TRZ Rear Mount, Shifter Bushings, Still Grinding Gears

[cymx5]

It's the inevitable shifting issues. I'm looking for the next step. From OEM, my car would be fine shifting 1-2, but would grind the 2-3 shift. To resolve this, I did my searching and replaced the rear engine mount with the TRZ "Dog Bone" , aluminum shifter bushings from SU, and just this weekend my roller-coaster shocks to stiffer Koni's. Everything feels more solid, however now it consistently grinds the 1-2 shift and periodically the 2-3 on a hard shift over 5k rpm.

What option is next? More mount replacements? TWM short shifter?

(I'm opting for the fiscally conservative options before doing it all , so opinions please )

 

[SubieKiller3]

how the heck are you grinding 1-2? anyway, id say yes on the twm short shifter. also see if you can find a shifter weight. that might help a little.

 

[GoFast]

try removing your counter weight

 

[ecniemann]

How about the TRZ transmission mount? That is suppose to be the most crucial mount to replace.

 

[ms6acton]

shifting lessons?

 

[Darth Vader]

How 'bout changing the trans fluid to Ford full synthetic 75W-90? See if that solves it.

 

[cymx5]

shifting lessons?

Awww, can't a man start a shifting problem thread without getting this comment. (hand)

I'm lining up the actions items now.
ln(e). Shifting lessons
1. Remove counterweight
2. Change trans fluid to Redline. What's the fluid capacity? (37k miles on what I assume is factory oil)
3. TRZ Transmission Mount

 

[derspi]

I know the MS3 isn't the easiest to shift because of the suspect OEM mounts but no one that knows how to drive a manual should have this much trouble.

Seriously, it's either the driver mod or there's something wrong with your synchros. Throwing more aftermarket parts at it isn't going to solve it.

 

[ms6acton]

+11 if ur having this much trouble maybe take it in to the dealer

 

[ecniemann]

I guess it all depends on the OP's wording.

He's saying 1-2 consistantly having problems now, 2-3 occasional (periodic). Not sure what the frequency of the problem was before. I've only had this happen 1-2x in 2.5 years on mostly stock parts with the 2-3 shift. I just upgraded to short shifter and bushings this winter, with some decent improvement. I think infrequent would be the appropriate word for me to describe problems (grinding) with the 2-3 shift for me.

BUT.... you cannot just discount the OP's problems, especially considering how much the engine moves under these hard loads. So either he has some other mechanical problems, or he is just shifting very fast under heavy loads a lot of the time. This should not happen under most normal driving conditions. If they are, I would take it in.

 

[cymx5]

You are correct ecniemann. I should clarify. My interpretation of consistently refers to the more commonly accepted reference: shifting quickly under load. One all factory parts, a shift over 4-5k rpm from 2nd to 3rd gear would induce a lockout/grind into 3rd gear with a quick or even moderately quick shift. I define quick shift as an attempt to burn the tires into 2nd gear (can you relate?), and a moderately quick shift is accelerating quickly onto a highway. After installing the new mount and shifter bushings, the 2nd to 3rd shift is acceptible. However, the original condition now exists between 1st and 2nd gear (heavy load with quick or moderately fast shift).

I have no problems downshifting under load or even the heel-toe turning under load. It's just that upshift.

A dealer would likely turn this one away. It's the same issue that they define as 'normal' during their tests and conclude that it is driver error.

 

[ecniemann]

You are correct ecniemann. I should clarify. My interpretation of consistently refers to the more commonly accepted reference: shifting quickly under load. One all factory parts, a shift over 4-5k rpm from 2nd to 3rd gear would induce a lockout/grind into 3rd gear with a quick or even moderately quick shift. I define quick shift as an attempt to burn the tires into 2nd gear (can you relate?), and a moderately quick shift is accelerating quickly onto a highway. After installing the new mount and shifter bushings, the 2nd to 3rd shift is acceptible. However, the original condition now exists between 1st and 2nd gear (heavy load with quick or moderately fast shift).

I have no problems downshifting under load or even the heel-toe turning under load. It's just that upshift.

A dealer would likely turn this one away. It's the same issue that they define as 'normal' during their tests and conclude that it is driver error.

If this is mainly happening with quick shifts, I would search for TRZ transmission mount threads. Most people have said this basically eliminates any sloppiness with quick shifts, as it limits the amount the engine can shift under these loads. It's odd though that your problems shifted from 2-3 to 1-2 with your mods though. Maybe that mount changed some things, but caused other problems.

 

[Sp33dFr33k]

In my experience and talking to other owners, the 1st to 2nd shift usually sounds more like clutch/driver issues and the shift to 3rd is mount related. I never once had a problem 1st to 2nd, but third was a bit problematic until I got the TRZ dogbone. I threw in the TWM ss and bushings later and I haven't missed third since.

 

[Russm]

You Just Shift TOO FAST!

 

[justanothermp5]

it does it on my p5 too, im thinking its the clutch cuz i ruled everything else out, trans fluid, shifter linkage, syncros...so this is pretty much the only thing left

 

[dizzin9]

1. try babying your clutch a bit while making absolutely sure your foot is flooring the clutch, especially when going to third
2. try avoiding "straight" shifts and do "s-pattern" shifts.
3. above all, CHANGE YOUR TRANNY FLUID ASAP. amsoil mtg or redline mt-90 works great (especially the amsoil mtg coz i'm biased (sssh) though it's doing great so far)

motor mounts don't really help you avoid grinding the gears. even doing #1, i still grind with my foot stomped on the clutch. yeah i got suckered into buying a sts w/ bushings coz some people recommended it, but i've been there and these worked for me.

 

[ericrapp]

uh oh

Awww, can't a man start a shifting problem thread without getting this comment. (hand)

I'm lining up the actions items now.
ln(e). Shifting lessons
1. Remove counterweight
2. Change trans fluid to Redline. What's the fluid capacity? (37k miles on what I assume is factory oil)
3. TRZ Transmission Mount

Before you modify any more i should let you know i am pretty sure you have a synchro or clutch issue. I have been down this road and i cannot take my car to the dealer for any warranty work ever again. I have gone too far. I had a 2-3 issue since i bought the car and yes i figured i should learn how to shift! Then i chased this issue with all the things you are going to do. Get it stock and take it to dealer, especailly if you have problems with one two shifts. I know you need to be a little patient with that one but i have NEVER missed that shift and i have tracked the car enough already. My 2-3 under load is very worrisome. as i said ithink its a synchro problem now that i have changed mounts fluids and shifting methods. I hope you can reverse your mods and get the Mazda tech to miss shift 1-2 also. The Aisin tranny is mostly good from what i have read but i think i have a gotten bad one and i will have to swap or rebuild eventually. Maybe you are unlucky on this too.

 

[Jacobra]

seriously dude dont let the clutch out before you are ENTIRELY in the gear. if someone like me whos only been driving since September doesn't miss and grind ears then you shouldn't be driving a stick.

 

[justanothermp5]

well idk what my trans problem was but i took it to the dealer and the guy took it out for a test drive and he shifted into 3rd no problem, now i can shift into 3rd lol

maybe u just need to treat it rough for once, thats what he did lol

 

[bani]

2nd gear is under-synchro'd in this aisin transmission unit. 1st and 2nd gear are on a heavier shaft and have more rotating mass to spin up. despite the triple cone synchros, 2nd is still under-synchro'd for this car.

changing trans fluid can help.