Toyota 5-Speed slides out of 5th gear

[Patrick67BJ8]

My transmission has been out of my car for a few years while I'm doing a frame up restoration and now's a good time to fix my 5-speed.

Transmission guy says he can't see anything definitely wrong with 5th gear and the slider and as a precaution since the transmission is apart he suggested replacing those two items.
(chaalenge has been trying to find the right parts without knowing what year trans is from. It is however from a Supra.

Anyone have a similar problem??

Also, how can I tell if my transmission is really one with the 28% 5th gear? There are no identifying marks on the transmssion case that I can find.

I have a 3:54 rear end ratio on my BJ8. Do I need a special speedo gear to replace the one that came with the trans? I also had the original speedo rebuilt by Nisonger before the transmission was installed in 2007. I told them I had a 3:54 rear axle ratio when they rebuilt the speedo.
Thanks,

 

[Keoke]

Sugesstion replace it with aknown good one they are relatively inexpensive.

 

[Patrick67BJ8]

Sugesstion replace it with aknown good one they are relatively inexpensive.

A good idea and I thought about it, but this was was a suposedly known good one too having been opened up and inspected, etc.

 

[Bob_Spidell]

...

I have a 3:54 rear end ratio on my BJ8. Do I need a special speedo gear to replace the one that came with the trans? I also had the original speedo rebuilt by Nisonger before the transmission was installed in 2007. I told them I had a 3:54 rear axle ratio when they rebuilt the speedo.
Thanks,

Not sure I understand the question (think there's two in there). AFAIK, all transmission speedo adapters are 1:1, so as long as the cable fits the speedo you'll be OK.

Changing to a 3.54 rearend requires a ratio adapter or two differently-sized gears to drive the odometer and the tripmeter (the speed indicator is calibrated by moving the indicator needle). If Nisonger put the correct gears in and calibrated the speedo it should be accurate. Install the speedo and check against predicted values using a site like this (or a GPS):

https://www.angelfire.com/fl/procrastination/rear.html

 

[big6]

To determine the ratio of 5th gear on the bench, shift the transmission into fifth gear. Slide the clutch disk onto the transmission input shaft and put an alignment mark or pointer on the transmission case and an alignment mark on the clutch disk. Slide the yoke on the output shaft. Put an alignment mark on the case and the yoke. Turn the clutch disk one full turn and record the position of the output shaft. If it is 28% ratio the output shaft should have rotated about 1 and 1/4 turn around. You can also install a degree wheel on the input shaft clutch disk and install a pointer on the transmission case for an exact degree of movement reading. Turn the input shaft until the output shaft moves one full turn. Record the degree of movement of the input shaft. The input shaft should rotate 72 degrees while in 5th gear.
As a test put the transmission in 4th gear and the clutch disk and output shaft should both turn one full turn equally. You can use this same method to determine the ratio of 1st thru 3rd gears. The later Toyota transmissions have a closer ratio for the lower gears than the earlier Supra transmissions.

 

[Patrick67BJ8]

...

I have a 3:54 rear end ratio on my BJ8. Do I need a special speedo gear to replace the one that came with the trans? I also had the original speedo rebuilt by Nisonger before the transmission was installed in 2007. I told them I had a 3:54 rear axle ratio when they rebuilt the speedo.
Thanks,

Not sure I understand the question (think there's two in there). AFAIK, all transmission speedo adapters are 1:1, so as long as the cable fits the speedo you'll be OK.

Changing to a 3.54 rearend requires a ratio adapter or two differently-sized gears to drive the odometer and the tripmeter (the speed indicator is calibrated by moving the indicator needle). If Nisonger put the correct gears in and calibrated the speedo it should be accurate. Install the speedo and check against predicted values using a site like this (or a GPS):

https://www.angelfire.com/fl/procrastination/rear.html

I'll check the speedo against the GPS when I get the car all put back together again.

