having a problem shifting into 3rd gear at redline...

when i pull to redline, going from 2nd to 3rd it grinds. would it simply be a syncro going bad? someone sugested that it could be the slave cylinder, but i didnt think it would be focused on just 3rd gear. if i double clutch nothing happens. i have 53k miles on my car and am still on the stock clutch(proud of that). would a new clutch solve things?



thx for all the help,
adam

 

Sounds like your syncro... try using different oil... it tends to make the gear changes much smoother.

 

i use 10w40...someone mentioned to me that you dont need anything special just as long as you chenge it more frequently then usual. thats wat the previous owner used so i just kept using it.

 

well Im having the same problem its probably your syncro Im pretty sure thats what it is.

 

10w40 is a engine oil viscosity. You should be using a 75w90 gear lubricant, IMHO per API GL-4. If you're using engine oil you'll destroy the tranny. Exactly what oil is in there?

Yes, it's possible the synchro is damaged from bad shifts or incorrect oil. The shift slider and gear dog teeth are probably also damaged, so FYI if you get the tranny rebuilt then replacing just the synchro may not solve the problem.

Dave

 

I am beging to think that alot of years had this same problem with syncros my 91 does the same thing but from 1st to 2nd I have found that changing the oil every other year or if i take it on a trip like the one to sevenstock i'll change it again with 10w30 castrol this seams to help,the last change I used coastol 10w30 but think castrol is a better oil tranney is all original clutch everything 143,000 mi.

 

10w30 is also an engine oil.

I repeat. NEVER USE ENGINE OIL IN A GEARBOX UNLESS THE MANUFACTURER RECOMMENDS IT.

It's entirely different stuff from gear oil. I've seen gearboxes frag from the reduced lubrication provided by engine oil. Mazda recommends a 75w-90 GL-4 or GL-5.

Dave

 

Your right I stand corrected I use 80-90w sorry about the brain fart.

 

Try with Synchromesh from GM dealer.

 

I agree that it sounds like a synchro. I also hope that you don't actually put engine oil in there As Dave has pointed out, you're asking for big trouble using such a thin oil in there if you really are doing that.

I would check the oil level / replace the oil with new oil as a start. A car with that few miles on it should not have a synchro issue already really. Unless perhaps it was autocrossed/road raced extensively... and even then, I would expect 2nd gear to wear out first in the case of autocrossing and 4th to wear out first if it was heavily road raced. Third is an odd one to wear out IMO.

 

i got the car at 52k miles and the previous owner took such good care of it its insane. unfortunitually he has been using shitty oil, i thought it wouldnt hurt it because he has been using it from the start.(when he bought it new) he said he never had any trouble...but he never drove it hard.

i will drain the oil and start over...i really dont want to pay to get a tranny rebuild. thx everyone for the advise...

adam

 

Are you noticing 5th gear is getting hard to get in to at any RPM range?

 

to a small degree, but at high rpms. dont use fifth that much

 

It's not uncommon for the drivetrain to shift at high RPMs causing your 2-3 shift to be inaccurate and hit your 5th gear synchro. This can be fixed with poly motormouts and diff bushings. An engine damper can also help.

I'd suggest changing the tranny fluid and look for bits of synchro in the fluid.

 

but if it did go right to fifth it wouldnt grind...