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Highway speeds, wind and wandering
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Author:  Thalyn [ Thu Oct 25, 2012 5:13 am ]
Post subject:  Highway speeds, wind and wandering
I inherited an old A-body Mopar a number of years ago from my uncle. It's an Australian '68 VE Valiant Regal which, for the US crowd, is based on the '66 Dodge Dart. It's become my daily driving car and I'm still trying to sus out what needs to be done to really bring it up to scratch.

The latest issue I'm encountering is one of "wandering' when I get to about 90kmph (~55mph) on a flat road - particularly in high winds. Even without the wind I find myself having to continually make minor corrections to stay within my lane. Based on my father's history with a similar car (same year, but with a 273 V8 and power steering - mine's a 225 and a 20:1 manual box) I'm wondering if it's got something to do with body roll-induced steering, but there's probably other things I'll have to consider.

Now, before the questions start coming (and I'm sure they'll be good questions), I honestly don't know too much about the car's maintenance history. I only know what I've done to it and, so far, the only things I've done to the steering and suspension system are: checking the grease in the steering box, tightening the steering box a little and replacing the idler arm (the bushing collapsed). I've also got 4 new tyres and had an alignment done about 6,000mi ago. Everything else - the springs, the shocks, the bushings, etc - are all exactly as they were when I got it, and there's every chance they haven't been replaced in over 10 years.

Now, I have checked to make sure that the chassis isn't cracked where the steering box mounts. I also re-tensioned the front wheel bearings to take out a very small amount of wobble. But I'm wondering if there's something else I should be checking, or even a known solution?
Author:  Doc [ Thu Oct 25, 2012 9:07 am ]
Post subject: 
Did the shop give you the alignment results (computer read-out) on the setting they used? (all the newer alignment racks provide a read-out)

If older alignment "tools" were used and no read-out provided, call the shop and ask them where they set the caster, camber and toe settings, then provide us with that info. ( they will likely pull the info. out of a book or out of their "head". (or a$$)

In general, alignment settings do impact the way the vehicle "feels" and handles, during different speeds and driving conditions. Knowing where the alignment is currently set will tell us a lot and help us plan the next step.
DD
Author:  ESP47 [ Thu Oct 25, 2012 11:04 am ]
Post subject: 
Did the car wander right after the alignment as well?

A bodies are going to wander with high winds, there's not a whole lot you can do about it aside from updating to a newer style suspension and steering.

Does your steering box have a dead spot in the middle? My Duster has a very small dead spot so I can basically hold the wheel straight and only need very minor corrections once in a while to keep it going where I want it. My girlfriends Valiant has a dead spot about twice as big as my Duster's so you're constantly correcting and the car was to almost zig zag left and right. Remember there is also the crown of the road that will always eventually pull your car on to the shoulder no matter how well you're aligned.
Author:  SlantSixDan [ Thu Oct 25, 2012 2:29 pm ]
Post subject: 
The right-hand drive A-bodies like yours are prone to rust-out in the frame rail where the steering box bolts up -- sometimes hidden -- which causes flex at the mount and resultant wandering.

The steering gearbox itself could be out of adjustment (did you make both adjustments to it? Or just the one?), or could be worn out. The flex coupler from the steering column to the steering box could have slop in it. The bushings, ball joints, tie rods, pitman arm, strut (radius) rods...all are likely past due for service. The alignment could well be out of spec even despite the recent adjustment -- the question of whether you received a printout with before/after specs is a good one. The suspension height must be adjusted correctly before the alignment is checked and adjusted, and I bet there are just as few alignment guys in Australia who know this (or know how to do it) as there are in America!

(Also, the VE Valiant is based on the '67 Dart, not the '66.)
Author:  KBB_of_TMC [ Thu Oct 25, 2012 4:56 pm ]
Post subject: 
Just to 2nd Dan, I've often found the little metal sliders inside older (US) Mopar steering couplers to be split clean in two.
Author:  Thalyn [ Fri Oct 26, 2012 12:02 am ]
Post subject: 
Many good questions here - I'll try to provide what info I can.

