Regearing and why you need to do it (1 Viewer)

[jamarquardt22]

The subject of gearing has come up reciently. With out getting too crazy I wanted to give a brief statement about my experiences with gearing.

Once before most of you knew me I had a 98 tacoma. It came with 27" tires and 3.58:1 axle gears. It had good power and I got 21 mpg with it. I then upgraded to a 31" tire It became a gutless turd and my speedo was way off. I eventually changed the axles and had the factory 4.30:1 gears with the 31" tires. It had good power this way and I got around 20 mpg and the speedo was close. I eventually moved up to a 33" tire. I kept the 4.30's but the power was gone and my good mpg was gone too. The engine was just working too hard for what I was trying to make it do.

Later I bought my current 4runner it came with 4.10's and 31's. It had good power that way and was enjoyable to drive on the road. I moved to 33's and the 4.30's I swapped my taco axle and found a front diff with matching gears. The feel stayed the same as stock. Later I moved up to 37's with the 4.30's the truck was now undriveable! I had to ride the hell out of the clutch to get it going and 5th gear was useless and 4th wasn't much better. I regeared the axles to 5.29's. There is a 5.71 ratio that no one uses since the pinion gets really small. My truck was driveable but not by much. 4th gear was good but 5th dosent get used too often. So what happened, did I not use a low enough axle gear? nope. In fact it is slightly under drive. The extra weight of the wheel and tire combo I have is harder to factor in.

The lesson is that nothing drives like stock even with the numbers look stock.

Infact, playing with this gear ratio calculator. http://www.grimmjeeper.com/gears.html If my truck were stock at 3000 rpm in 5th gear It has me at 79 mph, my current setup I must be at 3300 rpm to do 79 mph.

By regearing you/I are attempting to restore lost power and lessen the strain on other drive train components. These could include universal joints, clutch, torque converter, brakes maybe some other things too.

Higher rpms do not always mean lower mpg. Infact if your engine isn't working so hard you will increase your mpg.

Automatic tranny's will hide the need to regear to a extent. The same goes for a engine with power to spare. The need is still there and I encourage everyone to look into doing this. Yes, it will likely set you back 1k or more, but so will a roof top tent that you wont use nearly as often.

If anyone has somthing to add or point out where I am wrong please do.

 

[Jakes40]

Andy I think you hit gearing on the nose.

 

[stock]

Yeah, I'm trying to figure out what to buy. My transfer case is shot in my 91 80. Mechanic has not got in any further, but metal came out of the oil in the transfer case, but no transmission fluid! So I think my trans is okay. I'm scouring info on Marlin. I've heard low low is what I need. I have 33's now but will be going to 35's.

 

[caz]

I've got my own thoughts on this one.... I have never had an automatic, so my experience only applies to manual transmission.

I have never regeared - even when adding lockers. I prefer to have a stock gear ratio so that if something happens I can get my truck on the road with parts from the nearest junkyard.... I have never found that I couldn't work around the gearing with my shifter.

I would spend my $$ on a crawl box any day of the week, but not so much for axle gearing!

 

[brian]

cruisers straight sixes are not as gutless as the 22r engine series.
33s and the oem 4:11s and even 3:70s are actually a pretty good combination.

 

[jamarquardt22]

I've got my own thoughts on this one....I prefer to have a stock gear ratio so that if something happens I can get my truck on the road with parts from the nearest junkyard....

I would spend my $$ on a crawl box any day of the week, but not so much for axle gearing!

Andy, I see the logic in your thinking here. But I think its flawed... If you were a Jeep owner I think it would be good logic. Every time I go to the junkyard I keep a eye out for useful parts. So dose everyone else. I have only ever seen 2 tacoma's, Never seen a cruiser of any kind, 1 sequoia, 3 t100's and maybe 2 tundras. Ive never seen a 1st gen 4runner and only a few 2nd gen mini trucks. Mostly I see 2nd and 3rd gen 4runner's all most all have the rear 3rd pulled with the axle shafts in the mud. The only time I have found something good is if there was something wrong with it. 3rd gen's have the option of the rear locker but almost all had 4.30 gears. The wrong ratio for you IIRC.

I can totally understand not wanting to spend money on something if its not broken. But If you did brake something, I would see it as a great chance to regear to something like 4.56 or 4.88

 

[caz]

Could be, but it makes me feel better somehow

I still have visions of trucks stuck at camp in Tellico waiting for 3rd members to arrive next day air at the general store...

