Thursday, February 16, 2017

Upgrade to a 5 Speed


Connor has dreamed of upgrading the 3 speed in his Mustang to the Tremec 5 Speed since learning this is a relatively easy drop in upgrade. Since the clutch was getting really bad and we would have to pull everything apart to do the clutch, we talked about finding one in a junkyard. The Bog Warner T5 transmission has been used in everything Ford, Chevy, GMC, AMC, Pontiac. It's been in use since the early 1980's and was still featured in the 2010 Mustang. It's popularity means you should be able to find one somewhere in a salvage yard.....

The price tag for a new transmission is well outside the budget for this daily driver. He scoured the local salvage yard and happened upon a 2002 Mustang GT with a 5 speed manual. The T5 he was looking for. He unbolted it and dragged it out to the register and had the envy of everyone in line. He even had a few offers to sell it on the spot, but Connor had different plans for this find. 

So we ordered up the parts we needed. A clutch, an adapter plate, a crossmember and a slip yoke. Once we got the parts in hand we were ready for a long weekend project!




We had a few snags along the way, the first one we hit and moved right on past without noticing. When we bolted the transmission to the bellhousing, we had a slight gap between the two. The bolts spanned the gap, and so we just cranked each bolt a little bit at a time and "drew in" the transmission to the bellhousing. More on this later. The second issue we had was that the new mounting bracket did not fit, we had to bore out larger bolt holes on each side so that it would fit the bolt pattern on the car that had shifted slightly over the 50 years the car has been on the road. The bracket was also needed a few slight modifications to make it fit our version of the transmission. Lucky for us, we had some steel plate laying around, and were able to weld up what we needed. The real fun however, was yet to come.


So we found out just a little too late, that the input shaft of the newer T5 used in Mustangs is a bit longer, and too long for our bracket. We wandered our way to a solution, first by cutting the throw-out bearing guide shaft down, then by adding more "adapter plate" by creating our own adapter plate shim from aluminum plate stock. If we knew the throw out shaft modification was only a partial solution, we probably would have skipped that and created a thicker adapter plate. We could have gotten away with 3/8" thick easily. So with all these issues behind us we were ready to road test.


And so we pushed it back into the garage, and removed the transmission once again. It went into reverse for our test, but we could not get it into 1st or really any other gear. This was quite odd since we had it running so smoothly before we put it in. When Connor brought it home, it did have some shifting issues, but when we disassembled it we thought we had it all worked out. Apparently we had more work to do.


So we removed the transmission yet again, and pulled it apart. Once opened up we found that the synchro key for Reverse had slipped out and was preventing a smooth shift between gears. This was the issue the transmission had when Connor brought it home from the salvage yard. When we did the original rework of the transmission, we did not realize that the springs that held the keys were out of place, and just re-inserted the key and slid the synchro into place. Since we did not fix the keyspring issue, it popped out once we were spinning at speed, shifting out of reverse. This time after a lot of detailed research, and watching a full disassembly video, we knew how to correct the issue. We fixed up the synchro keys and reassembled the transmission, then placed it back in the car and went for a test drive. This time we had success!

This project took from February 3rd through February 16th, 2017. We spilled some transmission fluid, lost some skin, and made some great memories along the way.


Monday, January 16, 2017

Electric Fan Upgrade

The 1966 Mustang has a fixed blade fan, attached directly to the pulley that turns the water pump. These fans are noisy, think of it as an airplane prop out in front of your engine. The faster it turns the louder it gets. Coincidentally, this is the opposite of what is needed for cooling. The fan is most critical when the car is stopped, and there is no air being naturally forced over the radiator to cool the engine. At speed, when the engine is running at higer RPMs the air from the car rolling down the road pushes over the radiator and cools it nicely.
Old fixed blade fan

 Over the years, there have been a number of improvements to cooling methods. There have been slip clutches on the fan shaft so that it will start to slip at higher RPMs and reduce noise. There have been flex blades, fan blades that flatten out and don't slap as much air at higher RPMs. By far, the best improvement has been the electric fan. Electric fans are controlled by a thermostat sensor attached to the water pump. When the temperature of the coolant hits the upper limit, the thermostat kicks on an electric fan until the temperature drops below the lower limit. It is significantly quieter, and more efficient since it is only running when it is required.


It took a bit of juggling, since the new fan was just a hair thicker than the space we had between the engine and the radiator. We ended up placing the fan in front of the radiator, and setting it up in "pusher" mode. This has the side effect of making the engine compartment just a hair cleaner.
Electric fan in place, in front of radiator
We wired up the sensor and fan relay and were ready to test out the new upgrade.