I have a 2007 150 XL, 2WD w 3.3 rear end and a 5 spd manual. Id like to add a limited slip rear end. I never ride off road but some of the gravel, one lane, steep, badly washed and rutted mine access roads would have you think you were off road. I would like both wheels to transmit power when in locked mode yet be able to turn a tight circle. Has any one experience with a detroit locker diffferential? Would this be an advantage over a Ford Factory limited slip. I would like to preserve as much mileage as possible so what gear ratio should I aim for? Would a 3.56 work for my rough driving goals? Thank you for your consideration.

 

Allow me to point you to this thread that I posted back in mid-November: https://www.f150forum.com/f4/bigger-tires-lower-gears-3-73s-4-10-a-13555/

I have the same setup that you do, and in that thread, I asked some questions related to going to a limited slip differential and what gear ratio to go with. Should provide some good information on the topic of interest. I'm not 100% decided yet, but I think I'm gonna go with 4.10 gears (effectively ~3.83 total ratio when you factor in the bigger tires I've added) when I do the swap/upgrade, as the 3.73 gears (effectively ~3.55 ratio) don't seem like enough of an upgrade for the money I'll be spending.

Read through that post, add to it if you like, and add to this thread to let us know if your questions have been answered or if you have more.

 

Nagata, That november post was excellent as were the responses. Let me know how this comes out when you finish your dream set up. Is a Trac Loc differen than Fords limited slip ? Thanks again.

 

Glad I could help! I believe that trac-loc, limited slip, posi trac, etc. are all different terms for a non-locking, but limited slip differential. I could be wrong, and each manufacturer would use slightly different parts, but I believe the general idea is all the same. I'll post up my results once I get the work done.

 

My thoughts are all limited slips are almost the same but some are different. I would like a rear end that locks tight when either wheel loses traction (power to both wheels), yet through clutches, allows the vehicle to turn while maintaining power to both wheels. Is this possible?

 

Get a selectable locker like an ARB. ARB uses air to lock it so you need an onboard source of air, there is one that uses electric instead but I don't know the name.

 

Since this thread is titled Limited Slip?, I figured this would be as good a place as any to ask this question.

I have a '94 XLT 4x4 (115,000 miles) and recently had the axle lube changed. As far as I know, the truck has a limited-slip rear, but the tech who does the work I don't/can't do said that it doesn't. When I asked him if he was sure, he said he didn't notice any clutches when he had the cover off, so though he changed the lube, he didn't add any friction modifier.

In the 3 weeks since the lube change, while driving the truck, I haven't heard anything that I didn't hear before. Sounds like it always did. But a few days ago, I had the rear of the truck off the ground and noticed that both rear wheels spin (in the same direction) when I turn a wheel by hand. Forward or reverse, both wheels turn in the same direction. To me, this proves that it's a limited-slip, but while the rear was in the air, I crawled under and took a few photos of the tag. To my eye, the codes on the tag say:

5837F (top code)
3L55 884E31 (bottom code)

Bottom-line is, I think my tech is wrong, and it is a limited-slip, and needs the friction-modifier added. I've included a picture of the tag if you want to see for yourself.

Thanks in advance for your help...