I have a 84 cj7 with 258 and full stock drive train. Its lifted 4.5" sprung under and is on 35"s. I feel like the rears are to small for this tire size. It seems as if its struggling to move them and while trail riding the other day, I broke the axle housing and have had nothing but trouble with them. Wondering what would be the best upgrade ? New rears and gears or stock rears with differnt gears? Any help would be greatly appreciated.
you broke the axle "housing"? where did it break?
you need to fill out more info in your profile so we know what you have and how to better help you.
you'll get multiple answers with these questions.
if you broke the housing and it cant be rewelded, you might need a new rear end all together.
stock gears just wont push 35's well as you've come to find by stating that is struggling. most folks would suggest gears in the 4.10 range.
if you have a D20, then 1 piece axles would be suggested too.
you'll need to find out what truely broke down on you so we can help you further.
if your an off-roader, then to answer your last question,
you'll be spending money by either buying smaller tires for your stock gears...would look funny on a 4" lift
or you'll be spending money on better suited gears and keep the rig the way it is.
it all depends on how you want to drive it.
ok pictures uploaded and more specs filled in. Im using the jeep for trail riding and also on the beach so that means it has to make it down the highway about 25 miles. The crack in the axle housing is mid way between the pumpkin and the tire on the passenger side. Also I am looking to complete replace the back rear and possibly the front if thats the best way to go about. If i can get away with putting a stock rear back in and replacing the gears front and back ill do that.
if i had the time and money i would try to weld up the stock housing, swap in some one pc axels for the rear and regear to 4.10/4.88 front and back. i say 4.10/4.88 cause it will most likely aleviate the struggling feel you get with the 35s. wether or not the stock amc 20 rear is worth a crap or not is a hot topic of disscusion in the jeep world.
I've done some research on the debate and I must say I am partial to the AMC 20. Simply BECAUSE IT'S THERE. I'm in the middle of a complete overhaul of my AMC 20 now. There are a few sites that tell you exactly how to make it sturdy enuf to drive it off a cliff and the AMC will be the only thing left. But basically this is what it is. I'm putting in superior one piece axles, gearing up to 4.10's (if you're doing more off roading you may opt for numerically higher like the 4.88's previously recommended.) trussing it up with a truss from BESRK, welding the tubes to the pumpkin and disc brake conversion.....(and a perty paint job) So the main things would be one piece axle, truss and tube welds for sturdiness then gearing down (or up numerically) for performance. This, as described by off road mag, makes the AMC 20 as good if not superior to the 44. What ever you do have fun with it.
To answer your original questions about what direction to go, it all depends on how much time, money, and effort you want to spend on the project. If you're more of a casual offroader, then you may want to get the AMC 20 crack fixed, get a better gear ratio in it, and be done with it and get back on the road. Note that if the housing cracked, then you might also need to consider replacing other parts as well (shafts, gears, seals, etc). If you want to go a step further, put in solid (1 piece) axle shafts to replace the factory 2 piece (shaft + hub) axles. You could also reinforce the AMC 20 as people above have mentioned. If you want to go all the way, find a totally new/different axle assembly and spend the time and money to get it installed and set up right.
A big part of the equation also involves how much of the work you would do yourself versus paying a mechanic to do it.
And also, welcome to Jeepforum! Glad to have you on board!
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