How to get speedo to read right after diff swap?

[Ryan_V]

Here's what I got.

I swapped the Supra 3.76 into my sc300.

I also swapped the Soarer R154 trans in.

Now my speedo is about 10mph slower than it should be.

Question is-

Do you think I could just buy the MKIII turbo R154 speedo gear and swap that into my R154?

Technically at that point...I'll have the R154 and 3.76 rear like the MKIII right?

 

[KingCobra]

I don't think that's going to work...

Your SC300 uses an electronic speed sensor in the tranny, vs the MK3 which uses a speedo cable that drives a speed sensor in the dashboard...

I'm going to go out on a limb here and say, I think the configuration you need is the speed sensor out of a MKIV TT Auto tranny... (it's the only one I'm aware of off the top of my head with that gear ratio that isn't cable driven here in the US that matches your your diff at 3.77).

According to the Toyota EPC, the part number should be 83181-24040 ...

g/l with that, Toyota wants just a hair over $270 list for that part, maybe you can get lucky and find it used... (I'm guessing, no guarantee I am right but i'm 90% sure that's what you need). You've kind of done a unique parts swap here so, I'm taking an educated guess based on the information you've provided.

 

[dubsupra209]

just dont worry about it untill you sell it....:biglaugh:

 

[Jeff Lange]

The speed sensor has nothing to do with the speedometer gearing. The speedometer driven gear fits into the speed sensor, and can be changed. In fact, if you order the speed sensor, you will not get a gear and you'll be in a worse position, lol.

What size tires do you have on that Soarer? I can figure out what your speedo gearing should be and I can give you the part numbers to order.

Jeff