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1970 Eldorado - Persistent Pulling (Mainly to the Left)

Started by Anderson, May 06, 2022, 12:40:23 AM

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Anderson

I'll resist the temptation to make too many political jokes with this, but my 1970 Eldorado has developed a persistent tendency to pull to the left.  We've checked the alignment, we replaced the steering box, but whenever I make a sharp turn to the left, the car will want to keep turning left (turning sharply to the right seems to reverse this, but doing that on the road isn't always practical).  The issue developed when we replaced the idler/pitman arms back over the winter.

My mechanic has run through the shop manual and he's stumped.  To quote the bill:

QuoteCheck over front suspension for any loose nuts and bolts. Attached sensors from alignment machine and check alignment values.
Caster, camber, and toe out of spec. Adjust caster and camber into spec then adjust toe-in. Dismount sensors and roll vehicle to resettle suspension. Attach sensors and measure alignment angles again. Adjust caster, camber, and toe. Road test performed, during road test vehicle tracking straight until u-turn performed. Returned to inspect for any pieces in steering hanging up. While watching steering system found steering gearbox to have a loose spot while turning. Steering gearbox will need to be replaced. After gear box replaced alignment checked. All alignment angles in spec. During road test found vehicle will pull left after hard u-turn to left. Inspect for any possible binding, rubbing, etc. Removed steering damper and road test to verify if damper causing push to left. No difference found. Remove wheels tie rod ends from spindles to check if ball joints or c.v. axle causing bind. Spindles turning freely. Reinstall tie rod ends and wheels. Unbolt steering gearbox to gain access to remove pitman arm. Remove pitman and idler arms. Find old units to compare length and verify old and new units identical. Reinstall pitman and idler arms. Reinstall steering gearbox. Set front end on turn plates and check steering ackerman. Set appointment with Bert's Alignment to have checked.

If it were "just" a matter of having to maintain a slight steer to the right, that'd be one thing - annoying, but not much else.  Unfortunately, doing so results in excess wear on the front left tire (it wore down to the metal over the course of a few thousand miles of this).

Does anybody have anything we might not have thought of as the culprit?

The Tassie Devil(le)

I suppose the question has to be asked, but why did you replace the steering box?

Now, with regard to the steering box, and the replacement, have you adjusted the box to remove the slop?   If you did when the steering was off centre, then this could be your problem, as this adjustment MUST be done with the steering straight ahead.

Adjusting the height of the Sector shaft to take out the play when on a turn, is really BAD, as there is an in-built "play" in all positions either side of centre.

Bruce. >:D
'72 Eldorado Convertible (LHD)
'70 Ranchero Squire (RHD)
'74 Chris Craft Gull Wing (SH)
'02 VX Series II Holden Commodore SS Sedan
(Past President Modified Chapter)

Past Cars of significance - to me
1935 Ford 3 Window Coupe
1936 Ford 5 Window Coupe
1937 Chevrolet Sports Coupe
1955 Chevrolet Convertible
1959 Ford Fairlane Ranch Wagon
1960 Cadillac CDV
1972 Cadillac Eldorado Coupe

Anderson

Quote from: The Tassie Devil(le) on May 06, 2022, 01:09:05 AM
I suppose the question has to be asked, but why did you replace the steering box?

Now, with regard to the steering box, and the replacement, have you adjusted the box to remove the slop?   If you did when the steering was off centre, then this could be your problem, as this adjustment MUST be done with the steering straight ahead.

Adjusting the height of the Sector shaft to take out the play when on a turn, is really BAD, as there is an in-built "play" in all positions either side of centre.

Bruce. >:D
The steering box was replaced because when it was checked, it appeared to have a "spot" where they'd turn the wheel and it would...for lack of a better way to put it, slightly jump to the left and tend to stay there.

I'll mention the question of adjusting to remove the slop.

[As an aside, any idea why this would have emerged when the idler/pitman arms were removed, since IIRC that's when this, at a minimum, became pronounced.  I believe we were "chasing" a slight pull starting back in September, since we did two rounds of balance/alignment checks.]

Edit: Trying to remember more of this issue (since it's been going on for a bit):
-There was a slight pull, IIRC, that we started chasing in September.  We replaced the idler/pitman arms in an attempt to deal with the issue in January, but as above...we'd already run it through an alignment, etc.
-The car always starts off driving fine.  As soon as you do a first U-turn or sharp turn to the left, the car keeps wanting to turn in that direction.  On the right side, the bias tends to be lighter.
-From January to April, the car wore the front left tire down to the metal (we didn't realize the likely wear and tear involved with keeping a "mild right turn" on to keep the car straight).
--In April I also started smelling what smelled like an exhaust leak or something similar following having the car jumpstarted.  We think this was probably the tire getting worn down to the metal.

Roughly in order, we did an alignment check.  We checked the tires for balance.  Both yielded minor changed and some limited improvements.

I believe the list at the start covers everything done on the latest check.  The steering box was checked...after the other stuff failed to resolve the issue.  The problem has persisted.

Our best guess, at this point, is that something is FUBARed in the front axle or something insidious like that.

