Jump to content
SAU Community

R33 Speedo not reading correctly

R33sedandenver
 Share

Recommended Posts

R33sedandenver Rookie

R33sedandenver

Posted
Posted

I just purchased a R33 GTST sedan that was previously manual swapped.    I’ve figured out it has a Rb20 transmission and my Speedo is reading about double what it should.   At about 45mph the cluster is reading 160 kmh.    Does anyone have any info on how I would figure out what Speedo gear I need to change to ?    
Thank you ! 

Link to comment
https://www.sau.com.au/forums/topic/482062-r33-speedo-not-reading-correctly/
Share on other sites
R33sedandenver Rookie

R33sedandenver

Posted
  • Author
Posted

So I pulled the Speedo gear and found the pinion gear is worn, guessing from improper mesh with the worm gear. So it seems the worm gear is skimming the top of the pinion instead of being meshed and causing it to over spin.  Looking for new pinion gears today 

D62F9AE3-35F0-4254-973F-071DA820E1D4.jpeg

PLYNX Mentor

PLYNX

Posted
Posted

Yep change it out and treat that RB20 gearbox gently and start saving your little lunch money for a RB25DET gearbox.

The RB20 gearbox is know to be quite frail when you load it up behind the RB25DET motor.

That way, after you change it out, you don't have to cringe when you give it a boot full worrying about breaking the RB20 box.

R33sedandenver Rookie

R33sedandenver

Posted
  • Author
Posted

🤞🏻 Crossed the new gear meshes Into the trans correctly.   Found 4 listed at dealers in the country left. 

Have heard that about the 20 trans which is sad but makes sense.   From the condition of the trans and pedal assembly it all looks to have been in the car for a long time now.  Definitely wanting to change it out eventually for the proper trans ! 

  • 3 weeks later...
R33sedandenver Rookie

R33sedandenver

Posted
  • Author
Posted

PLYNX

 

So it still had the auto cluster when I purchased it, was suggested to get a manual cluster so I found one and swapped it in.  Made no change unfortunately.     Seems what ever is translating the signal is on crack now 😂.  
 Have talked to people who said they had a 25 with 20 trans with the red gear on the Speedo drive and it worked as it should .    Starting to wonder if the drive unit is bad or have seen where people have gone and changed the lay out of things on the back of the actual Speedo but unfortunately can only find things for a auto to manual with the correct 25 trans 

Rusty Nuts Experienced

Rusty Nuts

Posted
Posted (edited)
34 minutes ago, R33sedandenver said:

I wonder if it’s the auto ecu can’t figure out the manual Speedo inputs

Nah, the signal from the gearbox sender is sent to the cluster the signal is converted at the cluster to the signal for the ecu and tcu.

Rb25det does not work vtc in patrol gr

By kike_kike, December 3, 2020 in Projects, Overhauls and Build-ups

Edited by Rusty Nuts
additional information
Rusty Nuts Experienced

Rusty Nuts

Posted
Posted

AC Sine wave speed sender (the transmission speed sender)

This type of sender, widely used in the 90s and early 2000's is simple and reliable but not infallible. It generates its own power and sends a weak AC sinewave signal to the speedometer by teeth spinning past a coil with 2 wires. The sender requires one wire to be grounded and the other is the signal. The wires can be reversed and the same result will work just fine due to the fact that the sender waveform is a simple sinewave. The downside is that due to the sender generating its own power by the speed of the reluctor wheel (teeth) it can often lead to an erratic signal at low speeds.

Suggest you check the output with a very good multimeter or oscilloscope. Its all in the workshop manual.

You cannot buy a workshop manual here. 

image.jpeg.d8b59fe5c0b68d4e9474e7acd9aec9f0.jpeg

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
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • oHBoy.
      Starter motor replacment teeth count.

