2000 E350 Quigley with 7.3 - tires cupping badly

[rgaller]

Hi all, I've got a recurring problem that I can't seem to solve. Ever since rebuilding the front end of my van (Kingpins, tie rods, etc), the tires cup like crazy. It was aligned right after I did the work, but the tires are just having all kinds of problems. Any ideas what could be causing it? It's basically stock except it has a dually conversion using Arrowcraft adapters (which was on the van long before the tires started cupping).

[REF]

Maybe the alignment that the shop did is not right. Check your tire pressures?

[mikracer]

What tires are you running?

[Lilnuts2]

Why did you replace your kingpins and other parts in the first place?

I would:
Take it back to the alignment shop and have them re check it.
Check wheel bearings.

Check or replace shocks.

[Twoxentrix]

Where is the cupping occurring ? Outer edges, inside the tread?
You can also get this symptom when the tires are unbalanced, or shocks are shot - do you experience any “shaking” when you are driving?
Although I only have experience with the SportsMobile West 4x4 conversion, I can only speculate that alignment specs would also be specific to other 4x4 conversions - having said that, did the Alignment shop use stock Ford van criteria ? The first alignment I had done after I took possession of my Van was done completely incorrectly - they used Ford specs and it drove like crap. Went back and had them utilize the spec sheet (initially gave this to them) I received in the SportsMobile binder, and all was great.
So question I would pose would be does Quigley have specific Specs for their 4x4 conversions?

[JWA]

If the alignment spec's are contrary to Ford's for any modified I'd hammer that point home with the "alignment shop" in no uncertain terms---I'd absolutely insist they show me the settings while it was still on their rack.

Then again I'd NEVER let one of the chain store tire sellers touch my front suspension---find a qualified bus or big truck shop, not a hobbyist bunch.

[doublevan2]

Greetings -- not SMB van related - but years ago I had a Jeep Cherokee - hit a very wide and deep pavement crack NY State highway - brand new tires - got back home - had appointment to have tires rotated and balanced - mechanic called and said both front tires badly cupped -- said front wheel bearings flattened and scored -- have your bearings checked ? Good was that front tires moved to rear - and eventually they wore evenly and did not have to replace. Bad was the $450 parts and labor for front bearings ! Good luck --

[Fool120]

I noticed that my tires on my '97 E350 Quigley SMB were cupping pretty bad on the front in Nov, and I had a long drive to do, so I swapped them all out. Had Cooper Discovery A/T, and replaced with Cooper STT Pro. I didn't notice any vibration from the tires. The tires were 5+yrs old too, so were on the list to get changed sometime soon anyway. My reading on the subject showed the need of getting more tire rotations and balancing.

[rgaller]

Thanks for all the suggestion, I forgot to mention I did replace both front shocks with Bilsteins. I had a really bad death wobble so I went through and replaced both tie rod ends at the knuckles, the drag link, kingpins, and shocks. I then put new tires on thinking that would also solve the tire cupping issues, but it hasn't. I went to an alignment shop (they only do frame pulls and alignments), but I didn't think about whether they were doing an alignment to Ford specs. Does anyone have a document that shows what it SHOULD be for a Quigley conversion? I have been holding off on doing a tire rotation since it's a dually van, but it sounds like I might have to. Here's how the tires are currently wearing:





You can tell there are high spots and low spots across the tread (cupping). There are zero vibrations on the van and steering wheel at high speeds, however there is higher than normal tire noise and at slow speeds you can feel the high and low spots.


I'm running Cooper Discoverer S/T MAXX tires.

[REF]

There’s an old thread on here somewhere that talks about specs, can’t seem to find it though.