 

[Patrick67BJ8]

To determine the ratio of 5th gear on the bench, shift the transmission into fifth gear. Slide the clutch disk onto the transmission input shaft and put an alignment mark or pointer on the transmission case and an alignment mark on the clutch disk. Slide the yoke on the output shaft. Put an alignment mark on the case and the yoke. Turn the clutch disk one full turn and record the position of the output shaft. If it is 28% ratio the output shaft should have rotated about 1 and 1/4 turn around. You can also install a degree wheel on the input shaft clutch disk and install a pointer on the transmission case for an exact degree of movement reading. Turn the input shaft until the output shaft moves one full turn. Record the degree of movement of the input shaft. The input shaft should rotate 72 degrees while in 5th gear.
As a test put the transmission in 4th gear and the clutch disk and output shaft should both turn one full turn equally. You can use this same method to determine the ratio of 1st thru 3rd gears. The later Toyota transmissions have a closer ratio for the lower gears than the earlier Supra transmissions.

If the trans mission is apart(gears off and available to hold), can you count the teeth of 5th gear to check?

 

[Patrick67BJ8]

To determine the ratio of 5th gear on the bench, shift the transmission into fifth gear. Slide the clutch disk onto the transmission input shaft and put an alignment mark or pointer on the transmission case and an alignment mark on the clutch disk. Slide the yoke on the output shaft. Put an alignment mark on the case and the yoke. Turn the clutch disk one full turn and record the position of the output shaft. If it is 28% ratio the output shaft should have rotated about 1 and 1/4 turn around. You can also install a degree wheel on the input shaft clutch disk and install a pointer on the transmission case for an exact degree of movement reading. Turn the input shaft until the output shaft moves one full turn. Record the degree of movement of the input shaft. The input shaft should rotate 72 degrees while in 5th gear.
As a test put the transmission in 4th gear and the clutch disk and output shaft should both turn one full turn equally. You can use this same method to determine the ratio of 1st thru 3rd gears. The later Toyota transmissions have a closer ratio for the lower gears than the earlier Supra transmissions.

If the trans mission is apart(gears off and available to hold), can you count the teeth of 5th gear to check?

Update: I counted the 5th gear teeth. The small gear is 33 and the larger gear is 57. Trans is apart and the car is at the Body/Paint shop. I've tried doing the math but I can't get it right. I'm used to business math and a friend told me "engineeering math" is different.
Thanks,

 

[Bob_Spidell]

.... I'm used to business math and a friend told me "engineeering math" is different.
Thanks,

... but a ratio is a ratio. The fifth gear has a 33/57--or 0.58--ratio; i.e. the input shaft turns 58% (roughly 208deg) for one full turn (360deg) of the output shaft. This would (usually) be described as a '42%' O/D. For comparison, Healey O/D ratios are either 23% or 28%, depending on model, and Toyota 5th gears are usually around 15-20%:

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

42% sounds way high, are you sure you're counting the right gears?

BTW, I think your friend is pulling your leg. Math is math, just the applications and terms may vary; e.g. the same Newtonian calculus--derivatives--is used to calculate present value of money as is used to calculate artillery trajectories.

 

[Patrick67BJ8]

.... I'm used to business math and a friend told me "engineeering math" is different.
Thanks,

... but a ratio is a ratio. The fifth gear has a 33/57--or 0.58--ratio; i.e. the input shaft turns 58% (roughly 208deg) for one full turn (360deg) of the output shaft. This would (usually) be described as a '42%' O/D. For comparison, Healey O/D ratios are either 23% or 28%, depending on model, and Toyota 5th gears are usually around 15-20%:

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

42% sounds way high, are you sure you're counting the right gears?

BTW, I think your friend is pulling your leg. Math is math, just the applications and terms may vary; e.g. the same Newtonian calculus--derivatives--is used to calculate present value of money as is used to calculate artillery trajectories.

I bought the transmission from Pete Delaney and specified a 28% 5th gear trans. I just never could get it to come out 28% no matter who's calculator I borrowed. GEARS: I'm going by what the transmission guy said is the two gears for 5th gear. I hoped I picked the "right" tranmission shop?! You don't suppose my friend flunked the "new math" course he took?(he's younger than me).

 

[Bob_Spidell]

All I know is 'old math;' i.e. basic, geometry (not really math), trig, differential and integral calculus (no differential equations, though). Not sure what passes for 'math' schooling these days; have heard it's been dumbed-down quite a bit (wouldn't want to hurt anybody's self-respect by flunking them, or making them feel dumb like I felt in some of my math classes).