      By oHBoy. · Posted

      I had 3 counts over the last couple of weeks once where i got stranded at a jdm paint yard booking in some work. 2nd time was moving the car into the drive way for the inspection and the 3rd was during the inspection for the co2 leak test. Fix: 1st, car off for a hour and half disconnected battery 10mins 4th try car started 2nd, 5th try started 3rd, countless time starting disconnected battery dude was under the hood listening to the starting sequence fuel pump ect.   
    • GTSBoy
      Mistakes were made, my R34 Story

      By GTSBoy · Posted

      This. As for your options - I suggest remote mounting the Nissan sensor further away on a length of steel tube. That tube to have a loop in it to handle vibration, etc etc. You will need to either put a tee and a bleed fitting near the sensor, or crack the fitting at the sensor to bleed it full of oil when you first set it up, otherwise you won't get the line filled. But this is a small problem. Just needs enough access to get it done.
    • suko
      J50 clock date suddenly reset to January 1

      By suko · Posted

      The time is always correct. Only the date is wrong. It currently thinks it is January 19. Tomorrow it will say it is January 20. The date and time are ( should be ! ) retrieved from the GPS navigation system.
    • MBS206
      Mistakes were made, my R34 Story

      By MBS206 · Posted

      Buy yourself a set of easy outs. See if they will get a good bite in and unthread it.   Very very lucky the whole sender didn't let go while on the track and cost you a motor!
    • Kinkstaah
      Mistakes were made, my R34 Story

      By Kinkstaah · Posted

      Well GTSBoy, prepare yourself further. I did a track day with 1/2 a day prep on Friday, inpromptu. The good news is that I got home, and didn't drive the car into a wall. Everything seemed mostly okay. The car was even a little faster than it was last time. I also got to get some good datalog data too. I also noticed a tiny bit of knock which was (luckily?) recorded. All I know is the knock sensors got recalibrated.... and are notorious for false knock. So I don't know if they are too sensitive, not sensitive enough... or some other third option. But I reduced timing anyway. It wasn't every pull through the session either. Think along the lines of -1 degree of timing for say, three instances while at the top of 4th in a 20 minute all-hot-lap session. Unfortunately at the end of session 2... I noticed a little oil. I borrowed some jack stands and a jack and took a look under there, but as is often the case, messing around with it kinda half cleaned it up, it was not conclusive where it was coming from. I decided to give it another go and see how it was. The amount of oil was maybe one/two small drops. I did another 20 minute session and car went well, and I was just starting to get into it and not be terrified of driving on track. I pulled over and checked in the pits and saw this: This is where I called it, packed up and went home as I live ~20 min from the track with a VERY VERY CLOSE EYE on Oil Pressure on the way home. The volume wasn't much but you never know. I checked it today when I had my own space/tools/time to find out what was going on, wanted to clean it up, run the car and see if any of the fittings from around the oil filter were causing it. I have like.. 5 fittings there, so I suspected one was (hopefully?) the culprit. It became immediately apparent as soon as I looked around more closely. 795d266d-a034-4b8c-89c9-d83860f5d00a.mp4       This is the R34 GTT oil sender connected via an adapter to an oil cooler block I have installed which runs AN lines to my cooler (and back). There's also an oil temp sensor on top.  Just after that video, I attempted to unthread the sensor to see if it's loose/worn and it disintegrated in my hand. So yes. I am glad I noticed that oil because it would appear that complete and utter catastrophic engine failure was about 1 second of engine runtime away. I did try to drill the fitting out, and only succeeded in drilling the middle hole much larger and now there's a... smooth hole in there with what looks like a damn sleeve still incredibly tight in there. Not really sure how to proceed from here. My options: 1) Find someone who can remove the stuck fitting, and use a steel adapter so it won't fatigue? (Female BSPT for the R34 sender to 1/8NPT male - HARD to find). IF it isn't possible to remove - Buy a new block ($320) and have someone tap a new 1/8NPT in the top of it ($????) and hope the steel adapter works better. 2) Buy a new block and give up on the OEM pressure sender for the dash entirely, and use the supplied 1/8 NPT for the oil temp sender. Having the oil pressure read 0 in the dash with the warning lamp will give me a lot of anxiety driving around. I do have the actual GM sensor/sender working, but it needs OBD2 as a gauge. If I'm datalogging I don't actually have a readout of what the gauge is currently displaying. 3) Other? Find a new location for the OEM sender? Though I don't know of anywhere that will work. I also don't know if a steel adapter is actually functionally smart here. It's clearly leveraged itself through vibration of the motor and snapped in half. This doesn't seem like a setup a smart person would replicate given the weight of the OEM sender. Still pretty happy being lucky for once and seeing this at the absolute last moment before bye bye motor in a big way, even if an adapter is apparently 6 weeks+ delivery and I have no way to free the current stuck/potentially destroyed threads in the current oil block.
×
×
  • Create New...