Bump steer?

[rittenrotton 4]

 I have a 70 coupe with a 302 and I'm having some issues with the steering.  At low speeds on the street the car is great, but on the highway, the car just handles poorly. It's just seems a battle to keep it traight when it I hit bumps or grooves. I've tried searching for causes and solutions but I little lost as this is all new to me. I have all original suspension with the exception of new springs, shocks and a new bushings. I have upgraded the wheels and tires with American muscle 17x7. What am I missing? How can I improve my handling while on the highways? Would a bump steer kit help?

Thanks!

[aslanefe 333]

Lowering the upper control arms 1" and modifying them to move ball joint back to increase the caster improved the handling on my cars.

[barnett468 418]

1 hour ago, rittenrotton said:

 I have a 70 coupe with a 302 and I'm having some issues with the steering.  At low speeds on the street the car is great, but on the highway, the car just handles poorly. It's just seems a battle to keep it traight when it I hit bumps or grooves. I've tried searching for causes and solutions but I little lost as this is all new to me. I have all original suspension with the exception of new springs, shocks and a new bushings. I have upgraded the wheels and tires with American muscle 17x7. What am I missing? How can I improve my handling while on the highways? Would a bump steer kit help?

Thanks!

If all your suspension parts are within spec, most of the problem is the wheels and tires. An alignment to specs other than stock may reduce the problem but won't make a huge difference.

 

 

[1969_Mach1 333]

Are you still running the stock type power steering?  If so, is the control valve in good condition?  I kind of agree with Barnett that the wheels and tires are most of the problem.  Or at least exaggerating another problem like not enough positive caster or a problem with the control valve.

[unilec 57]

I doubt the power steering has anything to do with bump steer.These car came out of the factory with bump steer, but not as bad as your are dealing with, have you had the alignment, caster, camber and toe in checked? The only way to check bump steer is to measure the position of the wheel center to say fender at rest and remove the drivers side spring and measure from there.

[rockhouse66 22]

I doubt this is your problem, but my Grande' behaved in a similar fashion.  It took me a long time, but I eventually stumbled on the fact that the stud for the idler arm had been installed upside down.  So when you hooked everything up, the angle of the passenger side steering link was much different than the angle on the driver side, causing a lot of bump steer when only one tire hit a bump.  How do the angles of your steering links compare when you eyeball them?  Same?

[rittenrotton 4]

Thank you all for your help. I am sure it has something to do with the difference in the new wheels and tires vs original, as I haven't really touched the suspension. What's the best way to measure/correct the bump steer? Should I get a Baer Bumpsteer Kit as well as a bump steer gauge? 

[RPM 1,190]

It may or may not be bump steer. Worn steering and suspension pieces, and toe out can cause your symptoms. Lowering these cars from stock ride height often adds to the bump steer these cars already have. After doing the Arning upper control arm drop, adding a bump steer kit, and doing my own alignment, my 69 handles pretty darn well.

[MN69Grande 203]

I had similar issues as well with new shocks, springs, larger wheels and tires.  I ended up having rock hard bushings in my spring perches and strut rods.  As well as a bent strut rod.  This kept the wheels from traveling correctly and added a bit of a wiggle.  Not really a bump steer.  I replaced them with roller spring perches and adjustable strut rods from opentracker.  It really improved my handling.  Though I also added roller LCAs as well.  Either way if these parts are worn out they are probably worth looking at to replace with stock or upgrade.

