Results 1 to 16 of 16

Thread: Speedometer Question

  1. #1
    Registered User
    Member ID
    CZCC-19407
    Join Date
    Jun 2009
    Location
    Glendale, CA
    Posts
    7

    Default Speedometer Question

    I've recently bought a '73 240Z and I noticed that the speedometer has been acting strangely. The needle bobs up and down constantly and doesn't really stay still. Is there a fix?

  2. #2
    Semi-retired admin Arne's Avatar
    Member ID
    CZCC-8596
    Join Date
    Jun 2005
    Location
    Eugene, Oregon, USA
    Age
    64
    Posts
    8,465

    Default

    Typically, that is a binding or damaged speedo cable, if I understand your problem description correctly.
    Arne - Former owner, HLS30-37705, 7/71, 905 Red
    Car blogs - 240Z - Porsche 911

  3. #3
    Registered User
    Member ID
    CZCC-19407
    Join Date
    Jun 2009
    Location
    Glendale, CA
    Posts
    7

    Default

    Well, to be more precise..

    The speedometer reads pretty accurately. Although, due to the car vibrations and whatnot, the needle tends to bob A LOT.

    But thanks for your input Arne!

  4. #4
    Registered User Jeffrey's Avatar
    Member ID
    CZCC-14182
    Join Date
    Mar 2007
    Location
    Moncton, New Brunswick, Canada
    Posts
    60

    Default

    As Arne said try pulling the cable, cleaning it and the tube and relubing the cable and tube the cable goes in. That bobbing is usually a slight binding in the tube which twists the cable slightly then releases.
    1974 Datsun 260Z
    1999 Nissan Frontier 4x4 Extended Cab

    www.atlanticz.ca

  5. #5
    Registered User Seppi72's Avatar
    Member ID
    CZCC-1248
    Join Date
    Oct 2001
    Location
    Marysville, Ohio
    Posts
    142

    Default

    My speedo only starts fluctuating when I get above 85 MPH. Unfortunately, that doesn't happen too often (often enough?) as I have a ride-along rev limiter; i.e., wife.
    Bob Kroshefsky
    Marysville, OH
    CZC # 1248

  6. #6
    Registered User
    Member ID
    CZCC-2139
    Join Date
    May 2002
    Location
    Salem Or
    Posts
    1,556

    Default

    To all: If you haven't done what Arne mentioned, you should. This is one of those PM things that'll result in one less thing hopefully going wrong in the future. If you don't do it it'll break and then its another "NISSAN doesn't have them any more" deals. A small tube of graphite lube will do the trick. Best to remove the cable housing from the car so you can get an even lube end to end.
    Bruce Palmer
    Salem Or
    Sales@ztherapy.com
    www.ztherapy.com
    503-587-9800

  7. #7
    Registered User Jeffrey's Avatar
    Member ID
    CZCC-14182
    Join Date
    Mar 2007
    Location
    Moncton, New Brunswick, Canada
    Posts
    60

    Default

    I pulled my speedo last night to install a metric one. I have 5 or 6 spares. I pulled one of the spares apart and they are pretty straight forward. Not much can go wrong inside them.
    1974 Datsun 260Z
    1999 Nissan Frontier 4x4 Extended Cab

    www.atlanticz.ca

  8. #8
    Registered User moritz55's Avatar
    Member ID
    CZCC-14684
    Join Date
    Jul 2007
    Location
    Raleigh, North Carolina 27617
    Posts
    186

    Default

    On my 73 240z that I sold last March '08, my speedomter was a bit unstable when accelerating only - ussually in 2nd or 3rd gear. It turned out while having the transmission rebuilt that the Nylon speedo gear to the cable was worm and even had a tooth missing. I think it was a white color gear with 17 teeth. Bought from the local Nissan dealer a replacement. They needed to know the transmission type and year, along with the color and tooth count of the gear to order the correct part. I had an 82/83 280zx 5sp manual transmission in the car.

    This took care of the porblem when the transmission was re-installed in the car.

    Many thanks..
    Last edited by moritz55; 06-11-2009 at 10:20 AM.
    Regards,

    Mark M. .........
    1973 240z HLS30-124668 (9/72), "Deep Beryl Green-PGV"
    2010 370z JN1AZ4EH3AM503017 (3/10), "Black Cherry-NAG"

  9. #9
    Registered User
    Member ID
    CZCC-3609
    Join Date
    Feb 2003
    Location
    Clearwater,Florida USA
    Age
    75
    Posts
    4,424

    Default

    Hi Mark:
    The speedo pinion gear has to be matched to the rear end ratio - if you want your speedo to indicate the correct speed.

    Giving the transmission type and year to the Dealer - will help them find the part numbers in the Parts Catalogs. Nonetheless, you want to order the speedo pinion gears based on the rear end ratio you have in your Z. That means matching the number of teeth on the speedo pinion gear to the rear end ratio. Color can be useful - - but it is easy to confuse the white gears with the yellow gears after extended use in a transmission.

    The 81-83 280ZX's with 5spd. came with 3.545 and 3.9 rear end ratio's. However your 240Z could have it's stock 3.364 or 3.545 if it was an A/T. Or your 240-Z might have had its rear gear changed along with the installation of the 5spd. tranny.

    16 Teeth, Yellow, 3.364 rear gear
    17 Teeth, Black, 3.545
    18 Teeth Blue, 3.7
    19 Teeth White, 3.9
    20 Teeth Red 4.11

    FWIW,
    Carl B.

