follow ft86club on our blog, twitter or facebook.
FT86CLUB
Ft86Club
Xero Limit
Register Garage Members List Calendar Search Today's Posts Mark Forums Read

Go Back   Scion FR-S Forum | Subaru BRZ Forum | Toyota 86 GT 86 Forum | AS1 Forum - FT86CLUB > Technical Topics > Engine, Exhaust, Transmission

Engine, Exhaust, Transmission Discuss the FR-S | 86 | BRZ engine, exhaust and drivetrain.


User Tag List

Reply
 
Thread Tools Search this Thread
Old 07-27-2019, 12:07 AM   #1
godbiggy
Junior Member
 
Join Date: Jul 2019
Drives: 2015 Subaru BRZ
Location: Canada, Ontario
Posts: 7
Thanks: 0
Thanked 1 Time in 1 Post
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Grind going into 3rd gear

Hi guys, I had this grind occur during my shift from 4th > neutral > 3rd




I was cruising around 4th gear at 40km/h and decided to put in neutral as I was coming to the stop light... and had the clutch in for a good 5-10 seconds, then all of a sudden the light turned green


so then I decided 3rd gear would be best at 30km/h... as I was slowly pushing it into 3rd, I heard this faint grind so I backed off and put it in firmly with no issue.


My question is... is this normal? and would the issue be I was holding the clutch in to long? so the shaft or gear (whichever is disengaged) slow down and not mesh?


this was all done during clutch fully depressed on a 2015 Subaru BRZ 45k KM.


thanks in advance
godbiggy is offline   Reply With Quote
Old 07-27-2019, 12:43 AM   #2
humfrz
Senior Member
 
Join Date: May 2013
Drives: 2013 FR-S, white, MT
Location: Puyallup, WA
Posts: 23,054
Thanks: 17,155
Thanked 20,516 Times in 11,375 Posts
Mentioned: 524 Post(s)
Tagged: 2 Thread(s)
Hi @godbiggy and welcome to Ye Ol Forum -

Yep, I reckon you confused your transmission gears and synchronizers.

I would suggest that when you shift from 4th down to 3rd, just push in on the clutch, blip the throttle and move the shift lever - in that order - all within a 1-3 second time frame.

If you would like a detailed explanation I will ring up ol @Ultramaroon for you and, if he not in a cranky mood, he will explain it to you. -


humfrz
humfrz is offline   Reply With Quote
Old 07-27-2019, 01:25 AM   #3
soundman98
Boost is Whack. N/A4LYFE
 
soundman98's Avatar
 
Join Date: Sep 2013
Drives: '14 brz limited
Location: chicagolandia
Posts: 2,382
Thanks: 3,916
Thanked 1,713 Times in 1,032 Posts
Mentioned: 24 Post(s)
Tagged: 0 Thread(s)
to be clear, are you not rev-matching the downshifts? that's the main reason to have a manual!

i grind occasionally, today, i accidentally started from a stop in 3rd. it happens. just let the motor sing to redline to apologize
__________________
my '14 brz limited "the return to normal" (or is it?)
led mods-10%(planning/designing/sitting on hands)audio mods-99%(done is never done)

hidplanet build log
soundman98 is offline   Reply With Quote
Old 07-27-2019, 09:27 AM   #4
godbiggy
Junior Member
 
Join Date: Jul 2019
Drives: 2015 Subaru BRZ
Location: Canada, Ontario
Posts: 7
Thanks: 0
Thanked 1 Time in 1 Post
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quote:
Originally Posted by humfrz View Post
Hi @godbiggy and welcome to Ye Ol Forum -

Yep, I reckon you confused your transmission gears and synchronizers.

I would suggest that when you shift from 4th down to 3rd, just push in on the clutch, blip the throttle and move the shift lever - in that order - all within a 1-3 second time frame.



humfrz

Hey Humfrz I see that you said blip the throttle and move into the selected gear, meaning rpms have a role in allowing the shifter to enter the gear?

