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Marc S Gombosi

F550 WEAK SPRINGS!

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In my fleet, I have two 4x4 F550's.  One's a '17 wrecker.  The other, an '18 rollback.   So far, I'm fairly pleased with the rollback (although the deck and winch speed leave a LOT to be desired).  The wrecker, on the other hand, I wouldn't recommend.  The rear "helper" springs are only one per side and are constantly against the bumper, even without a vehicle being towed.  When we load a vehicle, the helpers flatten, have zero affect, and the front wheels lift off the ground (or at least mostly, making steering nearly impossible).

 

I spoke with "Ford Fleet", after being on-hold 45 minutes.  Their response?  "It's a body upfitter issue."  Nope.  The upfitter did not alter the suspension in any way.  This is a #19,500 GVWR truck.  It should easily haul an F350 box truck, yet it won't steer with even a 2WD F150 / 1500 Silverado loaded to it.

 

I had the truck to this area's pre-eminent spring / suspension shop.  He told me, flat-out, that he's replaced the rear springs in over 100 of these trucks and for the very same issue.  It costs $1,500 to replace the springs.  I told Ford all of this.

 

Ford said they would not do anything for me.  $1,500 won'y bankrupt me, but it's the principal here.  After spending $111,000 on a truck, it ought to do what I bought it to do.

 

Moral:  If you're a die-hard Ford guy, be prepared to spend $1,500 on your new truck when you buy it.  If you're indifferent as to brand, wait for 2020 to roll around and get yourself a new medium-duty Chevy.  That's what I'll be doing.

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In the coming years, there will be major issues for people who purchased 4500 as well as 5500 chassis for roll backs when they go to trade them in or sell them and find that they do not maintain the equity that the customer was expecting. It is my opinion that a 550 or 5500 chassis is not going to give one the performance that a F650 will give. We are comparing apples to oranges.

 

There is no perfect truck. The manufacturers are concerned mainly with putting you in a new truck regardless of whether it is the right truck or not. A salesman is generally only concerned with getting you to sign the paperwork so they can post the sale to qualify the commission. Vehicle sales are a ruthless, cutthroat business. And the quality of vehicles is going down as the prices continue to rise. It just makes no sense to me, no sense at all.

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Steering has to do with your front end weight and how long of a truck you bought, not the rear springs for a wrecker.

What are your wrecker truck specs? or post up a pic of it.

gas or diesel, tunnel box, extended or crew cab ? 

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I agree the rear springs are not the best on a f550.  I am building one currently, but we also add springs to the top and bottom of the mains.  Have been doing this to ALL of our wreckers no matter the brand for the past 62 years.   The manufacturers haven't realized where a wrecker carries its weight; behind the rear axle.  

The better the rear suspension the less squatting it will do and better steering.  You are correct if is on a 60 ca/ with wheel lift at full extension going to have some issues.  

 I have a 2008 F350 with a 6 ton single line wrecker with sneeker wheel lift.  I am towing single axle tractors from rear, 350 box trucks from front and large SUV on wheel lift with no front end issues.  

20180707_083832.jpg


Nick Schade

Tony's Wrecker Service

Louisville, KY

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On 6/27/2018 at 11:29 AM, BlackAutoload said:

Steering has to do with your front end weight and how long of a truck you bought, not the rear springs for a wrecker.

What are your wrecker truck specs? or post up a pic of it.

gas or diesel, tunnel box, extended or crew cab ? 

It's a 4x4 extended cab 550, no tunnel box. (so it's the same length as a regular cab with a tunnel box).  But the weight on the front isn't the issue.  When the rear helper springs flatten without residtance, no weight is transferred to the front.

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With some basic assumptions since most light duty trucks are about the same, your truck should be able to lift approximately 7,000 pounds with the wheel lift fully retracted and 5,000 pounds at full extension. Now this is the calculated capacities, NOT the structural capacities as determined by whichever wrecker manufacturer you have. Most manufacturers limit light duty to 4,000 pounds at full extension due to structural issues not chassis capacity.

 

The way I determined this is using the basic tow capacity formula that has been industry standard for decades and some educated guesses as to what your truck weights. A typical F-550 4x4 should have a static weight close to 10,000 pounds with 60% on the front axle and 40% on the rear axle. The 2017 F-550 extended cab with a 60" CA body on it (you said no tunnel box) has a wheel base of 167.9" and typical light duty wheel lift overhang is between 72-96" (retracted vs. extended). Plug these numbers into the formula 1/2 front axle weight x wheel base / overhang = capacity. 3,000*167.9=503,700/72=6995.83 at full retracted.

 

If your rear springs are collapsing then they are not doing their job to support the load or you are overloading them. It is very likely your springs are weak, or the truck did not have the payload plus package installed properly. Off the line the F-550 comes standard at 18,000 GVWR and requires a dealer installed upgrade to make the 19,500 GVWR which includes a frame reinforcement between the springs. 

 

Even when working properly there is no weight transfer from the rear springs to the front axle in a tow truck. Wreckers use the rear axle as the fulcrum point in a lever and the front axle is the counterweight. Your steering can be improved by either increasing the front axle static weight with a counterweight like a push bumper or brush guard, reducing the rear overhang or lengthening the wheelbase. Installing stiffer springs will help with rear end sag and provide better support for the weight that you are towing but will not help transfer.

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     Correct me if I'm wrong, but I believe GVW ratings are relative to a load being placed over or in front of  the rear axle.  When you extend your underlift, you are transferring weight OFF your front axle depending on how much extension you have.  With that being said, I have owned quite a few WL trucks over the years and I prefer 161" WB on LD and ALWAYS beef up the rear springs.  On one 1-ton I built, I added 3 leaves to the main and 3 leaves to the overload - I think I had a total of 14 leaves on each side.  I could tow box trucks from the front with no problem with plenty of steer axle weight - the W/L of course was mostly sucked in.  I now have an 02 F550  12 ton  161" WB and I also have no issue with it as far as steer axle weight goes.  All the responses to your issue have indicated that it is a given to beef the rear springs on a wrecker.  As previously said, this will due little to offset front axle weight relative to W/L extension.  Hope this helps - thanks, Steve.


Steve Koob

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Instead of springs I would have airbagged the rear then hit the scale house to find out what my empty axle weights are. Then I would counter weight the front axle to the max listed on the door plate, just like the heavys do.

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I don't recall which wrecker you had mounted to your chassis. But, I can tell you that whoever estimated a 550 4x4 at 10,000 lbs your about 5,000+- light.  My 2001 550 century 602 aluminum body/tunnel toolbox is right at 15.000 lbs and that's on the original 17500 gvw before they went to the 19500. 

 

I recall the days of the 350's 11000 gvw in ford weighed around the 10/10500 mark empty with a wrecker and a 460, it was mentioned the weight is behind the axle not on top like a camper or trailer so we are loosing before we get going!! 

 

The part about your extra leaf or overload just touching the bumpers is in all actuality where you want it. So, as soon as you're loading they are working. Unfortunately, it's a single leaf and really doesn't do much. I believe due to the arch I'm not sure you can double or triple it up. 

 

In my opinion if it were me I would look at the 3 options. 1) (I did this with my 550) I put air bags in 5000lb kit if I recall had them 10 years now +- but I put a leveling valve on my rear axle and preset it to where I wanted- weight goes on valve opens auxiliary compressor and tank I mounted in the toolbox kicks in pumps it up to height again just like a big truck, unload and valve dumps air from bags like a big truck- "air lift" was the brand and it was a complete kit with relays/solenoids wire kit and tubing. I didn't want to mess with the pump the bags up at the shop every 3 days because they will always leak and it's when they are empty or low is when you need the capacity, wasn't cheap but worth the money I think.  Option 2) Is a product I installed on my 5500 Ram rollback it's called a sumo spring it is a similar design to a timbren but made by Super Spring it mounts right above or where the factory bump stops are located and they just rest on the rear axle or slightly above, I have mounted these on several "work trucks" they have different ratings but all I'm seeing for the 550 in your year is one rating part#SSR-120-54 (2800 lbs rating) not only do they take some load but the stability added to my rollback was tremendous they are available for the front axle also if you decide to counter weight.  Option 3) again is another product by Super Springs (6600lb rating) part# SSA-26  it is simply an additional 2 leaf kit mounts in conjunction with your overload and you can pre-load it to suit your needs basically we always put enough tension on them to stay put when unloaded to maintain a decent ride height and so your riding on the factory pack but they pick up weight load as soon as you lift. Basically it makes your empty ride as it is and not a lumber wagon but gives capacity as soon as you add the weight. 

 

If it were me not knowing what you do mostly I'd go with the add on leafs to carry the weight and the sumo spring (timbren style) to help with stability I really think you will like the results.  6600lbs is the highest rating they have on leafs  a couple less ratings are available. But, I wouldn't think they would apply to us in the towing world.  www.supersprings.com Warranty on commercial use is 3 years on your weekend boat puller it's lifetime.  Install time... you can pull it in your shop and have it back on the road in a couple hours vs. a day to disassemble spring packs add leafs and end up with a lumber wagon. 

 

I'm not trying to be bias to there product or dis respect your spring guy (I added 7 leafs per side on my f350 when I built it) but for the expense and quick turn around to install you can't go wrong. We use them on our equipment with no issues I have a pair on my Ram 2500 because I carry a plow on it, as mentioned I have both on my rollback I had the sumo style before the extra leafs and the stability they added was crazy. 

 

Let us know how you made out or anyone else who try's the product. 

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