First, my apolgies on the year of the Dart. Was only really going by what Dad has been telling me since I got it. Though I'm sure I checked, when you hear something often enough it tends to stick with you whether it's right or wrong. Cheers for the correction, Dan.

Unfortunately, I didn't get a read-out of any kind when I got my alignment done. I'll try and get what I can but, at this point, it won't be until next week before I can do that (it's just on close of business Friday here as I write this). I did query the guy earlier in the week and he was wondering if the caster could use a tweak, but there wasn't any hard numbers thrown around. So I'll get those numbers if I can and report back in a few days time.

I wouldn't be at all surprised if there aren't many guys around who know what they're doing when it comes to an A-body. The one I took it to was about the only one who didn't grimace at the prospect of actually having to do it, plus I remember him saying a few things about it which suggested he may actually have a clue. Of course, I've no way to verify that.

When I adjusted the steering box, I only made one adjustment. It was the one accessible from the top, which seemed to tighten up the whole system. I had to let it off a little because, yes, there is wear in the middle (I suspect it's the original, 44-year old box) and I pulled it up too much and had far too much resistance just off-centre. At present, there's about a half-inch either way of "slack" before the wheels start to turn.

I don't actually remember it wandering all that much just after the alignment was done. I remember it felt extremely light and unsure but that was more because of the old tyres and too much pressure in them - it all but vanished when I put on the new rubber and set the pressures a little better (250kPa, or ~36psi all 'round). But it hasn't been especially windy between then and now so it may just have been too minor to notice.

As far as updating the suspension, what exactly would that entail? It would seem a little silly to go about replacing everything only to have to replace a good portion of it again. Are we just talking replacing the springs and shocks, or is this getting into the territory of new A-frames and adding sway bars?
Author:  kesteb [ Fri Oct 26, 2012 6:17 pm ]
Post subject: 
Quote:
As far as updating the suspension, what exactly would that entail? It would seem a little silly to go about replacing everything only to have to replace a good portion of it again. Are we just talking replacing the springs and shocks, or is this getting into the territory of new A-frames and adding sway bars?
I would start by decreasing the air pressure to between 28 and 32psi. 36psi is too high.

If that doesn’t improve anything then I would start replacing the upper and lower ball joints, the tie rod ends and the pitman and idler arms along with all the rubber bushings with new ones.

I know you just replaced the tires, but the best improvement in handling is updating to 15" rims and 60 series radials.
Author:  SlantSixDan [ Fri Oct 26, 2012 6:34 pm ]
Post subject: 
Quote:
I would start by decreasing the air pressure to between 28 and 32psi. 36psi is too high.
Totally disagree. 28 is much too low for today's tires, and I routinely run 36+ PSI in radial tires on A-bodies without wander or other problems.
Quote:
I know you just replaced the tires, but the best improvement in handling is updating to 15" rims and 60 series radials.
Disagree here, too. Big tires are better than small ones, but there are a lot of big improvements that can be made without changing away from 14" wheels and tires. In fact, I'd argue there are a lot of big improvements that should be made before installing 15" wheels.

Back to the subject: we know the front end (bushings, etc.) hasn't had attention for awhile. It's due, probably overdue. We know the alignment was twiddled; we don't know if it was twiddled correctly. We know there's some wear in the steering gearbox, and that only one of the two adjustments was done. We don't know the condition of the steering column shaft to steering box shaft coupler. We don't know the condition of the shocks. We don't know the condition of the rear leaf springs.

There's a pretty good list of parts and systems to inspect and check before making any decisions on what to start buying/replacing/upgrading.
Author:  Thalyn [ Sat Oct 27, 2012 1:16 am ]
Post subject: 
I actually ran the tyres closer to 30psi for a long while, but found the car felt "loose" even at low speeds. 36 was something of a trial-and-error number that I felt wouldn't risk overloading the tyres while also tightening the whole thing up.

