1983 Nissan 720 Kingcab 4X4 5 Speed (FS5W71) no 1st gear

[WilliamSC]

Hello all,

 

The first gear quit working in my 1983 720 4x4. All the other gears work fine. Any ideas on what caused this?

 

Any thoughts are appreciated.

 

William

[datzenmike]

Does the shifter go into first gear position?

[WilliamSC]

Hi datzenmike,

 

Thanks for the response. Yes the shifter goes into the first gear position but nothing happens.

 

Thanks,

 

William

[Stoffregen Motorsports]

Likely a broken roll pin in the rear shift pawl, or in the shift fork itself.

 

Does the shifter click into place? Or is it mushy? Does it sound/feel the same going into other gears?

 

 

This is a Roadster trans, but you get the idea.

[WilliamSC]

Hi,

 

Thanks for the response. The answers to your questions are below:

 

Does the shifter click into place? Yes

Or is it mushy? Not Mushy

Does it sound/feel the same going into other gears? Yes

 

Thanks,

 

William

[Stoffregen Motorsports]

Then it might be a broken or lost roll pin at the shift fork.

 

The detent balls are what "clicks". They are in the mid-plate and work in conjunction with the shift rails. If it clicks into gear, it makes sense that the shift rails are working.

[WilliamSC]

Thanks, I'll check this out but it'll probably be awhile as pulling the tranny is a real @#$%^&!

 

Many Thanks,

 

William

[Stoffregen Motorsports]

Here's another question - does second gear work?

 

I'm assuming it's not an automatic trans...

[datzenmike]

Wouldn't the broken roll pin on a shift fork affect second gear also?

 

 

Just curious what happens if you are idling in neutral and you push shifter into first without using the clutch

[WilliamSC]

Hi All,

 

It's not an automatic and I put in a new clutch and release bearing when I installed it 2 years ago. Everything worked fine until I tried to use it to pull out my F100 when it got stuck really bad on a swampy road.

 

I can drive it in the other gears as they all seem to be working fine. It's just the first gear that is not working/engaging.

 

I haven't tried to put it in first without pressing the clutch but I'll try that the next time I visit my property and report back the results. The truck is stored at my other property at the moment as I drove the F100 home once I managed to get a neighbor to pull it out with a tractor.

 

I'll have to bring it home to pull the tranny anyways as my garage is at my house.

 

I'll provide an update as soon as I can get up there to the 720.

 

Have a great 4th of July!!!

William

[datzenmike]

So this happened suddenly while trying to pull a stuck vehicle. That would explain it.

 

Unlikely  the splines on the mainshaft used to hold the first gear are stripped. The synchronizer hub slides back and forth on it between first and second. Second obviously works so if the splines near first gear were damaged it's unlikely the hub would move freely into either gear.

 

1st gear on the mainshaft is stripped where the hub engages it.

 

I suppose all the first gear countershaft teeth could be sheared off or the first gear itself but it would have made a loud crunch. You would have heard it.

[WilliamSC]

Hi All,

 

I finally got a chance to visit my 83 Nissan 4X4 king cab truck (1st gear not working) and I could move the shifter into the first gear position very easily without any grinding with no clutch and the motor running. Does this help to pin point the problem any?

 

Thanks,

 

William

[Stoffregen Motorsports]

I think it's time to pull the trans and have a look inside.

 

Even if it's a simple fix, it's still inside the trans. No way around it.

 

Clarify one thing for us - you can definitely get second gear, right?

[WilliamSC]

Yes, all other gears work fine even reverse.