Detailed rebuild guide for 1303 steering rack

[Dodgy]

I haven't seen any detailed rebuild guides for the late 1303 steering rack unit, so while I was rebuilding mine recently I took some photos and notes to post some useful information here.

Here is the patient: a 1975 RHD steering rack - LHD will be the same components in a mirrored body.

These units are pretty simple and bulletproof. There was no obvious indication of any wear on the rack or pinion on my unit, and the movement was smooth - if I hadn't taken it apart it would have probably carried on quite happily with the original bearings, even though (as it turned out) they did need replacing.

So I would say that the rebuild is likely warranted by age, whether or not there are any obvious external signs of wear.

The following spare parts will be required:
• Rack gaiter (cheap and readily available, search for part number 823-419-831)
• 2x clips to secure rack gaiter (1x 45mm and 1x 55 mm), large cable ties will do
• 1x HK1814RS (drawn cup needle roller bearing, 24mm OD x 18mm ID x 14mm W, seal one side)
• 1x 6001 (deep groove ball bearing, 28mm OD x 12mm ID x 8mm W, open type)
• General purpose LM grease

So let's get into it. Disassembly and reassembly is quite straightforward and shouldn't require any special tools.

DISASSEMBLY

1) Remove the bracket on the passenger end of the rack; it is held in place with an M8 bolt through the rack body. Note that the rack end plug won't fall out yet.

2) Remove the 2x M8 screws on the rectangular cover plate. There is no need to loosen the 17mm nut or the set screw at this stage. Underneath this is a tension spring, a hardened cap under the set screw and 2x sliders which should come out of the bore fairly easily, mostly they will be held in by grease.

2) Bend up the lock washer under the pinion cap slightly and unscrew the pinion cap, it should come off easily.

3) The pinion can be drifted out of the rack unit once the pinion cap has been removed. It will come out complete with the bearing that is visible once the pinion cap has been removed. Tap the pinion on the splined end to remove.

4) Once the pinion is removed, the rack bar is free. Remove the spring clip from the rack body plug at the 'open' end (you may need to dig out some debris to see it) then the rack end plug should come out, hopefully with the (remains of) the end stop. The end stop may be attached to the plug or just free in the tube.

5) Next the needle roller bearing at the pinion input shaft should be removed. This is likely seized in place, but there is access to the inside to try and drift it out, it can't be removed without destroying it anyway. It is not clear in the photo, but there is no seating edge for this bearing in the rack body, giving access to the full inner face to try and extract in this way. Mine was just too stuck, so in the end I cut through the outer cage using a dremel - be careful not to damage the rack body bore.

6) The last item to remove is the end stop at the closed end of the rack body. However, mine was completely disintegrated, so I have no idea what should have been there, or if it is fixed in any way. Access to this end is pretty limited, to clean out any remnants of the old end stop or to clean out the old grease. I considered grinding the welds holding the fixed cap in place, but this seemed a bit drastic. In the end I drilled a small hole in the end cap that I could get a wire or hex key into, to dig around the perimeter, and that seemed to be enough. This hole proved to be useful later.

SERVICING

Pinion shaft
The pinion shaft is hardened and mine did not show any signs of wear, but there was a shallow ring of corrosion where the seal of the needle roller bearing sits. It could probably have been left as-is, but I covered the corroded area with JB-Weld and once set cleaned the surplus off on a lathe, so only the recess was left filled. It will help keep water and dirt out in future by providing a better surface for the seal to fit against.

Pinion shaft bearing
Replacing the ball bearing from the pinion is straightforward, undo the nylock nut and drift the bearing off, it should not be a very tight fit. The new bearing can be pulled into place and secured using the same nut. Note this deep groove bearing is the only part providing axial control on the pinion. This is probably OK for normal steering loads, but be cautious when hammering the universal joint on or off the pinion on an assembled rack as this can easily cause damage to the bearing race. (While the pinion is out is a good time to really clean out the splines).

Rack end stops
I couldn't find any information on the end stops. My one at the 'open' end of the rack had about 60% remaining, enough to see what it should look like - but the one at the closed end had disintegrated to crumbs. The closed end is tricky because there is a narrow section before the end, so it is not clear how an end stop could be installed here. Certainly it cannot be the same diameter as the inside of the rack body tube, like the 'open' end.

