88 Chief

Well ive herd that it might be a bid idea to get 31s with my jeep have 3.07 gears. Will it just be a pooch like others have said or would it be ok? Or should i just save up and swap out the front and rear diffs?

Donnie_K

I'm running 31's on 3.07's. It does ok, it sees a few highway miles every day. I do find myself shifting at a higher rpm now though.

mtparker97

honestly i dont have a problem at all. how good is your engine running? i dont think mines a pig at all. is can still $hit and get when it needs to. now rolling at 65-70 going up hill may need to down shift but big deal.

88 Chief

Mine seems to run good. It does have 253k miles so maybe not as good as what its sapposed too but i can still beat the hondas so its all good right?

Mike H.

I hated 30's with the factory 3.07's.
If you have any mountains around, expect to be around 4000rpm in 3rd to keep from being run over (that's what I was at with 30's).
On any decent incline, the amount of clutch slip was making me crazy.
When I went to 31's I also threw 4.56's in... life was much better around town, but a bit busy on the interstate... when I moved to 33's the 4.56's felt perfect.
If you plan on staying at 31's, I would suggest 4.10's... 33's work very well with 4.56's...

88 Chief

I do alot of in town stuff and i go on the interstate about once a week or more depending on whats going on. It has 29s? (235/75) on it now and it does decent. I was only thinkin 31s because of the tires i wanted to run. If i changed out the gears in it, how much would it end up being? If i went 4.10s. I dont plan on running anything bigger for a while. But if i did head east from my place i would run into hills, and i go out that way maybe once a month.

hood81

i got 31s as well with 307s and its fine not much of a diff. at all think i lost 1mpg from my stock tires ,i was planning on regearing and its about 1600$ for all parts (new) not including labor if you cant do it yourself.

88 Chief

Wow definitely not going new haha To far out of my price range. Would their be a difference if i went mudding. These are the tires im getting: http://www.treadwright.com/shopnow/p...rd-dog-mt.aspx I dont mind losing gas mileage its not all that important to me.

wapozzi

i run 31's on 307 gears and it does ok street or wheeling. i have stalled quite a few times wheeling even in 4low.

sandaddik2

1600? are the gears made of diamonds?????
randys ring and pinion sells them for roughly 130-150 a set so your at 300 for the gears plus rebuild kits if you think you need em your at 600. or just search the forums and do like i did and buy a set from someone used. i got 456s for 75 bucks and theyre fine for a dana 30 and my d35 gears for 100. gears dont wear out like tires or bushings.
and i was able to re use some of my old bearings so its not too expensive at all. look around and youll find someone to do the diffs for 150 each if you cant do the work. at worst case your into it 900.... a far cry from 1600.
whoever quoted you that was trying to rip you off

CRoading

31s on 3.07 gear works just fine for both on and off the road....

Donnie_K

not sure I'd be comfortable with 4.10's on 31's on the highway... lol. I think 3.55's or 3.73's would have you feeling about like it did on stock tires. Gotta remember, these manual transmissions have a lower output gear than the automatics do.

drakesword

If the 307 was stock for the d35 in an 88 then i'm running it with 33s. Don't take it wheeling but hell i'm getting a good 22-25 mpg when i drive it like a granny

96_xj

i run mine with 33's and 3.07's i just got 13mpg towing a 3500lb trailer... normal gas mileage is better and i wheel mine all the time. run it until you can afford gears or swap a 3.55 axle from an auto in!

Diesel

It will be fine, I just prefer the 4.10 with 31's