Samstag, 4. Oktober 2014

Construction Time

The construction of the "underbelly battery support structure" is progressing well now. In the video below you'll get a look at how I attack the topic which might give you an idea for your conversion. In the meantime I also messed up with my transmission. When I got the adaptor plate, the transmission shaft and the motor back, of course I had to put everything together and spin up the thing. It was exhilarating to also see the output of the differential spin when selecting a gear. I knew from Volvo's service manual that I'd have to take care so the differential doesn't start to move the wrong direction. So I only selected a gear with 500rpm. All went well the first time. The second time during a demonstration to some friends, I was distracted and forgot to switch back to neutral. At 2500rpm: klong - krrrrrrrrrrrrrrrchchchch.. I immediately pushed the emergency stop button but due to inertia and no regen applied, it took about 10-15 very long seconds until everything came to a standstill. To say I was downhearted was an understatement. Looking inside the differential you could see loose gear wheels and a rod I didn't remember was there before. Comments from other car aficionados didn't lift my spirit either: "Looks like everything fell apart..", "This looks wasted..", etc.
So I went to the Volvo dealer/shop of my choice to ask if they could help with repairing the tranny. Apparently OEM's no longer fix transmissions. They just replace it with a new one. When the supportive mechanic looked up the price in the computer - keep in mind that Volvo's service part are not really cheap - his puzzled face and a "whoops!" didn't help my mood much either: 4200.- USD. !! :( That's not an option for my already strained budget. Then there's a transmission shop close to Lucerne: Automaten-Meyer. Their initial estimate: 1200.- USD for the work only, no parts included. That's better but still, there has to be another way. The used trannies from wrecked Volvo's were also in the range of 1500.- USD - with 200'000km on them, that's just to much. In Germany I found a dealer which sells new tranmissions for 1700.- Euro. This after-market transmission would be my fall-back. I found some details about the inner life of such a manual transmission on the net: here and and here. But what really gave me the right kick, was the detailed report of a diff replacement in an M56 transmission. Mine is a M66 but it was close enough, the M56 is its predecessor and told to be quite simmilar. Thanks to this post, I thought: Well, I have nothing to loose, let's open the darn thing and see what's wrong with it, maybe with a huge bunch of luck, I'll be able to fix it. Bear in mind that if anybody told me that I'd have to open and try to repair the transmission during this conversion, I'd have never started it at all. Opening transmissions was a big taboo for me - for someone with no machanical education, a software developer. Yet, I opened it.. found out what happened.. and ? The conclusion will follow in the next video.
Now that I've got all major parts, there's only one but very important thing missing: Nordlock washers. Based on experience and reports from, they are certainly a part I have to include in my conversion to secure the bolts in the batteries. As I have 120 cells with 2 poles and some other connection terminals, I will require about 260 pieces for M8 bolts. I will not do it otherwise. To my impression, these Nordlock washers are the only thing which ensure tight and reliable connection to the terminals. Non-secure power connections are cause of heat, increasing resistance, more heat and potentially fire. So no trade-off there. I just haven't got around to get my hands on them.