Finding no luck searching online for replacement parts (or even images of these items) and after some thought, I decided to 3D print some replacements. I solid-printed (i.e. 100% fill) replacements in 95 Shore A TP and they felt close enough on hardness. The material hardness is not critical, as long as there is enough 'give' to prevent hard metal-to-metal contact at end of travel.

The stop for the 'open' end is very simple, a 33mm diameter x 15mm long cylinder. I just left this stop loose in the tube as it will naturally be pushed against the end and stay there.

For the 'closed' end, because the stop diameter has to be smaller than the tube, I didn't want to leave it loose. So I designed a stop with a 'pip' that fitted into the hole I had drilled into the closed end, to locate it and hold it in place. The stop for the 'closed' end is 26mm diameter, so it can fit through the narrow part of the tube.

LH - original part 'open' end; MID - printed part 'open' end; RH - printed part 'closed' end

STEP and STL files for these parts can be found here, if anyone needs them:
[url]https://1drv.ms/u/s!AnyXCFmfDsVqh3zr-SmuRZ0Uo0a3?e=W1V06m[/url]

Rack sliders
The two rack sliders typically show wear over 80% of their face where they contact the rack itself. It is probably not necessary to do anything here, but I sanded then smooth with 400 grit paper on a machined steel block to provide a 'fresh' wearing surface. These parts are not hardened and polish easily. There is no need to eliminate all the wear marks, I just removed the unworn 'lip'. Before and after shown here:

Cover plate
The 17mm nut and set screw should be removed from the rectangular cover plate. The nut is flanged and quite thin, so is easy to round off. It includes a plastic locking or sealing feature (like nylock, but curiously on the seating face side) so best to not use heat. Careful use of penetrant and gentle persuasion were enough for me. The thread is M10x1, best to clean up the threads in all these parts while they are apart.

REASSEMBLY

1) After the rack body has been cleaned inside & out, reassembly is the reverse procedure. First job is to install the new end stop. For my new part with the 'pip', the end hole was opened out to 8mm. The new stop has to be carefully pushed in place on a long rod then the pip pushed through the hole in the rack body to secure in place.

2) Next install the new needle roller bearing. Simplest method is to use a M8 or M10 bolt through the rack body with some repair washers to pull it in, it should install easily. Ensure the seal is fitted towards the outside(!), and that the bearing is installed flush to the surface.

3) The rack bar can then be installed into the tube, add grease at the sliding points, but the unit does not need to be completely filled. Rotate the bar to approximately the correct orientation for the pinion.

4) The pinion can be reinstalled with the bearing already fitted. Once in place and greased, refit the pinion cap. This does not have to be very tight as it only holds the bearing outer race in position. Gently hammer the lock washer over the raised part of the rack body to prevent it loosening again.
There is probably a preferred orientation of the pinion (universal jount bolt recess) with the rack in centre position, but I don't know what it is... I don't think it is critical as the sterering wheel can be indexed to any spline position. The only difference will be what angle the steering lock engages.

5) Refit the two sliders with plenty of grease. The hardened 'lash' cap and the spring should also be fitted. Refit the cover plate without the set screw and secure in place with the 2x M8 bolts.

6) Install the set screw and locking nut. Adjust the set screw so that it is touching the 'lash' cap inside the rack, but not providing too much pressure. As the pinion is turned, it should feel smooth, not lumpy.

7) Install the gaiter (wide end first) and rotate so that the holes for the tie rod bracket are aligned with the holes in the rack bar. Fit new clips with the closure aligned (more or less) with the set screw as this will be towards the top when installed in the vehicle.

8 ) Install the end stop and tube plug to the 'open' end, and secure with the clip. Fit the bracket and the through bolt, but leave loose until final tightening once fitted to the vehicle.

ALL DONE!

I hope this information helps anyone else taking on this rebuild. Please add any more details you may have here, especially parts numbers, any info on the original factory end stops, workshop diagrams, torque values for fixings etc, I couldn't find any of this information.

