Alright, 01 F-150 4x4 5-speed with 78k miles. Just got Ford Racing 8.8" 4.10's front and rear with a Cobra Trac-Lok in rear. Royal Purple fluids. Had both axles completely rebuilt with new bearings / seals, etc. The idiots didn't fully secure the lug nuts on the rear driver's side wheel, so I lost that wheel doing about 30 mph, 100 mi. after having it done. A week after getting everything fixed, new wheel, etc. the rear pinion seal started leaking. Turns out the Ford Racing supplied Federal-Mogul / National seal fit sloppily on the pinion gear so I had them replace it with an OEM seal. Problem solved, but noticed an occasional loud pop at take off from a dead stop that wasn't there before the gear install. I ignored it for 1,500 mi. and it seemed to happen less and less, as well as getting quieter and quieter.

Last weekend while backing in my garage at real low speed, I noticed the rear end was groaning. Crawled under there and found that my rear serviceable "Heavy Duty" u-joint was trash after about 35k mi. Rather than fighting with the R&R, I had a reputable shop (Inland Truck) do the job and check balance. They installed Spicer Life Time (non-serviceable) u-joints and said it was in perfect balance.

Well, before reinstalling I tried something. If I put the truck in 1st. on a level surface and take the parking brake off, then rock the truck forward / backward from the rear bumper, it will make a single ping that rings thoughout the rearend, then a second if I push it just a hair further. It only pings while rolling forward. I thought it might have had something to do with the parking brake, but it does the same thing with the parking break lightly set and in neutral. Same thing with / without driveshaft. It pops twice at seemingly the exact same spots.

I'm wondering if this sounds like it could have something do to with the Track-Loc or maybe one of the bearings. Seems to come more from the differential than either side of the axle, but it's hard to say. Annoying as hell. Maybe I'll have a buddy at work rock it for me tomorrow while I crawl underneath to see where it's coming from. Would have the wife do it, but she's all knocked-up.

 

Pull the diff cover and look to see if all the ring bolts are tight. Also check the bearing cap bolts. Check for chipped teeth. Look for a crack in the differential carrier. Check the differential pinion shaft and lock bolt.

Regards

Jean Marc Chartier

 

AHHH HA! It's coming from the pass. side rotor dust cover. Going to take it back to the stealership that adjusted the parking brakes after having the gears done.

 

Well $#!^. Took it to work today and she ran nice and smoothly all the way there and almost all the way home. (about 25 min. ride) All highway running 75 mph. About 2 miles to the offramp home, I made a sweeping right hand turn around the cloverleaf and, it started shaking so I slowed it down to 45 and babied it home. Once I hit the offramp it was fine again. I dropped the ol lady off at home and took off on a short cruise up to 90 mph and hit the same section of highway. Nothing, perfectly smooth again. Any ideas WTF?

 

E-Brake linkages were rusted and sticking so they cleaned everything up and anti-seized everything. Unfortunately after an hour's labor the parking brake bottoms out against the floor now. I assume they can be adjusted by simply removing the rubber dust covers and rotating the star wheel. Any idea which way to rotate them? I'm assuming clockwise on each side...???

 

In searching the site to figure out which direction to rotate the star wheel on each side and coming up completely empty handed, (even after checking the factory service DVD) I stumbled across tons of threads talking about sticking parking brakes causing tremendous shuddering...enough to make you pull over and stop. I'm convinced this is the exact issue I had been having. Now if I could just get the damn parking brakes dialed back in without having to sit around a stealership for 2 hours.