What I'm really just confused on is why did it grind when I had my clutch fully depressed? I never had this happen

Thanks for replying tho
godbiggy is offline   Reply With Quote
Old 07-27-2019, 09:28 AM   #5
godbiggy
Junior Member
 
Join Date: Jul 2019
Drives: 2015 Subaru BRZ
Location: Canada, Ontario
Posts: 7
Thanks: 0
Thanked 1 Time in 1 Post
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quote:
Originally Posted by soundman98 View Post
to be clear, are you not rev-matching the downshifts? that's the main reason to have a manual!

i grind occasionally, today, i accidentally started from a stop in 3rd. it happens. just let the motor sing to redline to apologize
I usually blip and downshift into 3rd gear, which goes in like butter but this time I cruised in neutral holding clutch in for 5-10 seconds

And when I decided to push it into 3rd it just had a faint grind, this all occurred during the clutch being fully depressed which is confusing
godbiggy is offline   Reply With Quote
Old 07-27-2019, 09:55 AM   #6
soundman98
Boost is Whack. N/A4LYFE
 
soundman98's Avatar
 
Join Date: Sep 2013
Drives: '14 brz limited
Location: chicagolandia
Posts: 2,382
Thanks: 3,916
Thanked 1,713 Times in 1,032 Posts
Mentioned: 24 Post(s)
Tagged: 0 Thread(s)
i see. the simple answer is the revs fell too far.

the longer answer is the input and output shaft speeds became drastically different, forcing the syncro's to work harder, which created friction and more force on the gearstick lever.

it happens to all of us, but it's generally something you don't want to make a habit of
__________________
my '14 brz limited "the return to normal" (or is it?)
led mods-10%(planning/designing/sitting on hands)audio mods-99%(done is never done)

hidplanet build log
soundman98 is offline   Reply With Quote
The Following User Says Thank You to soundman98 For This Useful Post:
humfrz (07-27-2019)
Old 07-27-2019, 01:17 PM   #7
humfrz
Senior Member
 
Join Date: May 2013
Drives: 2013 FR-S, white, MT
Location: Puyallup, WA
Posts: 23,054
Thanks: 17,155
Thanked 20,516 Times in 11,375 Posts
Mentioned: 524 Post(s)
Tagged: 2 Thread(s)
Quote:
Originally Posted by godbiggy View Post
Hey Humfrz I see that you said blip the throttle and move into the selected gear, meaning rpms have a role in allowing the shifter to enter the gear?

What I'm really just confused on is why did it grind when I had my clutch fully depressed? I never had this happen

Thanks for replying tho
That's correct about the rpms.

I see ol @soundman98 explained "how it works" -

https://auto.howstuffworks.com/manua...chronizers.htm


humfrz
humfrz is offline   Reply With Quote
Old 07-27-2019, 01:25 PM   #8
Howaitoguru
Senior Member
 
Howaitoguru's Avatar
 
Join Date: Mar 2019
Drives: 2016 Subaru BRZ
Location: GA
Posts: 201
Thanks: 102
Thanked 75 Times in 37 Posts
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Sometimes mine grinds going into first, and acts like it wants to pop out. Iíve put about 5000 miles on my car since I got it though and havenít really had any real issues. The gearbox is funky sometimes, but like everyone else said when down shifting you always want to give it some throttle. Also down shifting to 2nd gear make sure youíre not over 50mph or youíll probably be in a bad mood for the rest of the day.


Sent from my iPhone using Tapatalk
Howaitoguru is offline   Reply With Quote
Old 07-27-2019, 01:41 PM   #9
RToyo86
Senior Member
 
RToyo86's Avatar
 
Join Date: Mar 2018
Drives: 17 Asphalt 86
Location: Ottawa
Posts: 456
Thanks: 303
Thanked 292 Times in 171 Posts
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
I notice sometimes 2-3 shift sounds a little crunchy like a grind.

I think it mostly has to do with a lazy shift, and not being 100% on the floor with the clutch.
RToyo86 is offline   Reply With Quote
The Following 2 Users Say Thank You to RToyo86 For This Useful Post:
churchx (07-27-2019), humfrz (07-28-2019)
Old 07-27-2019, 01:58 PM   #10
churchx
Senior Member
 
churchx's Avatar
 
Join Date: Mar 2015
Drives: 2014 orange GT86
Location: Latvia, Riga
Posts: 3,449
Thanks: 470
Thanked 1,568 Times in 1,084 Posts
Mentioned: 40 Post(s)
Tagged: 1 Thread(s)
If grind doesn't repeat, non fully disengaged clutch is one of most probable reasons. Slight clutch drag - synchros not working well to even out speeds, and here you go, gears grind.
churchx is online now   Reply With Quote
Old 07-27-2019, 02:02 PM   #11
soundman98
Boost is Whack. N/A4LYFE
 
soundman98's Avatar
 
Join Date: Sep 2013
Drives: '14 brz limited
Location: chicagolandia
Posts: 2,382
Thanks: 3,916
Thanked 1,713 Times in 1,032 Posts
Mentioned: 24 Post(s)
Tagged: 0 Thread(s)
Quote:
Originally Posted by Howaitoguru View Post
Sometimes mine grinds going into first, and acts like it wants to pop out. Iíve put about 5000 miles on my car since I got it though and havenít really had any real issues. The gearbox is funky sometimes, but like everyone else said when down shifting you always want to give it some throttle. Also down shifting to 2nd gear make sure youíre not over 50mph or youíll probably be in a bad mood for the rest of the day.


