i need some fellow cruisers advise and opinions on this. im currenty running 1ton axles with 5.13's on my fj-40. i shaved an inch off both diffs for some clearance. but im also running a 205. horrible low gear.

im debating on going to rockwells. would you think this is a good swap? or should i just stick with the 1tons. im running fj40 springs with revolvers over my axles right now. flexes great. but if i go rockwell i'll have to upgrade to coils or coil overs. just wondering if the extra money is worth it. any input from you guys would be great. thanks

Put your money into lower gears....

Wait, what type of wheeling do you do?

it all depends how cheap you can get some rockwells. and there is no reason you can't use your exsisting leaves. i am putting a set of rockwells under my main trail rig[88 fj62] because they have the right gears and they are cheap. i have a sey of 1 ton axles i could bolt in also but i would need to buy one more locker and a new gears. rockwells are just cheaper for me. i am mounting the spring pads tonigt for my rear axle and will finish the brake also on it. one word of caution, that rockwell third member is a heavy sob and it can be dangerous. also if you go rockwells, when you remove the rear brakes. cut the heads off the rivets and don't bother trying to drive the rivits out. just take a 20# sledge to the backing plate. it is much faster that way and you are going to junk the brakes anyway. it is super easy to weld the spider gears, there are 4 holes on each side of the carrier. just weld them up solid. i have detroit for the front. mike

i do a little bit of everything. im in michigan so i dont have the rocks they do outwest. i'll be making 2 trips a year down to tellico. and were starting a rock crawling comp here in michigan next season. so i want low gears. but i also run alot of mud. and love going to the sand dunes. think i should just wait for the 3:1 kit for my 205 and keep my present running gear?

I have been thinking about the Rockwell situation lately myself. I think I know where I could get a set cheap but don't know much about modifying them for pinion brakes, etc. Are there any sites out there worth studying?

If you are not breaking your axles then get the lower gearset.. .

Why go to rockwell if you are happy with what you got?

Given the near cult status Rockwells seem to have been placed in, I hope my thick skin and nomex will protect me;) I can't understand whay anyone would switch from 1-ton axles to Rockwells. As Mike points out the pros of the Rockwells seem to be the low OEM gears and cost. In my opinion, when these two factors are weighed against all of the cons associated with these axles (weight, brakes, width, clearance), the 1 ton units are much better for an FJ40. That of course is just my opinion.

I assume, with your screen name, you have some sort of Chevrolet drivetrain.

My humble opinion would be to keep the axles and add a doubler.

Best bet for the creep you want and keep the cash in your pocket.:p

rockwells are :rainbow:

i'd love to do a doubler.. but dont have the room. cant sacrifice anymore rear driveshaft. im running a 396 bigblock. 350 to a 205. my rear shaft right now is 24 inches from yoke to yoke. i think the doubler will cause me alot more problems with my rear drive angles. ive already flipped my springs in the rear for 3 more inches of wheelbase. but still dont think a doubler would fit. has anyone put a doubler in with leafsprings?

You can flip therear hanger 180 degrees and grab another 3.5" or so. I did it for the SM465 and np205 to center rear axle and have plenty of room for the doubler.

Jeff Moore, on this board has done the doubler and it will work.

You already have unbreakable axles, so go the next step!

Where are you in Mi?????

Originally posted by ChevotaSS
i'd love to do a doubler.. but dont have the room. cant sacrifice anymore rear driveshaft. im running a 396 bigblock. 350 to a 205. my rear shaft right now is 24 inches from yoke to yoke. i think the doubler will cause me alot more problems with my rear drive angles. ive already flipped my springs in the rear for 3 more inches of wheelbase. but still dont think a doubler would fit. has anyone put a doubler in with leafsprings?

It is possible but oyu have to move back the springs more..

Basically it works if you inboard the springs and use the rear bumper as the shackle hanger.

I am doing that exact same thing this weekend to my 40 except I am making room for dual mini tcases..

I'll see if I can get some good pics of it.

thanks.. pics would be great. i hear the new gen II doubler only adds like 6 inches? does anyone know if thats true? if so i could probably get away with it. plus moving my spring mounts back a bit. i have 3, 203's laying behind my garage for the donor.

rugburn. i live about an hour west of detroit.. metro detroit area.
if your in INDY.. we might have to meet up at the badlands sometime.