I can think of 3 times I saw this happen. Meanwhile, the local "Gary" was sitting on a pile of trucks not more than 45 minutes away.

 

[jamarquardt22]

@caz I put in your truck in the calculator and 4.56 are perfect for your 33's i know you wont. But if you did do it do it once and plan for the future. Like 4.88 for 35's

 

[YotaFun]

Coming a little late into the Convo, but I'm with @jamarquardt22 in regard to hearing diffs. I do agreed transfer case years are nice as well.

My set up is a 97' 4Runner with a 3.4l V6 rated at 186hp (supposidly) and from factory has 4.10 gears. It was never really a power horse from factory but it is a truck. I have had 4.10, 4.30, and currently 4.88 gears on 33s.

With 4.10s it was a little more sluggish with a fuel economy of 12-15 from.the stock 16-19...
With the 4.30, Speedo was dead on accurate and power was close to stock, but still could hear struggle in the driveline to move it.
Then I upgraded to 4.88 after shearing off my pinion on trip and what a difference. Probably a little too much for 33s but it's a nice change, I'm able to drive down the highway, and even I need it have a little extra umph to pass someone if I need to, before I'd have to give myself some more time...

When it comes to the trails is when I really notice the difference. With the 4.10s and 4.30s I felt I had no control, no crawl really, while yes this helps with a transfer case , after gearing the diff I felt I had Mich more control, again, not as much as with a case or crawl box but vast improvement.

I feel with gears you can get a best of boths worlds, a little hwy and a little trail.

 

[Cass007]

I know I will need to re-gear likely before next year when I can do suspension and tires. My decision right now is to do just the transfer case and leave the diffs stock. I plan on doing both the low end and high end gears to try and make the truck street compatible, but still have better capability off road.

IIRC, when speaking to Vince, he has both the low end tx case and diffs done, so best of both worlds. Sadly, my current truck budget does not allow for that possibility.

 

[dci blair]

I’m glad you posted this. I’m planning on going to 35s when I need new tires. I’ve been reading what most of the fj guys have done when they go 35s and seems like a split. Although feasible to go without the regear I think I’ll provably do it for several reasons. One being it’s my daily, and I’d like to keep the on road manners as close to factory as possible. Two being the stock gears aren’t the most ideal ratio. 3.something, I forget the exact number. The rear is going to be no sweat. I imagine the front with that clamshell diff is going to be a real pain.

 

[jamarquardt22]

@dci blair check out www.gearinstalls.com zuk knows toy gear setup! And when you figure out the axle gear ratio play with the calculator I posted above 4.56 4.88 5.29 it's the same price and work.

 

[dci blair]

I think 5.29 is far to aggressive for my needs. I’m thinking 4.56 is my target as it will keep the highway manners where I’d like them. I’m sure I’ve got at least a year if not longer before I’ll need tires. That gives me plenty of time to acquire what I need. Pretty sure 4.56 is the setup most fj guys are going with.

 

[El Dahs]

I’m glad you posted this. I’m planning on going to 35s when I need new tires. I’ve been reading what most of the fj guys have done when they go 35s and seems like a split. Although feasible to go without the regear I think I’ll provably do it for several reasons. One being it’s my daily, and I’d like to keep the on road manners as close to factory as possible. Two being the stock gears aren’t the most ideal ratio. 3.something, I forget the exact number. The rear is going to be no sweat. I imagine the front with that clamshell diff is going to be a real pain.

Toyota Gears, Install Kits, Carriers, Spider Gears - Precision, Yukon, Lockright

These are the guys I used for my 3rd member.
They build what you want. They send it, you drop it in and send them yours. Very little down time and an awesome company.

 

[dci blair]

Toyota Gears, Install Kits, Carriers, Spider Gears - Precision, Yukon, Lockright

These are the guys I used for my 3rd member.
They build what you want. They send it, you drop it in and send them yours. Very little down time and an awesome company.

I was considering using them when figuring out the “what’s my time worth” scenerio. At the end of the day, I still really want to do it myself. That, and I’m cheap.

I’ve been enjoying doing differential work as I don’t see it all that often since I primarily work on german cars. I’ll probably end up using Randy’s ring and pinion as our shop has an account with them. Prices were basically the same, just the account shaves a few bucks off. I was pretty surprised that I could do front and rear for under a grand.

Don’t get me wrong, if I was a DIY backyard mechanic I’d be using ecgs all day long. Prices are on point and have yet to hear anything negative.

