Preferred Gears For 33"/35" Tires

[Nay]

What is the preferred diff gear ratio for 33's (305's)? 4.56 or 4.88? 4.88 or 5.29 for 35's? Seems a lot of people leave it stock for 33's, but I won't do that given the elevations I drive (Colorado). I know that Slee runs 4.88's with 35's, but given that I don't much care about top speed I'd like the lower gears for 33's if they mate up well to the tranny ratios and shift points.

Coming from the Jeep world, the preference with 33's with four speed transmission and inline 6 engine is now 4.88's (4.56's leave a dead spot and lots of shifting at all the wrong speeds). It's 5.29 for 35/37's. But I doubt those comparisons are relevant here.

Please, no gearing math charts. Those things are useless and always overpredict overdrive RPM with lower gears. I want real world experience, such as "don't do 4.56 because the auto tranny will have a dead spot at 60 mph and you'll constantly be shifting between third and overdrive - 4.88's are much better unless you plan to drive 90 mph".

Thanks,
Nay

 

[WolfpackTLC]

Uh..... your top speed DECREASES as your ratio goes up... 4.88's won't let you touch 130 mph w/o a S/C... trust me... I know....

4.88's are a good compromise IMHO w/ the 35's. I'd rather have 5.29's.... se la vie'

 

[Junk]

There is little need for many people running 80's to ever really consider 5.29, plus they are more fragile.

I've heard guys in CO saying 4.88's are the way to go. Since you don't say if you have the 3fe or the 1FZ-FE, have forced air induction etc, there are a lot of variables.

I run 295/75's on the street and 36's on trail. I also frequently pull a heavyarsed dump trailer full of crap. I'm running 4.56's with a blower and have plenty of power.

Personally, I think for a road/trail combo, and anything around my tire sizes, this is the optimum set up. It is in my view. A little more power than the charts state is equal to stock with the bigger tires for street and a little under what they say for the 36's on trail.

I did not go 4.88 because I spend a lot of time on highway. If it was all around town + trail that would be a different story, but never entered the equation.

 

[Junk]

BTW, not sure on cost, but I know 4.88's are easier to find than 4.56 if that matters. I got one of the last sets of Toyota 4.56's from Christo a few years ago. Do you need Toyota gears? No. But it was the route I chose to go. All the internals were sourced from Toyota.

 

[landtank]

I've got 35s (315s) with 4.88s. Tons of highway and no problems at all. IMO this is the way to go, however you'll need to add a frequency modulator to the speedo to correct the error. 35s and 4.56s don't require this. After getting my truck setup this way I have put off any desire for a SC indefinately. Of course some will always want more from their trucks but it really performs great and no heating issues or pinging.

 

[WolfpackTLC]

Junk is correct! There is a breakage issue w/ 5.29's.... they have a REAL small pinion...

 

[robbie]

4.88 and 33 do not work well in my opinion as the cursing at highway speeds is over 3200 RPM's. I know I ran this set up for a couple of weeks. I hated it. I did pull a trailer with a vechicle behind my truck and it was great for this. But on a day to day basis it sucked. The cruiser engine delevops more torque than the j##p straight 6. The tranny has different gears to drive the truck different, matched to the torque and HP of the cruiser engine. Also do not know if you have a 91-92 or a 93-97. If you have a 91-92 then 4.88 would be better for the 33 if the later years then I would not regear unless you went to 35's then I would go with the 4.88. I have this set up and find it to work great with my truck with it almost 7000 lbs of weight. but I have also rebuilt my engine to get more power. Post what year you have so we can help better. IF you are going to run bigger tires then maybe 5.29 would be more better, but each person will set there truck up for what they need. later robbie

 

[MTNRAT]

I have 4.88s with 35" MTR tires. Works well for most situations. 4.56 would most likely be a little better for hwy. The 4.88 rev at 3000 rpm at 80mph. No flat spots. I am a bit of a power junky and even with the SC I find the truck a little weak. But that is how I feel personally. Now if you take what Robbie did to his engine, and add a turbo, I think that would be the ticket. Hmmmm???
Cheers,
Sean

 

[mabrodis]

I think preferred is a bit subjective. I have 35's on mine and have never regeared. I have thought about it, but I like driving fast on the highway and running fairly low rpms. There are times when I could probably use a lower gear but I can not think of more than one or two times in 3 years of wheelnig with mine that I couldn't make it somewhere because I didn't have enough lowspeed grunt.

