Edited 10-15-2020:

I know this thread can be a chore to read through, I detailed many changes I tried. My truck is a 2007 FX4 that's been lowered and has an Legato 3"SI/2.5"DO tailpipes cat back exhaust (like FM American Thunder but by Legato)as you'll see. If you want to read through it all, help yourself, or you can go to Post #20 and see how it stands now as of 10-12-2020.
To consolidate it all, to put it all in a single post, here goes. My truck uses OEM type / size 275/55-20 tires too. I used a Hellwig #7705 rear sway bar kit, it's a 1-1/8" diameter sway bar with three adjustment holes per side. It has a kicked-out leg to better clear a large OEM muffler, I have a small muffler and plenty room on that side, I flipped the bar up-side down, putting the kicked out leg on the gas tank side, the resultant upside down "lazy S" shaped arm then also cleared the gas tank better that a straight arm would. It's a solid steel bar, it twist both ways up side down or right side up, it doesn't care. If I draw a straight line through the "lazy S' arms from pivot C/L to link, it's virtually level. My end links are adjusted with 20 threads showing. The links tilt backwards only slightly due to my rotating pivots (under the axle) forward. those two pivots that hold the bushings under the axle are tilted forward 20 degrees. (I used a small level with adjustable vial, like angle finder.) I used the shortest / stiffest holes which are 15" from the pivots (middle hole is 16", end hole is 17"). The rear end of the bar tilts slightly downward behind the axle, it's 8" from the ground. The distance from the large 1/2-20 U-bolt center that holds the pivot and the nearest spring/axle U-bolt center is 6" on the left & is 7" on the right. I made and bolted on a 1-7/8" long spacer or side-extension to add to the right side arm next to the muffler where the end link mounts. I reinforced the clevises where the end links mount to the frame. All of this and pictures are in the thread. I needed the bar to clear my gas tank and to clear my left side tail pipe. It does that now under all conditions as of 10-12-2020.

Original Post starting the thread is here Below:

I have decided to add a rear sway bar to my '07 FX4 Scab, looking at Hellwig 7663 which is a 1" bar, but the 7705 which is adjustable and 1.125" is specified for newer 2009 & up trucks, but looking at pics, looks useable on a '07.

Any one have any experience with either or other comments?

Addco made a 1.125" replacement rear sway bar for 2004-2008 F150s, part number 2319, but I never saw a 2004-2008 with a factory rear bar to replace?

 

If you do a forum search for hellwig swaybar you will find a few threads on the subject.

 

I had looked and found that many, even most, threads concerned older series of PUs and different bar numbers.

I know what sway bars do, I have installed aftermarket sway bars on some of my vehicles over the years. I was gonna fish for some application info. The 7663 is listed for my truck, but the two ends bend rearwards and will likely hit my exhaust, on my truck … and the 7705 ends go forward the axle and it looked like would fit my needs, but Hellwig says it's for '09 or newer, I wondered what the difference was that caused them to change their bar with 2009 model year..

Today I talked to a fellow at Hellwig, he explained why the bars are so different, and likely I will go with the 7705 which is some little thicker & stiffer, but it's ends are longer and have 3 positions. My truck 's frame has all needed attributes (like square holes on bottom side shock crossmember) for an easy drilless mounting and where my truck has less spare space out back, it does have more ahead of the axle.

Now, on to shopping the I-net.

 

After you install it, go to a closed Kmart parking lot and drive in a circle while holding the steering wheel in the same position. If the truck makes larger and larger circles it is understeering. If it makes smaller and smaller circles, it is oversteering which could be dangerous if you make a sudden lane change at speed. Waaay back I installed large bars on my 70 Mustang. The front had an oe 5/8" bar and the rear had none. I was driving to work afterwards and changed lanes too quickly and the rear broke loose. After fighting it back and forth I went off the road into a shallow ditch. Nothing was harmed but afterwards I checked it for oversteer and installed 428 engine Mustang springs in the front to stiffen up the front. Checking it as mentioned in the parking lot revealed it steered neutral after the springs because it tracked the same circle every time around.

 

Sad to say, closed K-mart parking lot just got easier to find, our's has held on but signs went up couple weeks ago, closing.

Parking lot is better than Int. exit ramps. I'll post back here after get it / install.

Truck drives super on main highways, Interstate, etc …. but lately making more trips down into far reaches Floyd County, lots of curves. Looking to eliminate / lessen "the push"

Put fat Addcos F&R on our Merc GM, it loves a curve now. .

 

Interesting technique on the understeer and oversteer. I'm actually looking to add a rear sway bar kit to my '00 Dakota, but was wondering the same thing.

Speaking of Kmarts, you should all the people filming the closing of Kmarts on Youtube. Sad, but it's the circle of life.

 

When Walmart came to my small city, I compared their prices with Kmart. All of the items I checked were less expensive at Walmart. And the quality of clothing appeared to be better at Walmart. You don't have to be very bright to figure out what was going to happen.

I'm an old coot. Early on, I bought almost everything from Sears. But, they went to poor quality on everything (except maybe their hand tools) trying to compete with Kmart and they went under. The Sears model was to buy the businesses that they couldn't compete with. They bought Western Auto because their tire stores couldn't compete. Then they changed it to a parts store and sold it to Advance. Then they bought Kmart. It makes you wonder what kind of lower intelligence is needed to be a CEO or President of Sears.

 

That's why I can't be a boss of an already established business.... you become less brighter (AKA lower intelligence).

 

One of the last things I tried to purchase from Sears was a riding lawn mower. They appeared to have the best deals. It had to be ordered and delivery from the store (in NC) was arranged from the Chicago office. I was working out of town and couldn't pick it up. The day it was to be delivered there were torrential rains and it was not delivered and nobody contacted me. After several days, I called chicago and was told their computer said it was delivered. I kept calling and after a couple of weeks, I asked could I cancel and get a refund. By this time my grass was getting very high. They said yes. I then called my local Lowes store from my job location 800 miles away and bought a rider over the phone that was delivered the next day which was a Saturday. After several weeks I finally had to go to the Sears store and prompt them to refund the money to my credit card. I asked to speak to the manager but she refused to speak to me. I didn't want to yell at her. I just thought she should know what happened. No interest.

 

Oh, I understand the whys of the closings, at 64 yoa I've seen others fade away. Grew up going to Sears with Dad, then K-mart built closer to home in '60s so then buddies and I rode bikes for modeling stuff …. Didn't mean to redirect my thread, my bad.

Also looked at Belltech #5548 , but while saving a few $$$, it's a 1 inch bar and most pics show it as top (over axle) mount which would be OK with oem exh,
but I'm short on room above the axle with the 2" lower stance & aftermarket exh.

Thanks y'all !

 

The most notable stores I remember when I was a young kid was Jamesway, Bradlees, and Caldors...

 

Well, looked and looked at install pics and instuctions, went out into cold a few times to look under mine.

I was about ready to order the Hellwig 7705, but those long almost s shaped end links …. ???
I noticed the Belltech 5551 was bent to work with a truck lowered with a flip kit, springs under axle. That bar's ends pass over leafs ahead of axle.

I finally came to conclusion that the Belltech 5548 was what I really needed, even though only 1" diameter. It does have a hump that passes across top of pumpkin. I think I have enough room there. It also has end links that mount under the shock at the frame, but use short straight links. Belltech says this bar will fit a 2007 FX2 but not a FX4. Well, my FX4 is lowered 2" in rear, looks identicle to a FX2 underneath rear. Rear sway bar don't care about front drive axle or transfer case, and their instruction pics show the larger rear axle under that hump. … and so I ordered one. Hope / I think it will … clear two exhaust pipes under bed over rear axle.

Edit 12/19/18 It was due 12/10/18, now looking at Fri 12/21/18.

Edit 12/21/18 It was due today, then I get a message that March 19 is new date, so I rekon Belltech don't want to sell me one of their rear sway bars. OK …. Cancelled order and ordered Hellwig 7705 …. we'll see!

Edit 12/28/18 Hellwig 7705 …. arrived late evening, going on truck 12/29

.


This is how I used it in the end. Look closely, you can see how the one side above the words "as used" is formed with a "kicked out" arm, it's intended to clear the OEM muffler, this bar is laying on a floor "up side down", it is exactly as I used it. I didn't need the room for the OEM muffler, mine is smaller … so I used that to give me more room on the gas tank side and I added a 2.25" bolt on extension or "spacer:" on straight leg which is over near my muffler. My mounting also better clears my aftermarket exhaust.

My U-bolts for sway bar to axle are 7" from the right side's nearest Axle-Spring U-bolt center to center, 6" on e left (gas tank) side. My mounts are tilted forward on the axle to 20 degrees from level which moved the bar slightly forwards. I made some spacers for them too. (5/8").

Note, on 10-01-20 I removed the 5/8" spacers and readjusted the two end links to their shortest length, see post 20 below.

Read on.


Heard of Bradlees ….

 

OK, Hellwig 7705 arrived and I soon discovered no way it was gonna work with my exhaust as is, but by flipping it upside down (steel bar doesn't know difference, and neither does it cae about direction of "S" in arms …. as effective lever is a straight line from bar pivot to link end), and setting endlinks to short length, it worked OK. Could be better if I redid exhaust, like up higher and rightside up, but I can live with it. Took a drive today, takes a good whoopdedoo to get contact at exhaust, but I'm already to space it another 5/8 inch lower at the axle mount, which will gain about 3/4" (0.898" doing math and using dimensions of bar itself) at bar under pipe. If stock exhaust or with a re-routing of that left side rear pipe, it would have fit great. It doesn't hang much lower that differential as is, if it hits something, then whatever it was already smootered beyond recognition anyway . need to rotate mounts forward on axle tubes a few degrees I think, to move bar forward to better clear that pipe without raising it a bunch.

Drives really nice, I like it.

It would have suited me 100% if that rear, center most, zig-zag-zig behind differential as half as deep as it is, I'ld still need to drop bar at rear service time … but in use it would not be fighting the pipe for space. That would shorten the effective length of the bar so maybe 1" would be good. I understand their reasoning for the deep zig-zag-zig … just saying.

As it is, if doing rear service, I think if the truck is lifted and weight taken off the rear axle, the bar will swing out of the way now.



Note, on 10-01-20 I removed the 5/8" spacers and readjusted the two end links to their shortest length, see post 20 below.

 

Nice!

 

Flipping the bar means it's no longer level and not performing optimal. It's now weaker than it could be. But it's better than nothing