Jump to content
SAU Community

Recommended Posts

Hi all, I have recently brought an engine (RB25DE) / manual gearbox (small box) from Facebook Market place for a good price which I will be putting into my R34 RB25DE sedan.

As you are probably aware the gearbox is an RB20 box which the N/A manuals had.

The problem that I'm having is with the boxes sensors. There are 3 ports on the box 2 of which are missing cables

I'm not sure if the speed sensor will fit my loom / it looks to be missing a cord? ( On purpose?) And its bracket is broken so a replacement is required. Would my 4 speed automatic one fit?

I have attached the photos below including speed sensor :)

 

Any help would be much appreciated 👍

 

20240106_161301.jpg

20240106_161120.jpg

20240106_161116.jpg

20240106_161113.jpg

20240106_161110.jpg

Edited by RB25inside
Need to add tags

I'd start by seeing if your auto speed sensor does physically fit. If you go for something from another car it will need to have the same diff ratio to give you the right speed.

Also, both the neutral and reverse sensors seem to have their wires broken off too...whoever you go this from really looked after it. You probably don't need the neutral switch but without the reverse one you won't have working reverse lights

Thanks for the replys guys. I am yet to take out my auto gearbox but believe the R34 has two wires plug for the speed sensor? But currently the one in the box has 3 wires.

Does anyone know the exact model speed sensor I need?

I'll count the teeth on the sensor that it came with.

I can't imagine a 3-wire speed sensor. They're just (effectively) an electric motor that produces an AC voltage waveform as you spin them. 2 wires that go to the speedo. You should look at the R34 wiring diagrams to see if the auto speed sensor really is a 3 wire.

Yeah how interesting right! As I am in Australia maybe it was from a Commodore at some point? If I look up VL gearbox speed sensor it looks awful similar.

While searching this morning I found this https://vegaautosports.com/products/speedo-sensor-and-pinon-to-suit-nissan-silvia-s14-and-skyline-r33-n-a-gearboxes not sure if this would fit into my box seeming its an RB20 box of some sort. The images don't really show if there are any plugs. But yet again it shows Silvia parts in RB20 Boxes. What do you think?

I don't know enough about the CA/SR gearboxes. They are very similar to the small RB boxes, but as with all Nissan stuff, there are small and annoying differences everywhere you look.

I can say that there is no difference at all between an RB20 turbo and R33/4 NA box. Well, alright, again small differences. I'm pretty sure 3rd gear was a different ratio between R32 turbo and R34 NA boxen (I had both in my car). But the speedo drive (cable, for R32) just goes directly into the R33/4 boxes like it was made to, because it was.

 

19 minutes ago, GTSBoy said:

I don't know enough about the CA/SR gearboxes. They are very similar to the small RB boxes, but as with all Nissan stuff, there are small and annoying differences everywhere you look.

I can say that there is no difference at all between an RB20 turbo and R33/4 NA box. Well, alright, again small differences. I'm pretty sure 3rd gear was a different ratio between R32 turbo and R34 NA boxen (I had both in my car). But the speedo drive (cable, for R32) just goes directly into the R33/4 boxes like it was made to, because it was.

 

So If that's the case and the R32 speed (Cable) sensor goes into the rb20 box would that mean the R33 sensor should fit into my rb20 box?

Yes, so long as we're talking about the RB20 turbo box and the R33 RB25DE NA box. I cannot promise you that the R32 NA box is the same as these though. It probably is, as again it is effectively the same sort of box as the CA/SR boxes, and almost the same as the 20DET box. They are definitely not all the exact same though. The 20DET box is stronger than the 20DE box, for example, even if it is only a little stronger.

Okay so I have done some R&D the RB25DE sensor has 21 teeth and is a lot longer then my model.

 

RB25DE sensor model (purple)codes are:

25010-79T01 – Sender

32743-71T21 – Gear / Cog 

 

As you can see this is much larger then my speed sensor shown above. Further research has found that the S13 / SR20 / KA24DE sensors are the same size as the RB20 (R32) and still offer 21 teeth while supplying two output wires (As seen in red cog)

So I'm 99% sure it will fit into my box but the question is will it out put the correct voltage pattern??????

Screenshot_20240108_200433_Chrome.jpg

images (1) (1).jpeg

Well, the speedo sender is trying to work out road speed from the gearbox's output shaft speed...therefore the diff ratio (and tyre height) must be assumed in the speed sender. So, if your car/diff (r34 auto) matches the speed sender you are looking at it will be fine.

