The GTM Supercar Build Log

Archive for the ‘Transmission’ Category

Engine Cover, New Trans Oil Puke Tank, and Engine Oil Breather Tank Installed

Sunday, May 22nd, 2011

Enjoying a rainy weekend here so I got a few more ‘to-dos’ checked off the task list. First on the list was installing the carbon fiber engine cover to make the engine bay look ‘pretty’. Since my old breather/oil fill cap would not fit/work with this cover I opted to install a remote breather tank for any oil fumes/vapors that get emitted through the breather otherwise.  This was something I’ve been wanting to do as the oil vapors and junk collect on the rear glass…and I wouldn’t want that stuff all over the new engine cover. The breather tank was mounted in the driver rear wheel well (lots of space back there to work with), and connected it to a screw in AN adaptor that fits the LS valve cover oil fill neck.  The engine cover then installs by sliding down over 4 set screws that I installed in lieu of the fuel rail bolts used previously. I just need to have some badges/emblems made to fill out the inserts now.

The trans oil puke tank was another issue I’ve been looking to correcting. The trans likes to spew oil in considerable amounts into the puke tank that I had installed previously, as it seems that the breather was mounted right over 5th gear. I acquired a new tank and mounted it high in the passenger rear wheel well so that any overflow from the trans should hopefully drain back down into the trans rather than just collecting in the tank. Time will tell on how well this current attempt works.

Proper Calibration of the Brandwood Cable-Shift’s Fore/Aft Motion

Saturday, September 25th, 2010

Since I’ve had the GTM on the road (some 330 miles now) I have had a problem with it randomly popping out of reverse or first gear when starting from a stop, usually only when the box was cold. No grinding, just pops out, as if it wasn’t fully engaged. If I firmly put it back in gear it would then start moving fine. I figured either the cable that controls the fore/aft motion (that allows you to enter the various gears) was not calibrated properly, or my trans was injured.

I contacted Brandwood this week and they promptly replied with instructions as to how you should properly calibrate the cable-shift’s fore/aft range of motion. The directions I received with my cable-shift system were very general and really did not discuss this calibration at all, so I simply ran the cable and connected it and tightened up the jam nuts that hold it on place. With proper instructions in hand I could see that my cable was ‘calibrated’ in such a way that it had plenty of range for 2-4 shifts, but it was about a 1/2″ short of pulling the shift rod out of the transmission all the way on the R-1-3-5 shifts. No wonder I was having problems! With the proper calibration performed, I took the GTM out for a while and had zero issues. Nice!

Here is how to properly calibrate your Brandwood Cable-Shift system for proper fore/aft motion to ensure proper gear engagement:
1. Disconnect the fore/aft cable from the shift rod ‘coupler’ at the ‘ball and socket’
2. Push the transaxle shift rod forward, into the transaxle
3. Pull the shifter handle down, as if you were selecting 2nd or 4th gear.
4. Check that the ‘ball and socket’ connector moves past the shift rod ‘ball stud’
5. Pull the transaxle shift rod out, away from the transmission
6. Push the shifter handle forward, as if you were selecting 1st gear.
7. Check that the ‘ball and socket’ connector  again moves past the ‘ball stud’ on the shift rod. You should see  a slightly greater range of motion from the ”ball and socket’ connector in each direction than the ‘ball stud’ on the shift rod. This ensures that the cable is pushing/pulling the shift rod into/out of the transaxle all the way.
8. If the range of motion is lacking in the ‘1st gear’ direction (ie: when you pull the shift rod out), ‘tighten’ the rearward jam nut . If the motion is lacking when going to grab 2nd or 4th, tighten the ‘forward’ jam nut (the one that is closest to the  motor).
9. Once the range of motion is calibrated properly, put the shift rod in neutral, and the shifter handle in neutral. The ‘ball and socket’ connector should be able to slide over the ‘ball stud’ connector.

Here is a pic of how my calibration ended up looking.

