Tremor front limited slip?

[Raspy]

I thought the Tremors were supposed to have a nice Dana gear type limited slip in the front. Not. Here are some pictures of mine with the cover off. The only thing it may have is friction disks behind the spider gears, but I'm not even sure it has that. Very disappointed! This looks like a plain old open diff to me.

 

[Smindustries]

"The front axle is a Dana Super 60 that now, for the very first time, has limited-slip differential boosting traction to the tires. That diff is a Spicer Trac-Lok specially developed for the Tremor."

Test Drive: 2020 Ford F-350 Crew Cab Power Stroke Tremor - The Dirt by 4WP

Can Ford’s Heavy Duty Off-Road Package Whip the Power Wagon?

www.4wheelparts.com

 

[qpayne1989]

It’s a friction disc style. I looked it up in the workshop manual about a month ago. It’s the most common form of limited slip and what Ford has used in rear diffs for years. That was the best you could get in the rear before they came out with a selectable locker in I think 2011.

 

[Raspy]

I thought we were getting the Spicer Trac-Lok geared limited slip.

Here's a link to the Spicer Trac-Lok.

Dana Introduces Genuine Spicer® Trac-Lok® for Aftermarket | Spicer Parts

MAUMEE, Ohio – Dana Incorporated’s new Spicer® Trac-Lok® limited-slip differentials (LSD) for medium-duty truck applications autonomously delivers improved vehicle handling within a lightweight and compact design for maximum traction, durability, and performance.

spicerparts.com

 

[Raspy]

Here's a link to what 4 Wheel Parts lists in their Tremor article. But the parts list shows this for rear axles only.

Dana Spicer Dana 60 Track Lok - 707427X​

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Lowest Price! Guaranteed!

Get 10% Off Orders Over $500 | Select Pick Up In Store At Checkout

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• Dana 60
• For Use With 4.10 And Down Gears
• For Use In Rear Applications Only
• For Use With 35 Spline Axles
• California Residents: WARNING

 

[Raspy]

It’s a friction disc style. I looked it up in the workshop manual about a month ago. It’s the most common form of limited slip and what Ford has used in rear diffs for years. That was the best you could get in the rear before they came out with a selectable locker in I think 2011.

That looks like a very weak system with minimal torque biasing. And, of course, if one front wheel is off the ground, it will do next to nothing. It might help if both front wheels have traction, like in sand, but I'm not very optimistic.

 

[Rock Taxi]

I've had disc limited slips for years, and they are better than open for sure. Yet, they always leave me wanting for more - just like in my Tremor.

Mine works great on a muddy road with no crown. For anything where tires leave the ground, the computer running the ABS in slippery mode is more effective than the diff.

I still need a part number for a Detroit Locker or Yukon Locker. I might consider ARB, but I dislike air and electric lockers due to one more potential point of failure.

Ed

 

[Raspy]

I forgot about the ABS in slippery mode. If that works as well as it does in my Rubicon, it will be fine.

 

[Rock Taxi]

I forgot about the ABS in slippery mode. If that works as well as it does in my Rubicon, it will be fine.

It's not a locker, but it doesn't suck. Way better than an open front diff from the 1980's with no traction management.

Ed

 

[Ginja]

I remember someone posted this video about it

 

[Raspy]

I remember someone posted this video about it

I watched that. As I recall, the diff did respond to light brake application.

 

[Raspy]

Meanwhile, here are a couple of notes about changing the oil in the diffs:

In the rear diff, one of the lower cover bolts, the one on the bottom right, is the drain plug. You do not have to take the cover off to change the oil, just remove that one cover bolt. The diff is an M275, with 10.8" ring gear and the recommended oil is 75W 140. I used full synthetic. I changed it the first time at 1,400 miles after a very easy break-in, and it had metal in it (normal). I changed it again today at about 12,000 miles and a lot of towing, and it had less metal in it. Getting broken in nicely. The fill plug has a magnet. The cover bolts take a 12 point 13mm socket.

On the front diff, the cover has to be removed to drain and it has no gasket. It is sealed with silicone. Today was the first change, at about 12,000 miles and the oil has a small amount of metal in it. No problem. The fill plug has no magnet. The cover bolts take a 9/16" 6 point socket. Metric on the rear, Imperial on the front. Recommended oil is 80W 90. I used 75W 90 full synthetic.

The axle shaft U joints, just inside of the wheels, are greaseable and have conventional zerk fittings. Be sure to grease them! I used Lucas Red-N-Tacky because I have a lot of it in stock. A waterproof marine grease is probably best for those.

I don't know if the front driveshaft U joint is greaseable. Do any of you know?

 

[Loshad]

I got in a slippy situation and remembered that video about a light tap on the brakes and it worked like magic! As they say now - it was dope!

 

[Baddestt]

I installed a Truetrac in front of mine . It’s way better than the factory front diff . Both front tires spin. There is a “heavy feel” to the front steering when 4wd is engaged

 

[Raspy]

I was on a dirt road recently, late at night. It was snowing and the ground had partially frozen puddles and slush. I was towing a dump trailer and it was fairly steep in places. The front diff really worked well. Under a constant torque like that it was partially locked up and pulling with both front wheels. I could tell by the steering feedback as one wheel would get into some ice and the other would keep on pulling. I am surprised how well this simple limited slip works and how the torque going in really affects how hard it tries to lock. I was wishing it had a Torsion, which would be better because it does not need to physically lock the two wheels together to be affective, but this works very well. A system that locks harder would make the steering a lot harder to deal with too. And remember when stuck, you can load it up with light pressure on the brakes to make it apply torque to the tire with the most traction.

 

[MIXDEMOTIONSFOX]

It’s a friction disc style. I looked it up in the workshop manual about a month ago. It’s the most common form of limited slip and what Ford has used in rear diffs for years. That was the best you could get in the rear before they came out with a selectable locker in I think 2011.

What I was just going to say. Same style that has been in rear ends of fords for decades. Make sure and run a posi additive oil or you will end up with a chatter.

 

[Raspy]

What I was just going to say. Same style that has been in rear ends of fords for decades. Make sure and run a posi additive oil or you will end up with a chatter.

At almost 90,000 miles now and the front diff is extremely smooth. I see zero reason to put in an additive. Doing so would increase the oil's film strength, which would reduce the effectiveness of the clutches. I don't want to lose any aggressiveness in the system. Ram's AAM rear axles with the Trac-Rite limited slip begin to chatter at about 100,000 miles. The easy fix for them is to go from the 75w90 oil to 75w140 oil. I began to recommend this years ago. At first guys were reluctant, but it has proven to be a very good and easy fix.

 

[Leadmic]

It's always been a clutch-pack LS in the Tremors. Yours is an LS you can see the clutches in one of the pictures you took.