  • Thanks 1

Okay so correct me if I'm wrong my R34 is RC40 and according to this website it means my car is:

R34 GT – RB25DE – auto – 4.083

 

https://www.eatsleepboost.lt/tech-info/nissan-tech-info/nissan-r200-diff-ratios/

 

This website also lists the S13 diff ratios as the following:

S13 – KA24DE – USDM – manual/auto – R200/R200V – 4.083

S13 – CA18DE – JDM – r180 6 bolt – manual/auto – 4.363

S13 – CA18DET – EDM – manual/auto – R200/R200V – 3.916

S13 – CA18DET – ADM – manual/auto – 4.363

S13 – CA18DET – JDM – manual/auto – 4.363

S13 – SR20DE (ABS) – manual/auto – 4.111

S13 – SR20DET – manual – 4.111

S13 – SR20DET – auto – 3.916

PS13/RPS13 – SR20DE (ABS) – JDM – manual/auto – 4.083

PS13/RPS13 – SR20DET – JDM – manual – 4.083

PS13/RPS13 – SR20DET – JDM – auto – 3.916

 

So if my understanding is right I need a KA24DE USDM or a JDM version. Probably the KA24DE would be the easiest and safest bet to get?

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • So stock ECU does not like anything above 10 psi?  That Nistune one is just for "try" if it will be any different, I know it need to be tune for that. I know but YOU may know about these problem but i/we dont. They few little Skylines here let alone people who know anything about tham so that is why iam asking here  
    • So now we have a radiator with no attachments whatsoever. It lifts up with a particularly tight spot between the drivers side air box mount and the lower radiator outlet, but if you've got this far you will sort that too. This is the lower mounts with the rad out so you can see where the rubber bushes go, it is a straight shot upwards Done! Assembly is the reverse of disassembly, with blood less likely to be shed.
    • Right, onto the second last trick. The Air Con condenser is mounted to the front of the radiator and stays in the car when the radiator is removed. There are 2x 10mm headed self tappers holding the top of the condenser to the radiator, remove those The bottom of the condenser is attached to the radiator with clips. You need to lift the condenser out of those clips and clear (up, then forward). f**ked if  could work out how to do that last bit with the front bumper on. I hope you can, and you share the trick.  Bumper removal probably deserves its own thread one day once I've recovered the will to live, but basically you need to remove the wheels, front inner guard liners (clips and 10mm headed bolts), the self tapper between the guard and the bumper at the rearmost point of the bumper (same as an R32 that bit), any remaining clips at the top/front of the grill, an absolute bastard design with a plate that holds the top of the bumper above the headlight each side (only 1 bolt which is tricky to get to, but the plate catches 2 places on the bumper and must be removed....carefully!) and push clips between the bumper and guard under the headlight. If you've done all that you will be faced with wiring for the fog lights on both sides and in ADM Q50 RS at least, 4 nasty tight plugs on the driver's side for the ADAS stuff. So, the clips at the bottom look like this on drivers side (looking from the front) And on the passenger side (also from the front), you can see this one is already out Clearance on both of these are super tight; the condenser needs to move up but the upper rad support mount prevents that, and the radiator can't move down far because it is (rubber) mounted. Once you achieve the impossible and drop the condenser off those mounts so it does not stop the rad moving, you are good to go
    • OK, next the shroud needs to come off and there are a couple of tricks. Firstly, there is a loom from near the passenger side headlight to the fans, coolant temp sensor etc and there is no plug to undo.  In my case I was OK to leave the shroud on top of the engine so I just undid the passenger side fan plug and about 10 of the clips which gave enough free wire to put it aside. The fan plugs were super tight, the trick I used was a small falt screwdriver to push down on the release tab, then a larger flat screwdriver to lever the plug out of the fan unit....be careful with how much force you apply! If you need to remove the shroud altogether for some reason you will have to deal with all the plugs (tight) and clips (brittle)....good luck. I removed all of the clips and replaced them with cable ties that I will just cut next time. Also, in the Red Sport / 400R at least, the intake heat exchanger reservoir hose is bolted to the shroud in 2 places with 10mm headed bolts; so remove them (the hose stays in the car; no need to undo it at the t fittings down at the radiator lower mount. Once you've dealt with the HX hose and the wiring loom, there are 3x 10mm headed self tappers holding the top of the shroud to the radiator; remove those.   The shroud then lifts out of the bottom mounts where it sits on the radiator, up and onto the engine out of the way. Simples
    • Ok, disregard my “rate them” comment, sorry for my unrealistic input
×
×
  • Create New...