Sent from my iPhone using Tapatalk
not exactly.

Quote:
Originally Posted by FR-Sky View Post
I found this on other website:
"Road & Track, July 2012 issue, pg. 89.

At 7400 rpm the speeds in each gear are respectively:

1: 35 mph (too much commotion in town)

2: 58 mph

3: 83 mph (you could be in trouble)

4: 105 (you're probably going to jail)

5: 127 (do you have a lawyer?)

6: 135 (estimated at 6000 rpm, so I assume it's drag limited)

RPM at 60 mph in top gear: 2700

Hope this helps."

I was doing a pull on the freeway, and I didn't notice that I went over the redline on 2nd gear and it is showing 61mph before I shift to 3rd.
Does any one experience this?
because i routinely drop from 4th to 2nd into and out of cloverleafs, with a general entry speed around 40-50. i know i'm doing 60 at fuel cut..
__________________
my '14 brz limited "the return to normal" (or is it?)
led mods-10%(planning/designing/sitting on hands)audio mods-99%(done is never done)

hidplanet build log
soundman98 is offline   Reply With Quote
Old 07-27-2019, 02:06 PM   #12
Howaitoguru
Senior Member
 
Howaitoguru's Avatar
 
Join Date: Mar 2019
Drives: 2016 Subaru BRZ
Location: GA
Posts: 201
Thanks: 102
Thanked 75 Times in 37 Posts
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quote:
Originally Posted by soundman98 View Post
not exactly.







because i routinely drop from 4th to 2nd into and out of cloverleafs, with a general entry speed around 40-50. i know i'm doing 60 at fuel cut..


My shit red lines if Iím not at 50mph when I shift to second.


Sent from my iPhone using Tapatalk
Howaitoguru is offline   Reply With Quote
Old 07-27-2019, 02:06 PM   #13
Howaitoguru
Senior Member
 
Howaitoguru's Avatar
 
Join Date: Mar 2019
Drives: 2016 Subaru BRZ
Location: GA
Posts: 201
Thanks: 102
Thanked 75 Times in 37 Posts
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quote:
Originally Posted by Howaitoguru View Post
My shit red lines if Iím not at 50mph when I shift to second.


Sent from my iPhone using Tapatalk


Down shift*


Sent from my iPhone using Tapatalk
Howaitoguru is offline   Reply With Quote
Old 07-27-2019, 02:17 PM   #14
soundman98
Boost is Whack. N/A4LYFE
 
soundman98's Avatar
 
Join Date: Sep 2013
Drives: '14 brz limited
Location: chicagolandia
Posts: 2,382
Thanks: 3,916
Thanked 1,713 Times in 1,032 Posts
Mentioned: 24 Post(s)
Tagged: 0 Thread(s)
ah, didn't they drop the final drive ratio in '16? i want to say they did, which would then make sense..
__________________
my '14 brz limited "the return to normal" (or is it?)
led mods-10%(planning/designing/sitting on hands)audio mods-99%(done is never done)

hidplanet build log
soundman98 is offline   Reply With Quote
 
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
4th gear grind dallenj Engine, Exhaust, Transmission 15 06-03-2016 04:04 PM
4th gear grind aaguirre123 Engine, Exhaust, Transmission 8 08-03-2015 04:58 PM
5th and 6th gear grind... Basket Case Engine, Exhaust, Transmission 7 02-11-2015 09:53 PM
Grind Into 5th Gear Since885 Engine, Exhaust, Transmission 8 01-18-2015 06:47 PM
2nd gear grind (yup another one) SmartedPanda Issues | Warranty | Recalls / TSB 17 09-10-2014 04:02 PM


All times are GMT -4. The time now is 12:47 PM.


Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
Garage vBulletin Plugins by Drive Thru Online, Inc.