Just read the instructions

The new CV boot arrived on Friday just in time for a weekend repair. Replacing the CV boot required removing the right front axle.

So out comes the handy dandy factory service manual...volume chassis...section suspension....subsection front suspension..."Replacing CV Boot FWD Right Front".

One thing about the service manuals is that they tend to be repetitive. If you need to do work on the front end, whether its the CV boot, brakes, suspension, etc the steps are always pretty much the same. So each section in the front end section starts with the same set up steps...loosen lug nuts...jack up car...remove front tire..etc.

So I glance at the first few steps and the diagrams and see its the same as usual for front suspension work. Been there and done it so should be no problem. After about a half dozen steps I get to the part specific for the repair I am doing. Remove front axle from wheel knuckle.

Having removed the other end of the axle earlier in the conversion I expected that the axle should slide right out or maybe need a little bit of prying. I tug, and pull, and tug, and pry, and do it all again even harder. No luck. After about 20 minutes I give up and decide I'm missing something. This shouldn't be that hard.

So I call Chris and ask him if there are any special tricks or tools needed to remove the axle. And if not can I borrow a bigger pry bar. Chris says that usually once you remove the axle nut they slide out easily or can be hammered out.

"Axle nut", I say to Chris. "I don't think this axle has an axle nut. The other end definitely did not have an axle nut."

So after getting off the phone with Chris I go back to the shop manual. Section "Replacing CV Boot FWD Right Front"...loosen lug nuts...jack up car...remove front tire..etc. No axle nut. Lets look at the wheel. Hmm...there is a big nut holding the rotor on, but I'm not replacing the rotor. Let's look at the manual again.

Section "Replacing CV Boot FWD Right Front"...loosen axle nut and lug nuts...jack up car...remove front tire..etc.

OK. To be fair the instruction for loosening the axle nut was not in small print. The writers of the manual are a little bit more insidious than that. They made it the first line of the instructions! More importantly the section was otherwise identical to the sections not requiring the axle nut be loosened. So at first glance (and second glance) the instructions and diagrams look identical to the instructions not requiring the axle nut be loosened.

Of course once the axle nut was loosened the axle removal was so much easier :-)

Just a full circle

I stopped by the local auto parts store to get a replacement CV boot for the damaged one. They don't carry CV boots because at $30 bucks for a boot and $75 bucks for a new axle (including the boot) most people just replace the axle. I said ok, order me an axle. No problem. Until the phone call from them saying they can't get the axle for my car.

Next stop the internet. Do some searching and find an axle for the car. $70 bucks plus shipping. But it is an "off brand" aftermarket part. I do some research on the internet and find that this aftermarket one is a cheap version with lots of reports of unhappy buyers.

Since I can't find an OEM axle online I call a reputable US axle vendor. He doesn't carry the axle for my car since Saturn changes the spline configuration so frequently he can't keep up with them.

Next I call Saturn dealer. Figure I'm willing to pay a little more for the OEM axle. Well a little more is $400 more!

In the end I end up just ordering the CV boot from them ($35) like I originally wanted to do. Full circle :-)

Just two steps forward and one step backwards

As indicated in the prior post the next item of business is getting the speedometer hooked up to the vehicle speed sensor(VSS). I have two choices at hand for the VSS. I can use the OEM VSS that is part of the transmission. Or I can use the aftermarket VSS that came with the EVision.

Previously I had tried to use the OEM VSS. It's already mounted and ready to go. Unfortunately hooking it up to the speedometer gave no signal.

I had also tried the aftermarket VSS. The sensor is magnetic and generates an electrical signal when metal passes by (there are metal nuts under the black tape on the axle in the picture below).


This didn't work so I pulled the sensor and tested it using a drill with a couple metal nuts around the collar. This worked fine so I figured the sensor and nuts needed to be closer to each other. I went ahead and remounted the red sensor but couldn't find an acceptable position (either on the axle above or closer to the CV joint).

At this point I decided to go back to the OEM VSS. I had asked around on the Electric Vehicle Discussion List about the OEM VSS. Someone suggested that the newer VSS may need a pull up resistor in order to produce the necessary voltage for the speedometer.

So I went ahead and reconnected the OEM VSS with a resistor between the output wire and 12V power. Bingo! The speedometer started registering values.

Now to calibrate the speedometer. Luckily there are a couple of informational radar traps in the area. The speedometer requires a speed of 45mph to calibrate. So I buzzed by one of the radar signs and adjusted my speed till the sign said 45mph. Unfortunately it was a 25mph zone and I got a ticket....just kidding :-)

Once the sign said 45mph I pushed the calibration button on the speedometer. I now had a working and calibrated speedometer! Just to be sure I went by a couple more times at different speeds to check it.

Now the one step backwards part. In the process of fooling with the speed sensor I noticed a lot of grease on the chassis near the axle. This was definitely not there when I originally installed the VSS the prior week.

I tracked the source of the grease to one of the CV joints on the right front axle. Apparently there was a small hole in the boot protecting the joint. The grease was leaking out from the boot (actually flying out at 4000rpm). You can see the boot in the picture above (prior to it leaking).