  10. #10
    Registered User moritz55's Avatar
    Member ID
    CZCC-14684
    Join Date
    Jul 2007
    Location
    Raleigh, North Carolina 27617
    Posts
    186

    Default

    Thanks Carl great data!
    My prior 73 240z that I referenced above did have a 17 tooth gear - so it must have been the Black one. Must have had a stock 3.545 rear end in it.

    My current '73 240z has the 3.9 rear end with an '82 280zx 5spd and I know that's a 19 teeth speedo gear - this must have been the white one that I replaced when I had the transmission dropped and rebuilt as well. This gear was fine and I had no speedo bouncing - but I bought a new gear anyway and replaced it as a precaution.

    Many thanks again ..
    Regards,

    Mark M. .........
    1973 240z HLS30-124668 (9/72), "Deep Beryl Green-PGV"
    2010 370z JN1AZ4EH3AM503017 (3/10), "Black Cherry-NAG"

  11. #11
    AZ Z Fan duffman's Avatar
    Member ID
    CZCC-9965
    Join Date
    Nov 2005
    Location
    Scottsdale, AZ
    Age
    65
    Posts
    580

    Default

    Thought I would append my question on this thread. I have an R200 diff matched with a 3.9 5 speed from an 83 280zx installed in my 70 Z, along with the white pinion gear (white). I am running the standard 14" wheels with standard size tires. I am finding that my speedo is off by about 10% on the high side and was wondering if I should change to a different pinion gear to have more accuracy. Any thoughts?

    Thanks!
    January 1970 240Z
    HLS3001399

  12. #12
    Registered User ZCurves's Avatar
    Member ID
    CZCC-7312
    Join Date
    Nov 2004
    Location
    Spring, Texas USA
    Age
    56
    Posts
    1,052

    Default

    Quote Originally Posted by duffman View Post
    Thought I would append my question on this thread. I have an R200 diff matched with a 3.9 5 speed from an 83 280zx installed in my 70 Z, along with the white pinion gear (white). I am running the standard 14" wheels with standard size tires. I am finding that my speedo is off by about 10% on the high side and was wondering if I should change to a different pinion gear to have more accuracy. Any thoughts?

    Thanks!
    That's a lot of work for 10 percent improvement. I would leave it alone.
    Andrew (ZCurves)
    1978 Coupe - HLS30-440105
    Spring, Texas USA

    pro deo et patria
    My Albumz

  13. #13
    AZ Z Fan duffman's Avatar
    Member ID
    CZCC-9965
    Join Date
    Nov 2005
    Location
    Scottsdale, AZ
    Age
    65
    Posts
    580

    Default

    Yeah, Andrew, that is probably what I will have to do! Can't think of any other options, other than bigger tires.
    January 1970 240Z
    HLS3001399

  14. #14
    Former frequent poster sblake01's Avatar
    Member ID
    CZCC-3797
    Join Date
    Mar 2003
    Location
    San Bernardino, Ca. U.S.A.
    Age
    70
    Posts
    10,574

    Default

    Quote Originally Posted by poonamt93 View Post
    There is a cable of some sort connecting the speedometer back to the wheels. It could be the sensor or the cable or both. Since you started at the gauge, just keep working backwards until you solve the problem.Hope I helped!
    Actually, I had posted a response to this but changed it when I realized that the poster is a spammer originating from India.
    Last edited by sblake01; 03-08-2010 at 08:14 AM.
    2004 Ford Ranger EDGE Supercab
    (@Moonpup: This one really is an EDGE!)
    2005 Pontaic GTO
    2010 Mercedes Benz C300 AMG Sportline (Wife's car)
    2014 Kia Rio LX (Wife's daily driver)
    Certified HVAC/MVAC Technician

  15. #15
    AZ Z Fan duffman's Avatar
    Member ID
    CZCC-9965
    Join Date
    Nov 2005
    Location
    Scottsdale, AZ
    Age
    65
    Posts
    580

    Default

    I figured the same thing, Stephen, based upon the response ...
    January 1970 240Z
    HLS3001399

  16. #16
    Registered User 81 ZXT's Avatar
    Member ID
    CZCC-18629
    Join Date
    Jan 2009
    Location
    Oklahoma
    Age
    59
    Posts
    51

    Default

    Having read this thread and having a problem with my speedometer off about 10%, (speedo shows 10% too slow) is it possible that my cable could be in a bind, causing the 10% difference? I did have a problem with a bouncing gauge but fixed it by bending the cable (the short one that comes out of the gauge and screws in right inside the firewall) and lubricating with cable lube. This is in a 1981 Turbo and automatic, 15" wheels, 205/60 tires.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Speedometer question
    By GILDIA in forum Electrical (S30)
    Replies: 0
    Last Post: 06-11-2008, 09:34 PM
  2. Swapping Speedometer Cog
    By z_again in forum Open S30 Z Discussions
    Replies: 1
    Last Post: 03-20-2008, 03:05 PM
  3. need help with Speedometer
    By choua1855 in forum Help Me !!
    Replies: 6
    Last Post: 09-15-2006, 08:05 AM
  4. Speedometer problem
    By SteveInOakland in forum Help Me !!
    Replies: 7
    Last Post: 01-07-2006, 06:26 PM
  5. Newbie.. 810 question
    By GTO_AL in forum Open Discussions
    Replies: 2
    Last Post: 03-06-2005, 02:46 AM

Bookmarks

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •