Shifting into 3rd speed causes grinding noise

I have a 2007 v6 4x4 manual transmission.

When I shift from the 2nd to the 3rd speed, unless done super carefully, it causes a grinding noise. By "super carefully" I mean I first rev it up to 3K RPM, then keep the clutch pressed some 2-3 sec at least, then shift very slowly, much slower than other speeds. The process takes so long that the truck loses a lot of speed and when I am finally shifted into the 3rd speed, the RPM is more like 1.5K from about 3K where it was in the 2nd speed.

What causes this grinding noise and can it be fixed without replacing the whole transmission?

 

The 5 speed has its issues also

 

Check this thread out for more info.

https://www.tacomaworld.com/threads...ctually-upshifts-smoothly-to-3rd-gear.363955/

 

Sounds like the 3rd gear synchro is bad. The reason it's shifting more smoothly when you rev it is because your bassically doing what the synchro is suppose to do.

 

3rd and 5th on these trucks have poor synchronizers. They tend to clunk from the factory. My guess is that you have almost or totally lost the synchronizer in third. Forget about third and fifth, and just use 1st 2nd, 4th, and 6th. Rarely is 3rd and 5th needed.

 

Def third gear synchro. had the same issue.

 

Can I just replace the 3rd gear synchro ?

 

My 5spd does this but only to a minor degree when I'm hammering through the gears on the freeway late for work other than that it's silent and I drive like an old man in the city

 

I skip shift normally. Only time I've really used 3rd was in the mountains or in 4WL. The Times I've ground 3rd on the street it was because I was really hammering on the truck and the revhang caught me.

Normally I putt along going 1_2_4_6

***I actually meant to put this in the other 3rd gear grinding thread but I guess it's still mildly relivent***

 

Yes you can, I don't know the exact way to do it but I know a transmission shop can

 

Replacing just one gear synchro would be like pulling a head because you had one burnt valve and only grinding one valve. Grind them all on that head. So yes you can but that would be sort of silly since you have the thing out and tore down. Just replace them all while you are at it.

 

OK, I've decided to take my tranny down and rebuild it. Can you identify a list of items that should be replaced once I do that, in addition to the 3rd gear synchro ?

 

you mean all the moving parts/gears inside the tranny case ? I don't want to buy a replacement of the whole thing. I am trying to identify the most frequently worn out components.

 

Here is an insightful article: http://www.tacomahq.com/2872/6-speed-tacoma-transmission-review/