anyone have an opinion on 5.13's v. 4.88's?

[Tacoma]

So. Curious if anyone is running 5.13's, and even better, did you switch from like, 4.56's or what.

Right now I'm running 4.56's w/35's and a 700r4... but I'm going to 38's and TH400 soon enough I guess... and probably a Doubler in there too. My EFFECTIVE ratio right now is something around a 3.73, and I'd like it lower-- or would I? Truck is currently a DD around town, so no worries anymore about mileage. 4.88's are I guess the next step down, but I think 5.13's might make more sense... I'd like to end up on 40-42's if I can cut enough body out of the way w/a 4" lift.

What say you?

 

[iamsparticus]

sounds good but i would go with 4.88's 5.13's just is too low in my opinion

 

[Rot Box]

The difference in 4.88's and 5.29's (not 5.13's but close enough right ) in Toyota's doesn't look like much when you crunch the numbers on paper, but you really feel it when you're driving--the difference is BIG. That is all I know I personally went from 4.37 to 5.29/5.38's and I'm really happy I didn't choose the 4.88's.

With a V8 and an automatic I don't think the 4.56 to 4.88 jump is worth the effort... Just my $.02

 

[Bobzilla]

Some input on gear ratios

I calculated it out, dont know exactly your T-case gear ratio figured it was a 2.72 to 1 Ratio, also I'm sure you know the 700R4 has a lower 1st gear than the Turbo 400.

700R4 with doubler 2.72 T-case & 4.56 gears crawl ratio=99.7 to 1

700R4 with doubler 2.72 T-case & 4.88 gears crawl ratio=108.3 to 1

One thing to keep in mind on any gear reductions, ring & pinions, the higher gear on the axle ring and pinion the greater the strength,
the pinion will have more contact surface area on the ring gear the higher ratio you go.

Personally I will build with highest gears possible to achieve the desired crawl ratio, so I think your 4.56 Gears do not need changing? plus they are stronger than a 5.13 set.

THX, Bobzilla

 

[iamsparticus]

thats a good point i have heard of guys breaking ring teeth on 5.59's and 5.13's, something to think about if you have a V8 and especially if you have a heavy foot

 

[Tacoma]

That's a good point.. This thing is getting a healthy 454, which on a BAD day is north of 400ft lbs.

I'm actually kind of curious if the torque will make this a moot point. I suspect it may. 454's are the absolute bomb.

 

[iamsparticus]

:greg:Yeah thats what i was thinking, and if you put the torq and the heavy weight of the vechile add huge tires and a weaker ring gears and you have a recipe for breakage. Something i have learned in any sport is that just because the pros run those dosen't mean you should, some guys switch out the gears every comp, not saying thats why you were going for the lower gears but something to remember i guess

 

[I Lean]

With your axles, I'm not worried about gear strength. With your doubler, I'm not really worried about gear reduction off-road. So, the only remaining thing is on-road stuff. The 400 doesn't have overdrive, which will be the real deciding factor on your gears. In town, the lower gears will be better off the line and stuffs, on the highway you'll have to figure out your RPM's. Also, decide how much time you'll be driving each.

With no OD, I suspect 4.88's would be better--and I agree, switching from 4.56 to 4.88 isn't enough of a change to bother with, unless you run out of other things to spend money on.

 

[ChestonScout]

If it were me....I would do 5.13s


I dont have any numbers to throw at you....just my personal experience.

When the Scout was on tons I ran 5.38s. I started with 42s and moved up to 44s. With either tire I could cruise 65 without the RPMs going to wild. I have a C6 so no overdrive for me either. I can tell you that I wouldnt have wanted them any higher. I was actually dissapointed in them. I thought it would have felt a lot lower.

I broke shafts but never had a problem with gears. If you get them set up right, you wont have a problem. I would bet way over half of all gear failures are due to poor setup.

BUT........

If you are going to do a doubler, I would probably just stick with the 4.56 and just spend the money towards the doubler.....DOUBLERS RULE!!! My buddy Blazinzuk (#8 for TTC 2010) is running 44s with 4.56 on his K10 and it does decent on the roads but he has the doubler for the trail and its a pretty good setup. He does drive it a lot. I bet if you were to ask him, he would like lower gears in the axles tho.

 

[Gravy]

I agree with Carl. If you are going with a doubler, get gears that will work on the road, since you'll have no overdrive. That 454 will have no problem pushing them.

but it will kill you to tach out at 70.

 

[4554x4]

Tacoma, I have 4.10 gears in the Blazer with the 38.5 boggers. It will not hardly get out of its own way with the t-case in high gear. This is in part due to the weak ass 350. When the t-cases are in double low, it seems to crawl quite well. I do have a set of 5.13s to go in it soon. This will help the around town performance, as well as when I need to hit redline when trying to bump over an obsticle.

If I were going to a 454 and a Doubler, I think I would wait on the gear selection untill after running it through its paces.

You are welcome to come drive mine and try it in double low.

 

[Shawn]

5:13--4:88's.... doesn't really matter since the blazer will never leave the driveway......

 

[Tacoma]

Hey Shawn, I got you something today: a big glass of STFU!!!

The gears will be the absolute last thing I do to it.

 

[LT.]

5.13's and this is why. You had said you were running a 700R4 before and wanted to go to a TH400. The 700 has a lower first gear than the 400. Also, all things being equal you had 4.56 with 35's. If you go to 38's and you wanted to keep everything else the same then your new ratio would need to be 4.95:1. Since there are no gears with that ratio (that I know of) and you had mentioned going with a larger tire possibly, then you will need the 5.13's.

LT.

 

[Shawn]

Hey Shawn, I got you something today: a big glass of STFU!!!

Please.... you know that is not my nature...

 

[reddman]

My vote is to go low. I love my 5.86s and 42s. The only downside is that with the T400 I was limited to under 70 mph, but that's pretty darn fast on big unbalanced fortydueces.

 

[NOTATOY]

I have a huge healthy 3.0 in my runner with 5:38's and 42" tires and love them.

 

[mbryson]

I have 4.56 gears, 40" MTRs and a TIRED 350. I'd go with the 5.13 if it won't see a lot of highway miles.

 

[reddman]

I'm noticing a theme here, people rarely regret going too low, but often regret not going lower while they were throwing the same amount of money at it.

 

[UNSTUCK]

I run 4.88's with a 700r4 and a stock d300 and was on 35's. I already have a rear 60 with 4.88's and will build the front 60 with them as well. I plan on going to 40's with the 4.88's. I will make up the gearing with either lower gears in the tcase or a stak.
I will be lower then I was before, and still have much stronger gears.

Anyone know the gearing difference between 35's and 40's? What about the strength difference between 4.88's and 5.13 or 5.38's? Is any of this enough to even worry about?