Gearing Frustrations

[CJAKE7]

I need help with gearing/axel decisions!!
Stats: 85 CJ7 , AMC 258 i6 / 4.2l , stock Dana 30 and AMC20 (w/ solid axel upgrade) running 33 x 10.50, used for light wheeling, firewood getting(w/trailer) mostly road driving
Problem: gearing too high!!!
I want to keep the 33s but it is geared way to high. Do I keep my axels and just regear(can this be done in my garage, by me-marginal mech ability)? Or do I go to a junkyard and look for axels geared to what I need(if so what doner vehicles do I look for)? Not sure what gearing I have now. I have a tight budget but I am sick of not being able to use 5th gear. HELP!

 

[Torxhead]

I would suggest a 3:70 ratio, I have 4:10s and for the highways w/33s@28 psi, it puts the rpms a bit on the high side for a six cylinder engine. Driving a CJ7 w/33s faster than 65 mph is too fast, but that is just my opinion. If you want to go slower in the dirt, there is always lower gears for the Transfer Case

 

[harleydragon]

the 33's have basically geared your jeep so that 4th is geared about the same as 5th was originally..if your budget is tight I would just forget about 5th and use it like it is until my money got better..I don't feel that regearing is a job for an amatuer.. I don't know about axle changes as all I have ever swapped into cj's was full size chevy axles..my yj has 33's with 3.54 gears and it accelerates good and has a great road gear but might be considered a little high by some..it is a 4.0,auto

 

[IOPort51]

What a shop gets for setting up an axle is cheap!! just the crush sleeve on the AMC20 is a nightmare with out a 3/4 inch impact wrench. you could spend almost as much on micrometers and indicators as they will charge you.

I would say 3.54 or 3.70 would do good for you.

 

[CJAKE7]

Axel set up cheap?? Where do you get your work done? Everyone I am talking to say to figure $2,000 per axel for regearing w/parts. I not only want 5th but I do a little crawling and last weekend I blew out a side wall because I couldn't go slow enough- in other words I got to buy a $180 tire instead of putting it towards gears. I also want it for towing a trailer full of firewood.

 

[Torxhead]

A lot of guys add in a locker or two to optimize off road performance and that is where the big bucks can come in. Putting stuff like sharp rocks and branches through a sidewall usually comes from poor tire placement btw. It is a Jeep after all.

 

[cj7inthetwigs]

4 grand to regear your jeep should come with your own bucket of lube and 2 reach-a-rounds....I was thinking a couple hundred per axle?

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[IOPort51]

it is about $200 to put all the parts together which is a lot better than what you are going to go through to do it yourself. It is the parts that come dear. R&P, install kit, wheel bearings and more than likely a carrier with spiders or a locker. yea you can drop a couple of grand on an axle real fast but it isn't for the labor.


I try not to think about what I spent on this one.

 

[Jimbos76cj]

For $2000 an axle your in the range for a custom built G4 rock jock or other brand heavy duty axle. Should run about $350 in parts and $500 in labor per axle.

 

[Old Dog]

Since you have a 5 speed I'd go with 4:10's. There is a real good chance you have 2:73's now. If so you will need new carriers for any new gears that are worth running.
Setting up the gears should only be 2-300 bucks, but as IO said the rest of the parts will cost ya around 4-500 and that's if you stay with an open diff
Setting up gears takes special tools and some know how so if I were you I'd let someone else do it..

 

[Old Dog]

As far as other axles to look for the only bolt in is going to be another wide trak cj.

 

[Torxhead]

Another thing you might want to consider, is later on you might want to convert to one of the ultra low first gear truck transmissions which are not an Overdrive Transmission . There is a low first gear tranny with Overdrive out there, but it is a bit on the long side, making it hard and extremly expensive to adapt. The aluminum T-5 Transmission that you have is a weak tranny at best, but a few guys seem to get them to hold up.

 

[thescot]

I would suggest a 3:70 ratio, I have 4:10s and for the highways w/33s@28 psi, it puts the rpms a bit on the high side for a six cylinder engine. Driving a CJ7 w/33s faster than 65 mph is too fast, but that is just my opinion. If you want to go slower in the dirt, there is always lower gears for the Transfer Case

Im running 4:56's and 32's and a T-5 in 5th. My tach says about 2200 RPM doin freeway speeds of what I think is 60ish. The speedo says more like 80 so I cant verify. Id be thinkin at least 4:10, 4:27 or so with 33's.

 

[S76]

I just went through setting up a front and rear dif. To be perfectly honest, it cost a lot! Not $2k per axle, I have no idea where they are getting that number, but expensive just the same.

The best way to go about this is to find a complete set of axles all set up with the ratios you need. You will almost never pay more than $500 each and can bolt them in yourself.