I think a 42% O/D would be impractical; something else going on.

 

[Randy Forbes]

One of those may be an "intermediate" gear, is why your calculations aren't coming out right.

If you want the input driving gear and the output driven gear to rotate in the same direction, there has to be an intermediate gear. Simple physics :wink:

 

[Patrick67BJ8]

One of those may be an "intermediate" gear, is why your calculations aren't coming out right.

If you want the input driving gear and the output driven gear to rotate in the same direction, there has to be an intermediate gear. Simple physics :wink:

I'll stop by the Transmission shop tomorrow and see what's what with the gears and report back to the Forum.

 

[andrea]

Hi Patrick
This forum tread can be useful if you will dismantle the W56 gearbox
https://www.yotatech.com/f116/w56-rebuild-thread-219038/
Cheers
Andrea
https://picasaweb.google.com/lh/photo/dkUkwjnStSXNFcnfcvvFNtMTjNZETYmyPJy0liipFm0?feat=directlink

 

[rjc157]

since its a supra trans do you have the shifter tower in the front position

 

[Randy Forbes]

Yep, fifth gear ("laygear" driven by input shaft being the intermediate gear) typical of the 280ZX XMSN I rebuilt a couple decades ago, is outside of the main cluster of gears, seen here "overdriving" the 3rd motion shaft.

And being in "constant mesh" here's the method of engagement:
EDIT: AND therein lies the souce of it "sliding out of 5th gear" too! Either the indents on the selector shafts have worn, the spring tension on the detent balls are not great enough or the synchromesh hub (shown below) has worn. The synchromesh hub also has detent balls & springs, so renewal may get you by...

 

[Bob_Spidell]

Great photos. I always wondered how the 'mechanical' O/D gearing worked. Looks like 5th is chewed-up; did it vibrate, whine, or ...?

Seems to me there's a lot of side loading on the output shaft and gear. Do the roller bearings fit into a race embedded in the case? I gotta think a planetary gear O/D like the Laycock's is an inherently more elegant design--though somewhat more complex and involving electrics--as the power is carried through in a straight line.

 

[Randy Forbes]

Great photos. I always wondered how the 'mechanical' O/D gearing worked. Looks like 5th is chewed-up; did it vibrate, whine, or ...?

Seems to me there's a lot of side loading on the output shaft and gear. Do the roller bearings fit into a race embedded in the case? I gotta think a planetary gear O/D like the Laycock's is an inherently more elegant design--though somewhat more complex and involving electrics--as the power is carried through in a straight line.

To Clarify: those are pictures that I copied from the website Andrea linked us to__I should've pointed that out in my post above...

But yes, great pictures__a guy after my own heart!

From (albeit poor) memory, and only going by the Datsun/Nissan 5-speed that I worked on more than a decade ago, they do use a tapered bearing/separate race (of massive proportions) for the input, laygear and output shafts to ride in.

In the 5-speed I worked on, the car's owner was driving from Atlanta back to Lafayette (Louisiana) when he "lost" 5th gear. Turns out that a snap-ring dislodged on the output shaft, allowing the synchromesh hub to "drift" backwards (actually towards the front of the gearbox) enough to allow the SINGLE ball bearing to fall out, no longer "pinning" it to the mainshaft. There was literally zero damage (creampuff 20 year old car with barely 9k miles on it) AND the ball bearing was found in the bottom of the case! Prudence dictated that I replace the snap ring with a new one, a gasket set and some sealant to complete the job.

 

[Patrick67BJ8]

One of those may be an "intermediate" gear, is why your calculations aren't coming out right.

If you want the input driving gear and the output driven gear to rotate in the same direction, there has to be an intermediate gear. Simple physics :wink:

I'll stop by the Transmission shop tomorrow and see what's what with the gears and report back to the Forum.

Just got back from the tranny shop. Both of the gears, 33 (on the main shaft) and 57 (on the counter shaft) are engaged when in 5th gear. I think the suggestion of installing the clutch disk on the main shaft, etc. and rotating the shafts is the best way to determine whether or not I have a 28% 5th gear.

 

[Patrick67BJ8]

since its a supra trans do you have the shifter tower in the front position

Yes.