Difference between gear's

Going to be buying some gears for the cheromanche soon, looking like it will be 4.89 for the rear 44. Thinking about doing a soa in the rear and some kind of LA lift in the front of ~6" to level it out. If I kept it stock I'd probably have to go with around 4.09 due to the extra length and weight. Most people run 4.56 with 33-35's so I should be fine unless some think otherwise. What I'm mainly wanting to know is with all the different manufacturer's of gears out there, yukon, G2, motive, superior and all the other's I need to know from everyone who's run them what the noise level was like on-road as I'm wanting it to be pretty quiet.

lol, I couldn't tell you if my gears are quiet or not... I can't hear anything over all the other noises my Jeep makes.

I haven't noticed any gear noise with my Yukon 4.56s.

I'm glad you decided to lift it.

I have Yukon(front) and Chrysler(rear, 8.25)

The Cryco gears were 150 more then similar Yukons. Perfect pattern, and zero noise, which is what I paid for. Bought them based on a friends opinion(dealership mechanic)and the info on Randy's ring& pinion, which said basically the same thing.

I run ATs, and won't get aggressive tread on my DD. If you're running any kind of mud & snow tread, heavy lugs of any type, gear noise isn't going to be noticeable over tire noise at highway speeds.

tbburg said:

I run ATs, and won't get aggressive tread on my DD. If you're running any kind of mud & snow tread, heavy lugs of any type, gear noise isn't going to be noticeable over tire/engine/wind noise at highway speeds.

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Fixed. I ear my tires, wind noise, engine, fuel pump (ever since pulling the rear carpet), shock mounts, creaking body shell, etc etc. I've never noticed any particular noise from the gears front or rear.

Spicer gears for Dana axles!

Ok so that answers that for the noise from the gears and since I'll have a radio and stuff it doesn't sound like i'd be able to hear the noise over the other normal jeep noises. Now for the other part of the question, I'm planning on going with 33's or 35's depending on what i can find for a decent price. With the extra length of the wheelbase which would put me to 4.10 for factory tires I'm thinking I should probably go with 4.88 for the new tires. What does everyone think about that gear range as the max size it will get will be 35's and probably be either in a good AT or non agressive MT since it will be DD with some snow in the winters.

i have been running the Yukons from Randy's.had some break in issues. the gears are quiet. i broke them in as the install manual said.but the gear oil i used broke down and got hot and had a burnt smell.the manual recommends Synthectic.the ected locker says to use standard gear oil.i'm running synthetic now. they are quiet. i have run Spicer gears also in my Comanche. had no issues at all with those.

I think I have USA standard gears or some other brand in my 8.25, and they're awful. Super noisy.

I would go for the best you can afford.

for 33's- go 4.88's, maybe 5.13's

for 35's, go 5.13-5.38's

i cant hear any gear whine with my yukons over the sound of the tires.

Slush-O-Matic and mild/little offing 33s/35 go with 456 or 488
hard offing go with 488 for sure.
Factory stick (no super granny 1st or 4 to1 tcase) light offing go with 33 and 488 or better.
35s and/or max offing with factory gearbox 538 or as deep as you can go.
Got to go DEEP with factory sticks. Just stay off the highways.

I install about a dozen geras a week and sell that many more, so my experience...

To start, the chryslers use a different cut and can tend to be a bit noisy at times depending on the exact cut/factory that makes them, and the ratio, and the PERSON INSTALLING THEM...

The least expensive gears I sell have been great in every case we have installed them, and never got a complaint from a customer. The most expensive gears we sell, also same thing. The mid level we have had only one application have issues, both myself and customers(no longer sell those for fear of continuing issues).

I have to say in todays gear market with there being only a few importers and distribitors that the brand names are buying from and importing from, that you should be ALOT more concerned with Who installs them, then what they install.

Some gears are more straight cut for more strength, and some are less "straight" for quiet operation. In any rig with some lift (wind noise) and larger semi agressive tires (A/T or better), the cut or brand name means less I feel (within reason).

But if you were to ask me to rate, gear box brands, I would as such, best to least (in my experience), rating Noise and setup ease.
Yukon
Spicer
G2
Precision
Superior/Motive/USA standard (tie)
Nitro

Keep in mind though that a few of those up there buy from the same company, for some of thier sets and ratios. Not to mention that to the best of my knowledge, only spicer actually owns and uses in house Gleason machines to produce thier own gears. And Yukon some months ago, actually also bought 2 maybe 3 gleason machines so they too could produce and fully control 100% of the quality control of thier products. The rest all buy from factorys that they contract with. And when thier typical factory is behind or in some cases when a different known importer/factory has a better price/avail, a company will buy from them and box those.

Its so very hard to buy a brand name with confidence. But with a off road ride, its really not rocket science. If theres a bit of noise due to the cut, it will not effect anything and you wont even hear it. It they are installed incorrectly, you are screwed at some point.

IMO, if you buy Yukon though, you will always buy one of the best possible boxed sets, but you will pay for it.

dave92cherokee said:

With the extra length of the wheelbase which would put me to 4.10 for factory tires I'm thinking I should probably go with 4.88 for the new tires.

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What does wheelbase have to do with gearing?

Exactly what I was wondering reading this... vehicle weight, rolling mass, tire size, engine, and transmission are way way way more important.

AW4 and 33s - you could do 4.56s fine probably but 4.88s will be nice
AW4 and 35s - 4.88s for sure
AX15 and 33s or 35s - 4.56s probably would be fine, but you have the choice now and gear+install cost will be about the same, go for 4.88s instead of 4.56s then 4.88s later.

If you are going to do ANY towing with it, 4.88s for sure.

I've been told by many others that with having the wheelbase longer ~30" that the increased weight of the vehicle alone would mean that 3.55 gears would have to work harder to get the weight moving. Don't plan on doing any major towing with it but might do occasional light towing if something can't fit in the bed.

you are stretching the wheelbase 30"?

Not sure what the exact measurements are but if I remember from when I was doing the rough in the wheelbase was ~144". Will measure tomorrow afterwork to see what it really is. I do remember that the rear shaft was going to have to be a 2 piece as it was around 90" long.

144"? what?

are we talkin about a cherokee here?

and on 33's?

No we're talking about the cheromanche that i'm building.

You may have a longer wheelbase,but you dont have any "upper" steel,glass,or a hatch.Don't know the factory weight's but I bet they are close!

Just measured and the wheelbase is right at 150", I would think the extra weight of the bed and frame behind what would have been the back of the xj would add quite a bit but I might be wrong. Looks like I'll be going with 4.88 gears now just to see what kind of deals I can find on a new carrier, r&p, and install kit.