and verify that the correct type of fluid has been used.

EDIT: After thinking about it, it's possible that you are depressing the pedal fully but the clutch is not actually fully disengaging. There are a number of things that could cause this, but the first thing I would do is the clutch pedal adjustment procedure.

RoToR23

thank you for your post, ill try doing the fluids, and clutch assembly adjustment. when im taking it slow, you can feel that its not smooth just feels like notchy or something, but no clunking or grinding noise. when you are at WOT, it just wont even go into gear into the revs drop some (or you engange the clutch for a good second). I used to be able to push in the clutch and it would go right in. Again since ive had the car it hasnt be a clunk or grinding noise. Maybe im just paranoid after reading countless threads with people have new trannys and synchros at low miles.

rotary.enthusiast

Yeah, I would take it easy on it until you figure out what's up. You might be seriously shortening the life of the synchros with every shift you make.

Another thought: Have you checked your clutch fluid? Air in the system could possibly cause something like this. Bleeding it couldn't hurt anything

RoToR23

I'm the second owner and this is prob a dumb question but if the tranny oil and rear diff hasnt been changed, will it be bad after 5 yeard even tho it only has 12k miles?

SpecialBlend

I have the same problem as you. If i am shifting at high rpm from first to second it takes about a second before it will go past the "wall" and engage in second gear. Second to third goes fine however if you go from third to fourth it will do it again. High rpm's in third are at about 150km/h or 90mph so doing it on the street is a no-no.

Basically what i can decipher from this is that on the downward shifts it is taking a bit longer for the synco's to mesh up. I have 65000km and just recently replaced both diff and tranny fluid and still the same issue. I use standard fuild's but i heard that sythetics like redline and royal purple will help.

Does anyone have any insight into what this could be?

Thanks in advance

rotary.enthusiast

I'm hardly an expert on transmission fluids, but I would guess that conventional gear oils would break down over time (regardless of mileage). Synthetics probably are less prone to this, but again I'm no expert. I might change it just for peace of mind.

SpecialBlend: Do you know specifically what type of fluid you had put in your transmission? There is at least one thread specifically discussing this topic, and if I recall correctly there were a decent number of people out there having synchro issues based on the fluid they dumped in. I've heard many people speak highly of Redline MTL and MT-90, but RP GearMax will eat this transmissions synchros for breakfast.

shaunv74

I would check your clutch slave cylinder and bleed your brake fluid and clutch line. It's the same reservoir. Some of the '04's would have bad slave cylinders and couldn't disengage the clutch all the way.

Also your clutch bracket could be going. That is another common problem. Check those things first.

SpecialBlend

Mazda did the tranny and diff fluid replacement so i guess they would use OEM stuff.

Shaun74: How do i know okay if the clutch slave cylinder is bad? and if the clutch isn't engaging all the way wouldn't i get grinding not just this pause between gears?

To answer your last statement my clutch bracket just went last week and i had it replace

Just as a side note, my clutch makes a clicking sound on the way down, kind like it is winding up(click, click, click, click). This was there both before and after the pedal assembly was replaced. My friend that knows a bit about cars used his stethoscope type thing and said it sounded like it was coming from the slave cylinder.

RoToR23

ya ill need to take it in somewhere to make sure there is no air in the lines and to check the cylinder i don't know how to do it. About how much would that cost?

Georgia8er

That was only a problem on hot days after driving the car a while, so if the problem is happening even during the first few minutes of driving, it is something else. The problem was isopropyl alcohol in the boot around the shaft. A new slave cylinder is now part of the TSB.

rotary.enthusiast

No, not necessarily. If the clutch is partially engaged what will happen is that your synchronizers in your transmission will have to overcome the additional force being transferred from the engine in addition to changing the momentum of the clutch assembly/input shaft in order to synchronize to the speed of the gear you're shifting into. If the synchronizer is functioning properly it will not allow the dog teeth to make contact with the gear until they spinning at the same speed, which means you would not hear grinding.