Transmission R-A60 manual transmission information . Your 6 speed transmissiom (WRITE UP )

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^^^Sticky? Perhaps if it were first edited.
Although there is some good information here its the larger misinformation being repeated that is the problem.

First, lets put to rest the issue as to whether or not the T/O bearing rides full time on the fingers of the pressure plate. In our 2nd Gen trucks the T/O bearing spins full time whenever the engine is running. The bearing is actually preloaded against the fingers. The force of the preload is probably in the range of 5-20 lbs. and is provided by a spring in the slave cylinder. In a phone conversation I had with Luk they confirmed this range of pre-loading but will not reveal the specific value.

Why does it spin full time? SKF and other bearing manufacturers and clutch manufacturers claim that this prolongs bearing life because it is easier on the bearing to constantly turn than to be shock- and thermal-loaded by bringing the bearing from 0 to thousands of RPMs that it would have to otherwise achieve during shifts. Perhaps if a sufficient and decent amount of grease were used...

Next, for sure don't do this because of the obvious safety issues, but I have . The 6-speed has an inspection plate on the side of the transmission. Removing some things, a flashlight, and a running engine will confirm that the T/O bearing always spins. I have a new '14 6-speed and inspected it at about 700 mi. Same deal with the 5-speed although there is no inspection plate but only the boot that has to be removed; it too can be observed but is a bit more difficult. I also inspected my 5-speed and the T/O bearing is in constant contact on it.

Second, the issue of clutch free play. The factory manual is confusing at best and contradicts itself. I built a simple jig that is used to keep the clutch pedal travel and free play at the preferred specs.

There are two things that occur. Look at the back of the pedal with a light and mirror and you will see this. On the end of the master cylinder is a push rod. The end of the push rod should come very close to, but not touch, the back side of the clutch pedal. You can wiggle the end of the push rod to confirm. It should jiggle a bit but not have to be forced. Make sure you rotate the piece on the end of the push rod fully left-and-right and park it midway before you inspect.

There should be from 1-5 mm of free play that occurs at the pedal's foot pad (not between the push rod and the pedal) and this is the initial play you feel when you very slightly press on the pedal (best with your fingers). I often call this the push rod free play because its purpose is to keep the piston in the master cylinder from pushing more fluid to the slave cylinder when the clutch is at rest otherwise it would further load the T/O bearing against the pressure plate.

Keep pushing on the pedal a very little and you will feel another point of resistance. This second point is where the push rod's piston starts to move the fluid in the master cylinder. I call this the pedal free play.

So while pushing your fingers on the pedal this is what you should observe: from rest to about 1-5 mm there should be no resistance >> keep pushing a very little and note the 2nd point of resistance that should occur around 5-15 mm from where the pedal is fully released in the up position.

 

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Taco'09 thanks for proving that the TO bearing turns when the clutch is out. There's been a lot of wasted debate on that issue, so thanks again.

I fixed my noise by increasing the pre-load on the clutch. I changed the slave cylinder spring to one that applies more load on the TO bearing. That solves the problem.

 

Sure. This confusion raises its head every once in a while. Luk even has a technical document that states the bearing turns all the time. I think the root of the problem lies in the fact that a lot of T/O bearings on real old cars did not...my 1958 Jeep even had a spec for how far the bearing is supposed to be from the fingers. But that was then, this is now.

BTW I read your other thread on modifying the slave cylinder. Did you happen to measure the spring force by any chance on both the Toy and the Ford spring? Interesting that you did that mod. When I spoke with Luk they said that the leading cause of noise related to the T/O bearing was because of insufficient pre-load on it. I'm really interested in your long term results..

 

The lengths of the lever arms are uncertain but if you assume that the force at the TO is twice that at the slave cylinder then I'd say my replacement is 15 to 25 lbs at the TO bearing. I'd guess the Toy force is 5 to 10 lbs. Since I had it apart I got a Beck/Arnley replacement and it has a particularly anaemic and short spring.

Something you could ask Luk is how much force is required on the diaphragm spring to begin moving the pressure plate. Obviously we don't want the clutch to slip.

Two years + on my fix and everything is working fine.

Finally, someone who understands...thanks again Taco'09!

 

So you're saying I should have gone with an automatic.. Just kiddin, I love shifting. I have heard some noise while in neutral sitting still, with no pressure on the clutch pedal and it went away at some point (not sure where in the position of the pedal) when I floored the pedal. it comes back from time to time. I should probably do something about it, but after reading 7 pages on this topic, i'm not sure there is a simple fix and will most likely let it ride till something mechanical stops working like if the clutch starts to slip. Tacomas make so many weird noises, but just keep on keepin on.

 

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The clutch master cylinder has free play to insure that the TO bearing does not ride on the cover with any great pressure. It also allows the piston to return enough to refill the bore. As the clutch disk wares the fingers or the cover do extend. If this is something you don't believe please explain why they collapse when you tighten the cover down on a clutch assemble and why they wouldn’t extern as the disk became thinner. All non-hydraulic clutch setups have adjustment provisions, I don’t remember exactly when it was in the 80’s that they changed but Toyota trucks still had adjustable rods on their hydraulic clutches and the slave cylinders would bottom out then the clutch would slip from lack of clearance.

 

Maineah, not sure who you are addressing this to but I happen to agree with you.

 

is there anyone on here that might be able to help me diagnose why my truck will not stay in reverse without holding the stick in the reverse position? This started happening about 2 weeks ago, and everytime i try to back up the stick falls out of reverse and grinds the gear. 2013, TDR Off-Road, 4x4, DCSB, 4.0-V6. R-A60 Trans.

 

It is internal the trans has to come out.

 

could someone help me understand a few things? I drive a 2007 tacoma with the A750F tranny, and i am planning to swap it to the RA60F transmission. From what i have been able to tell though there are no differences between the RA60 and the RA60F, is this true or am i mistaken? also i am not sure if anyone will be able to answer this or not but will the transfercase interchange from my truck now?

 

R-a60 is 2wd ra60f is 4x4, adaptors,

Y are u stepping fown to a ra60?

 

They're a lot easier to find around here than the RA60f's, I'm just wondering if the transfer case will bolt up to the RA60

 

no, for one, the auto tcase and the manual tcase have different splined input shafts

 

I don't think it is going to work. The RA60 has a tail shaft end member coming right out of the transmission where the rear ujoint flange attaches. But on the RA60F a splined stub shaft comes out the front of the transfer case and inserts into the back of the transmission where that tail piece should be. On the 4WD the transfer case rear output is being used for the ujoint flange for the rear drive shaft instead. The question in my mind is whether that end section (tail shaft piece) of the RA60 has suitable bolt patterns and something like that splined stub shaft that would allow a transfer case to bolt on in its place. When I get a minute I will peek into the illustrated parts manuals and see if any light can be shed.

 

Since this is the case, could the output shafts be swapped?

That is exactly what I need to know, if you could find out that would be great. And would the transfer case off of my truck now bolt up to it or would I have to get another one?

 

The planetary gear set that is the input shaft can be changed but u would still need another case to get the input from

 

Would I be able to use the gear set out of the one on the truck now? Or will those interchange?