2nd gear synchro?

RideMR2 · 10-13-2006, 04:55 PM

Hello

I have my 91 5sfe running pretty good, so I have been drivn it harder.

I am getting some grindage when shifting from 1st to 2nd, no other shifts affected.
It only grinds when I am drivn it hard, have the rpm's up near redline, and shift fast.
Taking more time to shift, or normal driving, it does not grind at all.

I have replaced clutch master, slave, plus bled, and adjusted clutch pedal.
Clutch is working great.

I have noticed a very minor leak on the input shaft seal for the CV axle(passenger side of transaxle), and was going to replace the seal, then add new gear oil.

Assuming it is a bit low on gear oil, would it affect the 2nd gear synchro first?

Is anyone using ATF in their transaxle, or is that a big mistake?

Thanks

Gairloch · 10-14-2006, 12:41 AM

The syncros in our tranny are notorious for wearing out. Flushing the fluid *might* make a difference but even if it does that's only a bandaid.

ATF is what the factory originally called for. That was revised via TSB to GL5 75W90 gear lube in '92 I believe.

These days you'll get people swearing on a stack of bibles that they were able to resurect their transmissions using anything from ATF to MT90 to various flavors of 75W90 gear lube to syncromesh.

I've used 75W90 gear lube and syncromesh in two different transmissions, one with bad syncros and one with good. No fluid made any significant difference in the tranny with bad syncros. I ended up learning how to double clutch until I put the new tranny in. You might find that if you take the time to shift slowly from 1 to 2 that you can avoid the grind thus prolonging the life of your syncros.

As far as fluid goes, if you do decide to change from ATF to something else make sure that you flush it a couple of times.

CyFi · 10-14-2006, 02:35 AM

i just say screw it and shove it into gear, i dont care if it grinds, your gonna eventually need to replace the tranny unless you wanna rev match every shift.

MR2NR · 10-15-2006, 03:11 AM

Speaking from personal experience with two different vehicles, if it is a synchro going bad, which it sounds like it is, there is only two things I would consider. Redline MT-90 or Royal Purple 75w 90. Personally I'm a fan of Redline products but I've heard good things about Royal Purple as well. In both vehicles that I switched to MT-90 I immediately felt smoother shifting.

PETC · 10-16-2006, 03:49 PM

Quote:

Originally Posted by CyFi

i just say screw it and shove it into gear, i dont care if it grinds, your gonna eventually need to replace the tranny unless you wanna rev match every shift.

You are WAY too obsessed with rev-matching dude. It's more of a way to achieve quicker downshifts than to save the tranny. You seem to obsess over the details of things and not let go of them. lol

EVERY part is a wear item. Period.

Hiighboost2 · 10-22-2006, 01:38 AM

Talkin bad bout cyfi??!? How could you!

Acet · 10-22-2006, 12:08 PM

I have the exact same problem, low rpms are fine but high RPMs grind.

CyFi · 10-23-2006, 02:31 AM

Quote:

Originally Posted by PETC

You are WAY too obsessed with rev-matching dude. It's more of a way to achieve quicker downshifts than to save the tranny. You seem to obsess over the details of things and not let go of them. lol

EVERY part is a wear item. Period.

well every tiome ive ever asked anyone about grinding problems they say revmatch, and if you dont they say revmatch to save the synchros..... so wtf am i supposed to say if everyone keeps telling me these things. Its like somene teaching you something at school, you repeat it and then get yelled at saying its wrong

EvanB756 · 10-23-2006, 12:24 PM

^^^ LOL

veritas731 · 11-05-2006, 02:38 AM

yeah, mine does that **** too. esp on the 3 - 2. I used to worry about it, but now I just say **** it.

CyFi · 11-05-2006, 01:46 PM

Quote:

Originally Posted by veritas731

yeah, mine does that **** too. esp on the 3 - 2. I used to worry about it, but now I just say **** it.

thats how i feel too. i dont care anymore i just put it in gear, it will take a heck of a lot of grinds to do any major damage, and when it does, il replace the tranny

mr2much · 11-05-2006, 02:33 PM

I got the exact same problem. Right down to the axle seals. The grind doesn't happen very often though (only when its way off the revmatch point) so it must just be starting on mine but its only 2nd gear. I had both seals replaced to stop the oil from leaking and had the gear oil changed while I was at it. The new oil helps a bit but eventually I'll have to fix the synchos. For now I just shift it gently into second to avoid the grind during most of my driving but whenever i feel like having fun with the car I just don't care.

