Calebrating The Spedomiter

[DaveS]

Because pathfinders have electronic speedometers would it be possible to recalibrate the speedometer for larger tires by putting a resistor or adjustable resistor on one of the speedometer wires. After looking at the factory repair manual the speed sensor looks to me like a small generator that creates more or less power according to the speed your going. i don't know exactly how the gauge in the dash converts that power from the sensor into the movement of the needle on the dash. if any electronic experts or any one that knows exactly how the system works could tell me if this would work. or better yet if anyone has tried it let me know how it worked for you or if this is a stupid idea and wont work.

[88pathoffroad]

It's actually a magnetic reed switch that feeds pulses to the ECU so it can calculate your speed. I think what you need to do is replace the plastic gear inside the trans that drives it with a new one to match your tire size. What size tire are you going with and what did you have before?

[DaveS]

I'm not entirely sure what size tires I'm going to put on it it depends if i can afford to change the gears and add a lift or not. how difficult is it to get at the gears would that involve opening up the tranny or not. But probably not that much bigger i have stock tires right now i think there about 28.5 If i cant lift it and change the gears I would probably go 30 or 31 31 by 10.5 is the biggest size i can go with out rubbing on the wheel well or frame on turns how much clearance do i have with the 31's if i launch the front end will they crush the wheel wells.

 

thx Dave

[Slick]

....... how much clearance do i have with the 31's if i launch the front end will they crush the wheel wells.

 

thx Dave

try it and find out!!!!

[DaveS]

thanks for that advice slick. I really wish I had the money that i could just do that but i don't. Just a poor kid between high school and collage so if people could tell me if i have the clearance with original springs or if i need to run 30's or get a lift.

[94extreme]

 

 

check the dr. door jamb as it is spelled out what tires your truck came with from the factory.

[aries247]

if i can find my old pic. of my 91xe it had 31's on 15x10 wheels with no lift. it shows how much clearance between the tires and the fender's. i don't know what you drive but if you launch into the air it will hit your fenders and the outcome would not be good. i posted it when i first joined but i have to look in my computer files to find it or scan it from the picture i have hanging on the wall. ***edit****scanned pic. no lift and 31's.

Edited June 8, 2007 by aries247

[DaveS]

Ive got original springs and I'm sure there sagging a little would 30's by 9 hit the fenders if i launched the front end. I try not to do any thing to stupid but I'm 17 so every once in a while I end up doing something stupid and it usually involves my car so i want to try not to make it to easy to hurt my pathy.

Edited June 8, 2007 by DaveS

[aries247]

if you want to fit 31's cheapest way would be to do a body lift. if you look in the waterproofing thread in the 90-95 pathfinder section you'll see mine with a 3" body lift with the 31's on 15x10's.

Edited June 8, 2007 by aries247

[88pathoffroad]

aries, where have you been? 31's fit STOCK and with stock wheels they usually don't rub anything.

 

Running 10" wide wheels with 31x10.50's will probably make them rub, yes. A 15x10 wheel is too wide. You can mount 31's on a stock 15x7 wheel no problem. My 13.5 Swampers are mounted on 15x8.5's. Not a single problem.

 

DaveS: crank up your t-bars slightly and level it out, (if you haven't already) I doubt you'll have any bottoming out problems. If you do, any vehicle would have the same problem and it'd probably be because you were abusing it.

[aries247]

those wheels weren't stock 88. they were 15x10's off my 87 suburban so they stuck out quite a bit. i was just saying that with 15x10's if he launched into the air it would damage the fenders. the picture was so he could see the clearance with 15x10's. i wasn't trying to sound as if he couldn't run 31's. now that i went back and actully read what i posted i guess i did kind of sound like that sorry. like 88 said put some 31's on 15x7 and have fun.

Edited June 10, 2007 by aries247

[MadManMike]

My pathy came stock with 31's... I think 31X10.5 R15's is what the door jam label says. Or maybe I am making a fool of my self because I don't know what I am talking about

 

I do get rubbing (somewhere.. probably rear) if I go over any big bumps with any substantial weight in the car. It hit pretty hard when I hit a steep freeway entrance at 65... But I think my rear shocks/springs are shot any way..

 

just my .02 cents

 

-Mike

Edited June 10, 2007 by MadManMike

[DaveS]

so i can run 31's on the stock suspension and gears without any problems unless i do something stupid. 88 i thought the cranking the tbars on stock uca's screwed with the pinion angles. correct me if I'm wrong but wont that cause problems in the future. also if anyone knows how to change the gears for the speedometer that would be great

 

thx for all the help

Dave

[aries247]

yes you can run 31's with stock suspension. but like 88 said put them on stock wheels or some kind of 15x7 or 15x8.

[88pathoffroad]

The speedo will be off by about 1% if you change tires, not enough IMHO to warrant tearing into the transmission to change speedo gearing. Have you checked your speedo with a GPS to see if it currently reads correctly to begin with? Try borrowing one and give it a try. You might be surprised. I went to 33's with no speedo correction and all it does is read about 5 MPH slow at 65 MPH.

 

Pinion angles? No, that's on the rear diff, nobody I've ever talked to has had any problems with that. The main problem when you crank the t-bars up more than an inch and a half or so is the upper balljoints. It's perfectly safe to crank 'em up as long as you don't overdo it and have the UCA's resting on the bumpstops. It also makes the tie rods slightly more likely to be bent if you wheel it hard, but it's not going to do it right away.

 

If you hadn't found out yet, there are no aftermarket gear producers for Nissans, you'd have to buy new gears at a dealership and IIRC they cost around $500 for one ring and pinion, not including install. It'd cost you $1000 minimum JUST to buy gears.

[DaveS]

thanks for all the help I so 31's wont throw off the speedometer enough to worry about. 88 thanks for correcting me I had read ball joint angles on another post on this forum but it is not a problem unless i really crank them and I couldn't afford after market rims if i wanted them which i don't. thanks everyone for helping me I'm new to the 4 wheeling thing and i want to try to get in to it. my pathy will need new tires in a couple of months at the most anyway.

 

Thx Dave