Lunch box lockers

[driver007]

With a AMC20 rear end would a lunch box locker do for a daily driver. It would see snow and mud when hunting and ice fishing? Nothing to hard core. Would there be a reason for going to a unit that needs to have the gears removed etc. If you did go with a lunch box locker would you change the pinion seal if it was not leaking just for preventive measures any other things to look for when a person is in the rear end? I would also put in 1 piece axles at the same time.

 

[CJ007]

No need to change pinion seal if its not leaking, really won't have anything to do with adding the locker or axles.

They are fine but tend to pop some if you let off gas and hit it again as they engage and disengage at lower speeds (5-15 mph). If that bothers you or someone else drives the vehicle, you are better off with a selectable locker. They also click a little as you turn a corner and they disengage.

If you do get one, make sure you follow instructions, on lock right you need to leave the thrust washers in place, on Spartan I am pretty sure you pull them out, not sure on Aussie. This will affect how quiet they are or if they are more prone to breaking the pins.

They can be looked at as annoying or cool, like evertything there are two sides. One is the pop and click, the other is you get to tell people what a locker is and how cool you are when they hear it!

 

[driver007]

Ok were do I start on the rebuild of the Dana 30 and AMC20 axles. Do you go all the way and pull out the pinon and put new bearings in or is it somthing that really does not wear out. I was planning on all new seals and bearings. The amc would be getting outter bearings with the new axles should I replace the inners also?

 

[CJ007]

Ok were do I start on the rebuild of the Dana 30 and AMC20 axles. Do you go all the way and pull out the pinon and put new bearings in or is it somthing that really does not wear out. I was planning on all new seals and bearings. The amc would be getting outter bearings with the new axles should I replace the inners also?

What are you trying to do? One piece axles and lunchbox locker or are you looking to regear as well.

 

[driver007]

I have no real reason to regear. For the type of driving that I do I think the current gears will work just fine. I want to do a proper rebuild, not one were I wish I had done something later and have to redo it a second time. A clean week end driver with a little better part or two.

 

[BusaDave9]

The great thing about a lunch box locker is they are quick and easy to install. No need to touch the bearings or seals. If the seals aren't leaking or the bearings aren't bad I'd leave them alone. Put in a lunch box locker (or 2) and be done with it.
Now if you need to rebuild the rear end don't put a lunch box locker in. They don't have cases as strong as a regular locker such as a Detroit Locker. An open differential never expects to have the jarring and torque that a locker experiences so they don't have to make the carrier as strong.

 

[CJim7]

Ok were do I start on the rebuild of the Dana 30 and AMC20 axles. Do you go all the way and pull out the pinon and put new bearings in or is it somthing that really does not wear out. I was planning on all new seals and bearings. The amc would be getting outter bearings with the new axles should I replace the inners also?

This isn't to be disrespectful, but the ring and pinion setup is nothing you want to be tearing apart if you are asking these questions. If there is no problem with it, leave it alone. Setting up preload and basklash and getting proper gear mesh is critical and if you are not experienced doing this, its best to have someone on hand who has done it before or take it to a shop.
That's not to discourage the learning process...but there is no tolerance for mistake here, and an improperly set up ring and pinion will end in disaster and cost a bunch more money.
Im a heavy advocate of lunchbox lockers in the 30/20 combo for the fact that I dont believe these axles should have a ton of money thrown at them. And a lunchbox locker will hold up perfectly for the limits of these axles.

 

[driver007]

Thanks for the information gentlemen. CJim7 Your right about the limit on the axles. I just cannot talk myself into new axles when I do not really need them. As far as set up I have a buddy who is well versed in rear ends. I would use his services for the install. I know when to spend a buck and have it done right.

 

[Old Dog]

I'm going the other way, and say the jeep probaly has way over 100k on it
so why not go ahead and replace all the bearings and seals if you can reset-up the ring and pinion. Now you know it's good for another 100k.
If this is a DD I'm not sure I would want any auto locker for the snow and icey roads. An open diff or selectable lockers would be better.
IMO if you are running 33's or smaller the 30/20 combo will take a lot of abuse with one piece axles in the rear.

 

[1986cj7]

I'm going the other way, and say the jeep probaly has way over 100k on it
so why not go ahead and replace all the bearings and seals if you can reset-up the ring and pinion. Now you know it's good for another 100k.
If this is a DD I'm not sure I would want any auto locker for the snow and icey roads. An open diff or selectable lockers would be better.
IMO if you are running 33's or smaller the 30/20 combo will take a lot of abuse with one piece axles in the rear.

Not to mention the AMC20 can be trussed and tubes welded and can be just as good as a Dana 44 if not better. The Dana 30 is also a soild axle. The autolocker is cheaper but a selectible locker would be well worth the extra money in the lone run for better road manners. I put the detroid trutrac in both my axles, but looking back on it for about $AMC 150 more I could have got a electric locker. But the cash was the bottom line at the time. My advice is to save up for the selectable locker you shouldn't regrete it like me.

 

[driver007]

What would be the proper way to tube up a AMC20 axle

 

[Saddle Tramp]

To start with the CJ AMC20 is a marginal axle at best and other than 1 piece axles and a lunch box locker I wouldn’t spend any more money than that on one. Sure it can be trussed but the bottom line is the tubes are thin and the pumpkin case brittle where the tubes are pressed in; to me it is just good money after bad particularly when you consider the high cost of axle work. Having said that I ran this same set up without a truss problem free for some time but I’m not into hard core beat it until it breaks wheeling.

