Bus Front Bearing Failure

This weekend during a test drive of added soundproofing, the front left started getting noisy and shortly later there was a pop and a slight swerve. I safely got it to a parking lot, but the front wheel bearings were metal-on-metal at that point, and the wheel had shifted outwards so it wasn’t possible to drive any further.
Broken Bearing

With the wheel shifted out I didn’t want to risk further damage when loading on a tow truck, so Christina came to pick me up and we returned with a trunk full of tools and spare bearing from home to replace the bearing on-the-spot. This would have been a ~30min job except that the spindle nut and inner race of the outer bearing had lightly welded themselves to the spindle. I returned with a dremel (and inverter to power it) – the spindle nut was removed, but removing the bearing race was not possible. I found a big metal spacer that served the purpose of keeping the wheel retained on the spindle, though it did not work as a bearing and wasn’t driveable more than a few hundred feet.

With the spacer in place it was safely towed back. The next morning with better light and bigger tools I was able to get the bearing race off of the spindle. The bearing was even available locally and I got it all back together quickly. Special attention was paid to the bearing end-play, this was set to the correct spec with a dial indicator and the bearing thoroughly greased. This was then repeated on the other side.

The front wheel bearings were perhaps the only area that I had not yet gone through since getting the bus; so the failure isn’t necessarily surprising. Both sides had minimal grease and light rust pitting which, along with the bus’s new faster speeds, contributed to the overheating and failure.

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VW Bus Adjustable Front Beam

During the original bus rebuild I had ‘flipped’ the front spindles to lower it some. Stock height on buses was alarmingly high, lowering allowed for better handling and gave the possibility of the bus fitting in the garage with a roof rack. The spindle flip, however, lowers by a fixed 4-5″; just low enough that the front wheels would rub the wheel wells during bumps or heavy braking/cornering. Cornering was particularly exciting since the outside wheel would rub, slowing down that wheel with the tendency to make the turn tighter – or “positive feedback” for those of us that are into control systems (not a good thing).

To remedy this, a way was needed to raise the front back up an inch or two. Old VW’s use a very unique front suspension design with two sets of torsion leaf springs inside of a beam with two tubes. The leaf spring packs are held fixed in the center of each tube and are capped at both ends with the four trailing arms. Minor raising and lowering can be accomplished by changing the angle the springs are held at the fixed center point. The center spring holder is held by divots crimped into the tube which engage with holes in the spring holder; these divots were drilled out which freed the holder. Toothed sections were then welded to the tubes; when the center is bolted in place a nut is tightened against a toothed plate that engages the teeth, holding the torsion spring pack at the new angle.

Lots of things had to be disconnected and then reconnected to get the beam in/out. This made it a greasy, awkward, and tedious job but overall it went well. The only hiccup was that after the beam was re-installed the shift linkage interfered with the adjuster bolts, though I had read this could happen. To solve this problem I welded a chunk of plate steel to the bottom of the linkage to hold the geometry and then ground out a strategic section of the linkage tube. The plate is as strong or stronger than the tube, and it’s in just the right spot to clear everything above/below it. After everything was back together the bus is level and no longer rubs the front wheels!

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Rear Lowered

In the video it’s readily apparent that the back is higher than the front. This is because I had flipped the front spindles but not yet adjusted the rear suspension. Tonight and last night I fixed this by re-indexing the torsion bar spring plates one notch lower. I didn’t get any pictures but it is much better looking now; it’s within a degree or so of being level. The rear is still very slightly higher than the front; this should be corrected by the weight of the parts that are yet to be installed (windows, interior). Even if this is not the case I prefer this to having the front slightly higher, which looks odd; nearly all modern cars are biased towards having the rear higher when unloaded.

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