Jason.MZW20 · 11-08-2006, 02:17 PM

Toyota redesigned the synchros for MY1994 (late 1993). Instead of single cones, they used doubles on most gears. Even 5th has a double synchro.

But yeah, pretty normal for those transmissions. Mine did that too, and upshifting into 2nd was very firm, while downshifting just grinded.

tHe kNiGHt FaLL · 11-09-2006, 05:10 AM

high rpms grinds is a worn syncro.

high and low rpm grinds are worn clutching teeth on the gear itself. created with poor syncronization.

veritas731 · 11-13-2006, 03:55 PM

when it goes out......just replace it with an LSD-Tranny. simple as that.

tHe kNiGHt FaLL · 11-15-2006, 04:37 PM

Quote:

Originally Posted by Jason.MZW20

Toyota redesigned the synchros for MY1994 (late 1993). Instead of single cones, they used doubles on most gears. Even 5th has a double synchro.

[IMG][/IMG]

But yeah, pretty normal for those transmissions. Mine did that too, and upshifting into 2nd was very firm, while downshifting just grinded.

there is no syncros in that picture...

Acet · 11-15-2006, 07:01 PM

Fully built racing LSD tranny FTW

Jason.MZW20 · 11-19-2006, 04:38 PM

Quote:

Originally Posted by tHe kNiGHt FaLL

there is no syncros in that picture...

Are you sure about that? The synchros are right there. The assembly on top of the 5th gear is the synchronizer hub with the 2 synchros inside of it, and synchronizer rings.

tHe kNiGHt FaLL · 11-28-2006, 07:22 AM

Quote:

Originally Posted by Jason.MZW20

Are you sure about that? The synchros are right there. The assembly on top of the 5th gear is the synchronizer hub with the 2 synchros inside of it, and synchronizer rings.

syncros inside the gear...?

i've never seen that...

i don't see how it works... the synco goes between the gears to slow (spinning on the cone) for syncronization with the free spinning gear so the slide can slide over the clutching teeth and lock the gear to counter shaft...

10-13-2006, 04:55 PM	#1 (permalink)
RideMR2 No Skills Join Date: Sep 2006 Posts: 31 Thanks: 1 Thanked 2 Times in 2 Posts iTrader Rating: (1/100% )	2nd gear synchro? Hello I have my 91 5sfe running pretty good, so I have been drivn it harder. I am getting some grindage when shifting from 1st to 2nd, no other shifts affected. It only grinds when I am drivn it hard, have the rpm's up near redline, and shift fast. Taking more time to shift, or normal driving, it does not grind at all. I have replaced clutch master, slave, plus bled, and adjusted clutch pedal. Clutch is working great. I have noticed a very minor leak on the input shaft seal for the CV axle(passenger side of transaxle), and was going to replace the seal, then add new gear oil. Assuming it is a bit low on gear oil, would it affect the 2nd gear synchro first? Is anyone using ATF in their transaxle, or is that a big mistake? Thanks

10-14-2006, 12:41 AM	#2 (permalink)
Gairloch Dreaming of apexes Join Date: Aug 2005 Location: Minneapolis, MN Posts: 4,472 Thanks: 115 Thanked 223 Times in 196 Posts My Google Map iTrader Rating: (7/100% )	The syncros in our tranny are notorious for wearing out. Flushing the fluid might make a difference but even if it does that's only a bandaid. ATF is what the factory originally called for. That was revised via TSB to GL5 75W90 gear lube in '92 I believe. These days you'll get people swearing on a stack of bibles that they were able to resurect their transmissions using anything from ATF to MT90 to various flavors of 75W90 gear lube to syncromesh. I've used 75W90 gear lube and syncromesh in two different transmissions, one with bad syncros and one with good. No fluid made any significant difference in the tranny with bad syncros. I ended up learning how to double clutch until I put the new tranny in. You might find that if you take the time to shift slowly from 1 to 2 that you can avoid the grind thus prolonging the life of your syncros. As far as fluid goes, if you do decide to change from ATF to something else make sure that you flush it a couple of times. __________________ "Inside the car, the world beyond the driver's immediate horizon ceases to exist. Alone with the solitude of his desire, survival sense numbed by the speed, he's outrun the mediocrity of the outside world, slipped the shackles it tries to clamp on us all. He is running free, chased only by a fear of failure, for failure is to risk ejection into the real world." ~Mark Hughes

10-14-2006, 02:35 AM	#3 (permalink)
CyFi ShamWOW! Join Date: Oct 2005 Posts: 1,390 Thanks: 12 Thanked 38 Times in 35 Posts iTrader Rating: (10/100% )	i just say screw it and shove it into gear, i dont care if it grinds, your gonna eventually need to replace the tranny unless you wanna rev match every shift.

