AXLE RATIO?

JEEPJUNK2

New Member
Joined
May 13, 2009
Location
SILER CITY
JUST WANTING TO GET SOME IDEAS. I HAVE A 97 TJ 6CYL 5SPD WITH 6INCH LIFT AND BODY LIFT RUNNING 36-14.50-15 TSL RADIALS WITH 4.10 GEAR NOW AND WANTING TO RE GEAR IT. DRIVE IT ON THE HWY MOSTLY BUT PLAY OFFROAD SEVERAL TIMES A MONTH. NEEDS LOWER GEARS BUT DON'T KNOW IF I SHOULD RUN 4.56 OR 4.88. THOUGHT MAYBE SOMEONE HAS DONE THIS BEFORE ME COULD MAYBE GET THEIR THOUGHTS ON IT. THANKS
 
I'm running 4.88s in my TJ with a 4.0/5speed and 35s. Actually I wish it were a little lower geared sometimes offroad, so I would definitely go with the 4.88s for 36s.
 
How does it do on the highway now? Which is more important, on road or off road performance.

I have 4.3:1 low and 4.88 in the axles running 37x14.5x15's with a I6 auto TJ. It won't do much better than 55 on the road, floored. You may have a little better experience with the five speed. Off road it was difficult to stop/control with an auto and all the torque until I upgraded the brakes. Again the five speed will help this issue too.

In either case you will probably be disappointed with 4.56's or 4.88's since you already have 4.10's. You may want to consider going to 5.13's. You'll turn more RPM's but with the five speed you should be fine. Btw, the lower you go the weaker the R&P will be, simply less teeth engaging.
 
I have 4.56s in my yj 5 speed with a semi built 4.0 (cam, injectors, headers, etc) swap runnin 36 13.50 iroks which are actually 37s and not in any need of a lower gear. Altough lower would be better off road its not worth it for as much as you would be driving on the road. with the 4.88s goin 60 or 65 down the road your rpms will be screamin.

if youd say you drive on the road 75% or more get the 4.56, will get you 4 or 5 mpg better and you wont be shiftin like crazy when you accelerate.

also i can smoke almost any car of the line, those 4.0s have crazy torque
 
Rox&Mud said:
You may want to consider going to 5.13's. You'll turn more RPM's but with the five speed you should be fine. Btw, the lower you go the weaker the R&P will be, simply less teeth engaging.
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Can't got deeper than 4.88s if he's running a 30 front
 
cj777 said:
Can't got deeper than 4.88s if he's running a 30 front
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Actually Chase has 5.38's available.
http://eastcoastgearsupply.com/i-126809-nitro-dana-30-ring-pinion.html

My point was mainly that since he already had 4.10 he may not realize the performance jump that he may be expecting compared to folks who were running 3.07 or 3.73 gears.

Also, for some reason I misread his post and thought he had 4:1 transfer case which made me think he had a Rubicon with D44's.
 
Gears

We have a 88 XJ, 4.0 and automatic with 4:56's. The Jeep was perfect with 35's, since we went with 33's and i can't go above 60-65 mph with out screaming the 4.0. Just my two cents.
 
2000F150SAS said:
We have a 88 XJ, 4.0 and automatic with 4:56's. The Jeep was perfect with 35's, since we went with 33's and i can't go above 60-65 mph with out screaming the 4.0. Just my two cents.
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My 98 ZJ with 4.0 and auto has 4.56's on 33's and does great up to 80+. I don't usually drive that fast but it has happened on occasion.:D

Unfortunately, every Jeep will be different and upgrade results will always vary from one Jeep to another.
 
Rox&Mud said:
My 98 ZJ with 4.0 and auto has 4.56's on 33's and does great up to 80+. I don't usually drive that fast but it has happened on occasion.:D
Unfortunately, every Jeep will be different and upgrade results will always vary from one Jeep to another.
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Do you have overdrive? I don't.
 
Yep, the ZJ does but the TJ doe not. With his being a five speed it would be the equivalent to my od but probably better. I should have gone 4.88 because on inclines on the interstate it struggles to keep speed but not bad enough to spend the money to change it again.
 
Rox&Mud said:
Yep, the ZJ does but the TJ doe not. With his being a five speed it would be the equivalent to my od but probably better. I should have gone 4.88 because on inclines on the interstate it struggles to keep speed but not bad enough to spend the money to change it again.
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Once I can swing for the 35's I'll removing the 33's so I can run 60-65 mph.
 
cj777 said:
wow hadn't seen that yet. :beer: Bet it's a tiny pinion
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Has to be pretty small. Anything over a 4.56 R&P in a D30 loses one tooth of contact between the ring the and pinion.
 
Dumb question... (still learning bout gears) why does the pinion get smaller as gears get lower? And why are teeth not engaging? Thought they were engaged all the time?
 
mtmech said:
Dumb question... (still learning bout gears) why does the pinion get smaller as gears get lower? And why are teeth not engaging? Thought they were engaged all the time?
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The lower(numerically higher) gear you go the less gears the pinion has, there for making it weaker because there are not as many teeth engaged with the ring gear. I really don't know all that much about Jeeps but shouldnt you be more worried about 36's on a D30? Thats just asking for something to break, esp with the torque of lower gearing. Correct me if I'm wrong.
 
i run 4.56 on 35's and i cruise at 70 down the interstate. plenty of power and run about 2400 rpm in 5th.at 4th i think im at 3500rpm going 70. she moves then. im loving it. im 4.0 5 speed.
 
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