Which Speedo Cable When Going 4kc (ke70) To 4age?

[adam-__-]

Hey guys,

 

I've got a KE70 which originally came with a manual transmission (K50) 4K-C and recently did a 4AGE conversion. I've pretty much finished the conversion, but still having problems with my speedometer. I used the standard speedo cable with the T50 box and it fits in fine, but the speedo reading is about 10kmh off. It reads ~67kmh when really I'm going 60km or ~90 when I'm going 80kmh.

 

My speedo was originally off about 5kmh with the K50. I've changed from a clock cluster to a tacho one and no change.

 

I was just wondering what speedo cable you guys have used when doing the 4AGE swap? Can I do anything to correct the error in the speedo or is it best/easiest to pick up a AE71 speedo cable?

 

 

Cheers,

Adam

[Des]

Changing the speedo cable wont rectify the problem, Has anyone changed the diff ratio ?

[adam-__-]

Not that I know of. :bash:

 

The car was dead standard when I bought it so I don't think anyone has touched it since coming out of the factory.

[irokin]

Is your diff a banjo or a borg warner? Its possible you've got a 3.9 diff if its a banjo giving you the incorrect readings with a T50 speedo drive that presumably came with a 4.11 diff.

[adam-__-]

I've got a borg warner as far as I know.

 

Is there any way of fixing this up? When I still had the 4k in the car, I would just drive ~5kmh over what it says it is, but I want to get this fixed up because the kilometer reading my car's giving is getting more wrong with every drive.

 

I really drive 100km, but my counter tells me I've driven 120km for example. I don't want my car to look like it's been driven more than it has. :bash:

[parrot]

The reason is that the speedo drive in the gearbox needs to be the correct ratio for your speedo.

 

If you unscrew the speedo cable from the gearbox, and undo the 10ml bolt holding the little plate, you can pull out the speedo drive. This is a rod with a plastic gear on the end. For a 4AGE T50, from memory there are 19, 21 and 22 tooth gears. Inside the box is the gear this meshes with, either a 5 or 6 tooth. You need to mix and match to suit your application.

 

Jonny Rochester wrote up a thread on this on ae86drivingclub, including how to calculate what combination you need.

 

Then you need to locate the gear you need. Also from memory, the K gearbox has a larger diameter plastic gear so you can't just pop that in instead.

 

Search for the thread on ae86dc or PM Jonny for the link.

Edited July 27, 2008 by parrot

[adam-__-]

Cheers for that mate. I'll see what I can find and take a look at it tomorrow.

 

I don't understand why with the standard engine and box, the speedo was off 5kmh. Would've thought there was something you can 'tune'. Anyway I'll take a look for that thread and see what I can find.

 

Thanks

 

 

Edit: For anyone needing this information, here's the link parrot is referring to,

http://www.ae86drivingclub.com.au/board/in...l=speedo++cable

Edited July 27, 2008 by adam-__-

[adam-__-]

I don't understand. :S

 

I've got the standard diff (as far as I know) and they've got a 3.9 diff, I want to run a 185/55/15 tyre which is 0.585m in diameter. Using Jonny's formula, it tells me I need a speedo gear ratio of 20:6. Also from that thread, Jonny says that boxes which is originally run behind a 4AC has 20:6 standard. Then why does my speedo read incorrectly?

 

I'm confused. :D I think I'll need to pull out the gears from my box and make sure it really is a box with the 20:6 speedo gears.

[turbo_rolla]

I had the same problem as you when i did my conversion, and my speedo is about 25-30% out from what i've compared it to (i've got JDM 4age, JDM t-50, t18 diff). I was going to do all the stuff to fix it up, but rang around and decided that I'm just gonna get my speedo gauge recalibrated as i can't be stuffed having to do new drives etc - costing about $180 from memory. I'd rather pay the extra $100 or so to have someone else do it and not have to worry about looking inside gearboxes etc :S

[adam-__-]

I'm tempted to just pay someone else to do that as well at the moment, because I don't know shit about what's going on inside the gearbox. I'm willing to learn so I will take a look and if it's too complicated, I might just get someone to recalibrate my speedo.

Edited July 27, 2008 by adam-__-

[adam-__-]

I don't understand. :S

 

I've got the standard diff (as far as I know) and they've got a 3.9 diff, I want to run a 185/55/15 tyre which is 0.585m in diameter. Using Jonny's formula, it tells me I need a speedo gear ratio of 20:6. Also from that thread, Jonny says that boxes which is originally run behind a 4AC has 20:6 standard. Then why does my speedo read incorrectly?

 

I'm confused. :D I think I'll need to pull out the gears from my box and make sure it really is a box with the 20:6 speedo gears.

 

Okay, I think I know why this is happening.

 

My speedo was originally out by roughly 5kmh, I was running 175/70/13 tyres, I moved up to 185/55/15 tyres and the speedo was better. I've now gone from the standard motor to a 4AGE which is using a ADM T50. The speedo is now out by 5 - 10kmh again (same as with standard tyres).

 

If my speedo was correct in the first place, all I needed to do to correct the current speedo with the T50 is to run these 185/55/15's.

 

I still don't understand why my speedo was off 5kmh at 60kmh in the first place. Oh well, I'll use this calculator again and see what speedo gear I'll need using standard tyre diameter, but then run these tyres (the 185/55/15's) to correct the 5kmh error it had originally.