Thursday, March 29, 2007

Fixing the Transmission

Well, these pictures are a little late, but here they are. I spent most of last week replacing the broken parts in the transmission.

Here are the two replacement bearings from Pelican Parts ($400!) that I pushed into the transmission intermediate plate after heating it up with the orange heat gun to the left.
They went in surprisingly easy.

Here are the new synchro rings to fix the grinding 1st/2nd gears. They are $65 apiece and have a special molybdenum coating for proper friction during shifting.

I removed the snap rings from 1st, 2nd and 3rd gear to replace the synchro rings.

Here we are torquing down the 12-point nuts that hold the bearing shield in place. This is the same 12-point tool that I used to remove the CV joints under the car.

Here is a badly worn 1st gear synchro ring. if you click on the picture and look at the cross-section on the left, you'll see the bottom edge very worn down. No wonder 1st and 2nd gear were grinding!

Here are the two transmission shafts inserted into the intermediate plate. There were too many parts to hold, so I had to wait for my friend Rick to come over (while on a date, no less) and hold this assembly together while I hammered on the inner race pieces for the shaft bearings.

Here is the gear assembly with all shafts, shifting rods and gears in place.

I'm almost ready to put these two pieces back together; however, there are still old gaskets on the transmission edges and I have to scrape those off first.

Tuesday, March 27, 2007

AC Motor Controller Installed

Tim, happy to get the controller installed

A closer view of the Azure Dynamics AC motor controller.

After purchasing hardware from Home Depot to install the controller plate, I came home and drilled all the required holes for the mounting bolts. After squirting all the aluminum and metal caulk around the plate, I realized that I couldn't tighten any of the bolts myself because one end was on top of the car and the nuts were under the car. Big thanks to my friend John for coming over on short notice to help me tighten the bolts before the caulking dried. I'll try to be better prepared next time.

Also, notice the larger, two-inch, holes cut in the trunk floor and wall to the left of the controller. The control and motor cables will route through these holes.

Next up: getting transmission parts delivered and putting the transmission back together.

Monday, March 26, 2007

The First Sawzall Cut for the Controller Plate

My first use of a Sawz-All. The hole for the motor controller plate.

All the transmission pieces (waiting for new parts) covered up to prevent metal shavings from getting into them.

The motor controller plate provided by ElectroAuto before being bolted and caulked in.

Today I got to try out my new set of cobalt metal-cutting drills and the SawzAll I borrowed from my dad. Both worked quite well and cut through the steel floor of the rear trunk like butter. I botched the hole rather badly, going outside the lines by an eighth inch in some places, but things should still work. My drill ran out of battery charge so I'll drill the bolt holes tomorrow after getting hardware and caulking from Home Depot.

The directions say to not cut the transmission ground bolt, but move it if you have to. I did cut the bolt off and will have to install a new one. I suppose I could have hammered the front edge of the controller plate hole flat, but installing a new transmission bolt will be much easier.

Sunday, March 25, 2007

A few measurements to not forget...

While taking apart the transmission, I took some measurements with a digital caliper. These are probably different from other 914s out there, but I wanted to record them here in case I lose them amid the rapidly increasing paperwork.

Distance from edge of flywheel to engine housing: 1.684-1.687 inches at various places

motor adapter cone depth: 1.318 inches

motor adapter socket depth: 1.373 inches

4th/5th gear shift fork to bracket on shift rod: 0.127 inches

2nd/3rd gear shift fork to ridge on shift rod: 0.202 inches


Saturday, March 24, 2007

Transmission Woes (More than I bargained for)

Today was an educational and humbling day. I appreciated having the new garage space after the engine went away. I started opening up the transmission because first and second gears were grinding badly and I wanted to see if I could replace the synchro rings.

Here's the back end of the transmission with the cap removed. The crescent-shaped shifting fork for first and reverse is on the left. The expansion bolt with the golden speedometer gear is in the center.

Here's the back end of the transmission. When I pulled off the back end, the reverse gear in the upper left fell out with all its various pieces all over the floor. I'll try to not do that again.

Here's a closeup of the first/reverse gear shifting fork. I took this so I could align the fork when I put the transmission back together.

Here's the synchro ring (just above the small teeth) for first gear. As I suspected, it's clearly worn down and probably not doing much any more.

To continue taking apart the transmission, I needed to remove the shift-lever fingers which activate the internal shift rods.

I also had to remove the reverse gear electrical switch pin (which goes in the small hole).

Here's the back of the transmission with the intermediate plate removed and all the gears pulled out. The large top hole at the back comes from the driveshaft and the larger hole in the center goes to the differential.