These racks were not fitted to 1303s for very long - only the last 6 months or so of sedan production, I believe. (Cabriolets had them for longer, of course). So information is often not existent in workshop manuals (even the Bentley).
_________________
'75 1303 (current project) owned since 1989!
'72 Squareback - full resto completed 2008 - now sold
356 Speedster kit, completed 2005 - now sold

[MuzzcoVW]

Thank you! This is an item I'll be checking on my '75 vert when the time comes..along with the inner control arm bushings that many forget about.

[Caledfryn]

Brilliant contribution to 1303 knowledge - Thanks!

Converting my car to rack and pinion steering and I've collected a few racks in varying states of wear and tear.

Wasn't sure of the various parts I'd need but you've saved me a lot of legwork!

[admvw78]

Does anyone have the secret to getting the spline to let loose from the universal joint where it connects to the rack? I've removed the clamping bolt, I've tried to wedge a screwdriver into the gap to spread (slightly) the clamp, I've tried hammering down (such as one can in the space) next to the spline on the steering bar along the axis of the spline, I've tapped on the coupler all around to try to release it.

Right now, I'm letting some kroil sit on it to see if that helps. I assume it hasn't been off since the '78 vert was built, but looking for secrets. At the moment I'm stymied.

I'm only in this far because I was replacing a torn steering boot and thought I'd pull the rack and clean and re-pack it... but if getting the spline off is this much of a problem, I'm worried it'll just make more problems when I have to try to put it back on later and considering steering it was working fine (except for the boot) I'm wondering if I ought to leave well enough alone...

Thanks

[Dodgy]

I assume you have removed the clamp bolt completely? It fits in a recess in the splined section, so the column can't be removed if the bolt is still in place.

Otherwise it sounds like you are using all the right techniques, just add some heat, and some time / patience. They will separate eventually. It is common for these splines to get corroded and stuck because they are fairly exposed.

Be careful hammering on the coupling where the bolt holes are as it is easy to deform (the holes go oval and the bolt can't be refitted)

All that hammering is likely to have caused some damage to the bearings, so best to plan on a rebuild of the rack now. As I found, the operation of the rack is not a reliable indicator of the condition of the bearings.

Good luck!
_________________
'75 1303 (current project) owned since 1989!
'72 Squareback - full resto completed 2008 - now sold
356 Speedster kit, completed 2005 - now sold

[admvw78]

I did use heat (with wet rag wrapped around the gear housing) to get the spline out of the universal joint, but now I have rack off, disassembled, and degreased.

I've laid out the parts below. Hopefully a second set of images can help others the way the first set helped me:

1. The exploded layout of rack and pinion cap, rack, pinion, needle bearing, and rubber seal:

2. Underside of pinion cap:

3. The exploded layout of slider (1 piece in '7, cap, spring, clamp plate and bolts (2 views):

3. End block for free end and c-clip:

Regarding disassembly, after getting the spline apart I did the following:

1. Use a small screw driver to pry the C-clip out of the free end then work the end cap out. (Not too bad, but a little stiff. Had to get the end cap moving by prying through the bolt hole to try to slide it a little at a time).

2. Remove the slider bolts, and that whole assembly (easy).

3. Use penetrating fluid and a crescent wrench to get the pinion cap off. it's narrow, so there's risk of rounding it off, but I held the body in a bench vise and it broke loose. (Fine if you can get it to break loose. Clamping the body to hold it with the vise really helped).

4. Remove the pinion by hammering on the end of the spline. Mallet might be a good idea to avoid mushrooming the end of the spline. (easy)

5. Remove the needle bearing by using an extension and the right size socket to push it out of the pinion bore (you have access to the face of the inner race, it comes out the same way as the pinion). (medium, mine was stiff but came out in one piece)

6. Remove the rack. Took some work due to buildup of grease. Work it back and forth and flood some solvent around it. It should slide out eventually.

After things were all apart, I spent a while with a mask, brakleen, a toothbrush, and a brass wire brush to get the old grease scrubbed off the parts and out of the tube (which was the hardest part to clean.

As for end caps, I'm not convinced there were any. Either mine were completely dissolved, or the image of one above was just packed grease?

I can print up TPU end caps, but I'm hesitant to drill a hole in the closed end to fixture that end cap as it would just become a water ingress location.

I've spun the bearings, and so far they all seem good and I'm vacillating between just greasing and reinstalling and going out and buying fresh ones because I'm in this far.

