Issues With Big Blue!?!?!

[Gary Lewis]

Bob - I had assumed that there was some flex in the bushings, if not the TTB itself, that lets the axle move a bit.  And I can see that the springs can act as torsion bars and twist.  Plus there's flex in their bushings.  But there's just no way to get around that the geometry of the 4wd F250's front suspension is just ... wonky.

I've frequently wondered why so many people bad-mouth the TTB's.  But I was thinking of the F150's TTB's, not that of the F250's.  And now that I have thought about the difference it is night and day.  With coil springs TTB's make sense, but add a leaf spring and they just don't.

And then there's the ride.  I was originally giddy about getting Big Blue and then getting him running.  And even after driving him for a bit I assumed that the horrible ride was just the way "big trucks" ride.  Then I rode in a later F350 and was blown away with the ride.

My mind is made up, so please don't confuse me with any more "facts".  

As for the lift, I don't think BB has one.  I really thing everything under it is stock.  However, 3.5" in front will level him out with the current rear springs, so when I pull some leaves out I may have to bring the rear up a bit.  But I'll wait to worry about that until I get everything together and find out how it sits.

Anyway, our plans for the day have changed.  We are under a severe thunderstorm watch and the National Weather Service has just raised the threat level for us, with large hail, high winds, several inches of rain, and tornadoes likely.  So, I'll be making my calls and will postpone the trip to 4wd Parts until tomorrow or even Wednesday.

[Steve83]

Gary Lewis wrote

With coil springs TTB's make sense, but add a leaf spring and they just don't.

I think it's opposite, because they didn't just "add a leaf spring".  They also deleted the radius arm, which is why the TTB's motion was so wonky to begin with.  With radius arms, the hinge lines are diagonal (from the axle pivot through the RA bushing, but NOT along either's axis); with leaf packs, the hinge lines are parallel to the truck's axis (straight through the axle pivot bolt).  So with leaves, there's almost no caster change through the wheel's travel; with radius arms, the caster, camber, toe, track width, and even WHEELBASE changes through the travel.

[ArdWrknTrk]

With the inverted leaf the wheel base change is negative.

Camber change is limited because of the lack of travel to the bump stop.

As is caster.
Because the rear of the spring is the pivot while the shackle up front allows the spring to retract.
(negative arch springs)

But those spring and pivot bushings take a real beating due to the twisting motion in both planes.
Where as the solid axle suspension of the 350 just acts on the bushings normal to their axis.

[Nothing Special]

Gary, if we should quit littering your thread now that you've made up your mind, feel free to let us know.  Otherwise...

Steve83 wrote

Gary Lewis wrote

With coil springs TTB's make sense, but add a leaf spring and they just don't.

I think it's opposite, because they didn't just "add a leaf spring".  They also deleted the radius arm, which is why the TTB's motion was so wonky to begin with.  With radius arms, the hinge lines are diagonal (from the axle pivot through the RA bushing, but NOT along either's axis); with leaf packs, the hinge lines are parallel to the truck's axis (straight through the axle pivot bolt).  So with leaves, there's almost no caster change through the wheel's travel; with radius arms, the caster, camber, toe, track width, and even WHEELBASE changes through the travel.

You're not wrong about the wonky steering geometry changes with a coil sprung TTB.  But overall the changes don't tend to be significant, at least in terms of how they work in a street-driven truck (with minimal wheel motion) or in a desert racer (with lots of wheel motion, but driven on relatively forgiving surfaces as far as steering geometry is concerned.

But with the leaf-sprung TTB, the rear half of the leaf spring acts essentially like a radius arm, forcing the outer end of the axle to move fore-and-aft as it moves up-and-down.  And with the essentially flat spring at ride height, that "radius arm" actually gets shorter as the wheel moves up or down, so it pulls the axle back even more than a radius arm would.  So if anything, even just the rear half of the leaf spring is worse than a radius arm.

By even worse than that, the leaf spring also has a front half.  As the axle moves up-and-down the axle swinging around its pivot makes the spring pad move right-to-left.  The rear end of the spring is fixed to the frame so the front end of the spring tries to move right-to-left twice as much as the spring pad.  But the front end of the spring is also tied to the frame through the shackle.  That's why the leaf spring TTB is fighting itself, and why I believe it inherently can't give good wheel travel.

[Gary Lewis]

Yup, there's so little travel that nothing can change.  I can't even slide my pointer finger between the bump stop and the spring as the knuckle is too large.  And I've measured my knuckle at less than 3/4".  While the bump stop isn't directly at the axle, so there's more movement at the axle, and there is twisting motion that may account for a bit more, I can't see more than 1 or 1 1/2" of wheel travel at most.  I'm not a fan.