On a side note, the transmission was covered with grease and, after removing the clutch throw-out arm, that there's a major leak in the transmission drive-shaft seal.

Here's the intermediate plate with all the internal gears still attached.

The same assembly turned over to reveal the golden shifting forks for 2nd/3rd gear and 4th/5th gear.

To get the gear shafts out, I had to remove the forks and the three shifting rods, shown at the top.

Oh, the horror! If you click on the picture above and zoom in on the right bearing, you'll notice that its cracked apart in several places. These bearings go for at least $185 at Pelican Parts, more elsewhere.

Oh, more horror! The pile of bearing parts and balls fell out of the driveshaft gearset when I removed it. This bearing costs over $200. I hope I didn't cause these failures when tapping the transmission shafts to get them out. I would think it would take much more force than that.

I was able to shake the gears and pieces loose from the pinion shaft and line them up on a 2x4 for inspection.

The synchro ring for third gear has significant wear, but is still marginally useable.

As I suspected, the synchro ring for second gear is completely worn down and useless, causing nasty gear grinding. These synchro rings are reasonably easy to replace but cost about $65 each.

Here are the balls and broken pieces from the broken pinion bearing inside the intermediate plate. Again, I hope I didn't cause this breakage. The inner race piece that rubs against this bearing on both sides is a bit tight on the shaft and I'll probably use heat to put them back on the shaft to prevent future breakage.

Again, this was a fun day with several runs to the store for obscure tools (like a ring spreader and a gear puller), but overall it was educational. I'm probably back about $600 in transmission parts just to put the transmission back together, but they needed replacing anyway. I'll have Alan over at A & P heat up the intermediate plate and replace the two broken bearings.

Next up: cutting the hole for the motor controller box...

UPDATE: I did a much closer examination of the broken bearings and the broken edges all had significant wear since they were broken, indicating that they've been bad for quite a while. Leave it to German engineering to keep things running past their time.

After ordering all the broken bearings, seals, synchro rings and such, the total bill at Pelican Parts (with a $20 discount they sent me) was..... $620.00 (Ugh!). I guess I'm a stickler for a good stickshift. On a more positive note, I was washing the intermediate plate in hot water and it heated up enough that the broken bearing sleeves just popped right out. I might not need to spend the $$$ at A & P to have the new ones installed if they are just like the old ones.

Make it go away! (The engine, I mean)

This morning, Jamie from Corvallis bought my engine and took it away, freeing up much needed garage space. Thanks, Jamie!

Engine in Jamie's van with a bunch of extra parts.

Me, enjoying my desperately needed garage space.

Friday, March 23, 2007

A Cheap Balancer and Transmission Issues

After talking with some engineers at HP and mulling over some ideas, I came up with the attached schematics for an inexpensive battery balancer. This one relies much more heavily on complex PIC programming and uses an off-the-shelf laptop or inkjet-printer power supply to deliver an isolated source of power for the battery charger. Any feedback you have is welcome. The analog engineers at work are still designing the current/voltage limited step-down buck converter so that will be coming when I get their feedback.

On a different note, I called Alan at A & P today to see how much it would take to rebuild the removed transmission. 1st and 2nd gear are grinding badly and I think the synchro rings are gone. His response was approximately $500 in labor and $800 in parts (OUCH!!!).

I'm going to try to replace the sychro rings myself based on the Pelican Parts article and, if I screw up, I'll take the whole thing back to A & P to put it back together. What's the worst thing that could happen :).

Wednesday, March 21, 2007

More Thoughts on Battery Equalization

Lee Hart, an EV guru on battery maintenance and equalization, has graciously e-mailed with me regarding the best way to equalize batteries. He's currently working on upgrading his battery balancer (see link at right) to handle a wider range of battery technologies and applications.

Lee convinced me that the flying capacitor approach that I originally thought would work is not practical in real world situations. I think Lee's battery balancer design would do a great job; however, I'd like to cost reduce it to something more suited to my own needs.

My plan is to create a relay board like Lee's that only handles 10 amps per relay instead of 30. If I costed out the parts and boards correctly, I can probably get that down to $100 per relay board vs. Lee's assembled cost of around $200. For the main controller board, I plan to use a similar design, but simplify the design to meet a narrower set of needs and replace the high-cost components with lower-cost, harder to use components.

For example, instead of a $80 complex STAMP controller, I'll use a $6 PIC that has more flexibility but will require more complex programming. Instead of the $150 Vicor BatMOD module, I'm using a free 100-watt 32-volt isolated power supply from an HP printer and making a current controlled buck converter to step down the voltage and charge the batteries (about $10). Instead of the $60 Radio-Shack meter, Lee is working on using an LM331 voltage to frequency converter to measure voltage and current of the charger which should cost around $10.

