Earlier I sent a post regarding the process for lowering the rear of my Supercrew with a 2" lowering shackle to even it out.

Well I'm back to say there is a problem with doing this. It seems this is just enough to change to the angle of the rearend in relation to the drive shaft to create a problem. I started noticing a vibration @ 20 mph and again at 60 mph. As soon as I changed back to the original shackles the vibration was gone.

I now have to call AIM Suspension to purchase an angle shim to be placed between the axle and the leafspring to correct this problem.

Lesson learned....even the simpliest of changes can have a big affect on performance.

 

Had the same problem with my 00 HD. I had a Bel Tech 3/4 kit installed, and kept getting a "rubbing sound" when I would hit it. Kept checking but did not see anything. When I had the SC installed by another company, I mentioned the vibration @ approx 18 mph. When they checked it out they found that the drive shaft was hitting the x member, and had actually bent the drive shaft. Had to special order a new drive shaft and they shimmed the axle as you mentioned. No problem since then, but it was an expensive lesson.

------------------
2000 HD FORD
HOLLEY "THUNDER" SC

 

I have had the BellTech 2" rear shackle on my truck for about a year now and have not had any problems ( that I am aware of )I haven't noticed any noises or vibrations from adding the just the shackle ... I have punched it a few times and have had the truck up to 160 km/h ... no problems ... maybe the SCrews have a slightly different suspension geometry in the back??

Also, I thought the BellTech 4" rear kit included shims w/ the pkg. ??

 

Actually Frank S you are incorrect. Quality shackle or not, changing the relationship between the back eyelet of the rear spring to the frame DOES have an affect on the suspnsion geometry. When the stock suspension is loaded down, all components move as designed to allow for the load. This is not the same as adding a 2" shackle drop. Imagine disconnecting the rear shackle completely and rotating that end of the spring so that the axle/ spring assembly rotates 90 degrees up or down on the front eye, what would happen to the relationship between the yoke of the rear differential and the rear yoke of the drive shaft? It would change, no? Well adding a 2" reat drop shackle has the same afffect, just not as drastic. I checked the AIM Industries (a quality company)web site and found they do supply differential shims to adjust for this condition. The shackle I used was the same as the one sold by BellTech.

 

I used to work for a contractor that had their light-duty f150s loaded so much that the rear sat at least 4" lower than stock. Not a comfortable ride, but no vibration. If quality is not an issue, then why have both people that installed Bell-Tech shackles reported with no problems. That tells me that the Aim and Bell-Tech pieces are not the same or the angle of the shackle is improper.

 

The shackle on the F150 Standard cab, Super cab, and Super crew are all the same. It is nothing more than a straight piece of steel with holes on boths ends for a bolt to pass through. There is no "angle" on these shackles. This is one piece where there is no discernable difference between AIM, BellTech etc. The only difference between aftermarket and stock is length.

 

The factory shackles on my truck were pitched at an angle. Not perpendicular to the ground. Might want to check that. My new shackles have Bell-Tech stamped on them. Who told you that the Aim shackles are the same as Bell-Tech?

 

Go with Bell-Tech and you won't have any problems. There is no difference between installing shackles and a contractors' truck carrying around a load 24/7. The angle change should not cause any problems if a quality shackle is properly installed. I've had 2" Bell-Tech shackles on mine for almost 3 years with no problems.

------------------
1997 XLT Reg. Cab, 4.2L V6, 5spd, Superchipped, '99 Lightning Grill, '99 XLT White Bumper w/Fog Light Kit, K&N Air Filter, Dash Mat, Clear Corner Lenses, Clear Tailights, MagnaFlow Muffler, Hellwig Rear Sway Bar, Edelbrock Shocks, Duraliner, Extang Saber Tonneau, Painted Tailgate Handle, Bell-Tech 2" Rear Drop, Amer. Rac. Atlas Wheels Clad in 275/60/17 Eagle GTII. Likes straightaways, loves twisties.
"If you're in control, you're going too slow."--Mario Andretti

 

The strange thing is that not all trucks require shims when lowering ... some of my friends who own "other" lowered trucks never needed shims ... AIM is the distributor ... Chassis Tech is the company that manufactures the stuff and their stuff doesn't seem to be up to par compared to other companies like BellTech etc. ... all over this site there are testimonials to not use Chassis Tech/AIM products ... even a shop that sells Chassis Tech says that it can be hit or miss with their stuff or not even at all ... With the F150 you should not have had to use shims with such a mild drop I can see 4 - 5" needing shims but not 2" ... thats ridiculous!!

------------------
98 F150 SuperCab XL
4.2L V6, auto, 4x2

K&N Filtercharger
APC clear corners APC Euro tailights
Belltech 2" shackles
Extang soft tonneau
ArmourThane sprayed liner
Cloudrider grille screen
DynoMax exhaust
Panasonic CD tuner
12" JL sub
Clarion 5x7 3-ways
Rockford Fosgate amp

Soon ...
new exhaust system
-DynoMax looks bad
lowered suspension
?????

 

1. For the sake of understanding the condition...please, everyone put aside brand names for one moment. For this type of discussion and condition, to say that brand name has an affect is like saying that different makes of tires having the same diameter will affect your speedometer. They will not as long as the diameter is the same. This holds true for this rear shackle. All things being equal (material, welding, metal thickness, paint), the only difference CAN be length.