As far as reassembly, any suggestions on cleaning up the inside and outside teeth of that universal spline so things slide in and out better? Maybe grease the spline? Maybe put anti-seize on it?

Thanks.

[Dodgy]

Nice, thanks for adding more photos, they are great.

You will definitely need end stops, for two reasons: 1) to prevent internal metal-to-metal contact at end of travel, and 2) without these stops the travel range will be too high and possibly allow undesirable contact between the tie rod and strut at extreme steering angles.

I understand your concern about water ingress with the new hole at the closed end of the rack body, but it's not as though the rack assembly is 100% watertight anyway. You could add sealant over the end, or share any other method to fit and retain the smaller end stop?
_________________
'75 1303 (current project) owned since 1989!
'72 Squareback - full resto completed 2008 - now sold
356 Speedster kit, completed 2005 - now sold

[admvw78]

Point on bumpers accepted, though without installing the rack with and without bumpers it's hard to tell whether or not you'll actually have a steering arm interference issue.

I downloaded your STLs (thanks for those) and printed the first version in 80% fill TPU, but the result was almost the same hardness as a standard plastic part. I'm printing a second version at 30% fill to see if I can get something that approximates rubber (I'm aiming for tires / pencil eraser hardness). I also have several layers on perimeters and top and bottom to try to provide support without losing the "give" that comes from lower infills.

One concern I have with the closed end, is that I don't know if I'd be able to fish it back out if it does fracture. My best guess is to skewer it through the pip and use that as a handle to push from the outside.

Thanks

[Dodgy]

For reference, the bolt recess in the splined shaft on the rack should be facing downwards with the rack in the centre position:

This means the bolt in the UJ under the fuel tank will be at the top.
_________________
'75 1303 (current project) owned since 1989!
'72 Squareback - full resto completed 2008 - now sold
356 Speedster kit, completed 2005 - now sold

[plextor]

[Dodgy]

The only difference it will make is the orientation of the steering column lock. If the rack pinion is out by 90 deg, the steering lock with the wheel at 90 deg too. It's a minor detail.
_________________
'75 1303 (current project) owned since 1989!
'72 Squareback - full resto completed 2008 - now sold
356 Speedster kit, completed 2005 - now sold

[plextor]

Okay, interesting.

TL;DR on below - what's the right process for centering a rack & pinion setup if you are starting from scatch? New tie rods, steering shaft, the works...

I centered the steering wheel on reassembly by making sure the u-joint was square with the steering box, and that the rack & pinion to tie-rod bolts looked visually centered on the body. The steering column seems to lock at around 30º when turning to the right. Photo of the steering box when I think it is centered below.

The gotcha is there is a slighty difference when turning lock-to-lock in how far the steering wheel can go.

Where the steering locks when turning all the way to the right... about 1 3/4 turns.

Where the steering locks when turning all the way to the left... about 1 7/8 turns.

Where the steering winds up from a natural drive as centered.

With all new tie rods, and my original ones being shot and also the steering not being centered, I started over with the toe and did a quick garage alignment. On my first couple of test drives, the steering wheel will drive straight when it is about 15º to the left, which doesn't seem too bad. I can do the normal tie rod adjustment to center the wheel from there, but I am left wondering if I'm not getting the centering on the rack correct in the first place.

I'm assuming that there is a difference in my lock-to-lock turning that I've got something done wrong.
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1975 VW La Grande Bug (Super Beetle, 1600 EFI, owned since May 2021)

[Dodgy]

Find centre position by counting turns of the wheel left / right.
You can remove the wheel and adjust it's position on the olumn spline to make it level at rack centre.
Final adjustment is at the track rod ends. These should be roughly the same thread position on both sides.
_________________
'75 1303 (current project) owned since 1989!
'72 Squareback - full resto completed 2008 - now sold
356 Speedster kit, completed 2005 - now sold

[vw356]

Thank you all for this thread. I need to either buy a rebuilt steering rack or rebuild the one I have.
Where do I buy the parts?
I have new boots and other parts from TopLine but I can't find the other inner parts in my searches so far.
Thank You.
_________________
Current projects:
1950's Volkswagens!
51,52,54's,55,56's,57,58's,'60's And then a bunch of '60's, but the '50's are my favorites..