156 gearbox replaceent guide
Hello everyone I changed the gearbox on my friends Alfa 156 JTS this weekend. I thought since I had extreme difficulties finding information about the procedure online. I should write something about it, if someone in need could benefit from it.
Itís not a super difficult job and you can definitely do it without specialist tools at home on the driveway. Thatís how I did it. But you definitely need to be prepared for snapped bults and other broken stuff that can halt your work. So donít plan this over a weekend if you really need the car on Monday.
Any way hereīs the procedure:
You start with removal of the battery and battery tray. Then remove the ducting for the intake, this is all straight forward but the hose clamps they used on the small air/vacuum line are ****. Then remove the gear links. Its two gear cables that attach to ball joints you just pry them off. Then remove the gear link bracket from the gearbox this is easy 3-4 bolts. Remove the line to the clutch slave cylinder, just slide the holding clip up hand remove the line. I clamped the line to reduce oil spill. Thereís also some electric connections that need to be removed. One for the back up light on the gearbox and an earth cable on the left engine/gearbox mount.
When this is done you remove the starter. Itīs a little tight but doable. Itīs three bults and you remove to from the top. There a little hard to reach but just get a flashlight and get your eye one them and feel with your hand for them. Move under the car and remove the last one. Just remove the starter and let it hang there on the cables.
Now you start with the suspension. Do I need to remind you to put the car safely on jackstands?
At first my plan was to remove the lower and upper ball joint and the bult for the fork. And then just lower everything with the subframe. But I had HUGE difficulties removing the left lower ball joint so I changed my plan. On the left side I removed EVERYTING! Brake caliper, Upper/lower ball joints and bolt for the fork. Then I removed the bolts for the driveshaft hand just removed the fork/hub/driveshaft/brake rotor as one assembly. Oh almost forgot you need to remove the ABS-sender to. Just one bolt and slide it out. On right side I removed the brake caliper upper ball joint and bolt for the fork and the bolts for the outer driveshaft. But I left the lower ball joint attached because I didnīt have the energy to fight with it. And you can leave the ABS-sender too.
Now itīs time to slide under the car.
Remove the exaust. This can be impossible if the flanges and bolts are rusted like mad. In thatís case just cut it. Donít waste your time just cut and deal with it later. Then support the engine under a jack and some wood under the oil sump, and remove the engine mount under the engine/gearbox. Now its time to remove the subframe and this is where you commit or decide to stop and leave the job to someone else.
The subframe is attached with six or so bolt under the car and two really long ones that attaches to the body in the wheel Wels. Remove the six ones under the car but save the two in the wheel Wels. You also need to remove like 8 more bolts that secure a support that run along the exhaust pipe. Remove these and let the support hang down on the last two bolts, the ones at the back. Now its time to remove the subframe. Oh you also need to remove two long bolts that secure the steering rack to the subframe. Now place the jack under the subframe and remove the final two bolts in the wheel Wels. Let the subframe down and slide it out of the way. The way I did it the right balljoint is still attached.
Now you remove the inner driveshaft on the right side. Remove the three bolts holding the bearing in, and wack on the end with a rubber hammer. The driveshaft will pop out after like 20 wacks. Depending on how corroded it is.
Now itīs time to remove the gearbox. Support it with your jack and remove all the bolts securing it to the engine. Then slide it out and lower it down and its out!
Itís a good idea to compare the old and new bow, you might have to transfer some stuff over. 4
When itīs time to fit the new box I find it easier to just ďbench pressĒ the box up on the engine then to use the jack. Then refitting is a reversal of removal. You need to bleed the cultch also. Just pry the clip out but not all the way. This allows the line to be pulled out a little bit. The get a friend to pump the pedal a couple of times.
I hope this will help someone. I have surely forgotten something but this is pretty accurate. It took me about 12 hours I total working time. With normal hand tools now air or electric tools. And no lift. You donít need any special tools really. Just a good set of spanners sockets. An 18mm socket and like 6mm allen socket I think is the most unusual tool for this job, so nothing special.
Oh almost forgot. Drain the gearbox before removing the inner driveshaft.