Anyhow...over the last few months, I also dropped about 1.0 MPG vs what I'd "expect" to get (depending on variables such as the A/C being on or off, windows up/down, etc.), so the impact on fuel consumption is non-trivial (i.e. on a road trip to/from Louisiana, the impact could easily get into the $80-100 range).

[I'm currently lamenting that I went with a '69 Continental Mk III for my "backup classic"...right now I might take a '79 Lincoln just to have *something* old and American to drive for a bit.]

As a note, the car is just over 150k miles right now.

Dave Shepherd

#3
Check for any binding  in the steering linkage first. If that seems good, that problem usually can occur if the gear box is not centered when the the wheels are straight  ahead. Another issue could be the outer cv joint is binding but you would feel that on any sharp turn. For that tire to wear down like that something is changing in the alignment,  or toe out on turns.

TJ Hopland

Have you checked your brake rotor temps after a drive to make sure you don't have one dragging for some reason?  Eldos for some reason seem to like to have internal brake hose failures that act as a return check valve so they don't fully release. 
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason

"Cadillac Kid" Greg Surfas 15364

If all else fails to turn up a culprit check the frame. With all that weight and mechanism up front it doesn't take much of a fender bender to move things around a bi. Frames are strong but not indestructible
Greg Surfas
Cadillac Kid-Greg Surfas
Director Modified Chapter CLC
CLC #15364
66 Coupe deVille (now gone to the UK)
72 Eldo Cpe  (now cruising the sands in Quatar)
73 Coupe deVille
75 Coupe deElegance
76 Coupe deVille
79 Coupe de ville with "Paris" (pick up) option and 472 motor
514 inch motor now in '73-

Anderson

Quote from: "Cadillac Kid"  Greg Surfas 15364 on May 06, 2022, 07:47:10 PM
If all else fails to turn up a culprit check the frame. With all that weight and mechanism up front it doesn't take much of a fender bender to move things around a bi. Frames are strong but not indestructible
Greg Surfas
So, I've passed these along to my mechanic.

Greg: As a practical question, why would a problem like this have gotten worse "all of a sudden" (admittedly, over the course of a few months)?  As far as I can tell, there's been nothing recent that "should" have caused her to "suddenly" start pulling to one side.

"Cadillac Kid" Greg Surfas 15364

What I have personally seen on a couple of bent frame eldos was the alignment and adjustments as they are available were empirically set ( not to factory specs) to those settings that gave a decent ride and steering geometry.  Not saying yours is bent for sure, but if it is and your mechanic set everything back to factory specs....
Look for the simple things first such as brake hoses and components and check carefully for evidence of any pars rubbing against the frame or each other.
Greg Surfas
Cadillac Kid-Greg Surfas
Director Modified Chapter CLC
CLC #15364
66 Coupe deVille (now gone to the UK)
72 Eldo Cpe  (now cruising the sands in Quatar)
73 Coupe deVille
75 Coupe deElegance
76 Coupe deVille
79 Coupe de ville with "Paris" (pick up) option and 472 motor
514 inch motor now in '73-

hornetball

But it starts after a sharp left turn, right?  That means something is shifting during the turn.  I'd be looking at ball joints and bushings.  I have seen bad bushings that have caused something similar.  A cracked frame could also act like this.

Big Fins

Current:
1976 Eldorado Convertible in Crystal Blue FireMist with white interior and top. (Misty Blue)
1969 Fleetwood Brougham in Chalice Gold FireMist with matching interior and top. (The Old Man) SOLD!

Past and much missed:
1977 Brougham de Elegance
1976 Eldorado Convertible
1972 Fleetwood Brougham
1971 Sedan de Ville
1970 de Ville Convertible
1969 Sedan de Ville
1959 Sedan deVille

Anderson

So, going down the list:
-Caster isn't the issue.  We tried fixing that.  It'll get straightened out, and then promptly revert when I do a U-turn/sharp left turn.
-They're going to re-check the bushings/ball joints, and look for a crack in the frame.  They said that neither was an obvious issue, but something might pop on a dedicated look.
--What y'all have described about the possibility of a bent/cracked frame seems plausible (there's been an issue with the hood not wanting to sit *quite* right).
-I think I mentioned brake rotor temps, but this would seem to be surprising (given that it happens when a turn is made, not after an extended period of time).

I'd also note that, IIRC, this is the same side where, when I had to jam the brakes back in November, the caliper locked up (we replaced both within a few days).

Anderson

I figure an update is in order:
I've got the car back and though there's still a pull to the left, the alignment work did seem to help and it mostly unwinds itself after a little bit (and/or a modest steering wheel tug to the right).

That said, the A/C evaporator exploded the day I got her back.  I was still driving her in "cooperative" weather, generally meaning "not raining and not over about 90-95, so usually in the evening only" (we locked down the A/C system in a shut-off condition)...when the driver's window decided to freeze in place on Friday evening.

We're dealing with that latter issue on Wednesday.  The A/C system is going to get a full replacement with a street rod kit (it's been a gremlin since the beginning), but that won't happen for a few months.

[On the bright side, I have a '69 Continental Mk3 which should be ready in the next few weeks...]