 

[jamarquardt22]

I have yet to purchase a install kit. As long as nothing is wrong with the bearings use em again. But buy a new pinion seal and a solid pinion spacer.

 

[shmukster]

Just some information gearing wise. Had my 40 out the other day after doing some transfer case work on it and noted that at 60MPH (GPS verified, my speedometer is a Dakota Digital that is easily calibrated) the engine is turning 3000 RPM. The truck has 4.88 gears in the axles and it's running 35" tires. I've never really gone over 65 MPH with the old girl as I try to avoid running the 2F much higher than 3200 RPM.
Over the last few years I've thought about swapping the 4.88's out for a pair of 3.70 third members. It would sure make it easier on the engine running down the highway. Since I have a Marlin crawler between the transmission and transfer case I'd still have same really low gearing for off roading. I would say while I drive the 40 more on the road than off that incurring the expense and trouble of swapping thirds probably ain't worth the effort and expense. That's maybe the main reason why I never made the change although I have serious concerns about the drivability of the truck with such a radical change to higher gearing. I like the "pep" the truck now has and the ease with which it is able to pull out from a stop without slipping the clutch a lot. Surely that would change in a negative manner if I changed from 4.88 to 3.70.
Had the 81 out yesterday, too, in fact put over 100 miles on it going up to Harry's U-pullit in Hazelton. At a GPS verified 72 MPH the engine is turning 2500 RPM. That's the speed at which I set the cruise control on the trip to Colorado last year. That truck has 4.10 axles, 33" tires, but runs an automatic transmission with overdrive. I have no idea what the overdrive gear ratio is but it makes a substantial and noticeable difference on the highway.

 

[Pacer]

Just some information gearing wise. Had my 40 out the other day after doing some transfer case work on it and noted that at 60MPH (GPS verified, my speedometer is a Dakota Digital that is easily calibrated) the engine is turning 3000 RPM. The truck has 4.88 gears in the axles and it's running 35" tires. I've never really gone over 65 MPH with the old girl as I try to avoid running the 2F much higher than 3200 RPM.
Over the last few years I've thought about swapping the 4.88's out for a pair of 3.70 third members. It would sure make it easier on the engine running down the highway. Since I have a Marlin crawler between the transmission and transfer case I'd still have same really low gearing for off roading. I would say while I drive the 40 more on the road than off that incurring the expense and trouble of swapping thirds probably ain't worth the effort and expense. That's maybe the main reason why I never made the change although I have serious concerns about the drivability of the truck with such a radical change to higher gearing. I like the "pep" the truck now has and the ease with which it is able to pull out from a stop without slipping the clutch a lot. Surely that would change in a negative manner if I changed from 4.88 to 3.70.
Had the 81 out yesterday, too, in fact put over 100 miles on it going up to Harry's U-pullit in Hazelton. At a GPS verified 72 MPH the engine is turning 2500 RPM. That's the speed at which I set the cruise control on the trip to Colorado last year. That truck has 4.10 axles, 33" tires, but runs an automatic transmission with overdrive. I have no idea what the overdrive gear ratio is but it makes a substantial and noticeable difference on the highway.

4.10s in the 40 may be a sweet spot, no? Too much work...
O/D = .73ish

 

[shmukster]

I have a pair of really nice 3.70 thirds from a 60 I parted. The axles under my truck are from a 62 so the 60 thirds bolt right in and have the proper bolt pattern on the pinion flange. I do have some older 4.10 thirds here but if I make a change it will be to 3.70.

As an aside one other reason I might make a change is to get away from the Detroit locker in the rear and go to some sort of selectable locker. I might even do that even if I never change the thirds. The Detroit is a very strong locker and constantly lets you know it's there and doing its' job. I'm used to it now but when I first got the 40 in 2000 the antics of the Detroit were a bit unnerving. I run an 80 series electric locker up front and changing to an ARB in the rear without changing the ring and pinion would be relatively easy. Stay tuned!

 

[jamarquardt22]

Gary, have you messed with the ratio calculator I posted above. I don't know what would of come with your 40 stock ie. Tire size, axle gears, trans, I do know that the difference between 4.88 and 3.70 is huge. I don't hate the 4.10 idea but would look at the calculator before doing that either.

You will definitely lower rpms but the engine may actually work harder and your mpg may actually not change or worse go down. Either way I'm interested to see what you do and how you like it. Maybe @Pacer would want the 4.88 3rds. Although unless he is swappig motors 5.29's would be better for him on the treker