Anyway, here's the morning update:

The lady at Mingo Salvage does not have any SuperDuty springs

The D60 that I found on eBay, but which is close to me at Catoosa, is really a 4.10 instead of the 3.54 as advertised.

The D60 in OKC that Shaun found is a 3.54 and has the tie rods on it, but there is nothing else with it.
 They do not have the track bar, the track bar bracket/mount, the driver's side u-bolt plate, nada.  (So, what do they do?  Pull an axle and crush the rest of the stuff that is absolutely necessary for a swap?)

So I think Jim's plan is the best: Work on what I have and keep my eyes open for a complete F350.  Maybe one with a bad engine or tranny.  Or that has been wrecked.  That way I'll have all the parts and won't have to piece this thing together.

[ArdWrknTrk]

Gary,
Do you know anybody that goes to insurance auctions?
Does anyone in your church know anyone?

Usually vehicles that will be up for auction are listed.
So you could give them a model and year range and a bid cap, see what they turn up.

[Gary Lewis]

Bob - There's no reason to quit talking about this.  I'm not in the least worried about the thread, so please have at it.

However, let me say that your analysis is good theory.  But, it is theory only since there isn't enough up/down movement of the axle to write home about.  

Seriously, what I found in the spring/bump stop clearance boggled my mind.  That is absolutely insane.

[Nothing Special]

Gary Lewis wrote

....  However, let me say that your analysis is good theory.  But, it is theory only since there isn't enough up/down movement of the axle to write home about.  

Seriously, what I found in the spring/bump stop clearance boggled my mind.  That is absolutely insane.

I think the lack of travel is because of what I'm theorizing about.  Effectively the spring has to get a LOT stiffer as the axle tries to push it from side to side, so the "progressive" spring would stop moving pretty soon, even if the bump stop wasn't there.  The bump stop might be as close as it is to prevent the spring from being stressed too much (but that's just speculation on my part).

I know that a very few people ('89F2urd being the only one I know of) have good experience with lifted leaf spring TTBs.  And I know that my own experience with my '97 shows that they can be acceptable in stock form.  But I still maintain that the design is terrible, even if it works well enough in some applications.  (If Ford had only put coils springs and radius arms on the '80 F-250 and F-350 TTBs...)

[ArdWrknTrk]

Gary already has an unlittered thread going with his thoughts and plans for what to do and how to do it.  

[Gary Lewis]

Jim - Yes, I have an unlittered thread, so I'm not worried whatsoever about continuing the conversation.  In fact, it will probably help others who might be considering what to do.  So, keep on truckin'!

As for someone in auctions, I don't know anyone.  But, I do know someone at church that is an insurance salesman, and he would probably know.  Good idea!

Bob - I agree that '89 is about the only person I've seen on any forum pushing the TTB's in an F250.  F100's and F150's yes, but not F250's.  And now I see why.  

[salans7]

Gary Lewis wrote

The D60 in OKC that Shaun found is a 3.54 and has the tie rods on it, but there is nothing else with it.
 They do not have the track bar, the track bar bracket/mount, the driver's side u-bolt plate, nada.  (So, what do they do?  Pull an axle and crush the rest of the stuff that is absolutely necessary for a swap?)

Driver's side U bolt plate is unnecessary with a u-bolt flip.

Also, here's your panhard bracket, brand new with no rust like a junkyard or parts truck would have.

HOWEVER, since you seem pretty insistent on trying to get every single part in one shot, I would agree with Jim and say that YOUR best option is to just find a complete parts truck. One piece at a time works great for Johnny Cash and I, but I don't think it's the best route with your intentions.

[Gary Lewis]

Shaun - Thanks.  But you brought up the u-bolt flip idea a bit ago and I didn't follow up.  Will do, but if you have a link it would save me time.  And, what are the benefits?

As for the panhard bracket, that may come in handy.  But David came up with a bunch of the parts on ebay, including that bracket, the left-hand u-bolt bracket, and the shock brackets.  So, the bits and pieces are available.

But, I may not be as sold on getting all the parts in one shot as you think.  Or, maybe I'm waffling.  I did a lot of calling around today and want to capture the notes here, and some of that may change my mind.

Harmon 4wd: Adam sent me to Billy Young's 4WD for parts, but we did discuss the locker idea.  He's not high on Ox, preferring the ARB.  But, he also said the ARB is a pain to set up and it is pretty sure that the o-rings will start leaking in 2 - 10 years and require re-work.

And, he thinks he probably has a double-cardan yoke for a BW1345.

