Steering gear differences?

[deepimpact]

I own a 2016 V6 Mustang, with a steering gear, model number: 'GR3C-3D070-AB'.
The sticker in my door tells me 17' wheelsize - but I have actually 18' wheels on it.

I want to replace it, but I am confronted with a various different model numbers of steering gears for mustangs.
There are seller, who sell steering gear which shall be compatible with eco boost, v6 and gt.

Using ford part search I'm confronted with:
- GR3Z-3504-B (Replaces: FR3Z-3504-D, FR3Z-3504-GE, GR3Z-3504-A, GR3Z-3504-FE, STE-249-, STE-260-, STE-307-, STE-313-)
- GR3Z-3504-C (Replaces: GR3Z-3504-GE, STE-314)
- GR3Z-3504-D (Replaces: GR3Z-3504-HE, STE-315-)

They shall vary on wheel size? Is the rack the same, but the tie rods different? Or what exactly varies?

I'm very confused about the wide range of different model numbers.
Is there anyone who can enlighten us or me?

thank you

Sponsored

 

[Cobra Jet]

The variances are due to the modules equipped in different S550’s - it’s not just a hardware variance, it’s software related too.

You cannot just throw any rack into an S550 like the old Mustang days - it has to be matched to the VIN and BCM’s for the EPAS programming.

Here’s some EPAS reading for you - which may help to understand the rack hardware and software.

The rack has an internal motor, complex circuit board and rubber drive belt...

https://www.mustang6g.com/forums/th...-steering-rack-not-fixed.149185/#post-3047891

 

[deepimpact]

Thank you, for your answer.

The background of my question is related to my other topic, where my rack got changed due to an accident. I had the Gr3c-3d070-Ab but now I have (read from forscan, maybe the number on the part is different): hr3c-3F964-ac.

Since then the steering feels hard, sometimes very hard, unnatural feeling. Sometimes, but very rarely, it feels like before, everything fine.

I changed alternator, let Ford check if steering gear was built in correctly, everything is fine they say. But I still have the experience that something istn right with the steering gear.

My every last thought was now to get a used other steering gear, and hope that's because of the steering gear which is not working properly.

I found a FR3C-3D070-BG from an eco boost, but I don't know if it will fit properly.

 

[Cobra Jet]

Thank you, for your answer.

The background of my question is related to my other topic, where my rack got changed due to an accident. I had the Gr3c-3d070-Ab but now I have (read from forscan, maybe the number on the part is different): hr3c-3F964-ac.

Since then the steering feels hard, sometimes very hard, unnatural feeling. Sometimes, but very rarely, it feels like before, everything fine.

I changed alternator, let Ford check if steering gear was built in correctly, everything is fine they say. But I still have the experience that something istn right with the steering gear.

My every last thought was now to get a used other steering gear, and hope that's because of the steering gear which is not working properly.

I found a FR3C-3D070-BG from an eco boost, but I don't know if it will fit properly.

I would reach out to @LevittownFordParts and give him your rack part numbers. He may be able to assist with exactly what rack you had vs. what rack you now have in the car AND what the correct rack would be as a replacement.

As stated in this thread and the other, the hardware (rack) is specific to the vehicle by VIN and the part numbers. If a S550 rack was installed into your vehcile that was from another, but did not match yours by VIN or correct part number - AND the Service Center who did the work did something via Ford IDS flashes to your software to get “x” rack to work in your vehicle (even if it’s the wrong one), that may explain your odd steering experiences.

As for steering feel on hard surfaces (ie: road, pavement, cement or tar) vs soft surfaces (ie: sand, dirt, grass, mud, gravel, etc) - of course the steering feel will be quite different. If turning on soft surfaces (off-road), your steering will feel loose, but only because the tires are either slipping or being drug through the soft surface.

I would not do any such comparisons from hard to soft surfaces.

If your rack is not performing to what you were used to feeling PRIOR TO the replacement of the original - then bets are, the “new” (replacement) rack that was installed is either wrong (not for your specific S550) OR the IDS software flash is incorrect OR both.

The only other things I can think of outside of the rack and IDS flash would be:

1) Other damaged hardware on your front end (control arms, tie rods, etc) that if bent or damaged in some way could be adversely affecting your steering.

2) Poor alignment. When is the last time the car had an alignment? If it had one recently, was it before or after the replacement of the rack?

 

[deepimpact]

thx for your answer.

1) After the rack was installed, I also let original FORD look, if it is build in correctly. They said yes.
2) Alignment was made after rack was changed.

I texted @LevittownFordParts and hope he'll give a feed back.

It' really weird.
Weird because the hardness is not even constant. It's like about 80% present, in different levels.
Everytime I start the car after a while, the hardness varies. So I don't think it's something mechanic, because there is no mechanically change when my car is standing still for some hours, no impact, no movement, no change. Even I've got no DTC. I also tried to monitor PSCM values in forscan, if I can see something weird. I wished I could reproduce the different cases, but I can't.


I don't know if the problem:

1) depending on board electricity... battery? (but I did changed the battery and even alternator too)
2) depending on the rack itself.
3) depending on harness damage?.

 

[Cobra Jet]

thx for your answer.

1) After the rack was installed, I also let original FORD look, if it is build in correctly. They said yes.
2) Alignment was made after rack was changed.

I texted @LevittownFordParts and hope he'll give a feed back.

It' really weird.
Weird because the hardness is not even constant. It's like about 80% present, in different levels.
Everytime I start the car after a while, the hardness varies. So I don't think it's something mechanic, because there is no mechanically change when my car is standing still for some hours, no impact, no movement, no change. Even I've got no DTC. I also tried to monitor PSCM values in forscan, if I can see something weird. I wished I could reproduce the different cases, but I can't.


I don't know if the problem:

1) depending on board electricity... battery? (but I did changed the battery and even alternator too)
2) depending on the rack itself.
3) depending on harness damage?.

Your 3rd item above -
“Depending on harness damage”...

Were harnesses repaired or replaced from your accident? If so, it is quite possible that a harness, whether rack related or engine related is not repaired 100% OR a connector is loose, causing intermittent signal failures. Think of it this way, is there is a bad connection, it would go from having full power to essentially intermittent “manual”, which may explain your steering feelings (harshness) sometimes and sometimes not.

A manual rack is and would be much harder to steer than a power assisted rack. If the rack lost power, again intermittently, yes I could see it being “manual” for those seconds or minutes it’s without power.

You can try to test the theory by replicating the issue. Meaning, if you are able to get the rack to feel harsh - remember what you did last - did you turn full right, partial right, did you turn full left, partial left, did you go over something in the road etc.... Can you make it do it if you sit idle and turn steering wheel side to side and at what point in that motion does the manual feel come into play... etc.

It’s very hard to diagnose online like this - but first see what Levittown can tell you about the rack part numbers and what they belong to for starters. If the response is that the rack used to replace your original is correct - then I would start checking any harnesses that were repaired OR replaced from the accident. Look for any loose connections to any engine bay harnesses above, below or attached to rack first by doing “wiggle test”. Then to really know or tell if a harness wiring is damaged, you would need to remove the black outer conduit casing to examine the wire bundle inside of it. Once you can access the wires, look for cracking of their outer cases, chafing, breaks or completely broken wires.

 

[Cobra Jet]

Found this thread today, it may be of some interest to OP:
https://www.mustang6g.com/forums/th...ower-in-their-steering-while-on-track.127352/

 

[deepimpact]

I was at the American car repair shop today, and he told me that it could be because of suspension. And this did not sound very faulty because the first time the steering was OK again, was when I brought it to Ford, so they can checkup if it is build in correctly. The shop told me, that when a car is lift up, the suspension does relax (or something like that) and the steering will feel much lighter.

This happened to me also when I drove a sands elevation to park the car. The steering was feeling light for some days. So in both case the reason why the steering was working well again had to do something with lifting up the car.

After installation of the new rack I think they also did resetup the cross member and maybe also the suspension? Because I'm not really into those topics I'm thinking loud
now.

Assume it has something to do with this, is there any adjustment tolerance on those parts which will have affect on steering hardness.?

Because what speaks against the steering rack itself is, that this misbehavior isn't permanent the same. But I think (and maybe I do think wrong) a faulty steering rack would permanently have the same misbehavior.

I'm really wondering what the solution will be haha

Sponsored