Was not sure where to put this so I'm going to put it here

I'm going to change out my 88 F150's open differential for a LSD.

I'm having a really hard time finding one. Anyone have any suggestions?

 

Just put a Ford L/S dif in there.
That's what I did and I'm putting over 500 RWHP to it. Holding up fine!

Phil

 

get a locker....

 

Where did you find it?

 

I thought we got it from Ford but I'm not sure. I know we only paid $200. or $225. for it.
I did a search and thees are the cheapest I found. I don't know what size yours is.
http://www.jawsgear.com/store/catalo...p?cPath=31_189

Phil

 

I'm pretty sure its an 8.8 based on the owner's manual for the truck. It says 8.8 Ring Gear.

What is the various spline sizes for?

Sorry if that seems like a dumb a__ question.

 

You can just go to a pick and pull yard and pick up one for cheap. I think the trucks had the 31 spline axles, therefore you need a 31 spline diff. You can get these out of explorers, mountaineers, and other F150s. It is easy to identify, the tag on the rear end cover will say something like this: 8 8 3L73 if it has a 3.73 with a locking differential. If not it should say: 8 8 3 73 for a non locker.

Hope this helps
Eric

 

Yea, I understand about the teeth/spline count now. I still don't know how to figure out if I have 28 or 31 without counting them at the axle. Anyone know for sure?

I'm going to buy new because I have no idea how to install it, I'm going to have a local shop do it and would hate for it to have a problem and have to pay twice for the install.

The gears are 3.08. I thought about changing them but don't really need to. I'm pulling a boat/trailer combo that weighs just under 2k (truck manual says 2600# max towing) with all my stuff. It pulls just fine, I've just had a problem at the boat ramp with a wheel slipping. Everyone says a LSD will take care of it.

 

For the nbs f150s the 8.8 ifs has 28 spline axles. The solid rear 8.8 has 31 splines. Im not sure if this holds true for the older axle setups, but would be a good place to start.

 

Nbs?

 

NBS = New Body Style

tnsilverfx4- I assume that you are quoting the splines based upon the '04 and up body style. I see that he has an '88 which is an old, old, old ? bodystyle.

 

If you're looking for the one that's like the ford oem one for around $200.00 or less (I don't know if it really is the same one), I believe www.4wheelparts.com carries it as their Genuine Gear line. Otherwise they have a good selection of better brands too.