Ontario BS Thread

not sure how to bring this up, but talking @cwisema ... what do the final drive numbers mean?
are larger ratios better? I have no idea what the charts mean, but i've seen the Nitro gear 4.88s name throw around once or twice with a handful of other threads



since putting the 33" Cooper ST MAXX on, i feel the truck is painfully sluggish on the highways and shifts a lot more at highway speeds (105-110) and doesn't really like going up inclines or hills without dropping to 4th at 3000RPM...

Would changing the rear gear be something worth doing for drivability?
would it help with economy?

 

Why not start with ovtune and go from there? One is a few hundred, the other a few thousand

 

The short answer - there are only positives in regearing after changing tire size.

A tune will not fix things and would be more of a Band-Aid.. (it may help the feel somewhat) but if you then regear after that tune, you'll still see a night and day difference.

Drivability is the main thing (especially if you plan on towing at all)
TYPICALLY maintaining the factory FINAL drive ratio will provide the best fuel economy.

You mentioned rear gears - assuming 4WD, you have to regear both front and rear differentials.


There are quite a few calculators for regearing available online.

 

ah right, forgot about Overtune

 

Just realized I didn't quite answer your initial question..

A higher number isn't "better" for all situations..

A higher number (lower gear) will provide better low end power which is why factory tow packages typically include a lower set of gears. This also translates to better driveability offroad as well as getting the truck going from a stop.
Like anything, you can overdo it to a point where you can't reasonably drive on the highway..

A lower number (higher gear ratio) will provide higher top speeds, but fall on it's face in low speed/high torque scenarios.

 

Actually both responses were quite helpful, the calculator helps give me a ball park calculation to where it would feel like "normal" from the looks of things.

the chart after helps visualize where i am/ where i would be.

red square would be where i am now i guess.

I'll need to look into what the actual gears are in my OR are, but implying i follow the chart i posted (as i'm an AutoTrans) i would have 3.909 cut gears. but if i swap out the rear gears to the 4.3 from a Manual transmission Tacoma, i would find an improvement then by putting myself into the middle of the field. i would be a little less fuel efficient than i am now, but looking into the Nitro gear guy's review
https://www.youtube.com/watch?v=XxBWZGQIScI
It seems like the truck isn't shifting as often with those 4.88 (and from the looks of things on the chart, the 4.88s would be overkill) and when it downshifts for me, i jump to 4th gear and up to 3k RPM for a lot longer than it should be until i completely lift off the gas and let it shift up to 5th at 1900.

i'm not hunting for top speed, i rarely go over a buck twenty, but don't want the truck to struggle by shifting all the time.

I might look into the OVRtune, but i'm sure i would be able to find a rear diff from a MT Tacoma somewhere. @Norilsk you doing that rear diff swap any time soon?

buuuuuut

you mentioned that i would need to change the front gears as well? why would that be?

 

Engage front diff with different gear ratio.

 

this is why i ask questions. as stupid as they may be - i know fuck all about modifications. i draw pipes in the ground and road curbs for a living



would the ass end move faster then the front end?

fine so that means i grab the same gearing off the front end of a used 3rd gen and swap out that.

fuck it, might as well get a MT 3rd gen

 

My RC trucks taught me about this just on a different size

When you flip the switch to 4H, you are linking your front and rear together via the drive shaft goodness.

Different ratio's at each end, results in

 

so similar outcome to what happened to Peter?

 

The chart is SLIGHTLY deceiving in terms of fuel economy..
To elaborate: being on the lower end(lower number or blue side) of the scale, you theoretically see better fuel economy ON HIGHWAY.
If you do a lot of city driving or towing/off-road driving though, the opposite will be true due to the starting and stopping. As mentioned, the lower gear (higher numerically) will get the truck moving much easier.

Gearing is ALWAYS a balance and it's a matter of compromising one thing for the other.
Manufacturers tend to find a decent balance overall.

Changing the gears essentially changes the speed of the truck at a given RPM.
Random example with no math being looked at - if you currently drive 60kph @ 2000rpm, changing to a lower gear (higher number) will require more rpm for the same speed (60kph @ 2300rpm for example) **again, I didn't do the math.

So with the ratios you have referenced - at one set RPM, 4.88 gears will turn the tires SLOWER than 3.91 gears.
So if you only regear the rear axle, when you use 4WD, the front of your truck will be trying to drag the back of the truck along.
BEST case scenario, handling will be awful and you lose traction.
WORST case scenario, you have a HIGH(almost guaranteed) chance of breaking components.

Hope that makes sense... If not, I'll try again
Understanding gearing can be complicated. Setting up gears, even more so.

 

Haha - I think I'll save this quote as my simplified explanation for future use

 

I type too long/slow and miss a bunch of posts.. LOL

Opposite - rear end would move slower than the front - (lower numerical number goes fast - higher numerical number goes strong)

3.91 faster than 4.88

 

this all sounds expensive and time consuming...
i'll just stick with what i have an i'll just press the ECT button more often


but i get the jist of things now, that helped a lot, Cheers bud!

 

LOL expensive and time consuming sums it up!
Glad I could help

 

From what little I've read, a re-gear isn't entirely necessary until you go bigger than 33" tires as the gearing and shifting sucks anyway. And if you're not towing it shouldn't make too much difference. Keeping in mind that a re-gear is probably $5000. Don't be fooled by YouTubers, they don't pay for anything.

 

Welcome to the rabbit hole... which gets deeper once you look at costs. Big portion of regearing costs are in the assembly/disassembly/setup labor, and replacement of wear parts like bearings. Then you start thinking if you should get the shop to put in a front locker to commonize labor costs, whether you should go with ARB or Harrop...

 

i figured it's probably not necessary, i wanted to ask the question since now i have a better idea of what re-gearing means and does for the vehicle.

wasn't aware that it becomes a bit different in a 4WD scenario since i've heard of people swapping rear diffs without issues for drift cars since well, they're mostly RWD.

i know there are probably a dozen options on what i can do to help improve the truck to more my liking, but figured to check in with the physical modifications first.
I've heard there is also the possibility to factory flash/update the ECU at the dealer for a "latest" version of the of the shifting patterns. Apparently the 2020+ drive differently than the 2016s-2018s/2019s as the confuser was fine tuned over the years. 2016 had a nightmare of a shift pattern but people are happier with the latest.

Granted anything i want to do will involve money, so it's all bang for buck at the end of the day.

or i can stop bitching and complaining, that's usually free

 

Based on family experience within the last couple of years, I'd bank on $1000-2000 per axle for a standard re-gear at a 4WD shop (gears, master install kit and labour) with that increasing based on the labour required to pull the front axle from an IFS truck.

If you have the ability to hand 2 axles to the shop, you'd likely land around the $1000/axle mark.



But agreed - it's hard to not find justification for traction aids when already ripping them open!

 

Just a side thought for ORO, while he's active here - We need some Canadian roof racks, and skid plates.