6 speed problems

I can tell you that I've never driven a transmission that is as sensitive to the oil used. I would strongly recommend Redline MT-90. There is no other oil that peforms as well in these 6 speeds. It makes a difference you will feel immediately. A quick shift kit helps shorten the throw to something reasonable. Beyond that, the adjustment will have to come from you.

If you're a driver who knows what proper shock valving feels like, it won't be long before you pitch the entire suspension and replace it

 

This may be a dumb question, but everyone speaks of MT-90 making a "difference". What exactly does it improve? Can anyone explain?

 

Thank you for the helpful answer! I plan to let the dealer take a try at it then see about the fluid change. Gotta get the prob logged in Toyota's service system.

Is MT-90 the best for helping remedy the 6 speed? I know there are other fluids out there with different additives too, won't matter to me if they're an extra $20, I'd be glad to try whatever will help best!

 

MT-90 specifically provides the right viscous coupling to drive the synchros. I've tried just about every quality oil out there, and the Redline manual transmission formulation is spot on. They make 3 or 4 variations and I haven't tried them all. I do know some have had good luck with Redline MTL which is their lightest formulation. Unless you see temps well below zero though, the MT-90 is a good place to start. $14 a qt, so $28 for a fill. Best $28 you will spend. It greatly reduced the nicking I used to get into 2nd and 3rd, and it pretty much has eliminated hangups between gears. It has made the transmission usable with smooth technique, where before it really wasn't. It's not a magic wand, but pretty close.

 

Thank you!!! You just bought my Taco another 2 weeks of opportunity to shape up before I ditch it.

 

Yeah I used to think that way.

 

Thanks! It never gets colder than 30s or 40s here. I've always had the "nicking" or "clacking" going into 3rd. I'll have to give the MT-90 a shot.

 

The '11 I test drove originally was great, this '12 I bought is nowhere as smooth. Neither had the short shifter or TRD knob. Could the box and clutch actually be different than the 2011?

 

If you drove one that you liked, then I would give this one a chance. Mine actually developed a burr or something on the synchros from using one of the oils I tried. It was terrible, and it took a while for that to smooth out when I switched to Lucas. The switch to Redline though really did the trick. If you still have a little problem after the switch, drive it awhile because you may have done some damage that needs to wear down as well. The sychros are brass and pretty soft. Everytime you get a grind into gear you're gnawing at that brass.

As critical as I have been of the 6 spd, I still wouldn't have a Tacoma without it. It was a real quandry for me because it has taken me damn near a year to figure out and fix the problems to the point that I'm happy (enough) with it.

Here's what I have done:
Modified the clutch pedal
installed URD short shift kit
Built a custom lever offset to move the lever closer to my leg
Sickspeed classic ball knob
Redline oil

Now my hand falls right on the shifter and I can get into any gear without any reaching. I always modify the clutch pedals on my vehicles so that the same leg reach required to brake the car, actuates the clutch. In stock form, if you set your seat right for the brake pedal and accelerator, it leaves you stretching to fully depress the clutch. Your stretching your leg to do that while your leaning right to reach 5th gear. Having things set right makes the process of shifting much easier to control, at least for me it does.

 

Ah, Badger and I are the minority around here who don't like the 6 speed. Many debates later, bottom line is this: You can remedy some of the shifting feel with a short shifter kit and shift knob as well as MT-90, but the gearing is the gearing. Ultra short first gear and close ratios mean you will be shifting a lot to get moving anywhere. Live with it man,

 

Badger and Xxaarraa,
I really appreciate your responses.

Update: Went to the dealer today (Toyota 101 and met Joe Bermudes - this guy was very helpful!).

The mechanic (yup actual mechanic, not just a "tech") who looked at it has been at that Toyota only dealer since 1985. He does all the transmission work at the dealer, so Joe Bermudes sent me on a test drive with the expert. He has credibility all day long and we had a lot in common regarding Porsche stuff (he's got a 993 and 996) thus we discussed Aisin's crappy gearboxes in the 996's 997's and of course Taco's.

Found:
1. Transmission notably / unusually "tight" and should "wear in" and accept gears better. If not, then replacement of synchros or gearbox will be necessary.
2. Clutch & bearings are loud but that's much due in part to the transmission and clutch components, there is no Toyota resolution for it.
3. Toyota will warranty the gear box for 5 yrs and the clutch for 3 yrs against defects. Also noted, they have a responsive system of regional management that inspects and warranties work when the dealer ordinarily can't i.e. original warranty expired.
4. It would operate with lighter oil or ATF and it would quiet it down, but 75w90 is the manufacturer's recommendation for wear and warranty compliance, and I should allow it to break in first. The Redline MT90 is a good alternative, same warm weight as the factory fluid.

 

Good luck with the "break-in" and keep us posted!

 

I've had 5 Toyota pick-ups (3 Tacomas) both 5 and 6 speeds, and NEVER had a problem. Maybe I'm a better driver, or at least a more experienced driver. I have a 2012 with 2500 miles and still no problem.

 

Well,
You are documented now so if there is a particular issue with your truck they will hopefully take care of it. I doubt a breakin will change much. I'll be watching for your follow up report. I assume you are aware of the throttle hang caused by the throttle by wire? That can cause problems because the RPMs don't drop as they would with a manual throttle. That makes rpm matching more difficult on upshifts. You can reduce the affect by subtley changing your throttle/clutch timing. Not so easy if you have been driving manuals for many years, but it will help. I actually replaced the muffler with a louder one so I could hear the engine better. This tranny will never shift effortlessly though. Might as well get used to that. It has to be shifted very deliberately. There is a point, past which you will never go. It reminds me of shifting the old "3 on the tree" vehicles.

 

I wonder if Sprintbooster released a version for the manual transmission. I know URD has it for the auto. May help with the drive by wire response, and aid you in shifting.

 

Guys what would the "break in" Process be? I'm at 250 miles now and have not done too much.

 

No sprint booster yet. IMO it's kind of overkill since the throttle response is acceptable to me. On a sports car it might not be, but for a truck it's fine. All we really need is a hang buster for deceleration.

Mating metal surfaces need about 1000 miles to marry. Probably 80% gets done in the first 500. That's for all the bearings, gear boxes, diffs, etc. I always change the fluids at 500 with dino oil, and then at 1000 with synthetic. You can hold the oil in the sun and see why. People usually think it terns of engine breakin, but really, its' the whole drivetrain that breaks in.

 

I believe that most modern day engines/ drivetrain don't require break-in period. Otherwise it would state that in the owners manual.

But, I do believe in break-in for when you re-gear.

 

Where exactly would one acquire this so called MT-90, and how hard is the change?

 

sub'd!