I drive all over in Colorado, one thing to keep in mind is once you are moving the low gear grunt is gone, then you are just in a differnet rpm/speed profile than stock. With my stock gears I can run 2nd gear to about 60mph on my speedo, which is about perfect, that means I have good power around 50-65 mph at the top of 2nd gear. Would I be able to run faster with lower gears, doubtful, since I'd have to drop down enough to then be using 3rd gear to run at 60mph. I can definetly keep with traffic and rarely get passed going up I-70, do at times, but I'm definetly not slow.

I would definetly drive your vehicle with the stock gears over passes, and wheeling before deciding to regear. I planned on driving mine a bit to see how it was, and after 3 years it's not that bad, I'm sure if I regeared I could accelerate faster but I'm not that worried about that. If you regear though I'd go with 4.88's just to make it worth it, to go through all the time and money just to go to 4.56's seems like a waste to me. But before doing anything I would drive it alot with your tires and stock gears, see what you think, for me it wasn't worth regearing.

Note: I also am running MTR tires, which do not steal as much power as swampers or something like that, so that definetly could be an issue here.

Good Luck,
Mark Brodis

 

[Kaderabek]

I run stock gearing with a Tru-Speed. Seems perfect.

TJK

 

[Doc]

What is the OE pinion ratio?

I'm running stock axles on 33's and it is fine for what we do. I'd love to stuff 35's under there though. How much lift are you running Mabrodis?

 

[Nay]

Uh..... your top speed DECREASES as your ratio goes up... 4.88's won't let you touch 130 mph w/o a S/C... trust me... I know....

4.88's are a good compromise IMHO w/ the 35's. I'd rather have 5.29's.... se la vie'

Ya, I know top speed decreases as ratio increases...

Sounds like a regear is unnecessary for 33's, but would make sense for 35's. I appreciate the info.

BTW, I'm shopping for a 93-97 and plan on doing everything at once so I'm gathering info.

Thanks again,

Nay

 

[sleeoffroad]

Junk is correct! There is a breakage issue w/ 5.29's.... they have a REAL small pinion...

Uhm, not really the pinion that breaks. I think it deflects and then it breaks the ring gear. Just to be technical, anyway when it is broken it is broken.

I have broken two 4.88 setups and no 5.29 setups. Go figure.

 

[WolfpackTLC]

I've broken a 4.88 setup as well... Yukon gear.... hmm..

And I HEARD that the pinion was really small in a 5.29 setup....

Course, I also HEARD that the world was really flat...

 

[Waggoner5]

So whats the opinion on the gears? Are Yukons to be stayed away from? Sounds like maybe 4.88s for me. Whose?

 

[sleeoffroad]

Yukon's are fine. One of the sets I broke was a Toyota oem set. Yukons are just a house brand for Randy's, just like Precision is the house brand for Reider.

We did have some issues with the finish of some of the Yukon gears but Randy's has always helped us out with replacing them before we set them up. Currently we are using Precision gears since they seem to be overall better finished.

None is as well finished as Toyota oem gears, but then you pay 2.5x the price for Toyota. I have Yukon 5.29's in the shortbus and they are still holding up.

 

[alia176]

Just curious about engine rpms vs mph. Can some of you post your engine rpm at 75 mph and what is the size of your tire?

Thanks.

 

[Safado]

Actual 75, or what our un modified speedo says is 75? There's about a 20% difference!

 

[alia176]

Actual speed not indicated!

 

[landtank]

First with 35s and 4.88s it's a 8% change in rpm at any given speed. I'll check tomorrow if I remember as I have corrected the speedo for the tires and gears.

A while ago there was a thread concerning using solid shims verses the crush sleeve. Any thoughts on this helping the breaking from pinion deflection especially with the 5.29s?