If you want to regear your axles, you will need new gears ($250 or more)and new carriers ($50 or more used) a rebuild kit ($125 or so) and then pay someone $200/250 to set it up. Then you will need some additional parts, axle seals and things, so another $75/100 and that is if you do not need ball joints, brakes, etc. while it is apart.

That is for the front. If you do the back it will cost all that, and add another $500 for a TruTrac, and you will then be able to use 5th gear.

The one thing I learned is it is cheapest to buy big pieces! You can probably get a partial project that didn't get finished for $1500 or so and get tons more good parts.

 

[Dolamite]

I'm in the same boat as you CJAKE7. I'm running a AMC 258 i6 / 4.2l with 33" tires and my differential is open with a 3.07 gear ratio. I'd like to get to a 4.10 ratio with a Limited slip. I'd love to find one in the junk yards, but I doubt it will happen. I just called one of the local drive train specialists to feel them out. I didn't get a solid quote, but it sounded like I'm going to have to take my wife out a few times before I tackle this upgrade.

Somebody please correct me if I'm wrong, but from what I have read the gearing in the rear has to match the gearing in the front which means that both axles will need to be upgraded.

 

[harleydragon]

I'm in the same boat as you CJAKE7. I'm running a AMC 258 i6 / 4.2l with 33" tires and my differential is open with a 3.07 gear ratio. I'd like to get to a 4.10 ratio with a Limited slip. I'd love to find one in the junk yards, but I doubt it will happen. I just called one of the local drive train specialists to feel them out. I didn't get a solid quote, but it sounded like I'm going to have to take my wife out a few times before I tackle this upgrade.

Somebody please correct me if I'm wrong, but from what I have read the gearing in the rear has to match the gearing in the front which means that both axles will need to be upgraded.

yes,it has to match if you ever plan to use 4 wheel drive...

it has always been cheaper for me to just go ahead and use a full chevy drivetrain plus it is much more heavy duty

 

[gert]

it is about $200 to put all the parts together which is a lot better than what you are going to go through to do it yourself. It is the parts that come dear. R&P, install kit, wheel bearings and more than likely a carrier with spiders or a locker. yea you can drop a couple of grand on an axle real fast but it isn't for the labor.


I try not to think about what I spent on this one.

:drool: IO that axle looks to sexy to be under a jeep, it should be mounted over the fire place so everyone can see it lol

 

[Petescj]

I'm in the same boat as you CJAKE7. I'm running a AMC 258 i6 / 4.2l with 33" tires and my differential is open with a 3.07 gear ratio. I'd like to get to a 4.10 ratio with a Limited slip. I'd love to find one in the junk yards, but I doubt it will happen. I just called one of the local drive train specialists to feel them out. I didn't get a solid quote, but it sounded like I'm going to have to take my wife out a few times before I tackle this upgrade.

Somebody please correct me if I'm wrong, but from what I have read the gearing in the rear has to match the gearing in the front which means that both axles will need to be upgraded.

Yes they do have to match. If your looking through the junkyards check some 4 cyl. models if you see them. Many of them came with 4.10s. If you find them make sure and open it up to confirm though.

 

[NorthwestCJer]

I have re-geared my current 84 CJ7 from 2.73 to 4.10's.. (have done many other rides)
I use my jeep for off road use.
But I still like to jump in it and run to the parts store or grocery store from time to time.

With that said, I chose 4.10's for many reasons. 4.10's are the strongest gear ratio because it has equal ring and pinion strength. And it fit with the speed I like to run trail at.
Here is a good calculator to use.
Gear Ratio Calculator

When I re-geared this jeep, I found a Dana 30 wide trak from a 4 cyl CJ7 with 4.10 gears and swapped in my locker, axles and outers for $400.00
I had acquired a good 4.10 ring and pinion for the "20" and pulled a carrier from a wagoneer with 3.31 gears ( used my detroit box locker). I also had one piece axles. Do to work schedule and other issues, I paid JT ring and pinion $400.00 to install my parts but they totally re-bearing and had to do some machine work that was needed.
I was re-geared for under $1000.00

As previously stated, you could change the trany, but that won't help on top end. Only in first gear and crawling. If you are happy with top end, then this might be the way to go, but remember, big tires work like a pry bar on the end of the axles. If you have a "week" ring and pinion, you will end up braking it.

I also know people that just install a "TeraLow" in the Transfer Case . This will lower your bottom end also.

To figure out what is best for you...
Decide what you are going to do with the jeep?
How much money you can spend?
And do some calculations on this site...
Gear Ratio Calculator


Good luck. its your call

 

[deadfeat]

4:10 work well with my 35s and an aw4 OD Transmission . Makes a great daily driver

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