ok, I have a 78 F-150 4x4. 4 inch lift and 35 in. tires. With all the money I'm putting into this truck I guess I'll be keeping it for a while so I decided to go ahead and spend a bunch on gears. Why not its only money right? I found a place that will do them ( going from 3.50 to 4.10) for $600, thats for just the gears and labor front and rear. I will also get new bearings as well. Now since this is the time to get limited slips I need to make up my mind. This truck is a daily driver but also sees plenty of very rough off road use at least once a week mostly trails and hills and mud. I will go thru (or try) any mud I can find. Ive had this truck buried almost up to the doors more than once. I know it sounds like I could really use a locker but I live in michigan and drive every day in the winter so that is out of the question , air lockers are out of my price range too. Now the place that will probably do the gears has trak-loks (what ford uses from the factory) for $250 and auburns for like $350 or $400. So my question is would I be fine using trak-locs front and rear or is the auburn a lot better ? Ive heard it is a "tight" limited slip. Maybe a auburn in the back and trak-lok in the front? what do you think. one more thing . Warn makes axle shafts that they say are 150% stronger than stock . Are these something I should maybe consider or are mine probably fine. What Im wondering is if I'll break enough to make the warn axleshafts worth it. All right sorry for being so long but thanks for any replys.

 

Nick,
I would suggest the Auburn in the rear and the Dana up front if you are looking for very good mud performance,but you would really want to go with the Auburn "Pro", I have seen this unit in action in the mud and it works very well. They(the truck owners) say it handles well on the road,but no one Ive talked to has had to use it in the snow. You deffinitely wouldnt be disapointed with the trac lock front and rear,they are very good units and very road friendly on snow and ice(I used them front and rear on several different trucks on the winding snow covered roads of Lake Tahoe for years). Many of the snow plow trucks also use them. The only time Ive been disapointed with the Trac Lock is when trying to use it for something thats its not designed for...when climbing rocks if one tire is wedged onto or into a rock very tight and the other is completely free, the LSD will index to the free wheel and will apply no or very little power(like an open diff)to your traction wheel. An occasional tap of the breaks will index power briefly to the traction wheel. But as long as there is at least some resistance to the free wheel it will affectively apply power to the traction wheel,(I had one in the front of my Jeep). You are stuck in the classic dillema of all of us who need to be able to drive on and off road. On the Jeep Ive gone to an ARB air locker front and I love it so much the rear on the Jeep and the front on the F250 are getting swapped soon. Doing you own installs can save a lot of money, but it is still big $$$. Use Timken bearings if possible and change your axle seals and vent tubes at the same time. Water in the gear oil is very hard on LSDs,and the main contributer to water encroaching into the axle is a plugged vent tube(its probably worse than a missing vent tube). Even with new seals you will draw water into the axle without a free breathing vent. You are going to love your trucks mud performance with your new diffs whichever way you choose. Later,
Jeff

 

Nick: The previous posting is right on the money, but I'd like to add a couple of things:
1. Ford has sold Auburn LSDs for years and recommend them in their Motorsport catalog; I just feel that you can't do much better than an OEM or manufacturer's recommended upgrade, therefore I'd use Auburn in the rear. I'd go with a Dana "Trac-Loc" in the front, for the same reason. After all, Dana made the axle and the LSD.
2. Aftermarket axles: Yeah, they're real stout pieces, and not really all that expensive, but...your truck's what, 20 years old and probably running the original axles? Take a look at them while they're out, and do a hard-headed cost-benefit analysis; do you really want to pay a premium price for something that is fairly easy to replace yourself, or just use quality standard replacement items? Give it some hard thought, are you really going to beat that thing that hard to really need high-dollar axles? The 9-inch/Dana 44 combination are easy to work on and hard to break, never mind what all those magazines say...after all, they just want to sell you aftermarket parts (axles, f'rinstance).
OK, I'm off my soap box.
Eddie

 

Nick,
I hadnt even addressed the aftermarket axle issue.I run aftermarket Warn Axles shafts in my Jeep, but it is due to the nature of the wheelin I do with it,(extreme rock crawling)and the current set up. I run a low range gear ratio at the wheel hubs of aprox. 120.0:1(6.69.1 1st gear, 4.0:1 Low range T-case , and 4.56:1 R&P) under those conditions if a wheel gets held up in a rock and you apply to much power you will snap something. The front axle U joints are usually the 1st to go,but they almost always take out the axle shaft with them. On my F250 even though it is modified with a lot of HP and large tires for mud bogging,I still use stock axle shafts. Under most conditions,(and if you use common sense),if you keep your front axle shaft U joints in good shape and if your current axles arent rusted out or previously abused, the stock axles should be fine. The rear axle shafts of a Ford 9" if in good shape are plenty adequate. I have been using greasable U joints in the front,due to the fact that you often have to use pressurized water to remove the mud from the knuckles and pressurized water is very bad for sealed bearings. I also grease them often using synthetic grease to make sure to displace any water that has contaminated the bearings. There are as many opinions on this however as there are truck owners,..so greasable or sealed I would replace them if thier condition is questionable. Later,
Jeff