Speedometer correction by T-case gear change (1 Viewer)

[2ndGenToyotaFan]

No problem, thanks for the work "Man"!

 

[TheMAN]

if you or anyone else can help me improve the list, it is much appreciated.... I don't know all of the model codes for the runner/mini-trucks, so all I was able to list was just the model codes

it'll be easier to find exactly what you need once you know what kind of truck you're looking for at the junk yard rather than cryptic model codes

for those who haven't figured it out yet, you can swap to a different speedo gear as long as your speedo DRIVE gear has the same teeth count... so for example, if you have a 20 tooth driven gear and a 6 tooth drive gear, the driven gear should say something like "6x20". You can then swap to something else that has a compatible gear cut such as a "6x17" (17 tooth) gear.

You CANNOT swap to a driven gear meant for a different drive gear count (6x20 to 5x17 for example). It will not go in. Even if you manage to get it into the tranny, it will break eventually. Don't do this! The only possible way you can do this is if you removed the extension housing/transfer case and swap the speedometer drive gear.... that's a lot more work and you're probably better off with those expensive correction boxes instead

I used this handy speedometer gear calculator to determine which gear I needed:
TCI - TECHNICAL INFORMATION: Speedometer Gears
If you have passenger size tires and not the bigger truck tires, it might be a little difficult to determine your tire diameter (which is what it will ask you). This was the case for me, so I used the famous Miata tire calculator to get that info:
Tire size calculator

 

[TheMAN]

It appears the automatic and manual 4WD speedometer gears are interchangeable based on the fact that the same gears are used between them as shown in the list below... I have added the "non-native" but (likely) compatible gears in the lists below for easier reference. I am fairly certain that you can only interchange between the same speedometer types, which means you can't put a gear meant for the electric speedometer to a cable one or vice-versa. This only applies to 4WD and not RWD.

again, I am not responsible for inaccuracies


Automatic 4WD speedometer driven gears for cable speedometer:

[B]33482-39135[/B]           18 tooth, 18x6 mark         VZN105/VZN110/VZN13*
[B]33482-39025[/B]           19 tooth, 19x6 mark         TCR1* (MTM)
[B]33482-39045[/B]           20 tooth, 20x6 mark         RN106/RN110/RN13*

[B]33403-29125[/B]           32 tooth, 32x10 mark        RN10*/RN110/RN13*

[B]33403-39345[/B]           31 tooth, 31x11 mark        RN131
[B]33403-19255[/B]           32 tooth, 32x11 mark        RN10*/RN110/RN13* (MTM)
[B]33403-29115[/B]           33 tooth, 33x11 mark        VZN10*/VZN110/VZN13* (MTM)

Automatic 4WD speedometer driven gears for electric speedometer:

[B]33403-39295[/B]           18 tooth, 18x6 mark         TCR11
[B]33403-39305[/B]           19 tooth, 19x6 mark         TCR1* (MTM)
[B]33403-39315[/B]           20 tooth, 20x6 mark         VZN110/VZN13*

[B]33403-29315[/B]           32 tooth, 32x10 mark        RN101/RN110/RN13*

Manual 4WD speedometer driven gears for cable speedometer:

[B]33482-39135[/B]           18 tooth, 18x6 mark         RN10*/RN110/RN13*
[B]33482-39025[/B]           19 tooth, 19x6 mark         TCR1*
[B]33482-39045[/B]           20 tooth, 20x6 mark         RN106/RN110/RN13* (ATM)

[B]33403-39345[/B]           31 tooth, 31x11 mark        RN131 (ATM)
[B]33403-19255[/B]           32 tooth, 32x11 mark        RN10*/RN110/RN13*
[B]33403-29115[/B]           33 tooth, 33x11 mark        VZN10*/VZN110/VZN13*

Manual 4WD speedometer driven gears for electric speedometer:

[B]33403-39295[/B]           18 tooth, 18x6 mark         RN10*/RN110/RN130/TCR1*
[B]33403-39305[/B]           19 tooth, 19x6 mark         TCR10
[B]33403-39315[/B]           20 tooth, 20x6 mark         VZN110/VZN13* (ATM)

[B]33403-39425[/B]           32 tooth, 32x11 mark        RN10*/RN110/RN13*
[B]33403-39415[/B]           33 tooth, 33x11 mark        VZN10*/VZN110/VZN13*

 

[shortbus12]

Just installed a lefty Am 10 MPH off at 50 reads 60 and gets worse as in increase speed. Thanks for this thread Just what I was looking for!!!

 

[Santabarbaran]

I just regeared from 4.30 to 4.10, so obviously my speedometer is 2mph off. What I do know is, I have a 20 teeth speedometer gear and I will need a 19 teeth one to match my axle ratio and tires. I looked through the parts catalog and see that the VZN85 uses a 19 teeth speedo gear. Does this fit on all the other runners (that has an automatic) of the same era regardless of engine? I thought about using a 18 teeth also, but that'll make the speedo slightly fast. I don't want that! Anyhow, if the speedo gears in the 90-95 mini truck/runners mix and match, does anyone know where I can find these cheap (other than junk yard or dealer)? I would love to have an accurate speedometer again

Hello, I am in the same boat you were in, need to replace the pinion gear in my 1992 Previa with a 4.10 also since there is no aftermarket 4.30 available. So how does your van perform now you have the 4.10 versus the 4.30 you had before? Of course the speedo will be off as per this whole discussion, but how did your Van perform? Was it real sluggish off the line, did it cruise much better at 70 miles per hour, and did your MPG improve noticeably? Thanks for your feedback, still considering a 4.56 but I think it will be to much the other way...... thanks again!!

 

[Michael1929]

I really appreciate the amount of time you put in on this as I'm trying to get the speedometer on my 84 toyota Xtra cab truck corrected.