My 1986 Subaru GL 4wd wagon. When driving on the freeway, when I hit a rough spot or divit in the road my car feels like it takes a bit of a dive on the driver's side and jerks to the right. A bit scary. I don't notice it on surface streets at lower speeds. It tracks fine when I let go of the steering wheel and the road is smooth. I tried doing the string alignment as described in the forums but there was no change.  I checked the wheel bearings on the driver side and they were OK. With the car on the ground and jacked up I grabbed the top of each front tire and shook it vigorously. Everything seemed tight. I grabbed each side of the tires trying to feel for any play. Nothing. I've been led to believe that there is no caster or camber adjustment on these old guys, just toe in or out. Is that right? Is it possible that I screwed up with my string alignment? Was shooting for a1/16 toe in. So the only other thing I can think of is maybe ball joints? Anyone got any other ideas? Do I need to get a real wheel alignment?

Your front and/or rear struts are the issue. Check for leaking oil if they’re original. If aftermarket they’re gas and die quickly from what I’m told. 

The oil units can leak but still work ok for some time then they result in the vehicle being really unsettled after hitting bumps. 

If only the tests are dead the giveaway is the vehicle will feel like it tries to crab when in a corner and you hit a bump/pothole/ripple in the road - quite unnerving! 

A shot ball joint or tie rod end would result in excessive tyre wear and the steering being floaty left and right - meaning very little feeling left and right that moves the car in the same direction. If this is the case you’ll find yourself always correcting the direction of the vehicle like they do when “driving” cars in movies when filmed in the studio… you may also experience a lack of confidence in your steering at speed. 

Cheers 

Bennie

Edited November 26, 20232 yr by el_freddo
Oil struts can work when leaking, not gas struts

6 hours ago, 3crows said:

 takes a bit of a dive on the driver's side and jerks to the right. A bit scary.

The spring has failed.

I've pulled out failed springs like this and compared them to others - and there's no visual difference.  They are the same length, no cracks, I assume the materials are degraded and not offering the right spring rate characteristics. So I don't know of any tests that can be done to confirm diagnosis.  But if it happens due to bumps while driving straight, that's a failed spring in a Subaru IME.

 

3 hours ago, el_freddo said:

. 

If only the tests are dead the giveaway is the vehicle will feel like it tries to crab when in a corner

That's true, his is happening only due to bumps, not while cornering, which is typically a failed spring. 

Although at this age and condition, it probably doesn't matter and both new struts and springs are on the menu.

If it's the struts, they're no longer available. I replaced the struts in 2019 and they were hard to find then. I couldn't find the struts for a 4wd and had to use 2wd struts instead. KYB no longer lists them. There was another outfit that sold them too but they say, "Out of stock" and they probably got theirs from KYB. If I'm lucky the old ones my still be in my scrap metal pile. They were a little spongy but they didn't try to kill me. The car only has about 131,000 mi. on it. It was a rare find even years ago when I bought it.

Edited June 2, 20232 yr by 3crows
left out a word

Found the old ones. I'll reinstall them and see if that solves the problem. If not, this will be my last Subaru.

On 6/1/2023 at 8:12 PM, 3crows said:

If it's the struts, they're no longer available.

It's probably not the struts.

On 6/2/2023 at 12:34 PM, 3crows said:

Found the old ones. I'll reinstall them and see if that solves the problem. If not, this will be my last Subaru.

I've never seen even horrific struts cause ghost walking like you're describing, why replace them?

It's probably the springs, not the struts. 

Scroll down to the Kia front springs:

https://www.ultimatesubaru.org/forum/topic/106807-improved-shock-absorbers-and-spring-coils-on-loyales/#comment-897956

 

Put the old struts back in. Not much difference. The KYB shocks self extended when I took the struts apart so they're probably still good. Guess I'll have to find different front Subaru GL springs. I'm not trying to stiffen the front suspension, just stabilize it. Thanks for the suggestions.

I had a similar issue on my 87 DL 4WD wagon last summer and it was one bad left front strut that must have had some internal valving issue. Since it compressed and extended at a different rate than the right side, it provided some weird driving situations when hitting large bumps. Right before I changed them out, the left one would sometimes remain stuck in the compressed position which made it feel like I had a flat tire on that corner. I could get out and give a hard jounce to the fender and it would suddenly pop back to normal ride height.  I replaced the struts but re-used the springs and all has been fine since. I purchased the wagon from the original owner and as far as I know, it still has the original springs at 244K miles.

Not long after that was fixed, my eBay saved searches came across another Monroe NORS left strut and then a right one a month later so I've now got a set stored away for future needs. I'm sure some of the Nitrogen has leaked out after 15-20 years sitting in a box but all that does is reduce foaming during severe use and I don't drive like that.

Back again. Since I started this blog I've swapped 3 different pairs of struts, swapped springs from side to side thinking that if it was the springs the car would crab the other way but nothing has changed. It still remains a mystery. My next experiment will be to replace the rear struts with new ones that I.have. Maybe instead of the front crabbing to the right it;s the rear crabbing to the left. I'm running out of things to try.

On 11/25/2023 at 9:34 PM, 3crows said:

Back again. Since I started this blog I've swapped 3 different pairs of struts, swapped springs from side to side thinking that if it was the springs the car would crab the other way but nothing has changed. It still remains a mystery. My next experiment will be to replace the rear struts with new ones that I.have. Maybe instead of the front crabbing to the right it;s the rear crabbing to the left. I'm running out of things to try.

Have you had an alingment anytime recently, including in the back.  There are alignment bolts on the rear control arms of EA82's. 

Check all bushings and linkages without load.  Jack the car up and pry on/around every bushing to see if any are loose.

Random guessing here but I'm still not 10)% on the springs.  The rear springs are clocked to the strut mounts, so I think it *should* work like you say, but I'd be hesitant enough to confirm without a doubt particularly with such a distinctive issue.  This isn't minor.