Perches

https://www.cjponyparts.com/cj-classics-coil-spring-saddle-1965-1973/p/C4DZ3388RI/

https://www.cjponyparts.com/cj-classics-coil-spring-saddle-high-performance-1965-1973/p/CSS4/

https://opentrackerracing.com/product/roller-spring-perches/

 

Strut rods or bushings

https://www.cjponyparts.com/scott-drake-strut-rod-bushing-kit-1967-1973/p/SRB8/

https://www.cjponyparts.com/scott-drake-strut-rod-bushings-heavy-duty-1967-1973/p/SRB10/

https://www.cjponyparts.com/strut-rod-passenger-side-1968-1973/p/SR3/

https://www.cjponyparts.com/strut-rod-driver-side-1968-1973/p/SR4/

https://opentrackerracing.com/product/adjustable-strut-rods-1968-1973/

 

LCA

https://opentrackerracing.com/product/drag-racing-roller-lower-control-arm-1968-1973-mustang/

 

[capemustang 15]

I had a similar issue with my 1969 .  It ended up being a combination of the idler  arm, worn out bushings for the upper ball joints, and then, needed an alignment. It handles so much better now.

[rittenrotton 4]

Ok, I might look into the shelby drop. I will also change all the bushings  in the ball joints and perches.

 

[aslanefe 333]

8 hours ago, rittenrotton said:

Ok, I might look into the shelby drop. I will also change all the bushings  in the ball joints and perches.

 

You can drill with 1/2 inch drill bit and file a little instead of buying the odd size drill bit for the dropped UCA. 

[rittenrotton 4]

So I decided to try the Shelby drop using a template I bought from daze cars. Once I got all the suspension removed and installed the template, I started with a 17/32-inch bit and drilled the initial hole (but thinking back on it now I guess my mistake was removing removing the template which I did thinking in I would have the same size template holes for the other side.) After drilling the 1/2" holes, i found out that they are not aligned correctly. They are just a tiny bit too apart from each other. I'm just curious what I can do to correct this without making a bigger mess? Should I drill one of the holes out to be 9/16"? Or should I just go with control arms like Specialty Products Company Adjustable Control Arms which give the Shelby drop from the factory holes? 

 https://www.cjponyparts.com/specialty-products-company-adjustable-upper-control-arm-1967-1973/p/UCA61/

[1969_Mach1 333]

They look fairly correct in the picture.  Will the control arms reinstall?  I wouldn't drill one hole to 9/16".  Do you have a die grinder with carbide burrs to simply open up one of the holes to the inside a little?  Bolt on the template to scribe where the holes should be.  Do you know somebody that can weld to simply fill in a little of the outer edge of one of the holes then dress it up again with a die grinder and carbide burrs? 

When I made my template, the new holes in the template were merely 1/8" diameter for a pilot drill.  I bolted them in place and drilled 1/8" pilot holes, then removed them to drill to the final size in a couple of steps.  It seems stupid to make these templates with the new holes drilled to the final size.

[rittenrotton 4]

No, unfortunately they won't fit. The hole towards the front is off by a few hairs. I used a cutting wheel and cut off the upper control arm shaft (as I couldn't get nuts off and was replacing it anyway) and test fit it only to discover my problem. 

[Rsanter 152]

5 hours ago, rittenrotton said:

So I decided to try the Shelby drop using a template I bought from daze cars. Once I got all the suspension removed and installed the template, I started with a 17/32-inch bit and drilled the initial hole (but thinking back on it now I guess my mistake was removing removing the template which I did thinking in I would have the same size template holes for the other side.) After drilling the 1/2" holes, i found out that they are not aligned correctly. They are just a tiny bit too apart from each other. I'm just curious what I can do to correct this without making a bigger mess? Should I drill one of the holes out to be 9/16"? Or should I just go with control arms like Specialty Products Company Adjustable Control Arms which give the Shelby drop from the factory holes? 

 https://www.cjponyparts.com/specialty-products-company-adjustable-upper-control-arm-1967-1973/p/UCA61/

Round file or use a die grinder 

if you make the hole larger all around that effects the side to side and the up and down location.

just elongate the hole a little one the one you drilled a bit off till you can slide the bolts in

 

 Bob

[rittenrotton 4]

ok, I'll give that a try. Thank you for the suggestion!

[Brian Conway 264]

Just a suggestion...  Before drilling, grinding cutting or any other alterations to your shock towers or control arms I would gather all the components you intend to install.  Just to make sure they will all fit into the conditions you have created.  The steering problem could be as simple as crappy tires.  Brian

[dcm0123 15]

Had a wandering problem once which turned out to be the nut was loose on the end of the "power steering control valve".