However, you were talking about driving on snow and ice which is never recommended for a lunch box locker as the rear end of your jeep will try to pass the front end when you least expect it. In addition the characteristics of the lunch box locker on the street when dry are not good either. Tire wear will be excessive and the handling erratic. In order to turn you have to back off the power, turn then power on again or the jeep will keep going straight and making turns the tires will skip, hop, and jump. Don’t misunderstand, all manageable if an experienced driver, however dicey under any circumstance but accentuated in a short wheelbase CJ5 . If you are going to spend more money (selectable locker for example) go for a Dana 44 .

 

[1986cj7]

To start with the CJ AMC20 is a marginal axle at best and other than 1 piece axles and a lunch box locker I wouldn’t spend any more money than that on one. Sure it can be trussed but the bottom line is the tubes are thin and the pumpkin case brittle where the tubes are pressed in; to me it is just good money after bad particularly when you consider the high cost of axle work. Having said that I ran this same set up without a truss problem free for some time but I’m not into hard core beat it until it breaks wheeling.

However, you were talking about driving on snow and ice which is never recommended for a lunch box locker as the rear end of your jeep will try to pass the front end when you least expect it. In addition the characteristics of the lunch box locker on the street when dry are not good either. Tire wear will be excessive and the handling erratic. In order to turn you have to back off the power, turn then power on again or the jeep will keep going straight and making turns the tires will skip, hop, and jump. Don’t misunderstand, all manageable if an experienced driver, however dicey under any circumstance but accentuated in a short wheelbase CJ5 . If you are going to spend more money (selectable locker for example) go for a Dana 44 .

Everyone has an opinion on what is the best axles. I guess if you can find a Dana 44 with all the goodies in it like a selectable locker, 4.10 gears or what ever your looking for, go for it. I'm saying the AMC20 is an overly judged, for being a weak axle, that can be made strong, with simple cheap welding of the tubes to the diff, and trussing of the axle tubes. Yes the one piece axle is a must. But no way would I put a lunchbox locker in it or any outer axle unless the main reason was to be an off road machine, but then there are alot of stronger options then the lunchbox autolocker for a true off road machine. Just my .02

 

[Saddle Tramp]

Everyone has an opinion on what is the best axles. I guess if you can find a Dana 44 with all the goodies in it like a selectable locker, 4.10 gears or what ever your looking for, go for it. I'm saying the AMC20 is an overly judged, for being a weak axle, that can be made strong, with simple cheap welding of the tubes to the diff, and trussing of the axle tubes. Yes the one piece axle is a must. But no way would I put a lunchbox locker in it or any outer axle unless the main reason was to be an off road machine, but then there are alot of stronger options then the lunchbox autolocker for a true off road machine. Just my .02

1986CJ7-

I think we are mostly on the same page. My point is if you are going to spend money on an axle it is important to take a hard look at what you are sinking your bucks into. I would not spend the money to do a selectable locker in a CJ AMC20 because there are better choices in terms of the overall quality of the axle. I see CJ AMC20 axles on Craig’s list with one piece shafts for $100-$200 but a used bolt in ready Dana 44 with one piece 30 spline shafts out of a Commando can be had for $200-$300 too. Yes the gearing may not match so more money may need to be spent than upgrading the AMC20 Driver007 already has but in the long run I’d rather spend money on an axle with good bones rather than one with issues right out of the box. We also agree on the lunch box locker, in a CJ5 they are dangerous unless the jeep only drives on dirt, sand, or mud.

 

[CJim7]

1986CJ7-

I would not spend the money to do a selectable locker in a CJ AMC20 because there are better choices in terms of the overall quality of the axle.

This was exactly my point as far as selectable vs. cheap lunchbox in my above post.
But....I would not upgrade to a Dana 44 , the difference is almost negligible between the 20 and the 44. If upgrading, just go on to a D60/14b/9"/8.75. The reason being is the cost of a swap....you might as well get a decent upgrade if you are going to all that work, and a Dana 44 isn't enough axle to justify it.

 

[Old Dog]

With a AMC20 rear end would a lunch box locker do for a daily driver. It would see snow and mud when hunting and ice fishing? Nothing to hard core. I would also put in 1 piece axles at the same time.

You really don't want a lunchbox for a daily driver.
IMO the AMC20 with one piece axles will serve you fine as long as you run 33's or smaller tires. Mine puts up with quit abit of abuse.

 

[Petescj]

Mine puts up with quit abit of abuse.

The Transmission pan though , not so much . Couldnt help it , just saw that thread a bit ago. Carry on now , nothing to see here

 

[CJim7]

Just a 'FWIW'...
I ran Lockrights in my CJ as a daily driver for years and living in Montana, it saw it's fair share of icy, snowy roads.
It's just a matter of getting used to it. And for the record, it handled better in those conditions then it did with open difs.
...except for the front axle. Dont run the front axle locked up in 4wd on icy roads, you wont be able to perform even the slightest steering. Offroad is different of course.

 

[Petescj]

Dont run the front axle locked up in 4wd on icy roads, you wont be able to perform even the slightest steering. Offroad is different of course.

Thats the way my CJ5 was. The front diff grenaded taking out the carrier as well when I first got it. I wanted a locker right away while the shop rebuilt it and shouldve went with a Limited slip Detroit but picked the Power lock to save cash. Spun her around in the snow a couple times. Ive seen the results now. Its gonna be worth saving for a selectable.

 

[CJim7]

The front tires need to act with a "ruddering" effect on ice. This is where you get your steering controllability. With normal 4wd and an open dif, you still achieve this at least to one wheel...but with a non selectable locker you lose the ruddering affect as power will go to both tires and you will lose the essential tire grip that provides that ruddering.

Unless Im in a serious amount of snow which requires powering through it, I will leave my Jeep in 2wd to maximize front end control.

It still to me does not justify a selectable locker up front on the Dana 30 .