5-speed Lowest 1st gear ratio

[]2eDeYe]

What is the donor? Looking for a 5 speed for the 4x4. I am eyeballing one from an 84 720, would that have a low ratio due to the high rear ratio? 

 

 

Keyword:  Asian Tranny :lol:

 

 

720 620 4x4

[ggzilla]

You want a wide-ratio box. Not necessarily the one with a larger overdrive.

 

720 Pickup truck gearbox, 4x4 and diesel came with the 3.592 first gear.

[datsunaholic]

79 620s (and 80 720) and the 720 diesel 5-speeds were 3.592 1st.  81+  720s were 3.321, but that's 2WD.

 

The only lower 1st was in a 4-speed, and a 63-series to boot.

[]2eDeYe]

Thanks fellas. Does the diesel share the same bellhousing as the L?

[deweyharding]

I have a 4x4 box. I would sell

[datzenmike]

Thanks fellas. Does the diesel share the same bellhousing as the L?

 

No, the starter is on the driver's side. It has more in common with the Roadster.

[uberkevin]

I too have a 4x4 tranny I'll get go of.

[datzenmike]

To ID a '79 620 or '80 720 four or five speed with the 3.592 first gear. Place in first gear and mark the input spline and the output spline. Turn the input 20 times. ( I use an old clutch disc) 

 

A 3.592 wide ratio 5 speed would turn 5.56 times.That's 5.5 times roughly.

 

A 3.321` mid ratio 5 speed would turn 6.02 times. That's 6 times roughly

 

A 3.062 close ratio 5 speed would turn 6.53 times. That's 6.5 times roughly

[]2eDeYe]

I have a 4x4 box. I would sell

 

 

I too have a 4x4 tranny I'll get go of.

 

Pasco is sorta close to me. Are they 5-speeds? Do you guys know what the first gear ratio is? Either of you going to Canby? :)

 

 

 

To ID a '79 620 or '80 720 four or five speed with the 3.592 first gear. Place in first gear and mark the input spline and the output spline. Turn the input 20 times. ( I use an old clutch disc) 

 

A 3.592 wide ratio 5 speed would turn 5.56 times.That's 5.5 times roughly.

 

A 3.321` mid ratio 5 speed would turn 6.02 times. That's 6 times roughly

 

A 3.062 close ratio 5 speed would turn 6.53 times. That's 6.5 times roughly

 

 

That will be a pain in the ass. Any way to tell from the under hood tag?

[ggzilla]

Any way to tell from the under hood tag?

Yes, look for where it says 1979 620 or 1980 720. Then count to verify the original transmission hasn't been swapped out sometime in the last 30+ years.

[]2eDeYe]

Yes, look for where it says 1979 620 or 1980 720. Then count to verify the original transmission hasn't been swapped out sometime in the last 30+ years.

 

 

Dammit you were supposed to say "this magical number says this transmission is in this truck"  :lol:

 

Guess I'll go play with all the 4x4s I heard were at the local PAP tomorrow.

[]2eDeYe]

You want a wide-ratio box. Not necessarily the one with a larger overdrive.

 

720 Pickup truck gearbox, 4x4 and diesel came with the 3.592 first gear.

 

 

So all 720 4x4s have the 3.592 first?

[ggzilla]

4x4 diesel came with the 3.592 first gear.

[]2eDeYe]

Diesel doesn't have the correct bell housing. Is it swappable with the L or Z bell housing?

[]2eDeYe]

You want a wide-ratio box. Not necessarily the one with a larger overdrive.

 

720 Pickup truck gearbox, 4x4 and diesel came with the 3.592 first gear.

 

 

4x4 diesel came with the 3.592 first gear.

 

 

Your confusing me :P

[ggzilla]

All 720 diesel 4x4 came with it. Simple, no? Maybe some non-4x4 too.

[]2eDeYe]

Not simple....

especially with you cryptic answers

 

 

My question was asking for clarification in regards to this post that you made, that is why I quoted it.

 

You want a wide-ratio box. Not necessarily the one with a larger overdrive.

720 Pickup truck gearbox, 4x4 and diesel came with the 3.592 first gear.

 

 

Did all 720 4x4 come with the 3:592 first gear as you stated there? Or just the diesel as you stated below?

 

 

4x4 diesel came with the 3.592 first gear.

 

 

That is the crux of my confusion. Thanks for the help :)

 

 

Also

Does the diesel bell housing swap with the L or Z bell housing.

 

If the diesel bell housing does not swap then that will not work for me so that would be out.

[ggzilla]

All 720 that came with both diesel and 4x4 has the low gear.

 

I don't know if any non-diesels used it.

[]2eDeYe]

Thanks for the clarification :thumbup:

[datsunaholic]

Well, it's even more cryptic because diesel 4x4s weren't sold in North America.  Australia, yes.

 

The 3.592 was used in the North American 720 diesel, though.  AND the 79 620.  AND the 1980 720.  All other 2WD  620 and 720 5-speeds (77-78, 81+) used 3.321 1st gear.

 

I do not know the 4WD ratios, because for some reason my manuals omit the 4WD information.

 

However, as GG said, it's impossible to know what gearbox it is if it was swapped.

 

The underhood tag does not list the transmission ratios, only the transmission model starting in 1981 (which will be FS5W71B for all 720s irregardless of engine/drivetrain options).

[]2eDeYe]

Sounds like I get what I can find. I will post up the results of my effort. :)

[ggzilla]

Thanks holic,

 

I meant all USA 720 that came with either diesel or 4x4 has he low gear.

[datzenmike]

 

 

The 3.592 was used in the North American 720 diesel, though.  AND the 79 620.  AND the 1980 720.  All other 2WD  620 and 720 5-speeds (77-78, 81+) used 3.321 1st gear.

 

 

This is true.

 

ALL 4x4 720s L20B, Z22 and Z24 used the 3.592 ratio.

 

The L front case will swap onto the diesel transmission.

 

The '84-'86.5 S12 with CA18ET and CA20E motors also use the 3.592 first gear FS5W71B 5 speed. Has modified and improved synchros and stronger shift forks. Again needs an L front case swap.

 

 

Steve I have a short FS5W71B from an '83 Z24  4x4 I don't need. It does not have the speedo pinion in it and I took it out myself. I can confirm the 3.592 first and bring to Canby.... All you need is the longer primary driveshaft and an L front case swap.

[]2eDeYe]

Thanks Mike, I think I will look for a long case as I would have to shorten the front driveshaft as well and I'd rather spend my time and $ reworking the cross members to flatten the belly. Not to mention I already need to get my Toyota rear re-geared by a pro $.

 

 

Good to know that that all the 720 4x4's have the 3:592 gear, there is like 4 at the Arlington PnP. Maybe I can get over there next week after Canby. :)

[Master-O-Turbonics]

Check this thread. I figured out a 3.701 1st gear.http://community.ratsun.net/topic/49938-the-mongrel-gearbox-for-the-4x4-guyand-the-land-speed-record-guy/