I would like to ask for you gentlemen's input about differential lockers please. I did do a search and found a little information but not like I would like to. I have a '85 F250 4X4 351W with an NP435 4 speed. I would like to make it a TRUE 4X4. It has Dana 44 differentials with a 4.09:1. Which lockers do you gentlemen suggest installing and where is the best place to purchase them. I do go in the mud fairly often and often times I am dragging a 16 foot trailer loaded with 1500 to 2000 lbs. Thank You

 

In the rear I personally like automatic lockers. Detroit is the most common one, but there are other brands as well, including "lunch box" lockers that replace the spider gears in an open diff, giving the same performance as a Detroit at a lower price (but not with as much strength). Automatic lockers do have some handling quirks, but they generally aren't too bad to live with. They are not good for towing heavy trailers, but at 2000 lbs you won't have much of a problem.

A selectable locker (like ARB or e-Locker) lets you unlock them on the street for no handling quirks, but they are more expensive, and they don't give any differentiating when locked, so they might give bigger quirks when you are using them. Still a good option (and better with heavier trailers or if your wife or kids will be driving it and you don't want them dealing with the quirks).

A Truetrac is another good option for less quirky behavior and better with trailers. They don't work as positively, and will still just sit and spin if one tire is in the air or otherwise has no traction. But lightly hitting the brakes will get them to engage then too. This would be my first choice in a mostly road-driven truck, especially if it will tow much.

I'd never recommend a clutch-type limited slip for anything.


In the front the only thing I'd recommend is a selectable locker. The quirks of anything else when driven at speed can be extremely dangerous. Some people say a Truetrac is acceptable in front, but I wouldn't risk it. Of course, you can get away with a lot more if you will never use 4WD except when driving very slowly (when you have time to recover from whatever quirk it throws at you). But if you will ever drive above 20 mph in 4WD I'd say stick with open or a selectable locker.

 

Thank you NS I appreciate your input. I pull the 2000 lb. load at least 3 times a week but about once a month, on average, I pull a load about 3 times that heavy. If I go with the TrueTrac will it handle this type of work? If I lightly hit the brakes to engage the "lock" (or what ever I should call it) does that mean I need to lightly hold the brake or basically just hit it and release it and it will stay engaged/locked?


Honestly I am the only one that drives my "baby" LOL. 90% of the time I will never get over 20MPH in 4X4 because I am older (wild mudding days are over) and I am in the woods in mud just hoping to make it out with out hitting any trees. But when the weather turns really nasty around here, snow and such, I will lock it in and drive the roads at 30+MPH.


Can you please recommend a brand of selectable locker for the front please?


I apologize for all the questions and my ignorance but this is the first time I have ever ventured into this area and I appreciate you sharing your knowledge.

 

I don't have any experience with the Truetrac, so I can't say how well they'll hold up. However I've heard that others have had really good luck with them, and they're made by Eaton (who also makes the Detroit). So I wouldn't have any concern about it, especially with the relatively light loads you are talking about.

To keep a Truetrac "working" You will need to keep some brake applied until the tire with the least traction gets more traction. It sends up to 3.5 times as much torque to the tire with traction, so you need the other tire to take some torque in order for the 3.5 times it to be enough to move the truck. You can use the brake pedal if it just needs a little help, but that'll apply the front brakes as well. Ideally you'd only apply the brake on the one tire that's spinning, but unless you've put cutting brakes on your truck, your best bet is to apply the parking brake a few clicks. The more you apply it the more the Truetrac will deliver to the tire with traction, but also the more drag you'll need to overcome. Just make sure to remember to release the brake after you're done with it!

Again, personally I'd probably pick an automatic locker for the rear for towing a 2000 lb trailer, although a 6000 lb trailer is getting a little marginal. The locker will hold up fine but you'll get some tire spin when starting around corners.

If driving on snowy roads in 4WD is expected definitely stay away from any automatic locker or limited slip in the front. I had a locker in the front of a truck for one snow storm. On the first lane change the truck jumped 10 feet to the side before I could catch it! The quirks in the front are DANGEROUS!

As far as recommending a specific brand of selectable locker for the front, I really can't. ARB is the brand you hear most about. I've heard good and bad about it (mostly good). And it does require an on-board air compressor, which is fine if you want one, but adds cost and complexity if you don't. Eaton's e-Locker is another I hear mentioned here a lot, but I don't know anything about it. OX is another brand I've heard good things about. Those are the brands that come to mind.

 

Thank you sir I really appreciate your input. If I may ask do you have any knowledge about or opinion on an Aussie Locker?


Dana 44 Aussie Locker 30 Spline Lunchbox Locker | eBay

 

It can be wild. My 1980 had the factory limited slip in the front and for some reason it really locked the front wheels together. I could go down the road with about 4 inches of snow, and turn the steering wheel back and forth, and the rearend would go back and forth instead of the front. And you always had to come to almost a complete stop before turning into a lane or another road.

 

No specific info on the Aussie. I think it's similar to the Lock Right and I had one of those in the rear of a '95 F-150 for about 9 years and 120K miles and was happy with it.

