Grind during WOT shifting

DrBacon · 02-06-2019, 04:14 PM

So lately I've noticed it seem to become increasingly more difficult to shift during WOT pulls, however today during one I went from second to third and it actually grinded, and I don't believe I've ever cringed harder in my life. Is this a sign of the syncros failing or could it be something else? The car only has around 32k miles on it. And yes, my foot was to the floor on the clutch before trying to shift.

B&W_Evader · 02-06-2019, 05:07 PM

Have you changed your gear oil yet?

FPenvy · 02-06-2019, 05:08 PM

granny shifting and not double clutching like you should?.......

SouthArk370Z · 02-06-2019, 06:18 PM

Could be a sign of a failing CSC.
Could be worn synchros.
Could be old gear lube (see B&W_Evader's comment above).

I suggest changing the gear lube first. It probably needs to be done and, if the synchros are worn, you should see some metal in the drained lube (in older xmissions, we'd look for brass-colored, dust-like pieces; not sure what color it would be nowadays).

Edit: Could be low clutch hydraulic fluid level or bad fluid.

DrBacon · 02-06-2019, 06:42 PM

I had the transmission fluid changed around 6 months ago with redline already. I checked the clutch fluid and it's full, but it is slightly darker than the brake fluid next to it (probably because I had the brakes flushed a few months ago, so it has fresh fluid where the clutch doesn't).

SouthArk370Z · 02-06-2019, 08:34 PM

There are quite a few threads about CSC failure on this site; it's an all too common problem with manuals. IIRC, dark fluid is a bad sign, especially if there are any solids floating around.

nis350 · 02-07-2019, 01:21 AM

if the master and/or slave cylinders are not leaking, bleed the clutch with premium fluid may help.

cold temperature also makes a difference.

Quote:

Originally Posted by DrBacon

So lately I've noticed it seem to become increasingly more difficult to shift during WOT pulls, however today during one I went from second to third and it actually grinded, and I don't believe I've ever cringed harder in my life. Is this a sign of the syncros failing or could it be something else? The car only has around 32k miles on it. And yes, my foot was to the floor on the clutch before trying to shift.

DrBacon · 02-07-2019, 07:09 AM

I'll see about getting the clutch fluid flushed next week, supposed to be a fair bit of snow upcoming so holding off until after. I really hope it isn't the syncros, not sure when the powertrain warranty ends (car is a 2014), it's very likely it already has. This is my second 370z and even though I absolutely love it, I will probably end up selling it if I have to end up replacing the transmission, been interested in a used Lexus IS-F lately.

DrBacon · 02-08-2019, 05:20 PM

I opened the cap on the clutch fluid reservoir out of curiosity and it is pretty dirty, lots of black looking stuff? laying on the bottom, guess that can't be very good. Note: the clutch still works fine, and there's been no fluid loss.

nis350 · 02-09-2019, 12:38 AM

that's quite common, especially with 32k miles. try to remove it before bleeding the clutch.

Quote:

Originally Posted by DrBacon

I opened the cap on the clutch fluid reservoir out of curiosity and it is pretty dirty, lots of black looking stuff? laying on the bottom, guess that can't be very good. Note: the clutch still works fine, and there's been no fluid loss.

Lvcky69 · 02-09-2019, 01:21 AM

keep it updated

02-06-2019, 04:14 PM	#1 (permalink)
DrBacon Enthusiast Member Join Date: Nov 2016 Location: Washington Posts: 285 Drives: 2014 Nismo Rep Power: 27365	Grind during WOT shifting So lately I've noticed it seem to become increasingly more difficult to shift during WOT pulls, however today during one I went from second to third and it actually grinded, and I don't believe I've ever cringed harder in my life. Is this a sign of the syncros failing or could it be something else? The car only has around 32k miles on it. And yes, my foot was to the floor on the clutch before trying to shift.

02-06-2019, 05:07 PM	#2 (permalink)
B&W_Evader Track Member Join Date: Aug 2011 Location: CA Posts: 972 Drives: slower than before Rep Power: 387	Have you changed your gear oil yet? __________________ \|RIP\|6spd-sport\|OSG-LSD\|XP8\|RBF600\|Eibach Sways\|RE-71R\|FI-34Row\|Gen3-CAI\|Yaw P.S.\|

02-06-2019, 06:18 PM	#4 (permalink)
SouthArk370Z Premium Member Join Date: Nov 2010 Location: South Arkansas Posts: 8,435 Drives: 2014 Challenger Rep Power: 324198	Could be a sign of a failing CSC. Could be worn synchros. Could be old gear lube (see B&W_Evader's comment above). I suggest changing the gear lube first. It probably needs to be done and, if the synchros are worn, you should see some metal in the drained lube (in older xmissions, we'd look for brass-colored, dust-like pieces; not sure what color it would be nowadays). Edit: Could be low clutch hydraulic fluid level or bad fluid. __________________ Steering Lock Links - Search The370Z Bookmarklet - FSM @ NICOclub Mankind has progressed past the need for war but we haven't evolved that far. - NachoMahma

02-06-2019, 08:34 PM	#6 (permalink)
SouthArk370Z Premium Member Join Date: Nov 2010 Location: South Arkansas Posts: 8,435 Drives: 2014 Challenger Rep Power: 324198	There are quite a few threads about CSC failure on this site; it's an all too common problem with manuals. IIRC, dark fluid is a bad sign, especially if there are any solids floating around. gomer_110 likes this. __________________ Steering Lock Links - Search The370Z Bookmarklet - FSM @ NICOclub Mankind has progressed past the need for war but we haven't evolved that far. - NachoMahma

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02-06-2019, 06:42 PM	#5 (permalink)
DrBacon Enthusiast Member Join Date: Nov 2016 Location: Washington Posts: 285 Drives: 2014 Nismo Rep Power: 27365	I had the transmission fluid changed around 6 months ago with redline already. I checked the clutch fluid and it's full, but it is slightly darker than the brake fluid next to it (probably because I had the brakes flushed a few months ago, so it has fresh fluid where the clutch doesn't).

02-07-2019, 07:09 AM	#8 (permalink)
DrBacon Enthusiast Member Join Date: Nov 2016 Location: Washington Posts: 285 Drives: 2014 Nismo Rep Power: 27365	I'll see about getting the clutch fluid flushed next week, supposed to be a fair bit of snow upcoming so holding off until after. I really hope it isn't the syncros, not sure when the powertrain warranty ends (car is a 2014), it's very likely it already has. This is my second 370z and even though I absolutely love it, I will probably end up selling it if I have to end up replacing the transmission, been interested in a used Lexus IS-F lately.

02-08-2019, 05:20 PM	#9 (permalink)
DrBacon Enthusiast Member Join Date: Nov 2016 Location: Washington Posts: 285 Drives: 2014 Nismo Rep Power: 27365	I opened the cap on the clutch fluid reservoir out of curiosity and it is pretty dirty, lots of black looking stuff? laying on the bottom, guess that can't be very good. Note: the clutch still works fine, and there's been no fluid loss.

02-09-2019, 01:21 AM	#11 (permalink)
Lvcky69 Enthusiast Member Join Date: Jun 2017 Location: Miami Posts: 385 Drives: 17 370z & 16 911 S Rep Power: 3922	keep it updated