Grinding in third gear., Mainly when down shifting. Options

[TClifton91]

So I've been having a problem with third gear. When shifting through gears some times 3rd grinds when going from 2nd to 3rd. But when down shifting it grinds every time, 4th to 3rd. Anyone had this problem or know what it could be?


As always thanks for any help!


-T

[VavAlephVav]

https://www.youtube.com/watch?v=aAWxZRuBXtw

there is some good demo videos on youtube of how a transmission works which will help you understand how the synchronizer works. the different(more expensive) gear oil will create more friction for the little drum to grab on to. and having somebody actually take it apart and replace stuff would be really pricey.
The little trick I use on mine basically uses the synchronizer from second gear to slow it down like this: say you're in 4th or 5th and you want to shift down to third. push in the clutch and then move the stick to the second gear spot but don't go all the way in you just need to hold it in that spot for a moment, and Then push it up into third and it won't crunch at all, now let out the clutch. Assuming you're not doing some kind of street racing where you'd need to shift down much quicker than that it really only takes a couple seconds to do. if you check out the vids of how the synchronizer works you'll understand better that we are just using the drum from second gear to slow the gear down so that it wont crunch in 3rd, most likely the drum/synchronizer for 3rd has been used hard so many times that it has worn away slightly and no longer grips like it should.
I run all 2.7 qts of Penzoil Synchronomesh in mine (the bottle says it was made for Chryslers), and other people have said they got even better results with Redline MT80 which is about $20 a quart. but I'm content enough with the results I've gotten from my little trick and don't feel the need to change the oil again. btw my drain and fill plugs were pretty rounded and I couldn't get them off with a regular 12 point so I went to Sears and got a 6 point box end for it, and I think I couldn't find the metric 22mm one but the 15/16" was the same size. then I went to Toyota and bought two new plugs. and you're going to need a little oil pump to refill it, you'll never be able to just tip the bottle up and pour it in to the fill hole.

This post has been edited by VavAlephVav: Jul 16, 2014 - 9:26 PM

[TClifton91]

https://www.youtube.com/watch?v=aAWxZRuBXtw

there is some good demo videos on youtube of how a transmission works which will help you understand how the synchronizer works. the different(more expensive) gear oil will create more friction for the little drum to grab on to. and having somebody actually take it apart and replace stuff would be really pricey.
The little trick I use on mine basically uses the synchronizer from second gear to slow it down like this: say you're in 4th or 5th and you want to shift down to third. push in the clutch and then move the stick to the second gear spot but don't go all the way in you just need to hold it in that spot for a moment, and Then push it up into third and it won't crunch at all, now let out the clutch. Assuming you're not doing some kind of street racing where you'd need to shift down much quicker than that it really only takes a couple seconds to do. if you check out the vids of how the synchronizer works you'll understand better that we are just using the drum from second gear to slow the gear down so that it wont crunch in 3rd, most likely the drum/synchronizer for 3rd has been used hard so many times that it has worn away slightly and no longer grips like it should.
I run all 2.7 qts of Penzoil Synchronomesh in mine (the bottle says it was made for Chryslers), and other people have said they got even better results with Redline MT80 which is about $20 a quart. but I'm content enough with the results I've gotten from my little trick and don't feel the need to change the oil again. btw my drain and fill plugs were pretty rounded and I couldn't get them off with a regular 12 point so I went to Sears and got a 6 point box end for it, and I think I couldn't find the metric 22mm one but the 15/16" was the same size. then I went to Toyota and bought two new plugs. and you're going to need a little oil pump to refill it, you'll never be able to just tip the bottle up and pour it in to the fill hole.

I tried this little trick, no grinding at all! I would have a little harder time rev matching seeing as how my tach is broken...both of them I think I'm going to try a nice blend of oils this weekend, partly synchromesh.

Thanks guys!