Manual transmission Fan Club and BS thread (All Generations Welcome)

My RA60 has a 6th gear ratio of 0.85, which is what I think you dyslexia'ed. I agree. The RA60F ratios are obviously selected for pavement. The solution is the FJC drivetrain swap, RA61F + manual transfer case. But I preach to the choir.

 

I remember the Corvette 7th was a super high OD. It sounded interesting.

 

Haha! That is always possible, but my mistake was picking off the AT 6th ratio. Sorry!



So yeah, then I am lovin' the F250 ratios all around.

 

What I really want is the RC60F from the Hilux. Geez Toyota, now that's useful gearing.

First Gear: 4.784:1
Second Gear: 2.423:1
Third Gear: 1.443:1
Fourth Gear: 1.00:1
Fifth Gear: 0.777:1
Sixth Gear: 0.643:1
Reverse: 4.066:1

 

Not that you would buy a Corvette for gas mileage, but I would imagine it does quite well out on the highway in 7th.

 

I'm barely a muscle car/super car/hot rod guy from the couch, but I assume that tall 7th only is useful to the EPA happy. Can't imagine even at top speed a ratio of 0.42:1 is still gonna be hit while still pulling anywhere but Bonneville.

 

It is nice to have that option if you're just slabbing it to somewhere. I believe the highway number was 28mpg?

 

I would agree another overdrive would be nice. I really wish I had a true high way gear, so I don't have the RPMs at 25+ doing 75 MPH.

 

I SMH every time I see this chart.

 

Yup! It would have been too easy to fix on the design side.

 

So you're an engineer as I recall. I've been wondering why the compromises were made in this 6 speed to give those funky ratios.

- Space in the case?

- Size of the individual gears (ratios) affecting the size of other gears in the box?

- Counter gear for reverse affecting things?

Love to hear your take, if you'd indulge lol..

I mean, the reverse ratio is an obvious one!!

 

The RA series has some versions with shorter or/and taller gears, so it's not a case size issue (perhaps the low gear is limited, the Hilux has an RC series). I think it's that Aisin had their AY-6 model in the catalog and Toyota just used it. The ratios in the 2nd gen stick are the same as in a few other vehicles around the world, mostly cars. I think with different final drive gears and smaller tires the ratios make more sense in a road car, where closer spreads are more important than low first/reverse and a tall O/D.

https://en.wikipedia.org/wiki/Aisin_AY_transmission

 

Yeah, I'm an engineer, but in aerospace. Mostly non-mechanical structures / materials and such.

Like you said though, without seeing the guts, space is the only reason that I can think of. Although, the current HiLux has the 4.0L 1GR-FE engine and the ratios that @DaveInDenver quoted (https://www.tacomaworld.com/threads...rations-welcome.406844/page-398#post-17786349) are great. Wikipedia says that it bolts up to the 2.4L diesel though. I don't know if the case is the same as ours.

It looks like the current HiLux uses the RC62F that has our same ratios.


In the end, my hope lies with the 2Lo mods, the electrical one that @BigWhiteTRD invented and down the road, @05Taco4x4 's free hub conversion. If I ever get a bonus again, the free hub will what I order.

I was backing my 4x8 trailer on to my slanted driveway trying to get it in my garage to fold it up. 2Lo wasn't any good due to binding. The too short distance between the hitch and trailer axle needed more steering than the tranfer case liked. Since it was unloaded, it was easier to do it in 2Hi not riding the clutch. The 16ft wide door was a good-enough target for me to get through.

 

I agree, but even in a car, the tall reverse is just strange. Both our volvo and our saab had taller-than-1st reverse ratios. They both sucked in real life. But then, I can't think of a reason on paper that a tall reverse is a good idea. Both had 3,500lb tow ratings . . .

 

My belief is the RA and RC transmission probably have similar interface patterns but that's based on a few assumptions.

1. The RA60 and RA61 fit the 1GR used in Tacoma and FJ Cruiser
2. RC62 fits the 1GR still used in Prado and Hilux
3. RC62 fits the 2GR used in the current Tacoma

An unknown to me is if the RA/RC are similar to the older W and R series 5 speeds. The 4 cylinder 2TR used the R155 and R156, which also bolted to the 2RZ/3RZ and 3VZ/5VZ engines before.

 

Good info. I think it was mentioned in the past that the interfaces were becoming more of a standard to make the applications easier.

I would be great if someone from Toyota would jump in here every once in a while to clear this stuff up. In other threads, folks who work in the manufacturing shops have posted great info.

 

I know I have posted my previous colorfilling of shift knobs on here and received many likes and questions about it, well my latest project went sideways unfortunately so I am just posting this for buyer beware. https://www.tacomaworld.com/threads...zes-factory-boot.534205/page-17#post-17787297

 

7th gear is like 0.42.

 

How is reliability of the RA60 tranny. I want to buy a 1st gen tundra regular cab with the 4.0 and the RA60 but can't find anything with low miles or that doesn't look like its been driven into the ground.

 

My RA60F only has 80k on it, so someone else will have to answer on longevity. It's got the squeaking throwout bearing so there's that (the sleeve it slides on is aluminum, which isn't ideal). Can't say it seems any better or worse really than my W56 in the old truck, which at 300k would just fall into gear but otherwise was still solid.