Speed sensor change with 4.08

[AZhitman]

I've been meaning to post this for a while...

Some time ago, someone posted on the process of replacing the gear in the speed sensor with a different (larger) unit... Nissan part...

However, i tried this. It's a simple matter of physics that the larger gear will not occupy the same space left by the OEM smaller gear.

What gives? Am I stuck with an "outta whack" speedometer?

[rsiwicki]

you have to turn and twist the new speed sensor into the transmission.....yes it is bigger and a very tight fit as I watch them do it and it was not easy, but it will fit and they will have to do a new quick little "tack" weld to hold the new gear in place otherwise it will pop out....I have a slightly used 4.08 speed sensor sitting in my closest along with my whinning 4.08 rearend. I had them install the new gear for about a week and then switched it back out to the OEM after I was not sure if I was going to still do the 4.08 swap

I don't think that if we go up to a 4.36 rearend that we will be able to stick in the new speedsensor gear to get the speedo working correctly...it will be way to big.

[Q45tech]

They make electronic black boxes that translate the pulses per rpm to other ratios using stock speed sensor.........electronic frequency convertors[ $130].http://www.blackrobotics.com/yb_home.htm

Should work with up to a ~~5.00 diff gear set.

There are other brands [first one I found in search no experience with this company].

[sijoko]

I am using the plastic VSS gear for a 3.9 rearend. It fits without any modifications.

I had read somewhere that the 4.08 gear would not fit on our VSS, so I just went with the next lower one.

It isn't really a problem for me because my tires are slightly taller ( 255/45/17).

Aren't you running taller than stock tires?

If so, then just get the VSS gear for a 3.9 rearend. No more problems.

-sijoko

[Q45tech]

255/45/17 is [some brands] the oem 26" diameter size as is 235/60/15 or 255/50/16. But less/more sidewall compression can vary the loaded rolling radius.

Try that little yellow box as it allows you to adjust in 0.25% increments ~~ 0.2 mph at 80 mph. You can even correct for tire tread wear [1/4"] of 0>-2% [new to wornout].

[AZhitman]

Siju - My tires are 245/40/18, so I'm pretty close to stock... Where does one get the "VSS" gear (not sure what VSS stands for).

Rob - I returned my gear. Wanna offload yours? I'm confused as to the need for a "tack weld".

Seems like the sensor gear on the shaft either fits in the hole or it doesn't.

[rsiwicki]

they had to move the locator tab or some other part to get the new gear to hold in place and did some sort of quick mini weld....it would cost more in shipping to send you the gear itself.....I bough mine for less than $7.00 for the local Nissan dealer......

[AZhitman]

Gotcha -

Any chance of getting the part number from you? We tried for 30 minutes to finagle that thing into the hole... Grrr. Wonder if I had the wrong one?

[rsiwicki]

search the old 4.08 thread where I posted the part number....you'll find it there. I don't have the part number any more...I think it was something like the 22 or 20 toothed gear.

[sijoko]

VSS refers to the Vehicle Speed Sensor. It is what the plastic gear attaches to.

The gear you need is either a 19(white) teeth or 20(red) teeth.

Stock is a 17(black) teeth gear.

The gear is held in place by a retaining clip.

If the 20 teeth gear fits without any problems, let me know so I can install one in my car.

-sijoko

[rsiwicki]

you need the 20 tooth gear....as I have the red 20 tooth gear sitting right next to me. The put it in my car and it worked fine...just had to redo the retaining clip to make sure the gear held in place otherwise it would pop out they said.