Hello, everyone,

Now that I've finished my 1997 Dodge Dakota SLT, the German TÜV doesn't want to give me a sticker.
Why?
I did the following:

Rear diff is now 3.21 and the tires with rims are 265/75 R16. So my speedometer with the 42RE gearbox is no longer accurate. Of course, that shouldn't be the case in Germany.

Now you can replace the speedometer in the gearbox, but how do you calculate that. Unfortunately, I didn't understand what GOOGLE said, so my question to you can you help me calculate it correctly?

Many thanks in advance
Peter

 

It's not "in the gearbox." It's a programming issue as the speedometer is electronic. The speedometer gets its signal via a pickup at the rear wheel speed sensor. The CAB processes that and then it goes to the PCM and then the cluster.
The Controller, Anti-Loc Brake is programmed for rear axle type and revolutions per mile.

You'll need someone with a DRB to do that.

 

I *think* on the 97, the VSS is in the tailshaft of the trans or t-case, depending on number of drive wheels, and is a gear driven tone generator, so, he *should* be able to change that gear, and be golden. Here is a calculator to get the right gear.

 

I calculated the following:
old configuration was 3.55 with 235/75 R15
new configuration is 3.21 with 265/75 R16

I would now use the following to get the display correct again:
A500 Transmission 40 Tooth Short Shaft Speedometer

Did I calculate it properly?

Greetings Peter

 

With all the changes in the "2nd Gen" I wouldn't be surprised.

 

I think HeyYou is correct here.

On 00+ it reads a 108 tooth ring on the rear carrier for speedometer and anti-lock brake

I believe on 99- the CAB reads the 108 tooth tone ring for ABS, but uses the output shaft of the transmission for speedometer.

 

Hi

I have a big problem here with my speedometer translation. The gearbox is a 42RE and the tacho ratio was previously 34 teeth. The original rear axle with the translation of 3.55 and the original 15" tires ran well and accurately.

Now I have done the following.

1. Rear axle has the 3.21 ratio
2. Tires 255/70 R16 and rims 16"

What speedometer ratio do I need now, since I have a speed of 62 miles with 40 teeth and a speedometer reading of 40 miles.

Who can give me a tip as to which speedometer translation I need now

 

What size were the original tires?

 

the original tires:235/70 R15

 

Have a look here. Have to check the drive gear, but, fairly straightfoward.