Hey I just bought 4:56 gears and after I get them installed what do I need to do to fix my Speed O?

 

Well since you bought the gears have you changed your tire size, that plays a big part in it. To simply put got to Gary matthews or your local dealership and get your Pinion Factor updated it's about 40-50 dollars to get done. Be advised though you are going to need to tell them what you have done i.e. gears tires etc. that way they can adjust it. Just to let you know do not be surprised when they tell you that your warranty is now void. Try and see you might get lucky. Well I hope this helps.

First in last out!!
N141

 

You really don't need to do anything if you change the gears. The pinion factor is something that has not been proven, to me anyway.

You only need to correct the speedo if you change your overall tire diameter.

 

ok so you mean to tell me that even if I change my gears and dont touch the size of my tires I will not need to get my speedo checked? I would think changing your gears would also mean you would have to get your speedo reclabrated, am I wrong? And for some reason my warranty is allready void, and I have not done anything to my truck I have been deployed! But thats a different rant I will try to fix that when I get home

 

As kenihemi said if you change your tire diameter you will need to adjust your pinion factor. That is why I asked you in the begining if you changed your wheel size. Any computerized vehicle has a tolerance where it can self adjust/correct as far as tire size let say your Dodge came with the stock 17's if you go up to say a 20 inch wheel with a meaty tire you will and I emphasize will need to adjust your pinion factor. I know this personally because on my 01 dodge ram I used to have I went from the stock wheel size and tire and went to a 20 inch wheel. I noticed a definate speedo differance. As a matter of fact as a local shop that actually knows what they are talking about. They will tell you the same vehicles now a day's have a wheel tolerance of what they can accomidate. Nissan comes stock with 18's and can go up to 22's without adjusting the pinion factor. As far as your warranty what year is your truck? Also check the soldiers/sailors act that mofracky helps alot. Warranty's can be tricky I voided mine within 6 months of getting my 04' Again I hope this helps you. Good luck

 

WRONG! The computer needs to know the gear ratio. ABS function too.

 

PCM gets its speedo signal from the ring gear. Not like in the old days when it came from the trans.

So, size of the gear doesn't matter, its the rotational speed of the axles, only tire size will affect that.

RMPs of the motor will be higher, but speed will still be right on.

That is for 03-06 rams. Not sure about earlier ones.

 

Ok I have another question now, where in the rear end is my speedo sensor? The reason I ask is because I do not rememebr seeing any wires anywhere in my rear end.

 

so how did they claim that your warranty was gone if you havent done anything to it?

 

Rak, the sensor is on the top of the rear differential.

John, because dealers suck.