I just had a set of Superior 4.88 gears installed in my 2 door Rubicon. The fronts seem fine but the rears are quite noisy, both on acceleration and deceleration. The installer was concerned and had a second set sent along with a new master install kit. The result was the same.

Has anyone else noticed these gears to be quite loud?

 

Superior gears are usually pretty quiet even on install. But the rule of thumb is after about 100 miles of proper breakin they should quiet down. That is common with lower grade gears like Genuine Gear.

 

no gear noise at all,

your the first I've read on here with this problem..

 

if its more of a lowed wine it quite likely could be your rear axle forward pinion bearing. I know of 3 that have fused so far, one being a good buddie of mines rigs.

 

How would I check this? I have the 4.88's and don't have a whine, but a squeek (I have an auto) when I pull off the gas... a chirpy squeeky noise out of the front end somewhere... everything looks good though.

 

You would know if it was the bearings. It gets to the point where it sounds like a jet engine powering down. Some slight chirping when your slowing down may go for a bit until you've gone through a gear oil change (500 miles I think for new gears). The real thing to pay attention to is if the noise gets lowder.

 

The installer has tried two completely new gear sets using a separate master install kit each time. It does seem to be quieting down a bit. I probably have about 100 miles on it now so will give it a week or so and see where it is then.

Thanks for the suggestion - I appreciate the help!

 

Aside from the noise, how do you like your choice of 4.88s over 5.13's?

Forgot to ask, what size tires you running?

 

I'm running 35" tires. I've only had it back from the shop for a day but so far like the 4.88s. I haven't driven a similar vehicle with 5.13's, so can't really make a comparison. I chose the 4.88s because they give an overall ratio with the 35's that is fairly close to stock (just slightly lower). I had a TJ with pretty intolerable driveline vibrations and this time wanted to keep the "driveshaft speed" closer to stock.

Acceleration seems fairly close to what it was before the changes. I should be able to get it out on the trail this weekend and see how I like its performance there.

 

Are you driving an Auto or Manual? Curious to see how 4.88 will stack up on my vehicle.