Anyway I'll need to get a new boot to replace the damaged one. In the meantime to keep the EV on the road I have duct tape securing the hole and it seems to be working.

Just the numbers

The Vue is now on the road. Over the weekend I was able to fasten some of the front batteries down. This allowed me to put the front end and headlights back on. So now I can drive the car without looking like a scene from "Mad Max" :-)

I still have lots of items on the checklist...fastening the remaining batteries and getting the speedometer to work are high on my list now.

Speaking of the speedometer I was able to track down part of the problem why it wasn't working. There was a bad splice in the sender wire that was easy enough to repair. I went ahead and hooked up my pulse generator (you remember homemade pulse generator I was using for the tach). Anyway I hooked it up and sure enough the speedometer started working. Now I just needed to get it working off the vehicle speed sensor.

Today I took the car for a bit more of a spin (19.4miles). I wanted to get an idea of what my "mileage" (energy use) would be so I could figure out the range. Based on this drive the max range should be in the 45-55 mile. In general you want to keep the average use at about 50% of the max range in order to maximize battery longevity. This is still well above my daily 15 mile roundtrip commute.

For those interested in the numbers:
Total pack energy: 32.5 kW
Usable pack energy: 19.5kW
Usable to prolong battery life: 9.75kW

Total pack amp hours: C/20 225 Ah
Usable pack amp hours: C/1 135 Ah
Usable to prolong battery life: C/1 67.5 Ah

Trip distance: 19.4 miles
kW used: 7.04 kW
Ah used: 52 Ah
Mileage 360W/mile

The last number is the mileage ("MPG"). It is important because it is a measure of the efficiency of the vehicle. It is a function of vehicle weight, aerodynamics, rolling resistance, etc. A very light, aerodynamic vehcile has a watt/mile usage of about 200-250 W/mi. A light truck about 350 W/mi.

Prior to the conversion I was basing my range calculations on 350 W/mi. The fact that I'm in the ballpark before doing anything to improve that mileage (driving habits, alignment, etc) makes me very happy :-)

Just more checklist stuff

I can now take reattaching the hood off of the list.

I also attached the vehicle speed sensor to the right drive axle (the little red thingy). It is a small magnet that senses the change in magnetic field from the metal bits (nuts) secured to the axle.


With the hood attached I figured I could go a little bit further without drawing too much unwanted attention. Who needs a bumper anyway :-)

I ended up driving about 5 miles. Other than the speedometer not displaying the speed everything else works fine.

With the EVision gauge working I was able to get some quick and dirty readings for the "gas mileage". Based on the drive today I should be able to get 18-20 miles easily and only use 1/2 the battery capacity. This should actually improve as the batteries "break in" and I learn to drive the car more efficiently.

Just the checklist

Now that I have the battery pack hooked up and the car running I'm starting to get to my checklist of things I still need to do.

Checklist:

1. Get the speedometer working

2. Check the tachometer calibration

3. Secure the batteries

4. Secure the charger

5. Put the hood and bumper back on

6. Feed the cat...okay...not needed for the car to run; and since we don't have a cat I guess I can skip it :-)

One item I did get off my checklist was getting the EVision working. This is the gauge that tells me the battery pack voltage, how much current is being used, what my "gas mileage" is, etc. Luckily the only thing wrong was a loose wire. My bad.

While I'm on the topic of the EVision I want to give a ringing endorsement to Victor at MetricMind for puuting together this great device. Not only does it provide every possible parameter one needs for an electric vehicle, it has a great interface and display for accessing that data.

Now back to the checklist. I anticipate securing the front batteries next week which means I can put the front end and hood back together. Once that is done I can get the car out on the road more (can't take it too far with the hood off).

Just that little red thingy

One of the items on my "to do" list is to troubleshoot the vacuum pump. The pump is used to provide vacuum for the brake booster.

There are two problems with the pump...it takes forever to create a vacuum and it's loud. So I went over all the hoses and connections to see if there is a vacuum leak. All the connections look good.

I went back to the instructions for the vacuum to see if I missed anything. Still no luck. But while looking for the instructions I found this in the box:


Not knowing what this was (it was not on the instruction sheet) I decided to call the supplier of the vacuum to see it he knew what was going on. He didn't have anything new to add to what I already had done. Then the conversation got interesting.

Me: Also there is an extra part that came with the pump (see attached picture). No idea what it is. Do you know what it is?

Him: Muffler - it goes on the exhaust port of the pump - will muffle the noise some.

Me: Will try the muffler on the output port. Is that the little red thingy on the pump?

Him: I'm surprised turning the pump on didn't "eject" the little red thingy - that port should be open so it can pump out the air. That could possibly explain why it is taking so long to draw down the vacuum.

Me: OK. Taking out the "red thingy" and putting on the muffler makes a huge difference. Vacuum come up in a few seconds.

Well at least the vacuum works like it is supposed to. One less thing on the to do list.