H42 Transmission, Tcase, eBrake Rebuild in a '76 FJ40` (1 Viewer)

[FishTacos]

The way you did it I bet it lasts at least as long as the factory finish.

That stuff is on there. Looks good.

 

[John Smith]

Too tight or too loose?

Too loose.

 

[Vae Victus]

13. Measuring Tolerances

13.1. Third Gear Oil Tolerance


Third Gear Oil Clearance


Measure outside of the hub


Measure inside of Third Gear

Take the difference between the two. Should be a max gap of 0.12mm. My tolerance was a little out of spec here - a bit too loose.

13.2. Synchronizer ring


Measure Gap between Synchro and Third


Minimum gap is 0.80 mm, but mine is 1.1mm.

The synchro has not worn down to the minimum yet, so still in spec.

13.3. Synchro Ring Number 1 and 2 Dimensions
These are the synchros for 1st and 2nd gears.


1st and 2nd gear synhros should be 2.8 mm and 1.8 mm minimum, respectively.
.


Second Gear - 1.74mm
.


First Gear - 3.2mm.

First is comfortably in spec, which is good, as these are not made any more (I don't believe).

 

[Pin_Head]

The specs say it is the the number is the limit. For synchros, it means that it can't be any less than the limit.

H42 synchros are beefy for first and second, any you get new 3-4 ones in the rebuild kit.

 

[Vae Victus]

14. Clutch Hub Sleeve

This was tricky so I thought I'd document more clearly.




Parts for reassembly







Note the clutch hub and hub sleeve orientation. This clearly matters. See how the clutch hub is larger on one side and sticks out a bit on the smaller side? Orient the hub properly with the sleeve according to the FSM diagram.


Drop the hub into the sleeve. Drop the 3 keys, bump facing outward into the gaps in the mated pair.


Add one Key Spring to grab the 3 Keys. Note the pen marks "I" and "II" by two of the keys.

This will hold the keys and the hub in place.

Flip it over and do that again.

NOTE: There is a notice in the FSM that says "Install the key springs such that their end gaps do not line up." So be sure that when you put the springs on, the ends are not in the same two keys on the front and back. If the front side clips ended at keys 1 and 2, the back side should be in 2 and 3 or 1 and 3.



Before Key Spring added


After Key Spring added. Note the numbers corresponding to the opposite marks on each side of the hub.

 

[Vae Victus]

The specs say it is the the number is the limit. For synchros, it means that it can't be any less than the limit. H42 synchros are beefy for first and second, any you get new 3-4 ones in the rebuild kit.

I didn't get new synchros in Bob's rebuild kit from TPI. Which ones?

 

[Pin_Head]

The 3rd and 4th gear synchros are the only ones available and should be included in a complete rebuild kit. I wouldn't reassemble it without new synchro rings. See if they are available from Toyota or other transmission sources. They are not expensive. They were about $15 the last time I looked, which was about 10 years ago.

 

[FJ40Jim]

I bought the 1-2 syncro package years ago for a resto. Cost was ~$450, IIRC.
Too expensive, I know, but the cust was OK with it, and the trans was already scattered on the bench.

 

[Vae Victus]

The 3rd and 4th gear synchros are the only ones available and should be included in a complete rebuild kit. I wouldn't reassemble it without new synchro rings. See if they are available from Toyota or other transmission sources. They are not expensive. They were about $15 the last time I looked, which was about 10 years ago.

I bought the 1-2 syncro package years ago for a resto. Cost was ~$450, IIRC. Too expensive, I know, but the cust was OK with it, and the trans was already scattered on the bench.

Wow, those are two different costs. I'll ask Beano if Mr T still sells the 3-4 rings. I guess since 1st gear is out of spec, that'll be my eventual failure point.

When all,the H42s are gone, what then?

 

[Pin_Head]

Your 1-2 synchro is not out of spec. The spec Is a minimum.

 

[Vae Victus]

Your 1-2 synchro is not out of spec. The spec Is a minimum.

Ah, missed that before. Ok, then with that logic, my 3rd gear synchro is ok too since the gap is larger than the lower limit. I'll go back and clarify my mess above.

 

[FJ40Jim]

The tranny is open, so replace the inexpensive 3-4 syncs.
Don't worry about the 1-2 cause it's massive and doesn't usually wear out.

 

[Vae Victus]

The tranny is open, so replace the inexpensive 3-4 syncs. Don't worry about the 1-2 cause it's massive and doesn't usually wear out.

Heard!

 

[Vae Victus]

Ordered the two synchros (#3 and #4) from Onur at Lowe Toyota today. About $35/each. Will post part numbers once I have them.

These are the small brass ones between 3rd gear on the output shaft, and 4th gear on the input shaft. They are the same.

The other two are discontinued I believe, and are much thicker.

 

[Vae Victus]

What does this mean WRT the Key Springs: There is a notice in the FSM that says "Install the key springs such that their end gaps do not line up."

 

[Pin_Head]

What it means is that the two rings start and end on different keys. Since there are 3 keys, the ends will be 120 degrees out of phase. Either way is OK as long as they don't line up.

 

[Vae Victus]

What it means is that the two rings start and end on different keys. Since there are 3 keys, the ends will be 120 degrees out of phase. Either way is OK as long as they don't line up.

Thanks Pin Head. I thought that's what it meant, but was concerned that one of the ends always would meet up with on on the other side since there are only 3 keys. Do you know why this is necessary?

 

[Pin_Head]

It is probably not necessary, but I think that the reason they tell you to do that is to randomize the force vectors on the synchronizer keys so that they do not resonate out of phase with the force vector of the flux capacitor and create an unsustainable environmental situation.

 

[Vae Victus]

It is probably not necessary, but I think that the reason they tell you to do that is to randomize the force vectors on the synchronizer keys so that they do not resonate out of phase with the force vector of the flux capacitor and create an unsustainable environmental situation.

You were doing well for a moment there. I see where the wheels came off.

 

[Vae Victus]

Ah, missed that before. Ok, then with that logic, my 3rd gear synchro is ok too since the gap is larger than the lower limit. I'll go back and clarify my mess above.

I edited step 13 based on my more complete understanding of the process.

In high school, I had to sign a pledge on all my work that said "On my honor as a gentleman, I have neither given nor received help on this work." Clearly, that is not real life. Thanks all for the help.