I have a 2000 Ford F-250 4X4 7.3 6sp 3.73 ratio with a open ( "one tire fire") rear axle!!! My buddy wants to sell me an original posi-unit from at 2003-2004 F350 srw 4x4 w/ 3.73 gear ratio truck!!! My question is will this unit work on my axle even if the posi is from a 2003 or 2004 truck???????????? What else would anybody recommend or say about this?
Thankyou
Luke

 

If they are both SRW trucks and both 3.73 like you said, then yes it will work, as they both have sterling 10.5 axles.... I personally dont think its worth the time or effort. The factory installed limited slips are hardly worth their weight as a paperweight IMO. Every one of our trucks hasnt had a limited slip since around 80k miles. At which point it was pretty much an open diff. I would look for a better traction device, as there is so many to chose from. I got a detroit locker for mine, and absolutely love it, but for the average empty street DD I would say its too much also. I would look into an eaton posi or a torsen limited slip if you want limited slips. As for lockers, ARB or Detroits for me. Have had good luck with both. If you get the limited slip for under 50, and know someone who your confident can do your swapout for a case of beer, it might be worth it, but I wouldnt put another one of those oem ford limited slips in again. (auburn posi IIRC)

 

Well i would think that the ford posi will give me more traction than an open carrier i was going to do this swap since it is way cheaper than buying a 600 locker plus installation!!!!

 

Well how many miles are on the posi, and how much is he going to sell it to you for? If you dont drive much, or pretty much stick to the roads, it technically is better then an open diff, if you go around a hard turn, and floor it, it will more then likely still spin one wheel. power brakeing will usually be both, gravel roads with equal traction will probably be both, one wheel in the stones and one on pavement will mean spinning in stones, virtually no power to the pavement. Me, I dont even want to see another one of the factory limited slips in my life, they do just that, sliiiiiiiiiiiiiiiiiiiiiiiiiiiip.

 

Does anyone else have an opinion or done anything similar????????????

 

No, I am in the same boat as you right now and following this thread. I do not like how my rear diff behaves either. I too am waiting.

Patience my friend, someone will be along. Rebel is just telling you what he knows. I don't like the $ figure either so maybe someone else will be along with a better mousetrap or I will live with mine.

BTW, my rig has 60k miles and I don't like one tire fire either.

 

Detroit Locker, hands down. A little noisy in low-speed manuevers, but trust me, when it comes to layin' 'em down... it's four big black ones from me!

I love dually burn-outs! Someone once asked, "why the garbage man always locks 'em up in front of my house?"

 

Haha nice comment about the garbage man lol. I think my locker is the detroit "soft locker" Its actually almost no noise, unless it randomly unbinds, which happens about once a month, (at a stop sign or just off the line a snap sound) Other then that, if your on the throttle, its locked, and you can tell that around every turn. Detroit has made their mark with me, and it sounds like its the same for you.

 

hey rebel i took your advise i am going to go with the Detriot truetrac limited slip it has no cluthes or gears to burn out!!! It has planatary gear and requires no special limited slip additive!!! I talked to a buddy of mine is says that i full locker is not for me since i do alot of towing he said i just need a really strong limited slip!!! So i guess for 510.00 is not too bad!!

 

To answer your question, they will work, as long as they are both SRW or both DRW axles. You will just need to take the ring off the carrier unit of your current case, and swap it on to the posi unit. Reason being ring and pinions are a matched set, they are ran together to be sure they mesh correctly. You can't take the entire posi unit with the 3.73 ring off the other truck and swap it in yours unless you also swap out the pinion also. You will need other tools to set it up, but its fairly simple to do.

 

Thats a pretty good unit, I havent personally used it, but just some words of advice from people who have. Because alot of people get upset and say they dont work and all thebad things. The biggest thing, is that diff requires *SOME* resistance on the wheel that has little to no traction. For instance, if you were at a stop, and one tire was on black ice, and the other was on a portion of pavement that wasnt covered by ice, you would more then likely spin the tire on the ice (making you think your limited slip isnt working) The thing to remember, is if your having an issue were only one tire is spinning, if you slightly apply the brakes to put resistance on the wheel thats spinning, it will lock up, and ahoy forward you go! That is just the most important thing to remember about the torsen style (detroit truetrac) differentials. IMO its a very good front end traction device, especially for pulling, I believe thats what mech2161 (sp?) runs in the front of his. And if you remember that bit of knowledge, you will be overly happy with that traction aid. You just need to remember that, when your one tire is spinning! Hopefully that will help you, and help you understand how to use that new diff your getting!

 

Are those the same diffs that Humvees use? Maybe someone will chime in, 'cause I know that the brake throttle modulation works like a charm on humvees, and not much else.

 

The AM general spec sheet says they have "Torque-biasing differential" which is another term for the same thing, so in short, yes!

http://www.amgeneral.com/vehicles_hmmwv_models_a2_components.php

 

OEM unit isn't that good, IMO

Truetrac is the way to go if you want something better in a lsd


Detroit or ARB if you want a locker.

 

What are the advantages/disadvantages with the locker vs limited slip (Detroit) ?