Cool on the 203's

My wife and I have a place south of Coldwater and the MIL is in Rochester Hills.

Any shots of the rig????

I'll be in Coldwater over Labor Day.......:D :p

Regear....no matter how cheap you get your Rockwells, I don't know how you could do the swap cheaper than just changing the R and P in your 1 ton stuff.....

rockwells are :rainbow:

That hurts jiMMy, it hurts bad...

How about a Klune? Maybe pricy but I think its the way to go

IVe never really researched the KLUNE-V. no idea what the prices are or length.

rugburn i sent ya a couple pics email.

A buddy of mine is putting 2.5tons under his rig and has had to make many a modification..including reworking the firewall to slide the 350 rearward to accomodate the chunks.

Anyway, I thought 1 ton was more fun...........

the jerk is right: rockwells are :rainbow:

here's my reasons and they are based on my previous and never again ownership of these boatanchors:
1) too frickin heavy! you're looking at at least 800 lbs per axle.
2) they are not that strong! i broke axleshafts without even trying!
3) very limited choice of gearing; 6,17 or 6,72 is all they got.
4) try to find a set of hubes!:flipoff2: without having to mortgage the house.
5) very limited supply of lockers available. you can buy detroits, but they are not cheap either.
6) what are you going to do for brakes? the stock drums are huge and heavy; you also have to run custom rims with a rediculous amount of offset or go to 20 inch plus rim diameter.
converting to pinion brakes is not the greatest idea becasue it puts way too much stress on the u-joints and buying a disc brake conversion kit (i did) will cost you upward of $2k. what are you going to use for the master and booster?!:confused:
7) clearance sucks!
8) try to find parts without having to order them!
9) ever had to use a cherry picker to pull a third member? you will!
10) do i have to go on?

i thought my truck, which worked just fine with 38's on it would benefit fro ma set of 2.5's with 44 inch swampers. here's the truth: not very streetworthy, too expensive to convert once you add up all the misc bs you have to shell out for, too damn wide (even with the housings narrowed, how may fix-it tickets does it take to get you pissed off?........
if i had to do it over again, i'd never put a set of rockwells in my rig. the only place they were an advantage was in the mud, but even then they're too heavy and hang too low.


spend your money on a well set up set of 1 tons and you'll have yourself a set of reliable, useable axles.just my $.02! ;)

I am far from the expert on the klune however....

You can get the klune, it dosent make you much longer if it even does at all. It replaces the adapter from the tranny to the xfer case. So you would have sm465/klune/205. You I believe they come in 4.0 gears and 2.7 reduction. So you would have 6.55/4.0/1.96/ 5.13 Your overall would be 263.4:1 :eek: I think that would be low enough. Even if you dont want to be that low you have other options with the klune. You can engage the klune and leave the 205 in 1:1, or engage the 205 and not the klune and have what you have now, or both engaged, many many options with this setup.

Klune engaged only
6.55/4.0/5.13 = 134.4:1

This is what I will run eventually. The cheepest I have seen is $1600

I say get the klune and be done with it.

Originally posted by ChevotaSS
thanks.. pics would be great. i hear the new gen II doubler only adds like 6 inches? does anyone know if thats true? if so i could probably get away with it. plus moving my spring mounts back a bit. i have 3, 203's laying behind my garage for the donor.


The Gen II ORD Doubler I have for sale (GM NP203 to FordNP205) is 25" with a NP208 adapter on it. Since your running a 350 tranny, you can use the narrow factory adapter which will save another 2", so you would be 23" from tranny adapter to 205 rear yoke.

oh and I would keep the 1 ton stuff. If you not happy with it the rockwells are not the answer, MOG axles are. :D

cmawwwn rockwells arent that bad...and for the $$ money over here, they are better than both 1tons and mogs for the $$$

BUT, heavy, slow, and OLD, they are strong though, i hardly think you broke them all the time........

over there....maybe 1 tons, or depending on mog costs

at least with 1 tons, you can keep it streetable...

Ive definelty decided to stick with my 1tons. they just look to good under my truck.. those big 2.5 tons might make it just look plain weird. thanks for the help guys. this winter will be my t-case project. either a doubler or the 3:1 kit supposedly coming out.

. rockwells:D :flipoff2: