Issues With Big Blue!?!?!

[Gary Lewis]

I don't know about having to correct the ride height in the rear: I've seen Big Blue up close, and there is already quite a rake! Keep in mind that it is the 250 HD, and therefore is kind of hybridized between the 250 and the larger animals...

And! (afterthought) it would be sad to not be able to re-use the TrueTrac, or whatever locker is in the TTB right now. Is it transferrable to the D60?

Ooops! Wrong "Ford"! Sorry Steve. I just saw the Ford and didn't read any further.

[ArdWrknTrk]

Missed the afterthought. But, I think I addressed it. If what I've read is right, that you do NOT turn corners under power with it in the front on slick pavement, then that has me worried already. So having the ability to lock it when needed would be nice instead of having it come in when it wants to do so.

In my VERY limited experience, driving with a front locker is like wrestling a bear while trying to drive your truck.

As for rake. The D60 with stock 350 springs will raise the front ~2", an RSK will raise that another 2, and then you can change the springs for more if you want. But at that point you'll be looking for a drop pitman arm and longer panhard or track bar.

[Gary Lewis]

In my VERY limited experience, driving with a front locker is like wrestling a bear while trying to drive your truck.

From what I've read that's an apt description. And I've also read that you shouldn't send your wife or daughter out on a snowy night in a vehicle that has one.

As for front height, 2" would be great and 4 might work.

 

[Nothing Special]

Missed the afterthought. But, I think I addressed it. If what I've read is right, that you do NOT turn corners under power with it in the front on slick pavement, then that has me worried already. So having the ability to lock it when needed would be nice instead of having it come in when it wants to do so.

A TrueTrac from a Dana 44HD or Dana 50 will not fit in a Dana 60.

As far as having them in a front axle goes, I have no personal experience, so take this as the thought exercise that it is. A rolling tire will resist moving sideways while a spinning tire doesn't care which way it slides. So there's no question that an open diff (or unlocked selectable) is the most stable option since it makes it almost impossible to spin both tires.

That said, how likely are you to spin both front tires? Driving on ice or in slick mud it can happen. But with the weight of the engine on the front axle it's probably pretty easy to avoid by having a light foot in those situations. So personally I don't think I'd sweat that too much. (The exception might be when on an icy or muddy side-hill, people that do a lot of that seem to be some of the biggest proponents of selectable lockers.)

Another risk with a locker or limited slip in a front axle is torque steer. With an open diff both tires are always pushing the same amount, so the torque steer from each side cancels out the other. But with one side getting more traction than the other a TrueTrac will send more torque to that side and you will get torque steer as the front tire with traction tries to turn the steering wheel in your hands. Will that be a problem with a TrueTrac? I don't know. I know that it can be terribly dangerous with an automatic locker (which is why I never suggest a front auto locker for anyone who might drive in 4WD at higher speeds). It makes sense that an auto locker would be significantly worse at this than a TrueTrac, and a few people I've chatted with say that a TrueTrac is almost invisible in this way. But I'd be a little concerned about a front TrueTrac if driving on snowy highways was in the trucks future.

And for what it's worth, I finally have one winter's experience with a rear TrueTrac to go with the many years experience with rear auto lockers. I'm a little torn there. A rear auto locker is noticeable (in a bad way) most of the time, while a TrueTrac is invisible most of the time. But in my experience the TrueTrac isn't much, if any, more stable on truly slippery roads, while the auto locker is much more effective when you've got one tire on an ice patch and the other on bare pavement. I'm keeping the TrueTrac in my rear axle, but I'm not sure I'd do it again.

Also for what it's worth, with one week of 'wheeling with an OX selectable locker in the front of my Bronco I do really like that. There is a contingent that doesn't like selectables in the front (too much trouble steering when locked, and too frequently bind up and won't disengage when you want them to), but in my relatively limited experience neither was really an issue. You can't turn the wheel while stationary with it locked and both tires planted, but it seemed to steer fine as long as I was moving. And when it bound up just sawing the wheel back and forth a little seemed to let it disengage pretty quickly.

So taking all of that for what it's worth, I guess I wouldn't expect you would have much trouble with a front TrueTrac with your expected usage. But if you are getting a new axle and need to pick a new diff, then I think a selectable locker might be a better choice for you (and I like the OX).

