4.56 to 4.88 potential overgearing?

[jrowell]

I've had 33's and 4.88 for over 10 years. I've been intending on going to 35's... for over ten years! I broke the stock carrier/ lock right just last year. Replaced it with a detroit. It is NOT my daily driver, but I do drive it to work once a week. I have no problem with the slightly higher RPMs, and actually prefer it. I normally drive 65-70 (never over 75) and rpm's are around 2800.

 

[Outlander560]

ouch 2800 that'll kill with mpg.

 

[cal]

Not necessarily. I run 37's and 5.13's, ~2700 RPM's at ~75 mph.. and get 17 mpg.

 

[jrowell]

ouch 2800 that'll kill with mpg.

At 70mph and with the aerodynamics of a brick, the difference between 2600 and 2800 rpm are not going to be much.

 

[Vanimal]

Not necessarily. I run 37's and 5.13's, ~2700 RPM's at ~75 mph.. and get 17 mpg.

i still have no idea how, even if i babied it i couldnt pull near that with 31's or 33's with 4.56's. don't you have a stroker?

 

[Darky]

I'm running 4.88s and 33s. I love it. The power is nice, rpms aren't bad. I say go 4.88.

 

[cal]

i still have no idea how, even if i babied it i couldnt pull near that with 31's or 33's with 4.56's. don't you have a stroker?

I do, but that makes almost no difference.. just makes driving it that much more awesome.

 

[clean4drxj]

4.56's are perfect for 33's, you'll have plenty of grunt for whatever you decide to do..

 

[ktm racer 419]

ouch 2800 that'll kill with mpg.

i ran at about 2800 rpms for 10k miles one month and averaged 15 mpg.

and thats in a fully loaded xj with 3 people in it and loaded with tools, spare parts, and camping gear. with 5.38sand 35s.

thats better than most empty, undergeared rigs on 35s, so i mustve been doing something right.

 

[Vanimal]

i ran at about 2800 rpms for 10k miles one month and averaged 15 mpg.

and thats in a fully loaded xj with 3 people in it and loaded with tools, spare parts, and camping gear. with 5.38sand 35s.

thats better than most empty, undergeared rigs on 35s, so i mustve been doing something right.

how fast were you going?

 

[ktm racer 419]

how fast were you going?

around 70 mph for the most part. there were some stretches going as much as 80 mph.

 

[the_weirdo]

I run 4.56'ss with 33" MTR Kevlars. I wish I had 4.88's, especially when hauling a ton of gear up in the Sierras.

 

[Outlander560]

damn you guys are killin me...thought i made my mind up guess im back to deciding which one to go for......maybe i should flip a coin

 

[Vanimal]

with an automatic, you'll probably be fine with the 4.88's.
with a manual trans, i'd say 4.56's if you street it.
i just hate shifting 4 times before i hit 30mph LOL

 

[wheelinscott]

My wife's DD is geared to 4.56 with 32s and it runs great with 20mpg on the freeway. I run 4.56 on 33s and wish I went lower, buts its not bad.

 

[Outlander560]

Vanimal it is an automatic....i just dont want to be killin the mpgs with 4.88s..I'm probably going to upgrade the gears when i go to 35s...probably my best bet

 

[VAhasnoWAVES]

go 4.88 now if the price on the other axles is right.

people who run 4.88s on 33s rarely post claiming they wish they had 4.56.
people who run 4.56s often claim they should have gone 4.88, while some are content.

you said the 4.88 geared axles have disks and chromos. do yours have disks and chromos? your 8.25 has a detroit, but what locker is in the 44? are they ready to run other than the CAD axle? id weigh the options of what will cost less.

fixing your axle and being happy?
or buying axles, and selling what you have?
does buying the axles gain you less/more than the cost is worth?

if you plan to regear later, the choice is obvious unless you intend to swap both carriers to selectable lockers. if you do in fact end up regearing yours, i suggest a selectable now.

 

[Outlander560]

I do not have discs or chromos in my 8.25 now. The only thing the 8.25 has over the 44 is the jks shock relocation brackets

The 44 also has a detroit locker

I would have to order another pair of jks shock mounts and weld them on $65 bucks isnt to bad...

For the most part they are ready to run even tho i'd put new rotors/pads, seals to switch out the CAD, and the shock mounts...SO a couple hundred bucks

I already have someone who will purchase my axles if I do decide to sell them. And the price I'm selling them at I will not lose any money getting the new axles

I do plan on going for a selectable locker...more then likely OX locker would be my choice of locker...not going for ARB

So it's 80 bucks and rebuild one of the D30s I have
Or a couple hundred and go for the d30/d44 running chromos front and rear

One thing I have to say though is something is bothering me a little bit about being at 2800 rpms in OD at 70mph

 

[cal]

Go for a long drive. Put it in '3' and find 2800 rpm's (whatever speed that works out to).

Drive for 30 minutes, see how you and the jeep feel afterward. It doesnt bother me and my strokers at all, you may feel differently. At the end of the day you have to live with it, so go with whatever makes you happy.

But do not fear that the equipment won't take 2800 rpm's all day - the 4.0 will.not.care. Its all how the driver feels.

 

[Outlander560]

i ran at about 2800 rpms for 10k miles one month and averaged 15 mpg.

Where on god's green earth did you go to put 10k miles in one month :roflmao: