Power steering update

[sheffieldcortinacentre 764]

10 hours ago, Stuwindsurf said:

 

Here's a pic of the parts after they were media blasted and epoxy primed, don't know if you can tell from these...

Nope they look correct, if memory serves think Granada are a bit squarer 

[Stuwindsurf 4]

These are the ball joints and track rod ends I fitted, both listed for Mk3/4/5 Cortina, anyone had any issues with these brands?

 

[sheffieldcortinacentre 764]

Both good brands.

[TimB 102]

Whilst drilling the ball joint fixing holes put the camber back to negative camber the process shouldn’t have been necessary.

How are you measuring the camber and Toe?

As Craig said I’m only clutching at straws, but it sounds to me that the suspension subframe, components and the rack are not a compatible match. But like I said before I am not familiar with MK3,4 or 5 front suspensions.  But I do know suspension technology and what you are experiencing is very strange.

The bump and rebound action of the suspension should not affect the Toe. The distance between the tie rod ball joints is a set distance so pulling in the wheels should not happen when the suspension moves in either direction. 
Sorry possibly not a lot of help and probably telling you what you already know.

Hope and answer comes up soon.

[Stuwindsurf 4]

13 minutes ago, TimB said:

Whilst drilling the ball joint fixing holes put the camber back to negative camber the process shouldn’t have been necessary.

How are you measuring the camber and Toe?

As Craig said I’m only clutching at straws, but it sounds to me that the suspension subframe, components and the rack are not a compatible match. But like I said before I am not familiar with MK3,4 or 5 front suspensions.  But I do know suspension technology and what you are experiencing is very strange.

The bump and rebound action of the suspension should not affect the Toe. The distance between the tie rod ball joints is a set distance so pulling in the wheels should not happen when the suspension moves in either direction. 
Sorry possibly not a lot of help and probably telling you what you already know.

Hope and answer comes up soon.

 

For the camber I used both an angle metre and a builders square against a level flat surface. It is only to get it in the ball park before I get it set up properly with the correct tools. Again I could physically see the wheels lean out the the top which I why I then checked them and adjusted as mentioned.

 

For the Toe measurement I set the car at ride height again on a flat level surface and measured between the front of the wheel rims and the back of the wheel rims and adjusted accordingly to get them the same. Again only to get them in the ball park for now.

 

I agree with you that it appears that the rack and suspension components aren't compatible but what I don't understand is how others like Craig have fitted the same components with no issues! In fact Ford fitted the same front subframe as the MK3 to the MK4 which the power steering rack came off!!

 

It is certainly a srange one, when I get a chance I'm going to remove the springs so I can see exactly what's going on throughout the whole suspension movement bump stop to full droop

Edited July 11 by Stuwindsurf

[sheffieldcortinacentre 764]

As said loads have done this ,the cradles have minor differences over the years but nothing that would cause this.

In 40 years of messing with these I've only once had a problem in the mid 90s as mentioned above ( actually the opposite ) but it was as baffling .

I've had the lopsided rear ( one side lower than other several times which again defied all measuring one of mine is now 1 inch lower on pass side, so is spaced to level it up) drove the same either way but was noticeably wrong when measured at arches ( original  not replaced) but not at axle mounting points ???? Twisted shell ?????? Again who knows, loads of people have come across this over the last 50 years but no one ever seemed to know what it was???

Edited July 11 by sheffieldcortinacentre

[sheffieldcortinacentre 764]

Some more measurements for you mk4-5 "cast iron rack" ( not late half Ali type sometimes called the German rack as fitted to continental built rhd cortinas not very common in UK)

 

Main body tube overall length 57cm.

Trod end to Trod end ( ball joint centre of pin vertical) all horizontal 127 cm.

Driv side trod pin to end of tube ( main body)  35 cm

Pass side as above 35 cm

 

The late rack mounts are same distance & trod end to Trod end will be same as the racks are a straight swap as a complete unit.

 

All racks use the same track rod ends wether manual or pas . Mk1-2 Granada racks are physically bigger & held by U bolts, Capri are  mounted at an angle to cradle so neither will fit.

2wd sierra can be fitted with cradle mount mods only has one mounting bolt per side .

Edited July 16 by sheffieldcortinacentre

[J2S 169]

Take the shocks out see if the spring compresses and wheel sits right when you lower it

I'm still thinking it's shock or spring problem

[Stuwindsurf 4]

15 hours ago, sheffieldcortinacentre said:

Some more measurements for you mk4-5 "cast iron rack" ( not late half Ali type sometimes called the German rack as fitted to continental built rhd cortinas not very common in UK)

 

Main body tube overall length 57cm.

Trod end to Trod end ( ball joint centre of pin vertical) all horizontal 127 cm.

Driv side trod pin to end of tube ( main body)  35 cm

Pass side as above 35 cm

 

The late rack mounts are same distance & trod end to Trod end will be same as the racks are a straight swap as a complete unit.

 

All racks use the same track rod ends wether manual or pas . Mk1-2 Granada racks are physically bigger & held by U bolts, Capri are  mounted at an angle to cradle so neither will fit.

2wd sierra can be fitted with cradle mount mods only has one mounting bolt per side .

 

Thanks Craig, much appreciated 😊

[Stuwindsurf 4]

2 hours ago, J2S said:

Take the shocks out see if the spring compresses and wheel sits right when you lower it

I'm still thinking it's shock or spring problem

 

Yes I will try that, thanks

[sheffieldcortinacentre 764]

5 hours ago, J2S said:

Take the shocks out see if the spring compresses and wheel sits right when you lower it

I'm still thinking it's shock or spring problem

They can't affect the geometry only the travel.

[Stuwindsurf 4]

4 hours ago, sheffieldcortinacentre said:

They can't affect the geometry only the travel.

That's my thinking, but hey I'll try anything!

[Stuwindsurf 4]

MASSIVE update, I think I have finally found out what the issue was causing my bump steer, I think it was incorrect castor angle! I can't believe it might be something as simple as this after months of scratching my head and racking people's brains.

 

I had set the castor angle so that the front and back wheel centres measured 101.5" as mentioned by others as a start point. I assumed it was ok for now but didn't realise how much it effects bump steer if not set correctly.

 

I've just been out to the car and wound the nuts on the tie bars on a few threads just to see what would happen and I could literally watch the front wheels straighten up as I did so. I noticed at the weekend when the steering was at full lock the inside edge of the tyre touched the anti roll bar etc. I thought thats not right, maybe the castor angle is incorrect pulling the bottom suspension arm back too much and when I checked this morning I was right! 😁

 

I will be so relieved if this is the issue, I was beginning to think I had a twisted or messed up suspension set up. 

 

Thanks to everyone for your help and input, it was much appreciated! Hopefully problem solved, Yaay!!

 

Just got to find someone reputable that can set it all up once I get it on the road 🧐

Edited July 23 by Stuwindsurf