I've been reading some of the posts on 5.13's breaking. That makes me a little nervous since I'm not a diy axle guy, am on a budget, and the Jeep IS my daily driver. Now, knowing that the lower the gear the smaller the pinion, hence, weaker gear set; what would I be gaining/losing by going to a 4.56 or 4.88 ratio? I know the RPMs are not really an issue since they don't vary much between the sets.

60MPH
1621RPM stock

1812RPM w/35's and 4.56's

1940RPM w/35's and 4.88's

2039RPM w/35's and 5.13's

My big question is, what do you gear guys/gals recommend for a RELIABLE, DURABLE ratio that will see 90% street duty?

 

I would have to say it really depends on what typoe of driving. Highway /City or Highway. If you do Highway /City i would recommend 488

Just my two Cents.

Gerry

 

is it safe to do interstate driving between 70mph and 75mph w/ 5.13's and 35's in an automatic?

 

Ok..makes complete sense! My jeep will never see elevations and rarely even go above sea level hahaha...I was just wondering b/c I've read that any automatic should do 5.13 and manual should do 4.88..and I also read somewhere that 5.13s are not made for interstate speeds and that they could have complications and/or break at 70 to 75...is all that right??

 

I've got a 4dr, automatic with 35's and 5.13's and it is about ideal at 70-75. Rpm at 75 is 2600. Truth be known I'd really rather be at 2700-2800 rpm. The JK wants to go down the freeway above 2500 and below 3000. My gas milage is the same as when it was a stock Rubi with 4.10's and 32's.

Keep in mind I'm in Colorado at 4500 ft and have a fairly heavy 4 dr. The only downside I see to 5.13's is that if you go with 37's you'll wish you had 5.38's!