Speedo Correction (1 Viewer)

['69 Yota]

Since we are on the subject. How hard is it to change the drive gear? I can't get my speedo to work and I changed the driven (plastic one with a plate holding it in?) and it still won't spin the end of the cable up at the speedo (I put it up on stands and unhooked it at the speedo and turned it over). With someone on both ends of the cable, it seems to be solid, but turns easily. I do the gps, but it eats the batteries and like someone said above, it tends to want to fall off the dash.

 

['69 Yota]

'course I don't know why it matters. It sounds like it's gonna fall apart at 55.

 

[dgangle]

'course I don't know why it matters. It sounds like it's gonna fall apart at 55.

LOL, True!

....Instead of replacing gears that are no longer available, why don't you just paint a new set of numbers on the dial. A little white out and a sharpie should do

To me it's due to the fact that I like things to work, and work as they should. I liken it to the certain coolness to having your go-faster aftermarket gauges work AND your OE's too. How does one put a price on cool? I guess this all may sound trivial to some. If you're going after hack, why not just break the glass out of the speedo, bend the needle so it indicates the correct speed and call it good?

 

[Klunky Chris]

I agree with dgangle. I have very nice mechanical autometer temp gauge, but my factory still works as well. It's cool to see the difference

reality is, for those of us that have hot rodded their 1.5 F and have 35" tires..... 80mph is definitely possible on the interstate! and no... it doesn't sound like it's going to fall apart. (although the 3 sp whine gets pretty bad at that speed )

a cruise of 70-75 is very comfortable and therefore, nice to know HOW fast you are really going...... especially in a 55 mph zone

 

[dburnum]

I've contemplated taking an old instrument cluster. Blanking the speedo widow with metal and installing my Garmin GPS 3 flush with the face of the cluster. It accepts 12V DC in the back of it, is backlit, and has a serial output, that if you used a little ingenuity could be cabled down to the back of the dash on the passenger side, as a plug-in to connect to a laptop or such for mapping or whatever. I've also thought about doing the same thing, but using the ashtray (since I don't use it anyway), instead. Problem might be, I'd end up reaching through the steering wheel to press buttons on it. Also, it might be a bit distracting. Though...not as bad as holding it.

 

[IDave]

Since we are on the subject. How hard is it to change the drive gear? I can't get my speedo to work and I changed the driven (plastic one with a plate holding it in?) and it still won't spin the end of the cable up at the speedo (I put it up on stands and unhooked it at the speedo and turned it over). With someone on both ends of the cable, it seems to be solid, but turns easily.

1) remove rear driveshaft and partially drain transfer case oil
2) remove stake (or cotter pinned) hex nut from parking brake
3) remove parking brake drum
4) remove parking brake assembly (4 bolts) and speedo driven gear from speedo housing
5) remove speedo housing: DON'T Lose the shims!
6) you now can slide drive gear off of rear transfer drive shaft and inspect it. I would make sure the spacer is toward the front and the drive gear is toward the vehicle back.
7) replace your old speedo housing with a mudrak dual seal speedo housing (you'll be glad you did: http://www.mudrak.com/products.html) and send your old housing to gary as a core.
8) put everything back together making sure that the preload is correct.

 

[cxh10]

I'm going to have to agree with the others. I'd prefer not to have a ghetto rigged cruiser with painted numbers...and I'm trying to keep mine as stock as possible so I'll definitely be keeping the original gauges. I'd probably go back to stock tires before I ripped out the old gauges. If the gears are in fact unavailable and I can't locate some other kind of speedo correction device then I guess mounting a gps somewhere else in the car is a plausible idea and would give me a great excuse to buy a gps device lol but I'd definitely like the original to work accurately if possible.

 

[Klunky Chris]

I'm supprised this hasen't been mentioned sine I've seen it in a few of these threads before (maybe that's why...)

Supposedly a good Spedo shop can rig you a gear box to go between your transfer and cable to correct this. I haven't checked this out yet myself but it was the route I was going to try

 

['69 Yota]

Thanks IDave. I appreciate it. Is there anyway to check that the drive gear is ok without pulling it?

 

[IDave]

The only way I would be able to tell is if the driven gear is working and the cable is spinning at the speedometer head end. Of course, you have to make sure the speedometer cable engages the driven gear and if you have it out of the speedometer, the driven gear end can pull out of the drive gear slot.

 

[IDave]

Bringing this to the top to bring some real life info into the picture (also, I know this is now being discussed on the Land Cruiser Mailing List, where apparently they've concluded it can't be done!)

I purchased a 33403-60030 (16 tooth) driven gear (from CDan) and matched it with a 33481-60030 6x17 drive gear (which is what came in my transfer case). I stuck it in my FJ40 and for the first time, today I had a chance to test it out. I have standard differential and BFG 33x9.5 mudder tires.

With that combination using GPS (7 satellites, good exposure) the speedometer was dead on throughout the range of 0 - 65 mph (which is the max I drove on the fresh rebuild of Ed's old F engine).

 

[Klunky Chris]

cool!

now..... what do I do about my 35's

 

[IDave]

I guess I'd get as close as possible. Besides, your "35s" may actually be 33.5s, depending on the manufacturer, model and wear. Anyway, it is easier to guestimate if you start out in the ballpark!

 

[Klunky Chris]

aggreed. closer is better!

 

[CruisinMT]

how do i get my speedometer to quit spinning circles, It's driving my nuts.

 

[IDave]

how do i get my speedometer to quit spinning circles, It's driving my nuts.

Take it off the unicycle?


















(sorry couldn't resist)

 

[pbgbottle]

FYI ,the plastic gear counts are 15,16,17,18 , no 19 15 in a 79-80 fj45

more info just to clarify what was posted earlier ,looks like there is new part #'s for the plastic gear if i am reading it right

pics show you what transfer gear will mesh with what teeth count ,other pic should be new #'s for plastic gear i think

 

[TLC Norway]

Good tech... I'm looking for this info on a 81 and 87 split case.
Have the teeth out now, 15 on the 81' case from a 6x series with 3.7 diff and 35's. That is within the ballpark, pretty close.
Now, I have a 17 teeth gear from a 87 case, with mating drive gear.
15 and 17 is different in OD, so drive gear must mate.

I guess the speedo will be off (higher) with 17 teeth, as with the 15 I am off on the low side. 16 teeth would be perfect for 35s on 3.7 diff.

I'm planning on swapping in 4.11 diff ratio, I think that means I sound opt for the 17 teeth gear, right?

 

[cuencanolenny]

What confuses me is why there isn't a "standard" for the stock vehicle. I will have to dig through some receipts to find out what speedo gear I bought a couple of years ago for my '70 FJ40 which has 4:11/1 gears. My "new" '79 has 3:70/1 gears, but the speedo gear was leaking so the mechanic switched out the newer one from my '70. I am indicating faster than actually going. But Toyota just lists numbers for the gears available rather than listing what a standard unit would be.

 

[Vossie]

Okay...Okay....you guys are spending way too much time on this issue

Instead of replacing gears that are no longer available, why don't you just paint a new set of numbers on the dial. A little white out and a sharpie should do

my solution was to use one of those cell phone holders with the suction cup, and i stuck it straight to the glass on my gauge cluster