92 Gearing from 3.55 to 4.56

[XJonAZ]

Hey all, wondering what is needed to swap out gears from 3.55 to 4.56 on my 1992 4door. Currently running 275x70/17 and am going to be bumping up to 33x12.5x15. Want to make sure I gear it right. For the rear D35 i am pretty sure I can just swap out ring and pinion, but in the front what else is needed? From what I am finding online the Dana30 front carrier only will go up to 3.55. Also, thoughts on the gearing selection for the 33s? 4.56 or 4.88? What about lockers?

 

[Johnnie Walker]

4.56, Ecceptally if you plan on running your heep on the highway. While you're there. Get rid of the D35. you will need a new carrier anyways. Upgrade instead of polishing a turd. D44. C8.25, exploder 8.8, etc

 

[garr]

Double tap on ditching the D35, don't waste your money upgrading it! 8.25's & Ford Disc brake equipped 8.8's are very inexpensive & everywhere!

 

[denverbusa]

Not 100% sure by your comments that you understand those parts do not just simply bolt in and out. Look into gear set up. Its another science altogether, of the black arts variety LOL

 

[WyoCherokee]

the 3.55 dana 30 carrier will not fit 4.56's, You need the larger carrier. and R&P installs are not just swap in and out. If you have never done them, do a ton of research or take it to someone who has done them before. You can run the Turdy Five, but dont expect it to last long. Be on the lookout for an 8.25 or a 8.8. Go for 4.56's with a 33" tire. The 8.8 will probably come with a lim slip already in it, and get a trutrac for the front unless you want a full case air or e-locker

 

[dan1977p]

Not sure why the hate for 4.88 on 33's. I run 80mph at 3k rpm and my jeep loves it. I think it only goes down to 2800 with 4.56's so it's not enough of a change to matter. If I felt I needed to go faster than 35 in 4L at 4k, I would go with 4.56.

 

[1990JEEPXJ]

Go 4.88s

 

[Rod Knee]

IIRC 4.88 is not an option for the c8.25, which would be the easiest swap if the OP were to take the advise of ditching his d35.

 

[reddragon72]

So I just threw some 33's on my 94 auto. Still running the 3.55 gears.

At 65 I am running at 1850 RPM.
at 70 2k
75 2100

Going up and over steep bridges on the freeway with a couple of those hills I turn 45 degrees in the bend I can make it with just a little more gas but rarely do I drop out of OD.

So why would I want to run 4.56 at 3k... in all my years of working on vehicles you usually want to run around 2k 2.5k but I have never heard 3K before.

Because of this I have swayed away from the regearing at this time.

So why run at 3K, seems to put more wear on the engine and tranny as well as killing gas? Just wondering.

 

[dan1977p]

IIRC 4.88 is not an option for the c8.25, which would be the easiest swap if the OP were to take the advise of ditching his d35.

It's an option. I'm running 4.88 in my 8.25

 

[Demonoid369]

It's an option. I'm running 4.88 in my 8.25

I can confirm also, I have 4.88 gears for my 8.25

 

[dan1977p]

So I just threw some 33's on my 94 auto. Still running the 3.55 gears.

At 65 I am running at 1850 RPM.
at 70 2k
75 2100

Going up and over steep bridges on the freeway with a couple of those hills I turn 45 degrees in the bend I can make it with just a little more gas but rarely do I drop out of OD.

So why would I want to run 4.56 at 3k... in all my years of working on vehicles you usually want to run around 2k 2.5k but I have never heard 3K before.

Because of this I have swayed away from the regearing at this time.

So why run at 3K, seems to put more wear on the engine and tranny as well as killing gas? Just wondering.

Stock power band is around 2800 iirc. It's not ideal to run 3k but I still get same gas mileage. My point is the difference between 56 and 88 is so negligible in rpm that the loss in gearing isn't worth it.

 

[AceWhite]

IIRC 4.88 is not an option for the c8.25, which would be the easiest swap if the OP were to take the advise of ditching his d35.

I have a 8.25 rear/ D30 front with a Detroit locker and 4.88 gears. What's not an option? The D30 will not accept anything larger tho
Oh not quick enough

 

[Serious Offroad]

IIRC 4.88 is not an option for the c8.25, which would be the easiest swap if the OP were to take the advise of ditching his d35.

Got 'em on my site.

 

[Serious Offroad]

I have a 8.25 rear/ D30 front with a Detroit locker and 4.88 gears. What's not an option? The D30 will not accept anything larger tho
Oh not quick enough

Yes they will.
5.13 is available.

 

[AceWhite]

Yes they will.
5.13 is available.

Dang I was unaware of that- thought 4.88 was the largest available for the D-30. Thanks for the info....

 

[Demonoid369]

Dang I was unaware of that- thought 4.88 was the largest available for the D-30. Thanks for the info....

The 5.13 is new to I think this year so last year and before, there was no 5.13 for d30's

 

[dantheman!]

pretty sure im going 4.88 when i regear mine.

also 92 auto with 33s. it hated doing 75 in OD. had to run it in 3rd to run highway speeds without having to floor it constantly to force the down shift on any sort of grade.

 

[RWKHausSupply]

fyi.

Dana 35 - 3.55 carrier WILL fit up to 5.13 ratio.
Dana 30 - 3.73 up carrier will take up to 5.13 gears.

And there are Plenty of us on here that offer gears for these. Some lower price and more knowledgeable than others. Except if you want 5.13 for the D30 or D35 you would need to get them from someone that offers Revolution gear or a 'white box' repackaged revolution gear.

 

[dan1977p]

fyi.

Dana 35 - 3.55 carrier WILL fit up to 5.13 ratio.
Dana 30 - 3.73 up carrier will take up to 5.13 gears.

And there are Plenty of us on here that offer gears for these. Some lower price and more knowledgeable than others. Except if you want 5.13 for the D30 or D35 you would need to get them from someone that offers Revolution gear or a 'white box' repackaged revolution gear.

Does anyone do thick cuts for the 30? That could be another option if you don't want to get a 3.73 carrier.