Sticky Shifting Dilemma and CAI Reinstalled

Sunday, September 5th, 2010

After each of my several longer drives in the GTM (20 min+) I noticed something that should not be happening – after 20 or so minutes of driving it became really difficult to shift the transmission into gear. I can only describe the feeling as ’sticky’ or ’sludgy’, as it would still shift fine, but it took considerable effort to move the shifter up and down into gears.

My first thought was it was because I did not have the trans oil cooler running. My second thought was that the clutch stopper was potentially stopping the pedal too soon and the clutch was never fully deactivating when shifting and when it heated up it was creating friction, and thus the sticky shifting. I activated the cooler pump, moved the clutch stopper back some more, and hit the road. Same problem after extended driving.

After numerous replies on the GTM forum I turned my attention to the thicker of the two shifter cables that run from the Brandwood shifter box to the trans shift rod. This cable controls the fore and aft motion of the shifting (ie: going into gear), and it also runs very close to the exhaust. The responses I received pointed to a potential overheating issue with the cable, causing the shifting issue. I ordered an Earl’s Flame Guard insulation sleeve for the cable, but in the mean time I used some extra 3/4″ corrugated high-temp resistant wire loom to wrap the shifter cable. I took the car out for the longest drive to date and when I pulled back in the garage the shifting was as smooth as it was when I first started the car. Problem solved :)

With the shifting issue taken care of, I set to reinstalling the cold-air intake. To create a buffer between the exhaust and the intake sleeves I actually just loosened the exhaust collars and rotated them so the bolts that run through the collars would support the intake. I then stuck some Thermotec heat barrier to the bottom of the sleeves where they rest on the collar bolts. I took an extended drive with this configuration and it worked great. Intake air temps dropped from 140+ degrees at speed when previous drives were logged, to 75 degrees. HUGE difference. Leaving the car at idle for several minutes after the 30+ minute drive had the IAT’s sitting at around 100 degrees. Previously the IAT’s would see 150+ degrees while idling. The CAI is pure win.

Exhaust Centered, Transmission Oil Overflow Tank Completed

Sunday, June 20th, 2010

The Kooks exhaust is finally centered. An inch of piping had to be cut off the driver’s side cat pipe to get it to center properly. We are still working on mounts for the exhaust. The Kooks system comes with a set of mounts that are meant to connect to the trans (you create a bracket for them), but they fasten around the nice polished mufflers, and I’m not a fan of that.

The transmission overflow tank was completed with the fitment of the barb connector into the transmission case, and then connecting it to the tank.

Cold-air Intake Installed, Mesh Painted, Trans Oil Overflow Tank Installed

Monday, June 7th, 2010

I recently revised my CAI design again and moved on to ‘version 3′. This version eliminates the bends as the piping goes towards the side ducts. Instead, I purchased 2 45-degree silicone sleeves and ran straight pipes with the intake filters on them to sit directly behind the side ducts. Very nice clean look. I will install some hangers to help support the ends of the straight pipes as well, and probably fab a heat shield to sit between the exhaust and intake.

Painted the remaining mesh inserts (front/rear small ducts, and hood ‘mouth’) black. They are ready for install.

I noticed when driving the go-kart that the trans was spewing oil from the breather cap on the top of the trans. Not a lot, but enough to make me want to do something about it. The solution is an overflow tank that will catch any leaked oil. The tank has a petcock  that allows me drain the oil when needed.  To complete this setup I need to install a hose attachment in place of the breather cap, and run a short hose to connect the tank to the trans.

Transmission Oil Pump Wired

Friday, April 24th, 2009

Wired the oil pump up tonight. A keyed power source runs to the inline oil temperature sensor on the cooler inlet, which activates a relay that turns on the oil pump on when the sensor hits 180 degrees. The relay also grounds an oil pressure sensor that will trigger a dash-mounted led that will turn on when the pump reaches 15+psi.

Cable Shift Routing, Cooling Fan Grounds, Misc.

Thursday, April 23rd, 2009

Not too much going on right now with the build. I shipped off the TAC module to Fparts today so they can send me a replacement. All the diagnostics I have done point to a faulty TAC, so hopefully the new one fixes the problems!

