shifting into 4th - Toyota Nation Forum : Toyota Car and Truck Forums

T_MAN396 · 01-28-2010, 12:01 AM

I just bought a 2006 Corolla S and everything is a ok except for 4th gear grinding when shifted normally. However, when I shift to slowly it goes in just fine. I was wondering if there was anything that I could do in order to get ride of this issue.

Any suggestions would be appreciated.

***silver04rollas*** · 01-28-2010, 01:32 PM

Looks like your 4th gear synchro is going. Do you have warranty coverage i.e. certified warranty?

p.s. You can try this trick as it may help and possibly eliminate. Buy Redliner synthetic MT-90 gear oil for the transmission (I think you will need 4 bottles) and get your transmission oil changed. That is what I am using in my 6 speed and it is just unbelievable. Synthetic gear oil is more viscous so it allows the gears to slip easily especially when the tranny oil is very cold.

T_MAN396 · 01-28-2010, 08:40 PM

Thanks for the Info.

How much work is envolved in replacing synchros? I have a good amount of mechanical experience and have worked on many cars and motorcycles and I'm not affraid of putting work in to save a lot of $$$.
Cheers,
Trev

rsirois · 01-29-2010, 06:31 AM

Synchro's are on the output shaft of the transmission. The only way to replace is to remove and rebuiild the transmission, replacing any worn parts.

My advice is to treat it gently for now. I've gotten into the habit of double clutching mine, it reduces the speed of the input shaft and greatly reduces wear on the synchro's.

DubblClutch · 07-25-2010, 12:11 PM

Hey everyone! It's been a long time since I read through the forums. Oh how I've missed it. =)

I drive a 2008 Corolla CE, MT.

So, I have the same problem; gear grinding when shifting rapidly into 2nd. This problem started after I returned from my first year of college (about 2 months ago). What worries me is that my car is only 2 years old and has 11k miles on it. I just can't believe that it could be a synchronizer problem.

Because I think that it is a synchro problem, every time it grinds I swear loudly. I drive my sisters around a bit. I'd rather avoid having them listen to my sailor-mouth.

A little more background might help: As my username suggests, I always double-clutch downshift and use engine braking (more fuel-efficient and it uses less brake pad). Since this problem began I have shifted gently into second in order to avoid destroying anything important.

Thanks for any help you can provide me with.