W58 speedo drive issue - how the hell do i fix this!?

[LUXPWR]

Cant see the metal gear, its in the box still! Where is it stamped, on the side of the gear ?

[CrUZida]

Yeah, on the side of the gear.

btw, a 10/36 gear in a W58 is suited to a 4.555 diff.

[LUXPWR]

Thanks Cruzida i'll have a look inside on monday

[LUXPWR]

Ok so i got under the ute again and pulled the speedo drive out. After much stuffing about, peering through a little hole, and squinting i was able to make out the following:

worm gear - '33'

It was kind of etched into the side of the gear. Im guessing as my speedo drive has 10 36, my worm gear should also have a 36 on it? Is that right? I couldnt see a 10 on there though? It was bloody hard even finding that 33 mind you.

Also, regarding the diff ratio im not quite sure how to tell what mine is. So i jacked up the back right wheel and turned the tailshaft. I found that 4.5 full revolutions of the tailshaft give me 2 revolutions of the back wheel. Now as the left one wasnt moving, does that mean the right one does twice the revs? If so, i guess it means its a 4.5 diff. Can someone confirm?

So sounds like the gears have been mismatched, which has caused excess tension on the spring that holds the worm gear in place, stretching it and making it pop out. What do you blokes reckon the best thing to do would be?

[CrUZida]

The other number on there is just as important, if not more important. It HAS to match the speedo drive gear.

Best thing to do is to work out if that diff is the ratio you want to run.
If it is, pull the back of the box off and chnge the metal gear for the right one.
If not, get the diff ratio you want, and then source the speedo gears for that diff, then pull the box apart.

OR

Find out exactly what the metal gear has written on it (33x10 or 33x9) and then get a speedo gear to match, and then buy a calibration box to bring it back to where it should be.

[LUXPWR]

Thanks Cruzida, I'll take another peep inside and see if i can spot the other number.

I have a feeling that I'll need to replace the spring clip on the worm gear anyway as its lost its springyness and pops out very easily.

I think I'll stay with the diff ratio i have, it seems fine, has decent acceleration and fuel economy is good.

Can yosomeone confirm if my little test with spinning the tail shaft and counting rear wheel revolutions works for figuring out diff ratio?

Really appreciate the help everyone. Cheers!

[CrUZida]

Your little test is right.
However, I've never personally experienced the '2 revolutions of the wheel' thing, even though I've seen others post it.

Every time I've tested it, I've rotated the tailshaft X times and only had the wheel turn once.

[LUXPWR]

Ok got under the car again tonight did all the fun things again. Managed to read the whole number on the worm gear.

11 x 31-33

Damn! So as you said Cruzida this first number def is not matching up! So my options are:

Put in speedo drive that matches. However as the spring is a bit loose it may come unstuck anyway. This would be easiest though. I had a bit of a read about installing a speedo corrector and it doesnt sound tooooo bad lol (though i have never played with electronics)

Pull box out, swap worm gear over. Then put it all back in and hope everthing works. Anyone know where i can get a suitable worm gear???

[CrUZida]

Buy a new worm gear and clip from Toyota.
Shouldn't be too much.

You can get mechanical speedo correctors, but if you have an electronic sender, its easier to use an electronic one.

[LUXPWR]

I have an electronic sender. It looks like the guys who built the car just pulled the drive out of the hilux speedo and jammed it in!

What worm gear do i need to get, one that says 10 x 35-37 or something ( just guessed the last two numbers, as 36 is between them lol no real logic)????

Am I best going to a local toyota dealer, or is there a direct spare parts line or something i can call?

Rep + Cruzida!

[CrUZida]

If you don't have a part number, then yes, local dealer is the best option.

If you work out the part number, Amayama is the best bet.

[takai]

Use ToyoDIY to find the teeth on the gears. Its listed as part of the part number listing.

Edit: like here:

[LUXPWR]

Hey Takai, how did you get get the part description with the N=33, mark 33:9 etc??? When ever I look at the same thing i dont see as many options?

[CrUZida]

Not all cars have those numbers shown unfortunately.

Also pity thats not the one we need, we need the SPEEDOMETER DRIVE gear, a 33481 part number.
Its under the "TRANSMISSION GEAR (MTM)" section.

[LUXPWR]

Yeah Cruzida, i looked through all the manual gearbox supras i could find with a 1ggte and a w58. I checked both the speedometer drive gear and the gear assembily, and whenever i looked at it i didnt get anything that mentioned the markings on the gear. Having a look on wikipedia it says that the supra had a 4.3 final drive anyway, so it may be necessary for me to get a matching gear set then use a speedo healer or something?