On the end of the valve there is a cap which is held in place with 2 screws. Remove the cap and it exposes the nut. It should be torqued to a specific value then replace the cap. You may want to check this.

[barnett468 418]

SLOT the incorrect hole with a round file or die grinder, do not enlarge the entire hole.

In case it was not mentioned, you will need an alignment after doing the shelby drop.

There are no bushings in ball joints that can be replaced, and it is far simpler to buy new control arms instead of replacing the inner bushings on them.

Exactly what tires are on it?

 

[rittenrotton 4]

 Ok, so I did the Shelby drop; replaced the upper control arms, ball joints, the coil spring saddles and notice a big improvement of the suspension but the handling was horrible. So now I'm replacing all of the steering components (as most of it is original). I also noticed that my slave cylinder is leaking and the control valve is somehow missing a chunk of metal from the end cap. I just watched an episode of roadkill where David Freiburger just replaced the slave cylinder, control valve and steering box with the borgeson steering box, which I'm going to do as well. Not just because I saw it on TV but from what I've read the Borgeson steering box makes a big difference in steering feel and response. Then once all this is done, I'm going to try doing an alignment myself or maybe bring it to a alignment shop. So we shall see how the handling and wheel response is. I hope better lol

 

Barnett -. I have a Michelin Pilot Super Sport 225/45Z17's mounted on 17x7 American Racing Torq-Thrust M

[aslanefe 333]

1 hour ago, rittenrotton said:

 Ok, so I did the Shelby drop; replaced the upper control arms, ball joints, the coil spring saddles and notice a big improvement of the suspension but the handling was horrible. So now I'm replacing all of the steering components (as most of it is original). I also noticed that my slave cylinder is leaking and the control valve is somehow missing a chunk of metal from the end cap. I just watched an episode of roadkill where David Freiburger just replaced the slave cylinder, control valve and steering box with the borgeson steering box, which I'm going to do as well. Not just because I saw it on TV but from what I've read the Borgeson steering box makes a big difference in steering feel and response. Then once all this is done, I'm going to try doing an alignment myself or maybe bring it to a alignment shop. So we shall see how the handling and wheel response is. I hope better lol

 

Barnett -. I have a Michelin Pilot Super Sport 225/45Z17's mounted on 17x7 American Racing Torq-Thrust M

Incase you didn't know, you need more than just the Borgeson steering box. You will also need manual steering drag link, idler arm and pitman arm; or a "manual steering adaptor" if you are using PS drag link, pitman and idler. I think Borgeson also recommends GM style pump instead of Ford pump.

[rittenrotton 4]

aslanefe Thanks, I spoke to CJPony parts who told me I could use the stock ford pump but from what I've read on here you need a strong pump, like the GM style pump. I purchased the adapter.  Also, is there a difference between the power steering vs manual center link (other than 1 additional hole for the power steering slave cylinder)? 

[aslanefe 333]

1 minute ago, rittenrotton said:

aslanefe Thanks, I spoke to CJPony parts who told me I could use the stock ford pump but from what I've read on here you need a strong pump, like the GM style pump. I purchased the adapter.  Also, is there a difference between the power steering vs manual center link (other than 1 additional hole for the power steering slave cylinder)? 

Yes, PS center link and idler arm are different than MS parts. MS centerlink also has the stud to connect the pitman arm to and do not have threads on DS end to connect the control valve.

If you are purchasing the PS to manual adapter, you can use PS center link and idler. Remove the ram and discard it, remove the control valve and install the adapter in place of it.

If you have some fab skills, you can install a Prius EPAS for about $100 instead of Borgeson box. You will still need the PS to manual adapter but can use your current steering box if it is in good condition. You get 3.5-4 turn from lock to lock steering with PS box and get rid of pump, hoses etc.

[aslanefe 333]

Had a typo on above post, the MS center has hole to connect the pitman arm to, not a stud.