Here is the calculator to end all calculators.

http://www.gtsparkplugs.com/SpeedoGearCalc.html

Interestingly, mine came from the factory with 31x10.50/4.56. PO changed to small tires (but no one knows if it was speedo re-geared) and now it reads 4 over with 31's.

It's pretty far down on my list, so I'm just letting it go.

 

Thanks! Does anyone know how many teeth are on the transmission side?

r151f

 

According to Toyodiy.com, your speedometer gear has 18 teeth.

 

It probably did from the factory... But doesn't anymore...

However, if I have 31" tires and 4.56 gears the factory gear should work right?

So an 18 tooth speedo gear should be right for 4.56 and 31" tires?

 

Might not be! My 86 has an 18 tooth gear and I'm running a 32.5 inch tire(235/75/16) with 4.88's and my speedometer is pretty well right on.

 

just pulled the speedo gear and its 6-18tooth.

what gives!how come it was reading about 7mph fast at 60mph with the stock tires/gears!!!!?!?!??!

 

When going 60mph, my speedo is reading 66-67...

The speedo gear I have is an 18 tooth. Gear reads 6 18

I'm guessing that the drive gear in the trans has been changed because with the factory tire/gear combo still has the speedo wrong.

I am now running 4.56 gears and 31" tires...


What speedo gear do I need to correct it?

Also does anyone know the speedo gear part #s?

Thanks

 

Cheap gps

 

Speedo gears are cheaper than any gps...and take less time to install lol

 

This is your third thread on this topic...just sayin.

 

Wow, I forgot about the one I started in April... I'm on a couple different forums... Mods feel free to delete that thread.

I started the one a few weeks ago to find out info about the gears.

This thread is specifically asking about the calculations to correct the problem...I have searched all over and cannot find out how to determine which gear I need based on the current error.

It is such a cheap easy fix I'm suprised there's not a Sticky on how to determine how to fix it or a database for tire/gear combos and whitch speedo gear is accurate for that combo.


Again, I'm not trying to Spam and start multiple threads... for 20$ I could have an accurate speedometer and better yet odometer...and I'm just trying to figure it out...

 

Great now I get to search for your duplicate thread.
As far as finding a gear calculator.. grim jeep gear calculator

My gps installed in about 32 second


Edit: mergeD All 3 of your similar threads together....

 

great thanks!


Yes I found grim jeeper gear calculator...its fantastic lol, best i'v seen. unfortunately it doesn't tell me how many teeth speedo gear I need...

Ive found some speedo gear calculators too but they all tell me I need 18 teeth..which is what I have... I think the speedo drive gear in the trans must have been changed at one point in the 310k miles.... because the math just doesn't add up.

I think to slow the speedo down you'd add more teeth...lol but how many for 10ish%

Toyota sells them for around 20-25$ ish and the install is about two minutes

 

How do you know for sure you have stock gears?
Did you install them or pull them to verify or just going off the VIN?

 

I know for sure I had the 4.10s when I got the truck because I swapped in a less noisy third in the rear to keep things quiet. they were both 4.10

And now I swapped out both front and rear for new 4.56 while installing a elocker.

The speedo was fairly accurate with the 4.10's and 31" tires...and it shouldn't be lol Now with the 4.56's I put in two weeks ago everything is out of whack again.

 

There's your problem!

 

As I've already stated, several times, that's not the problem because the speedo was inaccurate with the 4.10 gears and stock sized tires.

If you check any gear calculator you will realize that 4.10's and stock small tires (truck had from factory) are nearly identical in RPM as 4.56's and 31" tires(what's on the truck now).

Check it out.

 

Sounds like you have it all figured out then.

BTW, these trucks read a few MPH fast from the factory.

 

So, got it all fixed.

Using the help of an awesome parts guy at Lithia Toyota (Aaron) and some part numbers compiled in this thread (specifically the second page) http://forum.ih8mud.com/79-95-toyota...ar-change.html

I bought the 20 tooth gear 33482-39045 for around 20$. Came with o-ring and clip to hold it in the gear housing. Took about ten minutes to change.

20$
10 Minutes
correct speedo and no need to create clutter with a gps

And i kept the 18 tooth gear in case I want to go with 33's in the future :hillbilly:

 

Well I'd like to know where I can buy a different speedo gear too. I have spent a couple of hrs surfing here and elsewhere and mostly get ebay junk and baloney "bestprice" type responses. I've got a '91 Toyota motorhome with the V6 and a 5 speed. I'm sure the tires are stock size. My speedo is about 10% high and I'm suppose to have 4:10 gears. I'm pretty sure someone changed the differential and I don't mind the extra power but I'd like to know just some place I can get a speedo "driven" gear that is for a 4:56. Then I should be fine. Ya the dealers probably have one, but these days parts help seems to be pretty bad. I'd go in, explain the whole thing and end up getting a gear just like I have now because they'd screw it up.