Need Some Help w/ all this Regearing Information Please

Gachrid

New member
Hey all, new JK owner here. I'm sorry for another gear thread but I've been doing a lot of research and just a getting confused with the different information I find. I recently purchased a 2010 4DR Sport 3.8L Auto after wanting a Jeep for over a decade. I want to make some upgrades to get a more aggressive look and I'd like to upgrade to 35's to start. I want to make sure I make the right changes to support them without breaking the bank. I am currently on 3.73 gears with a D30 up front and a D44 in the rear. I am thinking of going to 4.88 gears at the moment. I understand that the charts say 5.13's on 35's but I've also read that it puts the RPM's a little high between 70-80mph on the highway. I do a lot of highway driving with it so I thought the 4.88's would be better.

The problem I'm having is that I read too many conflicting threads on the different forums. Some people say that going with 5.13's will grenade the D30 easily and some say it will only cause problems if you're wheeling a good amount. I'm guessing asking this will only get me the same responses but I'd like to see ha. So, are they strong enough in the D30 for daily driving? My Jeep is only a DD. It either sits in the garage while I drive the work truck or is out on the main roads/highways. I do not off-road at all and probably never will until my Jeep is longer a DD. What are the thoughts here?

Also, I know I need to add C gussets but are the needed right away? I don't have anybody that welds so I'd need them installed by a shop. With a wheel and tire package being bought, the added cost of buying and installing these will be tough. Also, they get installed in the front and rear correct?

I apologize again that this has been asked so many times but sometimes it's hard to get facts reading some many different threads. I'd like to be able to ask questions somewhere. Hope somebody can help me out. Thanks!
 

thardy

Banned
First, welcome to Wayalife. With going to 35s and you already have the 3.73, I would suggest doing the C-gussets (they're only in the front), over the gears. You might get a couple MPG less, but with being you do mostly hwy driving, I wouldn't worry too much about it.

I could be completely the opposite of what everyone else says, but I would prefer to have the c's protected if I had to chose.

Also, depending on what lift, wheels, and tires you're going with, you might be able to get away with something less expensive to be able to get the gears and the gussets. What parts are you planning on going with?
 

chipper

Member
The c gussets get installed in the front. Highly recommended when you go with a bigger tire. Hitting a pothole can bend your c's. But I do know lots of people that don't have them, no reported problems YET.
 

Gachrid

New member
Thanks for the help guys. Planning on a small lift. I as planning on either a 2.5" Teraflex Lift or the 2.5" budget boost with Bilstein 5100s. I would like to go with 315/75r16 Duratracs with Crager Soft 8's. Not sure if it's better off going with the 17" versions though. I've read that having too much sidewall can be a bad thing. Not sure what that decision will be yet.

I do plan on adding the c gussets just wanted to know if it should be right away. Seems like its the best interest to do so. I'll have to figure out how to get those installed.

Otherwise, what gear set is safe for the D30 but decent to use as a DD with 35's? Are the 4.56's a better fit?
 

cozdude

Guy with a Red 2-Door
Thanks for the help guys. Planning on a small lift. I as planning on either a 2.5" Teraflex Lift or the 2.5" budget boost with Bilstein 5100s. I would like to go with 315/75r16 Duratracs with Crager Soft 8's. Not sure if it's better off going with the 17" versions though. I've read that having too much sidewall can be a bad thing. Not sure what that decision will be yet.

I do plan on adding the c gussets just wanted to know if it should be right away. Seems like its the best interest to do so. I'll have to figure out how to get those installed.

Otherwise, what gear set is safe for the D30 but decent to use as a DD with 35's? Are the 4.56's a better fit?

IF your going to do the teraflex lift make sure you get the BB and not the coil lift. Trust me I have it and I thought it was a rough ride.

As for tires and wheels get 17" wheels. Trust me. I had 16" wheels and 35's and when I wanted 37's I needed to move to 17" wheels. Also there is more options available for a 17" wheel than a 16" wheel.

17" atx chamber pro w/ 35/12.5r17 on the left and black rock soft 8's (crager knockoffs) 315/75r16 on the right.
ImageUploadedByWAYALIFE1440209314.542456.jpg .


As for gears if you see yourself running larger than a 35 in the future than do 4.88's. They will be amazing for the 35's now and still be strong enough for 37's later. Or you can do what I did and do 5.13's now and just swap in an aftermarket axle sooner than later to ditch the d30
 

Gachrid

New member
Good point on the 17's. That is one thing I thought about. Many options to switch 17" rims. So you're saying just go with the basic 2.5" Budget Boost and use stock springs and shocks? Better ride quality?

Also, I don't see myself going bigger than 35". So 4.88's would be good for the 35's and safe in the D30?
 

Gitzen

New member
I have 35's with 3.73 gears and its my daily driver. I chose not to regear just because I plan on upgrading my front axle sooner than later. My advice is put your lift on and tires and drive it to see how you like it. It may be fine for your liking and then you can put the $1000+ towards something else.
 

Rccrwlr

New member
Only experience I can comment on is from putting 35's on our 08'. We had 4:10 gears and couldn't hold 60-70 on the freeway. The 3.8L sucks and has no power. Pretty sure you have the same motor we do.

Now we went with 5:13 and wow does it make a large difference. Not sure that ratio is recommended on the D30. I believe the statements are the pinion is really small. We have a Rubicon with a dana44 so there wasn't an issue
 

cozdude

Guy with a Red 2-Door
Good point on the 17's. That is one thing I thought about. Many options to switch 17" rims. So you're saying just go with the basic 2.5" Budget Boost and use stock springs and shocks? Better ride quality?

Also, I don't see myself going bigger than 35". So 4.88's would be good for the 35's and safe in the D30?

Yes the BB will allow you to keep the factory ride.

If you don't see yourself going larger than 35's than yes 4.88's will be perfect for them. Also that is the max size I would suggest going in a d30 so yes it's safe.
 

aldaman

Member
I had an 08 JKU and ran 5.13s with 35s on 16" rims (2.5" TF coil lift) for over 4yrs and had no problems. It too was my daily driver and I did the occasional mud trails and beach driving. The 5.13s held up well with the D30 axles. Just go easy on the skinny pedal.

Like what others recommended get it gussetted as cheap insurance for your front axles. As for 16s vs 17s there isn't too much difference with off-roading, but would get 17s just because of the greater tire/rim selection available.

If you take the BB route I would run that with the heavier duty Rubi Springs instead. If not then I would go with 2.5" coil springs from a different manufacturer other than TF or Rough Country.

Lastly, at the minimum I would regear to 5.13s (power wise) Even at that gearing, with the 3.8 engine and auto trans it still left me wanting more, but 5.13s would be the highest I would go with the stock front axle.

image.jpg

:beer:
 
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Gachrid

New member
Thanks for the replys thus far. As expected the opinions are well mixed. Seems like I should do the wheels & tires, lift and gussets then see what I need for gears.
 
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