After several topics on gear grinding, synchro failure, and questions on 02J strength I decided to post a tech topic, how the tranny works. This topic will cover 1st gear assembly onto the output shaft. How it all works, and what gets damaged when you cant get into 1st or second gear. I am not an expert, but i have taken a few of these apart, and I did stay at a holiday inn express last night.
Ok for starters. Here is your output shaft. Notice that there are no gears attached. The gears actually do not attach to the shaft. At the bottom is a bearing flange that holds this to the bell housing side of the tranny. underneath that is a gear that contacts the ring gear on the diff and delivers the maad powa.
Notice the needle bearing installed. Now this next pic shows first gear. First gear has several functions. 1 the inner part is part of the bearing. 2 the lower part is a thrust bearing. The angle on the teeth makes them quiet, however it creates a thrust load pushing the gear down. 3. the teeth, these recieve power from the input shaft gear which is machined in as part of the input shaft. 4, the synchro teeth see the tiny tapered teeth just above big teeth. these teeth connect the gear to the output shaft through the hub (coming soon). 5, the synchro cone. This is the interface between the gear and the synchro. The synchro rubs on this cone slowing the gear down to the same speed as the output shaft so that the hub ring (coming soon) can match up.
Ok, now whats a synchro you ask?
Brass rings that rub on the gear.
1st and 2nd are actually made of a few pieces. I believe this is for wear purposes.
Ok, sow now you see a brass ring that rubs the gear to slow it down to the right speed, and you see the tiny teeth on the gear and the tiny teeth on the synchro. These match up, so the hub ring can slide down.
First we install the hub
This is splined onto the transmission. Remember the gear is not attached it slides on a needle bearing. So this hub is attached.
Hub assembly consists of the following. Hub, hub ring, spring, and spring clips (im not sure what the full name of these clips are)
Hub is fixed on shaft, while the ring can slide up and down. Note the teeth on the inside of the hub ring. yep those match with the teeth on the synchro and the gear.
Here is a picture of it all installed and with 1st gear engaged.
HOST FOUND - thanks Chris
Note the ring slides down and first presses the synchro into the gear, then it goes beteen the synchro teeth and matches the gear teeth, and your in.
When you miss a shift you grind the tiny teeth on the gear, and the hub ring. The gear teeth are case hardened, so the ring takes the brunt of the grinding. If these get tweeked a bit, then they are ok, if they get bent over then they might never go in again. or you go somewhere in between. If you grind the isht out of them over and over the suckers get round and then it's like there is no synchro.
Now 2nd gear. Picture the exact same stuff, just upside down and installed on the shaft. The ring moves up and hits 2nd gear synchro and then hits the second gear tiny teeth. If you grind second real bad, then the hub ring teeth can get bent so bad that it can not slide down into first. the bent teeth get stuck on the hub.