All I can really say about checking out the parts is what I observe with my less-tuned eyes. I can tell you that nothing feels overly loose or wobbles in directions it shouldn't - that includes the coupler. But I can tell you that most if it is probably old. In the case of the ball joints, they're quite likely the original ones (I had to get new boots for them - the supplier commented that it was unheard of for the original joints to still be in use but replacements would have been metric).

I can get a front-end kit which includes just about everything that has been referenced, save the steering bits. The kit itself would be this one here. This is sounding more and more like a good idea as time goes on, and may be worth even looking into the rear as well. I can also source a coupling repair kit from the same place, which is also sounding like a good idea.

Unfortunately, my expertise doesn't extend enough to comment any further. Again, I can say that the shocks look old but clearly aren't original, however it's entirely possible the rear springs are original. As for checking ride height, well... there isn't exactly anywhere in the yard where it can be done accurately.[/url]
Author:  Slanted Opinion [ Sat Oct 27, 2012 2:43 am ]
Post subject: 
Buying the front end kit is a good idea. My '68 Dart had problems with wandering at highway speeds. Turned out just about everything was worn out (bushings, ball joints, etc). A suspension kit solved my issues.

There's always a chance the kit won't solve it.... but you'll be able to rule out a ton of possibilities all at once.

Get some really solid jack stands for this job if you are doing it yourself.

- Mac
Author:  Thalyn [ Sun Oct 28, 2012 5:25 pm ]
Post subject: 
I have alignment details!

At least, these are what they were set to by the mechanic - whether they're still set to that is anyone's guess due to the aforementioned age of the parts involved.

Castor: +1º 06' LH, +0º 55' RH
Camber: -0º 45' LH, -0º 30' RH
Toe: 3º 6' total

The numbers are hand-written but I assume them to be accurate. I'd have had a print-out but their printer is on the fritz. Keep in mind that this is an RHD car so they may be backwards from what's expected.
Author:  Doc [ Mon Oct 29, 2012 10:12 am ]
Post subject: 
If you drive flat roads (little to no "crown") then put more caster into it and tell the mechanic to make both sides even.
See if they can get 2 degrees of caster, on both sides.

Also, need more info on the "Toe"... do we assume that is "toe-in"??
DD
Author:  slantsik [ Tue Oct 30, 2012 2:41 pm ]
Post subject:  Chassis rail
Gday.
I own an AP5 and an S series.
As Dan said earlier,check the chassis rail where the steering box mounts. If yours is anything like mine , chrysler provides a lovely little pocket on top of the rail for dirt and crap to sit in and promote rust..

Do yourself a favour before ordering bits and pieces,and jack the car up. place on chassis stands. remove both road wheels de grease and clean thoroughly, and inspect the tops of the chassis rail, as well as inside where steering box bolts to ,use a little mirror and torch if need be. feel around for rust bubbles.

You will probably be unpleasantly surprised!!
Clean out all the crap, an check for rust.
sand blast and paint if you can!!
If the area around the steering box is rusted it will flex and cause "wandering."

Imagine spending all that money on steering/suspension bits and the problem was the rail!
Get yourself a factory service manual from the link you posted earlier ,or from Hemi performance.best $60 odd dollars you will spend on the old girl.
http://www.hemiperformance.com.au/store ... r-Sections
If the rail ckecks ok you are in luck. No expensive /tricky rust repair!
Good luck and happy motoring ;)
Brendan
Author:  Thalyn [ Wed Oct 31, 2012 10:44 pm ]
Post subject: 
Quote:
Also, need more info on the "Toe"... do we assume that is "toe-in"??
I can only go by what he wrote. Suspension isn't my forte - I'm more electrics and electronics. I figured it was positive which, if I'm right, means toe out. *Ed: I'm wrong. Positive would be toe in. If it were out, that may explain why it wants to wander a bit...

I'll definitely have to get in there and check out that chassis rail, though. A rather brief inspection didn't suggest anything was majorly wrong but, to be fair, that was mostly because the layer of crud over the bodywork hadn't cracked or fallen off.
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