Billy Young's Performance Differential: A friend of his has two D60's and he wants $1400 for each, and they are complete lock-out to lock-out.  But he doesn't think they include the springs.

On the spring subject he suggested using the springs I have.  But when I suggested SuperDuty springs he liked the idea.

As for gear ratios, he has 2-3 sets of 3.54's and he will swap for $50.

He will go through any axle, whether from his friend or elsewhere, for about $500, including parts such as bearings, seals, etc.

Regarding a locker, he's high on even the factory unit as wells as the Trutrac.  (He might take my D44 Trutrac in as trade for parts or labor.)  He really doesn't see the auto-lockers as being a problem since you won't be driving in 4wd at high speed on a road.  But, if I want a locker like ARB he can install it, whether I buy from him or not.  Just price the unit and check w/him to see if he can get it cheaper.

And, he says the track bar is not needed unless you have a diesel or large camper that is always on the truck.  Says that it limits the travel of the axle to about 3", but that the springs will do a good job of locating the axle w/o the bar.

Insurance Auction: I contacted my friend that runs an insurance agency.  He pointed me to the auction company that handles the vehicles that have been totaled.  That is TRA Auction, but looking at their website they currently don't have any SRW 4wd F350's.  

So, it doesn't look like the insurance auction approach is going to pay off very quickly.  And, the bits and pieces are coming out of the woodwork, so that approach may be viable.  And, it would save me parting something out.

Anyway, I'm still exploring.  And, I'd like your thoughts.

[ArdWrknTrk]

When Billy suggests using the 250 springs you already have, all my faith in him goes up the chimney like smoke.

And his buddy with the D60?
To me @ $1400 it is already gone through, seals and any questionable bearings are replaced.
$500 on top of that?
I want some of what he's smoking.

Just my 2c, but I would exit stage left - in a hurry

[salans7]

Gary Lewis wrote

Shaun - Thanks.  But you brought up the u-bolt flip idea a bit ago and I didn't follow up.  Will do, but if you have a link it would save me time.  And, what are the benefits?

With the U bolt flip kit, you will not need either of the U-bolt plates, the driver's side being the removable one and the passenger side being the one that is welded on. Most passenger side U-bolt plates are corroded past usability, so if you have a corroded axle, you'll more than likely be cutting it off anyway for a replacement. Rather than buy the replacement from Sky, you can just remove both plates and run U-bolts just like the rear axle. That keeps the threaded ends of the U-bolts pointing up rather than down like factory, which keeps them from catching on obstacles. The only downside is that you have to trim one notch into the webbing of the pumpkin, which really isn't that big of a deal if done right.

[Gary Lewis]

I was surprised about the springs as well.  Perhaps I misunderstood?  Maybe he was saying the F350 springs would fit the F250 perches?

As for the $1400 axles, maybe that price is after they've been gone through?  The one in OKC is $840, so $1400 might be about right for one already to use.

We are planning on going into Tulsa tomorrow, although given the weather we are seeing right now who knows what is going to happen tomorrow.  Anyway, I do want to talk to 4WD Parts and may also go by to see Billy.  Not that I'm buying into what he was selling, but I'm not confident enough with my notes/understanding that I want to clear things up.

What was your take on the panhard bar?

[Gary Lewis]

Shaun - Thanks.  That makes a lot of sense.  Get the flip kit awa the u-bolts.  

Add the SD springs and Sky's kit and it'll bolt together.  However, with the flip kit where does the panhard rod attach?

You might talk me into the piecemeal approach after all.  

[ArdWrknTrk]

I might go no panhard if I was into rock crawling but I've heard too many stories of death wobble and I like the idea of having the front axle attached by more than just the springs in a road driven vehicle.

Ford didn't put it on to piss away profit margin, did they?

[ArdWrknTrk]

Stay battened down.
I hear there's potential for 2"+ hail out your way.

Have you considered looking at Copart, or any of the big auctions?
Maybe Brandon has a line on someone who frequents the salvage auctions near you?

[Gary Lewis]

You guys are really watching things!  Just got a text from Chris saying he now understands why I have the safe room in the shop.  And you are seeing it as well.

Fortunately they just lifted the tornado warning, although we are still in a watch until 1:00 AM.  But, we are certainly in a flood warning.  I posted a video of the creek behind the shop at about noon today on FB.  It rarely has water in it but lately it has been running about 3" deep and 10" wide.  Today it was probably 3' deep and 10' wide.  Yes, really.

On the panhard rod, that was my thinking as well.  Was curious what you thought.

[ArdWrknTrk]

The springs are mounted in rubber at both ends.
An oscillation that becomes harmonic can get out of hand quickly.

Not something I want to deal with, let alone pass on to my kids.