speedo troubleshooting.

[dave_hl]

hi lads.

just thought id get a few suggestions as to what to do about my broken speedo.

I thought originaly it may have been the cable but i pulled it out and its not snapped or kinked or anything. So im assuming its either broken down the gearbox/drive train end or in the actual dash.

Also where it goes into the gearbox it has a little connection which i am able to easily and freely spin with my finger. This made me think the problem is quite likely down that end because at an educated guess the only way that could spin is if the drive train was spinning with it. am i correct?

Im guessing it would be a pain to replace the little plastic cog i think it is in under there. i remember reading about them on one of the zed forums a while ago.

any help would be appreciated.

thanks!

[gav240z]

Hi Dave, I know on my 240z about a year ago I managed to snap mine after a day of hard work down at Calder Park. It may be broken in the middle somewhere and not immediately obvious.

 

If the cable spins at both ends then I guess it's fine and you may be correct in that it could be the dash or the gearbox end.

 

I'm a bit unfamiliar with the 280zx dash configuration so I don't know what to suggest in that area. I'd be suprised if the plastic cog in the gearbox has broken, but I guess like anything it's possible.

 

Try troubleshooting the cable again and get back to us.

 

Cheers,

[dave_hl]

well im pretty sure its not the cable. i pulled it completely out and its fine. what dad suggested doing is connecting the gearbox end to a variable speed drill and seeing if it registers on the dash, this would then eliminate the possiblilty of the problem being up there. i'd rather not have to pull off the instrument panel if i dont have to, i can just see it not going back the way its supposed to. Well yeah its probably not that gearbox end then. its not actually the stock speedo in the dash, its a 250km/h one that was put in by scuderia motorsport back in '88 when all the other work was done. so i dunno if that says something.

It actaully stopped working while the guys at EFI hardware were tuning it... must have been thrashing it a bit :? but i guess you kinda have to to tune it right.

ill have another play tomorrow... ive got the day off uni... im also trying to sort out a kawasaki KV100 dirt bike i just bought :lol: the geabx is a bit funny but shouldn't be too bad i dont think.

cheers.

[dave_hl]

im trying to pull the main console above the steering wheel out so i can disconnect the speedo and see whats gone wrong... but i cant pull it out any further because the speedo cable is holding it back, but i need to pull out the console to disconnect the speedo cable, but it cant be pulled out wihtout disconnecting the speedo cable. its like some sort of confusing loop of death.

I'm following some directions from the haynes manual but they're not detailed enough for my intelect. anyone ever taken the console above steering wheel out? (as in the speedo/tacho/and all that) Kinda unlikely as most of the guys here have 240s and 260's with probably diff dashes as gav said, but any 280zx owners... help please...

its really shyting me up the wall... i just want the car to all work at once so i can freakin get a RWC.

sankyou...

[pauly_adams]

hey dave i had the exact same prob using the same book if u find out can u pm me plz thanks

pauly

[twosixty]

hmm, I've removed the console and speedo etc from a 280zx wreck. But that was a while ago and I remember I was there for friggin ages. I prolly wasnt being very gentle with it either.

 

I dug out my old service manual for the zx and it reckons that...

1. remove steering wheel & column cover

2. Remove instrument lower cover on left side.

3. Disconnect speedo cable at intermediate connection.

4. Disconnect combo switch to get the rest of the console out

 

Soz, I dont have a scanner to show you the diagram.

 

Good luck

Luke

[dave_hl]

yeah ive got both the haynes and some other manual.

Anyway the problem is not in the dash. i managed to get my hand behind there to unplug the speedo and then spin it with my fingers, got it up to like 45km/h and the trip meter registered.

so i pluged it back in, and went down to the geabox end and reconected it there, then back up the driverway (had no steering wheel so couldn't actually drive anywhere) and then fast back down but didn't regsitered anything.

I then connected a hand drill to the gearbox end to see if it was gonan work upstairs in the dash but failed to push the cable into the speedo line, hold it up high enough so it would actually stay in at the other end and also turn the hand drill all with 1 hand. (i dont have the car on jack stands atm).

so im thinking the problem must be in the gearboxy end. Has anyone replaced/fited/fixed it down there. whats invovled? is it just a little part i can pull off and fix or does the whole gearbox need to come out.

thanks lads.

[warrenz]

If the gearbox is the same as the 240 then you can just screw out the adaptor and see if the gears are stripped on it.

 

I would suggest you drain the oil out of the gearbox before you take out the speedo cable adaptor.

 

Warren

[dave_hl]

ok well now that ive had time to have a bit more of a play ive taken out the speedo adapter thing in behind the gearbox and its been fairly shredded, its missing about 4 teeth and about another 6 or so have snapped and are about to fall off. so i figured that was the problem. but then i stuck my finger in the hole and had a feel round to see what it connects to (ie another gear) but failed to understand how it works.

theres a thin round cog type gear running parallel with the drive train that freely spun but it was just a ring with 2 bits coming off it right next to each, it didnt feel like it had more which had snapped off though. further back towards the rear of the car in the hole was a metal sleeve of some sort whcih also freely spunand could move along paralel to the drive train to some extent.

It all seems a bit odd and like its all fallen apart in there or something. does anyone know how it all works or can link me to a diagram/old post they know of.

oh and pauly, i cant remember if i PM'd you or not, (dont think i did), but to get the main speedo/tacho part of the dash off i just kept pulling and eezing... and found it a bit easier by give the speedo cable some slack at the other end. to get the whole thing off you have to take off the windscreen wiper controls i think, but i didn't go to that extent; just enough to get my arm in behind it.

sorry for the long post.

cheers.

[road rider]

Dave, as long as its just the plastic gears on the drive thats sheared, hopefully nothing else should be damaged. The spindle on the drive wasn't broken, so there should be nothing metal thats fallen into g/box internally to really damage anything. You didn't actually mention if the box was noisy or not.

 

You should get another drive(same colour as the shredded one) and see if that fixes it. Be sure to drain your old g/box oil, and then flush with some fresh oil(leave drain plug off g/box and put at least a litre of oil thru box to flush out any debri. You could use elcheapo no name brand engine oil for this too!)

 

Top up box with fresh gear oil, go for a drive and see if it works

 

Good luck!

[dave_hl]

ok well ill try that. where can i get a new drive/cog? is it something i would need to source from a zed shop or could i source it from any mechanic place so long as it has the same amount of teeth, and size and all that.

 

And just another thing i noticed now i have the car on jack stands. Didn't want to bother starting a new thread, but how freely are the front wheels supposed to spin? because it takes a fair bit of force to get them to move. to give an idea if i tried spinning them as hard as i could with my hand they would do maybe 2-3 revs before stopping from friction. seems like more friction then there should be and as though the brake pads or something are too tightl. any ideas?

thanks.,