Manual Transmission/Transaxle Class Update

Straight cut gear and helical gears

While most vehicles on the road have an automatic transmission, and a lot of them now have dual clutch transmissions, there are still some good old manual or "standard" transmissions, so it's been fun to take this class and learn how they work. The biggest project we've worked on in the shop is a big old 1981 GMC roll-back tow truck, and man it was a little dirty underneath! 

Part of the inside of a transmission. Here you can see two synchronizers, one would shift 1st and 2nd gear, the other 3rd and 4th gear. 

The transmission was fine on this truck, but the clutch needed replacing, and the flywheel needed to be resurfaced, so to get to those components we had to remove the transmission, disconnect the drive shaft, take off some of the cross members holding all that stuff in place, disconnect the Power Take Off connections,  and take off the gear shifter up in the cab. 

A shiny new flywheel on a Mustang. 

The new clutch you can buy from the store, but we had to send the flywheel out to be resurfaced by a machine shop. Once the new parts came back, we put it all back together too. 

Differential

One good tidbit of information we learned in the classroom is that a dual clutch transmission is really built like a a manual transmission that has the capability to be be shifted by the computer. The computer doesn't have a robot arm exactly, so it uses hydraulic fluid to operate the clutch, and then shift the gears. 

Inside one type of CV joint. 

Another fun tidbit is the Porsche name for their dual clutch system, which they've used since 2009, commonly called PDK. That's just an abbreviation for the German language Porsche Doppelkaplung, which I guess is double-coupling, but it just sounds cooler in German. Hey, and guess what? Since my Cayman is a 2009 model, it's from the first year of this transmission too!

Mazda truck and Ford Mustang on the lifts.

Right now we're studying drive shafts and differentials, so we've gradually worked our way from the front of the vehicle to the rear (for rear wheel drive systems.) Along with this class I've gotten used to calling a plain front wheel drive a trans-axle, since the transmission is directly connected to the front axles and differential. Go ahead, impress your friends, and make sure they know that your front wheel drive car has a trans-axle!

CV axles, with CV meaning Constant Velocity. The one on the right has a damper on it in the middle. 

Coming up after transmission class is my final automotive course, all about electrical fuel systems. Should get a charge out of that one!