2. I'm not saying there isn't differences between brands of suspension components such as leaf springs, coil springs, control arms etc. There is, however for this particular component, there is not. How do I know, well at one time BellTech offered just the lowering shackle and a friend purchased one for his 99 Supercab. Now however Bell Tech does not sell this seperate. I tried to purchase from them. After experincing the problem (and debating it on this site) I went over his house, crawled under the truck in the rain to look at his shackle. Guess what? NO difference in design between brands.

3. Now...if a shackle is say 6" long, then you lengthen it 3" more....doesn't matter what brand (remember it's just a piece of straight metal, no angles here!)...what affect will this have on the relationship between the drive shaft and the rear pinion? No one has addressed my "turn 90 degree" analagy yet.

The fact is it has to have an affect on the driveline. Just because many members have not had a problem, does not mean some will not.

My whole point of mentioning this in the first place was to make sure members are attune to the affects even a minor change will have on your vehicle.

 

For those who are genuinely interested in this subject, read the posts on this matter under the SuperCrew forum.

 

This is what i'm worried about, was planning on either a Bell Tech 2/4" or 3/4" drop or a Ground Force 2/4" drop. Now both of these kits not only have the shackles but the front hangers as well which correct me if i'm wrong would keep the Angle about the same, maybe a slight difference but only as if you had a big load in the bed. Someone needs to straighten my *** out here before i spend the money on 1 of these kits. Thanks for any help.

:smokin

------------------
All Black 2000 F-150 XLT,5.4,Auto,3.55's,Super Cab,Class III Tow Package,Rear Slider,Keyless Remote,Cruise,Tilt,A/C.
Mods:
Pioneer 45Wx4 AM/FM CD SuperTuner 3,2-10" SubWoofers/enclosure under back seat firing down pushed with a 200 Watt Amp,4 pioneer 5x7" 2 ways in doors,2 Pioneer Tweeters in Doors near Pillars
Bug Guard
Black Nerf bars
Dash Cover
Bed Liner
Stainless Hide-a-Hook Tie downs
HellWig LP 25 Overloads
Billet Custom Grill
Billet FORD Valve Stem Caps
Billet F-150 Receiver Cover
Billet Pedals
Billet Antenna
K&N Filter,WMS Velocity Tube & 3" Adapter Through Fender
Flow Master Force II Exaust with Single in-Dual out Behind Rear Wheels
SuperChip
Euro Clear Carbon Fiber Tail Light Lenses
Driving Lights 55 Watts
Fog Lights & Driving Lights 55 Watts behind Grille(FogLights on Remote Control)
80/100 watt Superwhite Headlights
Smoke covers for Headlights/Corners
Front Clear Corners...SuperWhites for Corners 5/15 Watt
55 Watt Halogen Backup Lights
BedLights(2)
Lit Front & Rear FORD Blue Ovals(Remote Controlled,both on same Remote)
LED'S on Cup Holders
ExTang Black Max Tonneau
ExTang Cargo Cleats
2000 16" Expedition Wheels
Still on to do list:4:10 LS Rear Diff,Electric Fan,Bell Tech 3/4 Drop,Hellwig Front & Rear Sway Bars,B&M Shift Kit,Holley Thunder SC,Headers,Billet Door Sills & Strobe Lights.

 

Ok, I used to own a small custom shop where we mainly sold lowering parts... Everytime we sold AIM products, they were bad in some way, EXCEPT for their regular old lowering blocks. We once lowered an S-10 with 2 inch AIM Spindles and 2 inch AIM coils and blocks out back...the alignment needed to be done of course. But the customer could not get it done till the next day. He drove about 65 miles and his brand new tires were already showing steel...thats how bad their parts can be.

------------------
Steve
Mine:
1999 F-150 Sport Supercab
Bright Red 4.6L Auto
Billet Grill, Billet Ant, Clear Corners, Sony CD Player, Pioneers in all doors, Kicker 100si Amp, MTX preformed underseat box. Fiberglass Bed Cover
Hers:
2000 Expy Sport
Black, Grey Leather 5.4L
Clear Corners, Alpine CD Player, Punch 150 Amp, JL Audio preformed sub box in rear panel.

 

AIM, GodFathers, Chasis Techm Ricky Racer
all mainly owned % wise by the same person
and are very very well known for parts not being up to par
i have seen AIM: brackets need trimming to fit, shackles that are slightly warped, airbag mounts warped, Valve Leaking internally, air tank with a hole in it, compressor out line clogged from factory
seems xtreme but they seem to use poor quality products and thin metal in cetain cases
they use cheap materials
well known, look at any sport truck or minitruck site that is owned purely for the sport and not money making and u will find the message boards full of complaints

 

It has nothing to really do with bad parts causing a missalignment when raising or lowering a truck. The factory has a tolorance for drive shaft angles. If the truck is within the tolerances it goes on down the line. Now if your truck was on the edge of the tolarences from factory and you change the suspension you could go outside of tolerance easily. Or it could go the other way and make your trucks suspension right on the button according to specs. If it goes out you need an alignment job, if a suspension change actually makes the angles and such better you will not have to have an alignment done. This is why one guy with the 'same' truck as you will have no problems while you do.