Sorry, accidentally hit post before i had all relevant information...
Looking for some advice on how to proceed next... (my sincere apologies for being long winded)
I'm having a difficult time narrowing down a Darty or twitchy behavior that the van has on the highway. It's not really noticeable driving around town or below 60 mph.
2008 Toyota Sienna LE FWD, 183,xxx miles. My daily Driver. Owned since Nov of 2015 with ~ 127,000 miles on it when purchased.
(The Firestone Lifetime alignment has been priceless LOL)
Until late December '19/Early January '20 I'm pretty confident all the original Struts, shocks suspension and steering parts hadn't been replaced.
Early January I was pulling out of the parking lot at work and heard a strange rattling clanging sound. "That's weird... I've never heard that before" I am VERY in tune with noises and sounds that the vehicle makes. Even small detectable differences in how the engine sounds depending on which motor oil I have ran in it (quite a variety by now).
As I am turning onto the on ramp to hit the highway heading home I heard one more loud CLANG and see a semi circular object in my side-view mirror bouncing down the ramp and off into the ditch. (That better not be what I think it is). Get home, start looking at the struts and sure enough about 3/4 of a coil of the drivers side front spring was missing. I measured the wheel wells and the drivers side sat about 3/4" lower than the passengers side.
Got under the van and looked over all the suspension and steering parts, everything seemed to be fine. I ordered FCS brand Strut and coil spring assemblies off of RA as well as matching rear shocks and sway bar links.
Keep in mind that this is early January this year (2020) and I still have my Bridgestone snow tires and steely wheels on the van...
I spent a couple of hours on a Saturday in my garage replacing the front strut assemblies, sway bar links and rear shocks. Got everything put back together and took it for a short test drive, I knew the alignment would be out of whack so I didn't want to drive it too much. Everything SEEMED fine. Brought it to Firestone for it's second alignment since we had purchased it (elapsed probably 50,000 miles in between.)
Alignment checked out toe-in adjusted to spec ect.
Drove till late March and swapped my snow tires off and put my Aluminum wheels with my Cooper CS5 All season tires on. The tires are 2016 manufacture date and probably 60% tread left, purchased new well balanced haven't needed re-balancing in 40,000 miles and all are wearing evenly. I change over my snows/all-seasons at home in my garage.
As soon as the all seasons were put on i noticed a twitchy/darty sensation on the highway. Hmmmmm. Drove it that way for a few days then put it in the garage, got it up on the floor jack with jack stands under it so that it would be sturdy and started prying on everything again with a pry bar. Everything SEEMED fine except it felt like the drivers side inner tie rod was a little loose. Kinda wondering if Firestone overlooked this while it was in for the alignment.
SO... another parts order to RA for LH & RH ball joints, inner and outer tie rod ends, and new steering bellows boots since the hard plastic original ones are always a pain to get off without damaging them.
Two weeks later (Early April by this time) I spend a day replacing all those parts. Another appointment at Firestone for another alignment.
Still drives darty twitch on the highway. there doesnt seem to be any play between the steering wheel and the steering rack. The control arm bushings all seemed fine and rigid without any play.
I got under the drivers side of the van and am looking underneath and see grease leaking out of one of the U-joints in the intermediate steering shaft.
Dorman $255 at AA, Oreily etc, RA was out of stock or get an OEM Toyota part on eBay $268. So I ordered the eBay Toyota OEM steering shaft and installed that last Saturday (05/30/2020).
STILL feels darty on the highway. seems slightly better but not significantly. I rechecked all the lug nuts to make sure nothing had loosened up since i had swapped the tires, everything was torqued to 80 ft lbs.
I'm ready to give up and sell it! (My wife shot that idea down very quickly)
Any guesses? Maybe take it to a different alignment shop and get them to look at it, kinda get a 2nd opinion?
I don't hear of steering racks going bad often but it probably does happen. It's not hard to turn in either direction and is smooth in the whole steering travel range.
I've got close to $650 in parts into the van since January of this year, and was shooting for 250k plus. I hate to give up at this point and cut my losses.
(Again my apologies for being long winded