In the meantime I fastened the cable shift gate cable to the frame and re-wired the cooling fan grounds. FFR’s instructions have you extend the black wire from the engine fuse panel to the black wire on the cooling fans, but in reality you need to ground the black wire coming out of the fuse box and also ground the black wire coming out of the cooling fan harness itself.

I started piecing together the underbody skid bar system. This will protect the frame (and body) and keep the belly pans on as well without having to rivet them. Easy removal of the underbody panels will be nice!

I also obtained a OBDII scanner from my friend Brian (THANKS!) which will help me diagnose things easier as time passes instead of having to wait for the loaner Tech2.

Fuel Filter connected to rail, Transmission Cooler and Pump Install Completed, Fluids Filled, Fuel Gauge Tested, Clutch Bled

Sunday, April 19th, 2009

The other night the fuel filter output was finally connected to the fuel rail, and the transmission cooler was installed. With the cooler in place the AN lines were made and connected. I am using an inline oil temperature sensor that will activate the oil pump when the oil reaches 180 degrees. This connects to the cooler inlet and wires to the oil pump (wiring needs to be done yet). 

With the transmission and fuel lines completed the transmission was filled with Swepco 210 gear oil, the fuel system got 5 gallons of gas, and some coolant was added. When the engine runs the coolant fill procedure will be followed.

With some fuel in the tank I wanted to test out the fuel gauge. The gauge takes a switched 12v, ground, and the fuel sender wire in the painless harness. The first time I hooked it up it pegged at way past full, which was obviously not the case. After some research I realized I did not have to wire the fuel harness sensor ground to the PCM, so I cut the wire and ground it to the chassis and the fuel gauge worked. It reads at around 1/8th tank with 5 gallons, so it is reading low, but that is better than reading high!

I also replaced the oil-fill cap with a screw in K&N breather, and finished bleeding the clutch slave. To finish the clutch slave bleed the slave had to be removed from the transmission and held high with the bleeder at the highest point. This got the rest of the air out of the system and the clutch is extremely firm now. The pedal only needs to travel half its full range-of-motion to engage the clutch.

Clutch and Brakes Bled, Oil Pump Lines, Oil Cooler Bracket Fab, Steering Wheel, Underbody Panels, Misc Wiring

Wednesday, April 15th, 2009

Things are starting to fall into place. The AN lines were ran for the oil pump and cooler. Once the final bracket is fabbed up to mount the cooler I will mount it and connect it all up, assuming the last piece arrives. I am still waiting on the inline oil filter for the pump. The inline oil temp switch arrived today so that the oil pump will only turn on when the oil temp is at 180-degrees. I am also wiring a sensor that will trigger an in-dash LED in-case the pump fails, so I had to run that wire from front to rear.

The clutch and brakes are bled – mostly. The brakes are done, but the clutch will not fully bleed. Some further research on the forum afterwards shows that I will have to remove the slave to bleed it fully, then reinstall it.

An engine ground strap was installed, connecting the engine block to the frame, and more work was done in moving wiring away from the headers. The steering wheel was installed, and the fuel tank underbody panels were riveted in place, also.

The first start is coming soon.

Cable Shift Completed, Passenger Fuel Tank Installed, Most Passenger Tunnel Aluminum Installed, Engine Harness Cleanup

Sunday, April 12th, 2009

Finally got the cable shift working. Some extra fine-tuning and adjustments had to be made within the cable shift box to shorten the shifter cable, but things work great now. Nice short, crisp shifts.

After doing the cable shift I moved onto the passenger fuel tank installation. Before I could put the fuel tank in I had to rivet the second rear aluminum panel into place. With that out of the way I slid/forced the tank into place and connected up all the lines. The vapor exit tube was linked to the previously installed filter on the driver side fuel tank. All that remains to complete the fuel system is to connect the fuel filter output port to the fuel rail.

Finally, I cleaned up the engine harness some more by looming the starter wires, and moving any wires that stray too close to the headers.