Tires and gears???

[Mike]

Given that you are looking to do a more adventurous path, I have to agree with Jeri Lyn.

I have upgraded to 4.56 because I eventually want to go to a 6" lift with 35" tires. I suggest that you think about where you want your rig to end up, and pick gears to match the end result. It costs the same to install 3.73 or 5.18 so pick where you want to go so that you only have to pay for the upgrade once.

I just wish that I had used this logic when I chose a lift! Live and learn...

Like I said, I'm a reading geek, so I recommend that you search the Knowledge Center section of www.quadratec.com for tire size to gear ratios. From that chart you can chose where you want to go.

And Dude! Cali is so cool. It's the land of extremes. You can snow ski in the morning and watch the sunset on the beach in the afternoon. Come on out!

Malachi

[KNCJeeper]

i know man...i was stationed at camp pendleton for about 6 months and I loved it...for thanksgiving leave i went and camped up on the coastal highway...i went everywhere bro..i loved it so much thats why i want to move out there but i have to finish school first so i can afford to live there!!

[Old Fart]

Critical Path Method (you can guess what I do for a living)

Pick tire size that you want (which in itself is several tasks!)

Pick axles to support tires. This involves locker availability, differential strength and size (don't run 32's with a Dana 60, BTDT)

Gear axles to allow tire size to kepp you in acceptable RPM range. Note this will be different if you have an automatic or a real transmission

Lift vehicle appropriately to clear tires, other modifications depending on lift.

Now put all this in P3, I expect to review it on Monday

[KNCJeeper]

holy crap man...speak english please!! :p ok 1st of all i guess i have a fake transmission cuz i got an auto :p i heard lots of conterversy on that subject before i bought the jeep and since im not the best stick driver i went with the auto. now i really want 33s once i get a bigger lift, but for right now im getting some rubi 31s and going to go with the 2" BB RE lift until i can save some money to go real big...the biggest thing i dont understand is the axels gear ratio and all that jazz???? and what is P3??

[goodtimes]

Critical Path

AHHHHHHHHH!!!!!

Make it stop! Make it stop!!!!!!!

and what is P3??

I assume he is referring to MS Project '03. If he isn't, then ignore my recurring nightmare referenced above.

[JpPassenger]

I'm a big fan of manual transmissions, but I can't find any fault with the Allison in my truck.

My prejudice established, an automatic off-road is probably just as good as manual. It is far more tolerant of abuse than a clutch. I don't like the additional heat it generates and unloads into the cooling system. I think proper gearing is more critical for an auto because the harder it has to work, the more heat it creates.

A guy in our club has 35's with 4.11s in his jeep. He overheated his 700R4 on a trip to Johnson Valley, and now he sends the (recently-added) transmission temp gauge into the red zone every trip now. Sometimes we have to tow him on hills just getting to/from the trail head!

4.88's or lower would suit his wheeling much better.

3.73's are a great match for 31's. 4.11's are a very good match for 33's. If you are looking at rockcrawling, go a step lower, but you can also look at a 4:1 T/C mod. That's buck$ (~$1200 if you do it yourself at the same time you do the SYE kit) but you get a lot more bang for your money spent.

[KNCJeeper]

so what if i just went 4.88 with 33s..eventually i want to go 35s though..think that would be good?? and how bad will that take off my top end?? this is my daily driver as well

[JpPassenger]

With 4.88's and 33's, you won't need to downshift on freeway hills! It's low for 33's, but not unreasonable. It will be good with the 35's.

If your engine is about 2300 RPM at 55MPH (30" w/3.73) now, it will be about 2700 RPM with 33's and 4.88's. Your engine will be screaming at 80 MPH.

You may like these folks' tech library:
http://www.800-923-jeep.com/techCorner/

Especially the tire/gearing chart:
http://www.800-923-jeep.com/techCorner/gears.cfm

[Old Fart]

Acutally, Primavera P3

[goodtimes]

3.73's are a great match for 31's. 4.11's are a very good match for 33's.

IMO, 4.10's are not deep enough for 33's. My jeep (4.0, manual, 4.10's, 33's) is a ****ing dog on every hill I point it at. With the 4:1 t'case, it is fine off road (keeping in mind that I'm not out running the hammers....), but on the freeway it needs deeper gears. It was OK with 31's and the 4.10's.

[JpPassenger]

IMO, 4.10's are not deep enough for 33's. My jeep (4.0, manual, 4.10's, 33's) is a ****ing dog on every hill I point it at. With the 4:1 t'case, it is fine off road (keeping in mind that I'm not out running the hammers....), but on the freeway it needs deeper gears. It was OK with 31's and the 4.10's.

You are the voice of experience. Ours is an 01 with 4.0, manual, 3.73 and 31's. It'll go 65 up Cajon & the Grapevine loaded with weekend camping stuff, but not much more.

Numerically, the 4.10 & 33's is a lower final ratio than 3.73 and 31's.

Have you got a lot of armor/bumpers/winch adding weight? Ours has only a gas tank skidplate and Sun perf rockers. No winch and the stock bumpers. Hmm, maybe I'll have to reconsider my plan for 4.10's, since our jeep ain't going to get any lighter.

Greg

[goodtimes]

I do have 2 or 300 pounds worth of steel added to it, but that is not enough to account for how big of a dog this thing is. Even the slightest grade gets me out of 5th gear to keep 65 - 70 mph. I'm not talking mountain passes here either.

[JpPassenger]

Oh, man, I was never able to climb any grade in 5th!

I guess it never bothered me too much. But I can see how it could be annoying. With our traffic, you never get to go fast around here anyway.

[goodtimes]

I'm wide open in 5th gear to hold 75mph on flat ground with no wind. A gentle 1 - 2% grade gets me into 4th, wide open to hold the same 75. A typical mountain pass at 8% has me in 3rd trying not to get run over.

[Jerry Bransford]

IMO, 4.10's are not deep enough for 33's. My jeep (4.0, manual, 4.10's, 33's) is a ****ing dog on every hill I point it at. With the 4:1 t'case, it is fine off road (keeping in mind that I'm not out running the hammers....), but on the freeway it needs deeper gears. It was OK with 31's and the 4.10's.

I totally agree and say that 4.56 is a much better all-around ratio for 33" tires. At one point, I had regeared from 3.55 to 4.10 to run 33" tires, big mistake not going to 4.56 instead. I got sick of having to downshift so often with the 4.10 gearing, I should have listened to others who recommended 4.56. I learned my lesson on being undergeared and when I installed 35" tires, I went to 4.88 which is absolutely perfect/great.