Speedo not working 1990 R31

[MattBas1975]

Hi all, thanks for letting me join group. Some help here would he much appreciated. My son bought he's 1st R31 and we have no Speedo working. I have attached Pics if what we discovered yesterday. It's a conversation to manual.

 

Cheers Matt

[Duncan]

Welcome to the forums Matt, and well done to your son for making an excellent choice in 1st car.

I am not familiar with R31 setups, but R32 used a mechanical speedo drive from the gearbox to the dash and I suspect R31 might as well. Is there another connection further back on the gearbox on the passenger side? Of course this may never have been done properly when the manual swap was done.

[GTSBoy]

Here's an RP71C #2 (photo taken from this very site) showing an electronic speed sender.

http://i68.photobucket.com/albums/i30/0t1/more/IMG_0296.jpg

I'm not at all sure what that 3pin connector is all about - unless it is the wiring for the reverse and neutral switches brought together. It's certainly not the usual connector for the speed sensor.

Anyway - I'm pretty sure that the R31a used a mechanical speedo drive, and this gearbox, being an R33 turbo box (the best thing to have, by the way) usually has an electronic speed sender, as in the image above. So - you cannot make it work without building a mechanical speedo drive. You will need the speedo drive from a Navara from the same period to do this. I think you have to use the gear from your electronic drive to get the right ratio (Navara being different). There are howtos on here and elsewhere on the net, although I've never actually seen one as I didn't have to do mine - my bro'-in-law built the drive for me.

[Duncan]

Right, and in addition to that, you need an r31 speedo cable if one is not currently installed, as it will need to be the right length and have the right drive at the dash end

[MattBas1975]

On 31/07/2022 at 10:35 AM, Duncan said:

Welcome to the forums Matt, and well done to your son for making an excellent choice in 1st car.

I am not familiar with R31 setups, but R32 used a mechanical speedo drive from the gearbox to the dash and I suspect R31 might as well. Is there another connection further back on the gearbox on the passenger side? Of course this may never have been done properly when the manual swap was done.

 

[MattBas1975]

Hi Duncan, I'll have a look tonight and see where that other cable goes too past the rear of the box. 

[MattBas1975]

On 31/07/2022 at 11:19 AM, GTSBoy said:

Here's an RP71C #2 (photo taken from this very site) showing an electronic speed sender.

http://i68.photobucket.com/albums/i30/0t1/more/IMG_0296.jpg

I'm not at all sure what that 3pin connector is all about - unless it is the wiring for the reverse and neutral switches brought together. It's certainly not the usual connector for the speed sensor.

Anyway - I'm pretty sure that the R31a used a mechanical speedo drive, and this gearbox, being an R33 turbo box (the best thing to have, by the way) usually has an electronic speed sender, as in the image above. So - you cannot make it work without building a mechanical speedo drive. You will need the speedo drive from a Navara from the same period to do this. I think you have to use the gear from your electronic drive to get the right ratio (Navara being different). There are howtos on here and elsewhere on the net, although I've never actually seen one as I didn't have to do mine - my bro'-in-law built the drive for me.

Cheers mate. Will check to see if cable is actually in the back of the dash tonight and we'll take it from there. Appreciate your feedback a lot. 

[Scottyd 240z]

On 1/8/2022 at 9:02 AM, MattBas1975 said:

Cheers mate. Will check to see if cable is actually in the back of the dash tonight and we'll take it from there. Appreciate your feedback a lot. 

Hi Matt, I have a RP71C#2 gearbox in my car and it is the twin synchro RB20det gearbox from the r32 Skyline, my car uses a mechanical drive speedo which I recently replaced the speedo pinion drive as it disintegrated and jammed up and would not let me select 5th gear. 

 

[niZmO_Man]

I had the cable seize up (the one that goes behind the speedo), grabbed a replacement and good to go.

[MattBas1975]

Where from?

[GTSBoy]

On 8/4/2022 at 4:49 AM, MattBas1975 said:

Where from?

For an R32, JustJap, Kudos, et al.

[niZmO_Man]

On 04/08/2022 at 6:49 AM, MattBas1975 said:

Where from?

Off a forum member. You can try Nissan dealer, or Kudos or similar that can buy Nissan parts. Or gumtree/Facebook etc. for second hand