Not so Good Vibrations

[whtbronco]

The suspension or wheel speed vibration I have been chasing recently is not consistent. This morning it was pretty bad for the 35 mile trip to work, and it starts out around 37-38mph. On the way home this evening it was fine until I was just 4-5 miles from home. It changes based on load, such as my son in the back seat. No matter what I pushed, pulled, pried, turned listened to etc I could not find anything loose and out of round. This evening I was gonna mess with the strut adjustment knob and noticed a gap in the rear strut lower bushing and thought that could probably cause this. It's always under serious tension so I wouldn't be able to feel anything by hand, rolling down the road though would be a different story. Whatcha think. This is the right rear, the left rear is the same, the front lower bushings are not visible while mounted.

 

[whtbronco]

New rear struts are enroute. Rancho has a lifetime warranty against wear out, yet another advantage to Rancho in my book.

From the Rancho web page:
DRiV warrants qualifying Rancho products against defects and wear-out when used on private passenger cars and light trucks under normal operating conditions as described below.

 

[whtbronco]

So the rear struts have been replaced. That resolved the majority of the remaining wheel speed vibration and I had no change in vibration after driving 20+ miles on the interstate the last few days. That said I was surprised to have noticed a consistent vibration between 50-55 and again 70-75mph. At the 70-75 range the steering wheel even shakes a bit I thought it might be something in the front end even though it was just inspected and the inspector found no issues and he checks my stuff closely by request. I found nothing up front with play or loose this evening either. It does look like I might have a small gap in the front strut lower mounting bushings though similar to the rear, but much less. It's hard to see that though due to the mounting flanges. What can be seen is that bushings are cracking due to dry rot. Maybe it's the front struts causing what's left, if the rear strut mounting bushings were worn out the fronts likely are as well. I also cannot adjust the front struts. I took the knobs off and got those freed up, but inside the strut the adjustment it's rusted solid. Between the dry rot and adjustment maybe Rancho will replace the front struts under warranty as well. You can see a small gap under the bushing in pic IMG_1476, it's nothing like the rear bushings, but it's still there.

The new rear struts have adjustment knob and internal part packed in dielectric grease. I have had Rancho shocks and struts for decades and never heard of doing this, nor have I ever had an issue with Rancho stuff before.

I will add that I will be getting a spring compressor set before trying to replace the front struts. The rear were difficult, but the front are even more difficult and my hands and shoulders are not up to the fight anymore. I used a ratchet strap to hold the rear struts into the mount and used my jack to compress it so I could insert the bolt, can't do that up front.

 

[whtbronco]

The front struts have been replaced. No need for a spring compressor, just had to disconnect the upper ball joint from the knuckle, remove the tie rod and pop the sway bar loose and the lower control arm could be pushed down enough to get the bottom of the strut in place. I dislike getting the sway bar links on/off so I just removed the sway bar to frame brackets as it's much easier. Then use a floor jack to get the sway bar back up to the frame while you get the brackets mounted again.

The passenger rear toe link was also replaced. The outer tie rod on it is no longer tight, but I still could not feel any play. However, replacing it reduced vibration and resulted in better tracking on the highway.

The remaining vibration is from 65-80mph, haven't been faster this week. The steering wheel is not visibly shaking anymore from 70-80mph like it was previously. This weekend I plan to replace the passenger side rear lower control arm and upper ball joint. Maybe, just maybe I will then be done with vibration for a little while.

 

[whtbronco]

The passenger rear upper ball joint and lower control arm have been replaced. The upper ball joint moved easily, but I felt no play. The lower ball joint was not easy to move, but it was sticky. It would not move and then kinda stutter as it moved so I suspect the grease had dried up. I only took it for a 3mi test drive, but I think this may the end of the drivetrain vibration. I sure hope so. I'll know better after driving to work this week and then.

I still have to reinstall the front driveshaft. I left it out to ensure the driveshaft and front axle weren't part of the problem.

Here's the parts and tools list in case anyone is interested. Everything was replaced with Motorcraft parts unless otherwise stated. Most everything contributed to minor vibration that added up to major vibration. The front driveshaft u-joint created extreme vibration at times.

IWE's (one failed to hold vacuum) $105
Tires (it was time, so another set of General Grabber HTS60) $950
Front wheel bearing hubs (286k miles just barely starting to develop play) $210
Fuel pump, Bosch $160 (just happened to fail during this lengthy adventure)
Changed rear diff gear oil (was gonna change it in 2-3 months anyway) $30
Rear driveshaft u-joints, slip yoke, straightened and balanced (slip yoke splines excessive play and front u-joint just a tiny bit of play)(Dana SPL non-greaseable u-joints all around) U-joints all 4 $80, slip yoke $125, straighten and balance $300
Front driveshaft u-joints, clean and re-grease slip yoke.(rear u-joint rusted cup keeping driveshaft off center)
Transfer case new bearings and seals (rear bearing for front output shaft ruined by driveshaft u-joint) (USA Standard Gear overhaul kit) Bought 2 kits, 1 salvage yard T-Case and a Motorcraft front output seal. $400
Transfer case shift motor (was causing errors for the 4wd module and other modules on the bus and improperly engaged the clutch coil)
Water pump(weeping a bit and just a little play) $60
Fan clutch(just a bit of play and a little easy to turn) $80
Rear diff torque arm/support bracket (bushing had 3/16" play up, no play down) $205
Found transmission cooler lines rusted while replacing water pump. Cut out the rusted parts and replaced with rubber EVIL ENERGY 5/16" Transmission Hose. Only because I could not find a full set of 5 new lines. $20 (just happened to find during water pump replacement)
Battery failed, Interstate. $125
Harmonic damper. $143
Front main seal. $16
PCV grommet. $10
Rear upper left knuckle ball joint, Moog K80212. $52 (local parts store)
Rear lower left knuckle ball joint, DELPHI TD4312W. $21 (rebranded Dorman garbage)
Rear upper left knuckle ball joint/bushing, Moog K80212. 2 more $64 (I messed up the first 1)
Rear lower left control arm. $306
Rear lower right control arm. $345
Rear toe link. 2 of them $275
Rear struts, Rancho. Warranty replacement, $16 return shipping to RockAuto
Front struts, Rancho. Warranty replacement, $28 return shipping to RockAuto
$3,916 parts total

New tools and supplies purchased during this adventure:
12 point 12mm impact socket for driveshafts, Sunnex. $10
E-Torx impact socket set to replace transfer case front driveshaft protective cover studs, Duratech. $20
Line flaring tool to flare transmission lines, OTC. $40
Deburring tool for transmission lines, General. $10
Transmission line quick disconnect tools (seat the tool and listen for lock release, pull both tool and line out together and the line will unseat), ZKTool. $15
Low profile creeper 'cuz I'm struggling to slide in/out from under the vehicles, ATD. $105
Ratcheting crimp tool for single ear hose clamps for transmissions lines/hoses, iCrimp. $20
Single ear clamps, Oetikar. $25
Transmission fluid for T-Case and transmission lines, Amsoil. $70
Coolant, Prestone. $35
Front main seal installer. 3D printed
Ball joint press, Maddox. $55 (rental units at the local parts stores are just abused)
Foaming intake manifold cleaner, Amsoil. $14
Digital angle meter to set camber properly, Klein. $30
$449 tool total, though I'm sure there's brake fluid and a few other minor costs as well.

Total $4,365