Keith’s Schoolbus Conversion Blog

When I won the schoolbus auction Thursday, I was in Kansas City at a conference. Because the auction house is open Saturday mornings, I was able to divert through Manhattan on my way home, pay for the bus, and pick up the title and key.

Monday Retrieval Plans

I scheduled Monday off work and found that Lawrence’s daughter Mary could drive me to Manhattan to pick up the bus. Monday morning I went to my insurance company and got a liability policy. The $125 annual premium seemed low, but they explained they don’t expect the bus/RV to be driven every day so they have limited exposure.

Next I went to the courthouse to register the bus. I had already confirmed that I could register it as an RV, but there’s a matter of getting the correct weight on the title. The previous owner had registered it as a 3500-lb vehicle, and that’s obviously absurdly low. The vehicle department clerk (Ron Tozier’s wife Sandy) looked up other vehicles with similar VINs and found people registering them in the 7200 – 9000-lb range. (I love the helpful attitude in a small town.) She said she’d be happy to average them and call that the weight.

I wasn’t quite comfortable making up a weight like that, though; and I know I’ll be making a trip over the truck scale at the dump when I dispose of the ratty bus furniture anyway. So I got a 30-day tag and I’ll go back after I know the actual weight.

It Doesn’t Drive

Mary and I headed to Manhattan, I found out Mary listens to Fleetwood Mac (well done, young lady!), and Mary admired the lovely purple bus. I started up the engine (runs very smoothly!), ran through a pre-flight checklist (right rear turn signal doesn’t light; all others are okay), and then put it into gear and eased out the clutch.

Nothing. No movement.

Already bad. But I’ve seen manual-transmission vehicles that had a single gear — often a low gear — broken, so I tried it in 2nd. Still nothing. Tried several combinations of high and low on the split shifter with 1st and 2nd gears and couldn’t get it to do anything.

Went inside to ask how it had got to the auction site, and the front counter folks didn’t know but the folks in the back ALL KNEW THAT IT HAD BEEN TOWED IN AND COULDN’T BE DRIVEN. In fact, the previous owner had been driving it to the auction site when it broke.

I think that would be something I would mention pretty loud and clear if I were selling a vehicle.

“I Make Problems Go Away.” (Does That Mean Me?)

While they looked for a manager, I went back out, fumed, and pondered. My brother’s neighbor is a fleet and heavy equipment mechanic for the state, and I figured “Neighbor Dan” could easily fix the problem in his shop; but two hours from home in a parking lot, with probably not a lot of local options to buy parts for something that big?

The manager who came out was very helpful and indicated that just to get things started, he’d give me more time to explore my options without charging the “storage fee” for not having removed the bus from their lot yet. He almost offered to refund my purchase price — but if the problem has an easy fix, I do still want the bus, and I have no illusions that it’s in perfect condition and will never need maintenance. I just thought it was drivable, since I explicitly asked that before the auction and was told yes.

Driveshaft

I rejoined Mary in the SUV, explained the situation, and agreed to get lunch in town before heading home. Over lunch, I ran through the list of things I had tried with the transmission and wanted to tell Dan about. While doing so, I realized that just to be thorough, I should go back and see whether the driveshaft was spinning while the transmission was in gear. We went back to the bus, put it in gear, and indeed the driveshaft was spinning.

Ah, that changes things!

Split Shifter

I don’t know much about split shifters and I’ve never (knowingly) driven one before, but the idea is this: In addition to the transmission at the front of the driveshaft having different gears that vary the rotational speed between the engine and the driveshaft, there’s also a two-gear (in this case) selector inside the differential at the back of the driveshaft that varies the rotational speed between the driveshaft and the axle.

The split shifter is worth maybe half a gear of transmission; so when you shift 1L, 1H, 2L, 2H, …, it’s like shifting ½, 1, 1 ½, 2, …

Since the driveshaft was spinning but the rear axle wasn’t, it sure seemed there must be a problem with the split shifter. (I can’t picture a differential problem that would allow the driveshaft to freewheel.)

So where along the way was the problem with the split shifter — at the front of the bus by the switch or relay, in the line from the front to the back, or at the shifter in back? The split-shift switch on the stick shift had to be connected to the split shifter mechanically, electrically, or hydraulically, and just my luck — it’s electric.

I rolled under the bus and got into position, where I could actually sit fully upright. With the engine off but the ignition key in the run position, I had Mary toggle the split-shift switch back and forth. We could hear a relay click under the dash, but no whirring or clunking at the split shifter.

Electrical Testing

Neither of us had a voltmeter along (oh, the unbearable shame!), so we ran to Radio Shack and I bought what seemed like a nice pocket meter (in grey, not yellow). In retrospect, the battery compartment lid bulges almost enough to pop loose, it’s very hard to get the probe cables tucked away so the case closes properly, the lid is very hard to close properly anyway, and the way the lid folds back when open makes the whole tester very floppy and precarious. Oh, and the auto-ranging function — although it seems like a good idea — is incredibly slow, so it takes several seconds to take even the most basic reading.

Right, split shifter.

As Mary moved the switch back and forth, I could see (after waiting the requisite several seconds) 12V appear on the wiring harness connector at the green or yellow wire — so the signal was at least getting to the back of the bus.

I pulled the cover off the electrical panel, noted the differently-colored wires inside than out, and poked around the circuit board. I should have got a picture of the other side, but the short wires made it awkward. There are two (large) microswitches that align with two bumps coming out of the mechanical housing.

It looks as though the switches are NC and act as endstops. The 12V from the front powers the shifter gearmotor or solenoid until it fully engages the desired gear, at which point the “bump” pushes out to engage that direction’s microswitch and remove power from the shifter. Then the whole thing sits idly by until told to shift the other direction.

With the lid open, I was able to see the 12V on the appropriate traces on the circuit board — but still no action from the shifter. With this newfound information, I closed up and we went back home.

Monday Expenses

$125	annual liability insurance
$8	30-day tag
$20	lunch and frozen custard for self and Mary
$60	gas for Mary’s SUV
$213	total for first retrieval attempt

Repair Plans

“Neighbor Dan” thinks (as I do) that the problem is with the shifter, not the differential; that he has enough information to order a correct replacement part by the weekend; and that he can go up Sunday, fix the shifter in the parking lot, and let me drive the bus home.

More over the weekend.

This entry was posted on Tuesday, June 2nd, 2009 at 3:55 pm and is filed under Acquisition, Expense, Mechanical. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.