Differences on all 69-70 spindles:

69 spindles have smaller axle on all except BOSS 302 and BOSS 429.  69 non-Boss spindles use A2 and A6 bearings. 70-73 spindles have larger diameter axle and use A12 and A13 bearings.

69 non-Boss spindles use smaller tie rod, same as 67-69 Mustang.

70 spindles use a larger tie rod that is a little larger than the 67-69 spindle, but smaller than the Granada spindle.

67-73 spindles have same geometry.

Hubs and rotors from 65-73 will fit either spindle as long as the bearings that fit the spindle axle are used. The OD of the bearings is the same for all years mentioned. So, the 70-73 spindle has larger axle but the rollers in the bearings are actually smaller than the 65-69 bearing rollers.

Nos681 wrote:

Thanks guys.

How do 71-73 spindles compare to 69 and 70 spindles?
So are 70 spindles difficult to adapt to 67-68 with tie rod difference?
How does one adapt them?
Use of respective tie rod ends?
What year did drum and disc spindles become different design altogether? 69 or 70?

Since we are discussing spindles.
Are C6 spindles actually for 66 or for 67-68?
I’m still confused about this one.

RPM hooked me up with C5 spindles and hubs so I know I’m good.
THANKS BOB!!😁

That’s how these questions surfaced.
Just curious about the differences.
Figured others might be looking for this valuable information too.

71-73 spindles same as 70 spindles

Simply use 70 outer tie rods to adapt 70-73 spindles to 67-69

In 1968 became disc brake-specific. 68-73 used same disc brakes.

The C6 spindles found on 67-69 Mustangs were from the parts bin of the 66 Farlane, hence the C6 prefix.  They have different geometry than 65-66, but same as 67-73.
 

Follow up question Steve.
Just to clarify about bump steer.
I know they would bolt up just like the Granada spindles.

Should ‘70 spindles be used on the 65-66 models?
Can the bump steer be adjusted out of these on the 65-66?

I don’t think you can adjust out bumpsteer caused by different ackerman geometry. Much simpler to just use correct geometry spindles.

Ackerman is FIXED.  Built into the spindles and there is nothing you can do about it other than heat/realign the radius arms or replace the spindles.

Lowering a car makes the tie rod assembly approach the spindle from a different angle.  THAT can be adjusted by using a longer tie rod standoff.  That, by the way, is something I would NEVER install on my car since it adds a lever arm where more force can be applied to the tie rod than it would normally see.  Plus, most use the dreaded spherical rod ends that I abhor on street vehicles.

“Forum member formerly known as RPM”, I think you’re right. 😁

Oh no ! Dang!
I just installed spherical rod ends / helm joints to reduce bumpsteer on my 67 with 70 spindles.
That puts me on MSteve’s sh*t list of horrible people.
Dang!
(but I cured the damn bumpsteer and can drive my car again; it’s been on blocks since Bash in Glen Rose)

Hmmm...a bifurcated ironic juxtaposition.

Paul

Last edited by Prof (12/12/2019 7:52 PM)

Prof wrote:

Oh no ! Dang!
I just installed spherical rod ends / helm joints to reduce bumpsteer on my 67 with 70 spindles.
That puts me on MSteve’s sh*t list of horrible people.
Dang!
(but I cured the damn bumpsteer and can drive my car again; it’s been on blocks since Bash in Glen Rose)

Hmmm...a bifurcated ironic juxtaposition.

Paul

Since the 67 and 70 spindles have the exact same geometry, the bumpsteer was caused by a difference in ride height, and that CAN be corrected by those awful vertically extended spherical rod-ended tie rods that I hate. I did not state they would not cure that problem, only that I did not like the design snd would never Install them on my own car. For a track car that is not really a street-driven car, where noise and harshness and short life-span are not a consideration, and if you can keep them from shearing off, I suppose they are a workable solution to a self-induced problem.
I thought the 67’s bash drivability issues were electrical???  You didn’t have those battery terminal extensions on there, too, did you?😁

How does one’s use of a PART I don’t care for get anybody on that list? I just said I did not like the part.

Another attempt at humor. Most folks use the term self deprecating.

How do you plan on using your car and what size wheel/tire combo?

I had Granada spindles on my car for over 20 years and 235/60/14 on all corners.
When I really started noticing bump steer was when after steering components had worn out/failed.
And that was without the Arning/Shelby modification.

When I finally performed a rebuild and the Arning/Shelby 1” drop, I converted back to 65 spindles for MS brake upgrade.  I never ran the Granada spindles and  1” drop together.

Mine is setup for driving and cruising.

I have original 66 spindles on my 66 with 427 engine. The spindles are designed to carry the car weight, so I am not too concerned. I have now owned it for 30 years with those spindles. Many of those years with 13” cobra brakes on it.

Consider this: in 70, they went to a larger diameter spindle axle, but the OD of the bearings remained the same. That means the bearing rollers are smaller from 70- on.

Triton wrote:

I have those spherical rod-ends on the bump steer kit on my 65 and they work perfectly. I do inspect them a little more often. I have never seen or heard of them failing for any reason other than a crash. Vintage racers have been using them for years but you have to buy quality ends. There's nothing more scary to me than bump steer at freeway speeds and it even affects braking as well. I guess to each his own!

My thoughts exactly Triton.