[Nothing Special]

In my VERY limited experience, driving with a front locker is like wrestling a bear while trying to drive your truck.

From what I've read that's an apt description. And I've also read that you shouldn't send your wife or daughter out on a snowy night in a vehicle that has one.

As for front height, 2" would be great and 4 might work.

I had an auto locker in the front of an F-150 for one winter. At slow speeds (like when four-wheeling) it was very annoying, but not terrible. Certainly worth the annoyance if you valued the performance. But I wouldn't even use it myself on a snowy highway after the experience I had the first time I tried to change lanes, and certainly wouldn't send anyone else out with it. The front locker effectively made my truck a 2WD on highways until I went back to an open diff.

[Gary Lewis]

In my VERY limited experience, driving with a front locker is like wrestling a bear while trying to drive your truck.

From what I've read that's an apt description. And I've also read that you shouldn't send your wife or daughter out on a snowy night in a vehicle that has one.

As for front height, 2" would be great and 4 might work.

I had an auto locker in the front of an F-150 for one winter. At slow speeds (like when four-wheeling) it was very annoying, but not terrible. Certainly worth the annoyance if you valued the performance. But I wouldn't even use it myself on a snowy highway after the experience I had the first time I tried to change lanes, and certainly wouldn't send anyone else out with it. The front locker effectively made my truck a 2WD on highways until I went back to an open diff.

There are auto lockers and then there are auto LOCKERS. And the Trutrac falls into the latter category. Ford's unit had clutches that probably eased into full lockup. But not the Trutrac. When it comes in it seems to come in suddenly. That made things interesting when the rear decided to lock up on me, but I don't think "interesting" would cover it if the front locked up. With both rears spinning you can steer into it, but I'm guessing the only thing to do with both fronts spinning is to get off the throttle.

So, I'm more and more thinking that replacing that thing would be a good idea. Which makes the D60 swap even more interesting.

But, saying "D60" in the same sentence as "front axle" seems strange. Back in my day the Hemi came with a D60 in the rear axle. So it must be a capable diff.

Guess I'd better start looking.

[salans7]

There are auto lockers and then there are auto LOCKERS. And the Trutrac falls into the latter category. Ford's unit had clutches that probably eased into full lockup. But not the Trutrac. When it comes in it seems to come in suddenly. That made things interesting when the rear decided to lock up on me, but I don't think "interesting" would cover it if the front locked up. With both rears spinning you can steer into it, but I'm guessing the only thing to do with both fronts spinning is to get off the throttle.

So, I'm more and more thinking that replacing that thing would be a good idea. Which makes the D60 swap even more interesting.

But, saying "D60" in the same sentence as "front axle" seems strange. Back in my day the Hemi came with a D60 in the rear axle. So it must be a capable diff.

Guess I'd better start looking.

I vote D60, but keep in mind they are not cheap. Most run for at least $1500 and those are pretty crusty axles which need the passenger u-bolt plates addressed, which adds even further to the cost unless you do a u-bolt flip. I picked mine up for $700, but that's because it's a less desirable ball joint version from an Aeronose.

You do have the option of Super Duty axles, 99-04 are leaf sprung, however the perches are in different spots than the older D60's, the hubs are unit bearing, and the lug pattern is 8x170. If you grab a set of front and rear axles, the lug pattern isn't an issue and you also gain four wheel disc brakes. Also, Sky Manufacturing makes a Reverse Shackle Kit that would allow you to run the proper perch spacing for the Super Duty axles.

[Nothing Special]

There are auto lockers and then there are auto LOCKERS. And the Trutrac falls into the latter category....

Correction, there are limited slips and LIMITED slips (to use your form of differentiation, pun intended). Neither the Ford Traction Lock nor the TrueTrac are lockers at all, they are both limited slip diffs, albeit completely different from each other. The Traction Lock puts friction between the two sides so it functions like a spool until it exceeds the slip torque of the clutches. Then it acts like an open diff, but with a fixed amount of drag between the two sides.

A TrueTrac uses worm gears to send 3.5x (or 2.5x in front axle applications) as much torque to the tire that gets more traction. So if it takes 200 lb-ft of torque to spin the tire that gets the least traction it will send up to 700 lb-ft (or 500 lb-ft for a front application) to the other tire. Or if it takes 0 lb-ft to spin the tire with the least traction it will send 0 lb-ft to the other tire. In most situations a TrueTrac is much more effective than a typical Traction Lock (or any other clutch-type limited slip), but they are actually less effective when one tire gets no traction (like if it's in the air, or on ice). But it never locks.

