6 Speed Manual 3rd Gear Grind

I just purchased a 2005 Tacoma and it has a 6 speed manual transmission with the 4.0. I am fixing up a few things on it and getting it inspected to be road legal in my province. I drove it 1000km to bring it home. When driving it I noticed when shifting from second to third gear there is a grind in the transmission. Its pretty consistent and only going into third. When I am driving in town and going slow and I let off the accelerator and let the RPM's drop a bit the grind is quite a bit better.

I am assuming there is something wrong inside the transmission that speeds up or slows down the gears to allow for smoother shifting. I am not a transmission person so I am just guessing really.

Question I have is about the repair. Is it worth having a transmission shop take it all apart and repairing it or should I try and find another 6 speed manual transmission?

Thanks in advance.

 

I'll be watching this, as my '15 has a bit of a hiccup going into 3rd, like the synchro isn't lining up quickly enough. As it's a truck, I'm not shifting it like the WRX or Abarth the wife has...

 

You can try some sort of friction modifier. Synchromesh, or something of the sorts. I would do some research and find out what works best in the 6 speed taco transmission. Sometimes just changing the gear oil will solve these problems too! The wear properties of gear oil break down, it gets dirty, etc.

I owned a Celica with a C60 tranny and it would grind going into third when it was cold, I read about the mixture of Redline and Synchromesh and something else that was supposed to solve these problems. I lost the rear sub frame to the rusties before I ever got to try it out .

What happens over time, and it all depends on who is driving it and how they're driving it, (very simply speaking) the synchros, or blocker rings are little cones that "catch up" the driven gear with the drive gear before it'll let the shift collar slip onto the gear. There are little "sipes" on the inside of the blocker ring that gear oil kinda chills in and helps to speed up the gear. If these little sipes are worn, or the blocking section of the blocker ring has worn then it'll let you slide the shift collar onto the gear before its totally up to speed causing the grind.

 

I put Royal Purple Synchromax in my 2nd gen 6 speed right after I bought it and it shifted very smooth but still had a nice mechanical feel to it, even when it was really cold. I never understood why so many people complained about it. When I got my "new" 1st gen I put Redline MT90 synthetic manual transmission fluid in it and it immediately started to feel more stiff and fights me a little bit when it's cold. It's only been a few thousand miles but I'm already thinking about switching it to Royal Purple. I will subscribe to this thread and do an update when I switch.

 

I was running Royal Purple in my transmission for the last little while. I expected it to shift a lot nicer than it did with such an expensive gear oil in it. During I switched over to the Canadian Tire brand synthetic gear oil and it shifts a lot nicer (I also replaced my TOB, cleaned up the input shaft and cleaned up the pressure plate and flywheel). Truth is, as long as you keep up on the tranny maintenance and aren't jamming it into gear like its a racecar it'll work fine.

Where someone has neglected it before, friction modifiers are probably necessary to correct the grind.

My transmission is an R155 though. 4 banger life.

 

A good quality MT fluid could help smooth out the synchronizers a bit, BUT, there were problems with the early 6-speeds. There have been a significant number of silent upgrades to that transmission. It is very likely that your 3rd gear synchro is worn out.

 

I guess the question is, is it worth fixing the worn out gear or would it be better to just find a used (newer) manual transmission?

 

Well ultimately, it would be better to find a newer transmission, since it would have the various updates made over the years.
However, that would also probably end up being a lot more expensive.

And actually, if I was going to go the route of a transmission swap, I'd probably not even aim for another RA60 anyway, since its gear set is... crappy. Basically, they started with a 5-speed, and wedged an extra (and unnecessary) gear in between 4th and 5th. The new 2016 6-speed would be really nice, but you aren't likely to find it in a junkyard yet, so that would set you back a really good chunk of change.

Edit: A TR-6060 from a 2008 ford falcon ute would be a nice one. Its got a 1st gear of 3.36:1 and double overdrive at 0.71:1 and 0.57:1.

 

Is it worth while fixing the old Tranny?

 

Only YOU can answer that for yourself.

 

Sorry, what I meant was, Cost wise, is it worth fixing?

Or would it cost the same to find a newer tranny at the wreckers.

Thanks for the info. Its been helpful.

 

If you can do the work yourself, it will be cheap to fix.
If you can't, then you are at the mercy of your local transmission shop, which will set a price matching whatever they think they can get out of you, likely somewhere between cheap and "are you frikkin out of your mind?"

 

You'd have to get a repair estimate or two and compare that to the cost of a used transmission. Too difficult to guess through the Internet.

 

Fair enough. I thought maybe someone has some experience with this situation and can maybe share. All good. I have the information I need to figure it out.

Thanks

 

I too have a 3rd gear grind issue; sometimes. When the truck is cold it will happen, and only if the engine is under heavy load, like if I try to accelerate too hard. This has been going on for several years, and it has not gotten any worse than when I first noticed it. After the truck heats up there is no problems. I have found that if I double clutch into 3rd gear on a cold start, the grind does not happen. My $.02.

I am running Redline MT 90 currently, and have been for several years.

 

I am amazed on how well the Redline oil works. I wasn't a believer until today. The third gear grind isn't gone completely but it is definitely much better and sometimes not there at all. Amazing what the oil did alone.

Thanks for the tips.