steering and suspension Raise steering shaft

[Ian]

I need to raise the point in the firewall where my steering shaft passes through, but am having difficulty finding metric hardware.  I can find plenty of firewall bearings and universal steering joints, but they are all in inch dimensions, the predominant size being 0.75" diameter, and the 2002 inner steering shaft measures 18 mm (0.7").  Does anyone know of a source for metric steering joints and firewall bearings?  Alternatively, has anyone replaced or spliced the inner steering shaft with a 0.75" shaft? 

[Fatherof3]

http://www.ebay.com/itm/Hirschmann-SFC-18-18mm-ID-Heavy-Duty-Female-Rod-End-Germany-/162133824803?hash=item25bfedd523:g:Z0EAAOSwAPlXhKIF

 

 

Edited August 25, 2016 by Fatherof3

[FB73tii]

I think I used a Flaming River u-joint to connect the 2002 steering box when doing the same thing. I had to raise the shaft to clear the Tilton overhung pedal assembly, and added a second U-joint at before the new firewall bearing to get the steering shaft angle where I wanted it. I did not use metric shafts, may have been a 3/4" as you mention. If no-one posts the part number, I'll do so later tonight. --Fred

Edited August 25, 2016 by FB73tii

[Ian]

Hi Fred,

 

That's exactly the reason I'm doing it.  I've just got slop in the 3/4" firewall bearing, and thought I'd see if I could get better tolerances.

Ian

 

[FB73tii]

It was a Howe model 612 U-Joint (17mm-36 x 3/4”-36), which was the only 17mm-36 spline I found

In 2011 list price was $60.45, think I got it direct for $52.65

The joint is still listed at:

http://www.howeperformance.com/parts/u-joints-and-weld-couplers

 

BMW 2002 steering shaft dimensions
# splines at steering box        36
Spline base circle    15.96 mm (16 mm)
Spline OD        17.16 mm (17 mm)
Main Shaft OD        18.01 mm

 

The Flaming River was the 0.75"-36 x 0.75-36 I added in the middle of the SAE shaft. You can see the shaft heim joint mount in the photo below.

 

 

Edited August 26, 2016 by FB73tii

[Ian]

Fred, thanks for the great information.  In you pick, it looks like you are using a rod end to support the steering shaft next to the wheel.  Isn't the shaft diameter at that position 18mm? I'm curious what yo used to pass through the firewall.  Or did you use a second rod end at the firewall?

[Ian]

Alternatively, could I replace the 18 mm inner steering shaft with a 3/4" shaft?  Then I could use standard universal joints.  

I've never taken a steering shaft out, but I do have the entire inner/outer steering shaft and wheel assembly out of the car.

Edited August 26, 2016 by Ian

[FB73tii]

Right--3/4" rod end/heim joint to support the steering shaft. No ignition key or locking mechanism as track-only. The Howe model 612 U-joint is metric on one end and SAE on the other. So I used 3/4" components for everything after that, with a 3/4" bulkhead bearing at the firewall just as you did. I added a second U-joint between the steering box and bulkhead to allow me to drop the upper part of the 3/4" steering shaft--my seat bottom is much lower than stock, so I didn't want to be reaching way up for the wheel. I used a 3/4" weld-on spline at the end of the steering shaft, then a quick-release hub with a small diameter Grant steering wheel. I thought I had a photo of my pass-through put I could not find it. I'll try to post one this weekend.

Best, Fred

[FB73tii]

Here's a shot of the bulkhead pass-through. I fabricated a pocket for the firewall bearing to move it in and create a bit more room for the eventual airbox.It also reduced the angle of the U-joint a bit. --FB

 

Rag joint eliminated.

 

Edited August 26, 2016 by FB73tii

[Ian]

Do you notice a difference in the feel of the steering once you removed the RAG joint?  Was debating this, but wonder if it removes some of the NVH from the steering system for a car that will also be driven on the street.

Edited August 26, 2016 by Ian

[Ian]

One thing I'd like to do is move the steering wheel towards the driver a couple of inches.  It looks like the mounting bracket for the stock steering wheel is held to the outer shaft housing by a clamp held by two large screws (yellow arrows in pic).  It looks like if I could loosen the two screws I could slide the whole steering assembly out towards the driver.  But the screws have no slot or index on top, it almost looks as if they've been covered in epoxy.  I can pick the surface off, but there is no slot in the screw head.  Has anyone drilled these out and replaced them with standard bolts or screws?

 

[FB73tii]

You can back out those shear bolts with a small chisel/punch. According to Real OEM the part is a "fracture bolt" 32311152052. They are still available and appear to be 8mm x 45mm:

http://www.ultimategarage.com/shop/part.php?products_id=5025

 

BTW I am not concerned about NVH but suspect the rag joint is a safety feature--in a heavy impact perhaps it shears and avoids impaling the driver with the steering shaft. That is part of why I used two U-joints, more likely an impact would not be transferred straight back to the driver. Would be better if I had a bit more angle on both U-joints.

Edited August 27, 2016 by FB73tii

[Ian]

That's interesting.  Kind of a self-enforcing "torque to spec" bolt  On reading a bit, it appears to be an anti-theft effort.

 

Edited August 27, 2016 by Ian