10-15-2006, 03:11 AM	#4 (permalink)
MR2NR OPTion5 Join Date: Oct 2006 Location: Portland Posts: 40 Thanks: 0 Thanked 0 Times in 0 Posts iTrader Rating: (0/0% )	Speaking from personal experience with two different vehicles, if it is a synchro going bad, which it sounds like it is, there is only two things I would consider. Redline MT-90 or Royal Purple 75w 90. Personally I'm a fan of Redline products but I've heard good things about Royal Purple as well. In both vehicles that I switched to MT-90 I immediately felt smoother shifting.

10-22-2006, 01:38 AM	#6 (permalink)
Hiighboost2 Wiring fun! Join Date: Feb 2006 Location: Spring/Woodlands Posts: 1,265 Thanks: 10 Thanked 19 Times in 19 Posts My Google Map iTrader Rating: (2/100% )	Talkin bad bout cyfi??!? How could you!

10-22-2006, 12:08 PM	#7 (permalink)
Acet Banned Join Date: Dec 2005 Location: alpharetta,ga Posts: 440 Thanks: 5 Thanked 7 Times in 7 Posts iTrader Rating: (1/100% )	I have the exact same problem, low rpms are fine but high RPMs grind.

10-23-2006, 12:24 PM	#9 (permalink)
EvanB756 No Skills Join Date: Sep 2006 Location: Kearns, Utah Posts: 138 Thanks: 2 Thanked 2 Times in 2 Posts My Google Map iTrader Rating: (0/0% )	^^^ LOL

11-05-2006, 02:38 AM	#10 (permalink)
veritas731 No Skills Join Date: Mar 2006 Posts: 28 Thanks: 1 Thanked 0 Times in 0 Posts iTrader Rating: (1/100% )	yeah, mine does that ** too. esp on the 3 - 2. I used to worry about it, but now I just say ** it.

11-05-2006, 02:33 PM	#12 (permalink)
mr2much '90 JDM RHD Turbo Join Date: May 2006 Location: Waterloo, Ontario, Canada Posts: 122 Thanks: 2 Thanked 6 Times in 4 Posts iTrader Rating: (0/0% )	I got the exact same problem. Right down to the axle seals. The grind doesn't happen very often though (only when its way off the revmatch point) so it must just be starting on mine but its only 2nd gear. I had both seals replaced to stop the oil from leaking and had the gear oil changed while I was at it. The new oil helps a bit but eventually I'll have to fix the synchos. For now I just shift it gently into second to avoid the grind during most of my driving but whenever i feel like having fun with the car I just don't care.

11-08-2006, 02:17 PM	#13 (permalink)
Jason.MZW20 Torque Me!!! Join Date: Jul 2006 Location: Victorville, CA Posts: 691 Thanks: 9 Thanked 51 Times in 44 Posts Blog Entries: 5 iTrader Rating: (1/100% )	Toyota redesigned the synchros for MY1994 (late 1993). Instead of single cones, they used doubles on most gears. Even 5th has a double synchro. But yeah, pretty normal for those transmissions. Mine did that too, and upshifting into 2nd was very firm, while downshifting just grinded.

11-09-2006, 05:10 AM	#14 (permalink)
tHe kNiGHt FaLL I Work For Audi Join Date: Sep 2006 Posts: 41 Thanks: 0 Thanked 2 Times in 2 Posts iTrader Rating: (0/0% )	high rpms grinds is a worn syncro. high and low rpm grinds are worn clutching teeth on the gear itself. created with poor syncronization.

11-13-2006, 03:55 PM	#15 (permalink)
veritas731 No Skills Join Date: Mar 2006 Posts: 28 Thanks: 1 Thanked 0 Times in 0 Posts iTrader Rating: (1/100% )	when it goes out......just replace it with an LSD-Tranny. simple as that.

11-15-2006, 07:01 PM	#17 (permalink)
Acet Banned Join Date: Dec 2005 Location: alpharetta,ga Posts: 440 Thanks: 5 Thanked 7 Times in 7 Posts iTrader Rating: (1/100% )	Fully built racing LSD tranny FTW

12-02-2006, 09:10 PM	#20 (permalink)
blumr2 Cage Fighter Join Date: Dec 2006 Posts: 161 Thanks: 27 Thanked 0 Times in 0 Posts iTrader Rating: (0/0% )