TideLog Posts Tagged “clutch slippage”

Rikky did OK Friday night, but I think it was because she knew we were testing her, either that or she’s got the patience of a saint, which I’ve known for a while. The cab doors on Volvo B9TL buses helps too, all Rikky’s have the acrylic panels, and that channels noise away from the driver.

Given all the noise, I still couldn’t help notice a problem with the auto clutch during Rikky’s loud crowd test. I could feel it was hesitating during gearchanging. It was just starting to show slipping symptoms. It’s the judder that gives it away, and the not-so-right-as-usual gearchange whine. Some B9T’s have ZF’s that whine, some have Voith boxes that don’t. The B7RLE’s are dead easy to diagnose, I know the whining from the ZF’s on those by heart. Most drivers won’t notice, as the engine is at the back, and in the cab you can’t always hear it, especially with noisy passengers, but as an engineer who loves engines and listens to them, I do quite easily, and can often notice the slightest gearbox problem.

The auto clutch will eventually deteriorate so badly you’ll end up stuck at traffic lights because the thing won’t engage, and it’ll end up stuck in Neutral usually (when the brake is pressed, listen. That whine? It’s what I call temp neutral. Let go of the brake it goes back into Drive. All auto boxes do it, you can rev it with the brake pressed), and the engine will just rev uselessly. Sometimes it’ll be the relays and solenoids of the changer rack in the gearbox. My advice is to get it sorted ASAP before it gets that bad and you need Recovery, and annoy other drivers.

I took Rikky’s 59 plate B7RLE for a quick run last night. I love the new facelift B7RLE. Since Wright gave the Eclipse Urban body an overhaul in 2008, and Volvo changed the old dash to the one used in the Gemini B7/B9 double deckers it feels so much better. The dials aren’t cramped, and there’s two stereo mountings! Rik wants me to put a CD player in for the driver, and a radio/announcement system for passengers, which is a piece of cake on these new ones, as the wiring and mountings are there, plus gangway speakers. Ours even has the D7E320 320HP engine, which was a surprise, Volvo (and Dennis) normally only fit these to their refuse and tipper/artic truck line. They’re limited to the usual 74.15MPH, but I’ve had the limit off, and tuned the intake and ignition timing slightly. They can go up to nearly 100mph, which I observed using our diag computer. On a racetrack. Never do this on public roads, especially if you’ve knocked the TCS and SCS off. I think it can go higher, as Volvo seem to have given guys like me headroom for tuning. DON’T ever do anything like this unless you understand engines, are in a safe place, and won’t injure yourself or passengers. NEVER have passengers while doing this, unless they’re engineers.

I want one of these myself, given the chance! Volvo buses and Wright bodies are perfect!

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