Posted August 5, 200618 yr comment_177284 anyone have any different speedo gears for a 5 spd, somewhere between 77 and 83. Have white installed, boy just got poped for 63 in a 45 SAID he was doing 45 by the speedo who knows. But anyway got a bid on a blue and another white on ebay but trying to round up others so I can get this thing close to accurate!Setup is a 74 240 with a 77 L28, think a 77 spd but could be a 83, and I believe a stock rear end!Please leave me an IM or email to DWALK3@bellsouth.net!Thanks Link to comment https://www.classiczcars.com/forums/topic/21074-speedo-gears-needed/ Share on other sites More sharing options...
August 9, 200618 yr comment_177696 The speedo needs a "black" speedo pinion gear, known at your nissan dealer as a 17 tooth. If you try to order a black one they will just stare at you. The differential is what controlls the acuracy of your speedo so it doesn't matter what trans or engine or speedo you have in the car. I think the stock differential is a 3:54 which needs a black 17 tooth gear, the blue is for a 3:70 18 tooth, and the white is for a 3:90, a 19 tooth. If you had a white gear in there that means that your trans was from a 81-83 280zx NON turbo that had a 3:90 rear differential. I hope this helps good luck! Link to comment https://www.classiczcars.com/forums/topic/21074-speedo-gears-needed/#findComment-177696 Share on other sites More sharing options...
August 9, 200618 yr comment_177699 http://www.geocities.com/zgarage2001/z.htmlClick "performance tips" and scroll about halfway down. All the speedo gears and ratios are laid out for you. Good reference to bookmark. Link to comment https://www.classiczcars.com/forums/topic/21074-speedo-gears-needed/#findComment-177699 Share on other sites More sharing options...
August 9, 200618 yr Author comment_177713 Thank you very much guys! Link to comment https://www.classiczcars.com/forums/topic/21074-speedo-gears-needed/#findComment-177713 Share on other sites More sharing options...
August 9, 200618 yr comment_177723 63 and reading 45 is very far off. There must be more wrong than the gear cog. Mabey the speedo itself has some problems too. I would go out and test it next to a car with an accurate speedo, find out if the reading is that far off, then you might be able to say it is just the cog or if you need to look farther. My car has a 3.9 rear and very small tires with a 3.7 cog and read 55 at 45 mph. Link to comment https://www.classiczcars.com/forums/topic/21074-speedo-gears-needed/#findComment-177723 Share on other sites More sharing options...
August 9, 200618 yr comment_177770 a 3:90 cog in a 3:54 rear end WILLl through off the speedo that much. I had a 390 in m 354 and it made it seem like i was going almost 90 on the freeway I was probably really only going 67 mph or so cause cars were passing me like crazy that's how I new something was wrong.Does anyone know if they will ever do an "Overhaul'n" T.V. show on a Z? I submitted a request to have one done but that doesn't mean $hit. Just wondering. Link to comment https://www.classiczcars.com/forums/topic/21074-speedo-gears-needed/#findComment-177770 Share on other sites More sharing options...
August 10, 200618 yr comment_177908 Personally, I don't think they will do an Overhaulin' show with a Z. First, how could Foose make such a perfect car look better?Second, they only seem to choose muscle cars. I saw one episode where they had a Civic, and everyone moaned about it (dam Japanese car sort of stuff, not so much anti ricer).About the Speedo issue (the real issue in this thread)-wouldn't your local Nissan shop have the correct diagnostic abilities/equipment to check your gauge/accuracy?I asked the local Sherriff to gun me after I got my ZX, just to check. He said no (for liability issues) but did suggest the Dealer, FWIW. Link to comment https://www.classiczcars.com/forums/topic/21074-speedo-gears-needed/#findComment-177908 Share on other sites More sharing options...
August 10, 200618 yr Author comment_177925 Guess they could do it, but hey aint that why we have them to work on ourselves, and hell you seen their labor rate lately! Link to comment https://www.classiczcars.com/forums/topic/21074-speedo-gears-needed/#findComment-177925 Share on other sites More sharing options...
August 10, 200618 yr comment_177977 I have speedo issues as well. I've got the 82-83 5 spd, 4.10 gears and 235-40x17 rear tires/wheels. Knowing that the tranny has the cog for 3.90 diff and the relatively small diameter tires with 4.10 gears certainly provides an incorrect readout on the speedo....I've just gotten used to the fact that its off by some 20% to 30% and drive accordingly. Its an easy fix to swap to a cog for 4.10 gearing but with my tire size it will still be off to some degree, plus Its just not on my priority #1 list. I think I've read that the 4.10 cog may require changing out the assembly the cog is mounted to as well, due to more offset but I'm not certain. Anyone have a varification on this? Link to comment https://www.classiczcars.com/forums/topic/21074-speedo-gears-needed/#findComment-177977 Share on other sites More sharing options...
Create an account or sign in to comment