Automatic lockers are things like Detroit, Grizzly, LockRight, Spartan, Aussie, etc. They actually do lock up and are what can be a nightmare on a snowy highway. TrueTracs and typical (i.e. fairly loose) Traction Locks should be less dangerous than an auto locker in a front axle. But of the three, a TrueTrac is the only one I'd ever even consider using in the front axle of a truck that would be driven on snowy highways. But a selectable locker would probably be a better choice, at least in my opinion.

[85lebaront2]

There are auto lockers and then there are auto LOCKERS. And the Trutrac falls into the latter category....

Correction, there are limited slips and LIMITED slips (to use your form of differentiation, pun intended). Neither the Ford Traction Lock nor the TrueTrac are lockers at all, they are both limited slip diffs, albeit completely different from each other. The Traction Lock puts friction between the two sides so it functions like a spool until it exceeds the slip torque of the clutches. Then it acts like an open diff, but with a fixed amount of drag between the two sides.

A TrueTrac uses worm gears to send 3.5x (or 2.5x in front axle applications) as much torque to the tire that gets more traction. So if it takes 200 lb-ft of torque to spin the tire that gets the least traction it will send up to 700 lb-ft (or 500 lb-ft for a front application) to the other tire. Or if it takes 0 lb-ft to spin the tire with the least traction it will send 0 lb-ft to the other tire. In most situations a TrueTrac is much more effective than a typical Traction Lock (or any other clutch-type limited slip), but they are actually less effective when one tire gets no traction (like if it's in the air, or on ice). But it never locks.

Automatic lockers are things like Detroit, Grizzly, LockRight, Spartan, Aussie, etc. They actually do lock up and are what can be a nightmare on a snowy highway. TrueTracs and typical (i.e. fairly loose) Traction Locks should be less dangerous than an auto locker in a front axle. But of the three, a TrueTrac is the only one I'd ever even consider using in the front axle of a truck that would be driven on snowy highways. But a selectable locker would probably be a better choice, at least in my opinion.

Having had (a) a vehicle that came factory with a Detroit Locker (1966 GT350) and (b) a pretty powerful FWD car (1985 Chrysler Lebaron convertible with a roughly 200 HP turbocharged 2.2L engine) I am familiar with the locker's behavior on snow and ice (Shelby was my daily driver for a number of years) and torque steer even though the Chrysler had the equal length axles. I can appreciate the concern in both cases.

[ArdWrknTrk]

I vote D60, but keep in mind they are not cheap. Most run for at least $1500 and those are pretty crusty axles which need the passenger u-bolt plates addressed, which adds even further to the cost unless you do a u-bolt flip. I picked mine up for $700, but that's because it's a less desirable ball joint version from an Aeronose.

You do have the option of Super Duty axles, 99-04 are leaf sprung, however the perches are in different spots than the older D60's, the hubs are unit bearing, and the lug pattern is 8x170. If you grab a set of front and rear axles, the lug pattern isn't an issue and you also gain four wheel disc brakes. Also, Sky Manufacturing makes a Reverse Shackle Kit that would allow you to run the proper perch spacing for the Super Duty axles.

Which is why I suggested Gary find a bricknose that had a blown engine or been hit in the rear, or rolled.

I suppose aeronose or OBS will work as well as long as it has a 3.55 R&P.

Either way, cheaper than a $1250 cross member or a $1500 D60 that needs rebuilt.

While Gary has reservations, and an awful lot of other work swapping in all the Huck parts and F-450 bits.

To replace the cross member you have to remove the engine and drop the beams, anyhow.

Then to get the donor part you'd have to remove the panhard bar and swap the TTB pivots over.... anyhow.

When you have the cross member out you're already standing where the engine was, looking at the shackles and spring mounts.... anyhow

I'm of the mind 'in for a penny in for a pound'

It would never be easier to weld in a Sky RSK. In fact it would be a pita to do it while laying underneath and trying to work around an engine.

I guess a lot depends on whether Gary can find a 460/IDI cross member by itself, and how much it costs.

Or if Gary finds a donor 350 wreck with the right R&P.