Many of these components will be harder to calibrate and program, but I'm willing to do that to lower the cost and reduce the size of the system. I don't know how this will end up, but I'll learn a lot and that's the point.

Flywheel and Engine Mount Removal

I put the engine for sale on CraigsList and have to prepare it for delivery this weekend. There is very little space in my one-car garage so getting rid of the engine while keeping all the necessary components will be good.

In order to get a last measurement of the flywheel to housing distance, I got a digital caliper from Harbor Freight Tools for only $29. It's remarkably accurate down to .001 inches and is very easy to use.

I chatted with a local Porsche enthusiast named Pat and he let me borrow the tool on top which is a flywheel lock to hold the flywheel still while I undo the heavily torqued bolts. Thanks, Pat!

I've already removed the clutch assembly and here's the face of the flywheel. Note the long breaker bar and flywheel lock needed to remove the the flywheel. With these tools, the job was a total snap and only took me a few minutes.

Here's the end of the engine case with the flywheel removed. I was surprised by how gritty the flywheel bolts were after they came out.

Next up was removing the front engine mount. The engine was balanced on one end of the furniture dolly, so I used the floor jack to raise the front end. I was able to raise the engine far enough to drop off the unbolted engine mount and support the engine with a 2x4 instead.

Here's the removed engine mount ready to be used in the EV conversion. Jamie from Corvallis (who knows Otmar and his 914 EV - see link at right) may drop by this weekend to pick up the engine and help me free up some much needed garage space.

Ugh, it's late and I'm going to bed.

Tuesday, March 20, 2007

Transmission Removed!

This was a big evening of figuring out how to remove the transmission with one person.

First up was removing the rear portion of the exhaust system, shown here next to my trusty 34mpg 1994 Saturn. (Someone else converted a '94 Saturn Wagon to an EV, but I'll keep mine!)

Here is the removed transmission. I'll try to take more pictures as I go next time to document the process better. Notice the 2x4 blocks on the ground to hold up the transmission so that it doesn't stress the driveshaft with the bolts removed.

After removing the exhaust, I slid the engine over on the furniture dolly so all the transmission points were on blocks outside the dolly. Note the stack of 2x4s on the right edge of the picture to hold up the transmission half of the engine.

Here's the removed transmission on the ground. The inside is covered with black grease. I wonder if there's a leak somewhere. Note that there are still plastic bags covering the transaxle openings that connect to the CV joints.

Interestingly enough, there was a "plug" of something that filled in this notch in the bottom of the transmission. I'm not sure why it was there.

Here's the engine half of the two pieces. The clutch looks darn near brand new with very little wear. I'm selling the engine to someone in Corvallis and they'll get this great clutch since I've already purchased a new one as a replacement. My only concern is that I'll be taking the flywheel for the EV conversion. That'll knock off a buck or two off the selling price.

Again, note the two transmission bolts at the bottom of the flywheel jutting out and the stack of 2x4s to hold up the transmission so it's removal doesn't stress the driveshaft.

Acutally, the first thing out, even before the exhaust, was the starter motor.

For storage of the transmission, I supported it on blocks to prevent the clutch pulley, shift linkage case and speedometer connection from supporting any weight.

I looked at possibilities for removing the front motor mount on the engine that I'll need for the conversion, but it's looking rather nasty.

Next up: Clutch and flywheel removal. I might need to get a flywheel removal block to keep the crankshaft from turning to do this.

Monday, March 19, 2007

More engine drop pictures

Blogger just took me off of "spam blog" status, so I can now post more pictures of the engine drop procedure.

Here are some 2x4s under the chassis to prevent the car from coming down.

I also put 4x4 blocks under the axles to prevent the brake shields from getting damaged in case I lowered the body too much.

Here's the primary engine mount after I unbolted it. This was a royal pain because I had to hold the nut on the top of the mount to keep it from spinning in place and there's not much room to maneuver in there.

Here is the removed transmission mount with its two brackets at the top edge of the picture. The engine drop instructions specifically say to remove the entire mount instead of just unbolting the center.

A common problem when dropping the engine is to get one of the CV joints caught under the starter motor like this. I had to move the engine to the right and lower the body a bit to get this unstuck.

The left CV joint is now free and sitting on top of the engine.

In order to hold the car up high enough, you need the tallest six-ton jackstands you can get your hands on.

Here's a final shot, specifically focussing on the transmission since it's really the only piece I'm going to keep of this beast.