As far as the driver is concerned there's essentially no difference between a Detroit and a Lock Right (and I'd think any of the other lunch box lockers). They all give the same benefits with the same quirks. The difference is in cost (purchase price is less, and installation is an easy DIY job rather than requiring gear setup) and in strength. The Detroit (and other stand-alone automatic lockers) have everything in one package, giving you a new carrier that was designed to have a locker in it. The lunch box lockers on the other hand stick the locker's dog clutches into the stock open diff carrier, often being driven by the stock spider gear shaft. Those stock parts weren't actually designed to be used like that (although the aftermarket companies surely did a lot of testing before risking their reputations).

Personally I wouldn't hesitate putting another lunch box locker in the rear of a half-ton (or smaller) truck that wasn't going to regularly haul heavy loads or regularly see other hard use (like rock crawling). But for heavier use I'd pop the extra cash for a Detroit (I've had Detroits in my old CJ5 and in the Bronco I have now, both intended for rock crawling)

 

Thanks for your advice NS I appreciate it. I am the type of person that wants to fix it once and for all so to speak. If I have to pull a head because of a blown head gasket the I pull both heads and have them reworked and reinstall them both with new head gaskets. I also own a 2000 F350 V10, it blew out one of the plugs which is common for that year model and the aluminum head so while I had it down fixing that one hole I went ahead and fixed them all.


I am going to start hunting a Detroit for the rear. Do you know how difficult it will be to install as far as setting up the gears? Since we are on the subject, this may be out there in left field but....... How hard would it be, if it's even possible, to change everything to 4.56 gears?

 

Changing gear ratios isn't much harder than installing a new diff. Either one requires setting up the gears (lunch box lockers being the exception). Setting up gears isn't brain surgery, but it is one of those things that if you have to ask you probably can't. That said, if you can look up how to do it, and figure out what tools you'll need, and are patient enough to keep working at it until you get it right (it's a lot of trial and error unless you really know what you're doing), well then go for it. But if you want to ask someone to tell you how to do it, they should tell you to take it to a shop who will do it for you.

I should say that changing gear ratios obviously means changing both axles. If you were only going to put a locker in the rear, changing ratios would be twice as hard as just changing the diff since you'd also have to do the front. But if you're putting a locker in the front as well you're already going to be in there, so that's definitely the time to change ratios if you want to do that.

 

I understand what you are saying about the set up of the gears. How to do this has always fascinated me. I am not sure if I want to take this on but plan to do some reading and see how difficult it is. There are some shops around here I can always take it to and have it done but I would rather be able to do it myself. I have 2 friends that both own shops that do this so maybe they will advise me. Heck they may even help me learn how, don't know till I ask them. If I don't feel comfortable attempting this I will just hire it done. Again NS I really appreciate your advice and input, thank you sir.

 

By the way, I've mentioned that lockers have quirks, but I haven't said much about what they are. So in case it affects your plans (or helps anyone else reading this)...

I've had automatic lockers on 3 vehicles for a total of somewhere between 150K and 200k miles. 2 of the vehicles had/have Detroits, one was a Lock Right. One of the vehicles was my daily driver for 9 years (including snowy Minnesota winters). So this is based on some experience.

There is some freeplay in automatic lockers. This is almost unnoticeable if you have an automatic (the auto loads out the freeplay while a manual with the clutch in lets it be free), it is definitely noticeable, and maybe slightly annoying at times with a manual. But it doesn't cause any actual problems.

Automatic lockers only drive the inside tire on a turn. One thing that does is give you some torque steer. This is usually almost unnoticeable in a bigger vehicle (like a full size pickup) but can be very irritating in a small vehicle (like a CJ5). In any vehicle I'd hesitate to say you'd be OK letting just anyone drive it because of this without some advance warning. But if it's your truck and you want the benefits of a locker, you won't have much trouble getting used to it.

Also since they only drive the inside tire they can pretty easily spin a tire when starting, or on hills. In fact once I couldn't make it up a wet parking ramp without continually spinning a tire. Again, most people who want a locker will get used to this. But it will be a lot worse when towing a heavy trailer.

Another downside is that they will spin both tires. I know, the reason anyone wants something other than an open diff is that open diffs will just sit there spinning one tire. But that actually helps a lot with stability. It's a lot easier to spin out if you are spinning both rear tires. Even limited slip diffs will make a truck more likely to spin out (compared to open diffs) but lockers will do things a little more abruptly than limited slips. Even so, if you're a decent driver and dive the truck regularly it's not hard to get used to. Again, I grove an F-150 with a locker through 9 Minnesota winters and never regretted it. But it wasn't a truck I was looking forward to have my teenage boys learn how to drive in snow!

 

I have another question gentlemen. I have been looking at the selectable lockers mentioned in the above posts. Is a selectable locker a locker that is activated/engaged by an external means such as electrically or with air power like the ARB air locker or the Eaton E-Locker?

 

Yes. Generally (all of the time?) they are open when unlocked and spools (completely locked) when locked. But I think at one time there was a selectable that was a clutch-type limited slip when unlocked (not sure about that or if that's still available).

There are also cable-actuated selectable lockers (in addition to the electric or air that you list).

 

Thank you NS I am a little slow LOL. It took me a while but I finally realized it's called a selectable locker because you "select" when it is engaged LOL. I know the air activated locker is out because I am not going to add an air compressor to my truck, though it would help incase of a flat tire LOL. The electronically engaged locker sounds like it would be a good possibility as long as I didn't rip the wires out. I am going to check out the cable actuated locker and see which one I think will work better for my application.

 

OX is the cable shifted brand that a friend recommended to me. They ain't cheap though.