Monday, December 3, 2012

Disassemble Z27AG Gearbox 4G15 Getrag 5spd - Part 1


Disassemble Z27AG Gearbox


Pulled the gearbox apart. 18 or so bolts inside and outside the case.
From there you remove the clutch fork and the gearbox selector cable brackets.
The case has two doles. Only pry the case open on the tabs. It is a machined edge, you don't want to damage it or it may leak forever.










Bellhousing, you can see the bearings for the input shaft. And the race for the taper roller bearings of the diff.





gear sets and selector forks.


Inside the case is nothing that can just fall out. Maybe the output shaft bearing is just sitting there.
The diff is sturdy as well.











Stock diff and split case.










OEM bearing i can't just buy. It the input shaft roller bearing. It has a plastic cage, I don't think i can extract it with damaging it.
Will order a new one, they don't look cheap @_@








OEM bearing race for the diff. I use it to push the other in. It was easily removed by heating the case for about 5mins with a propane torch.










 Stock diff and its 10 ring gear bolts. Most threads were stripped on removal.
Tensile was 12.9



























Some marking i took photos of.






































Heating up the race to pull the pressed in bearing races. Made life so much easier.
You can use a welder to pull them out also.
You run a mig/arc around the race surface and it falls out.









This is the output shaft race/housing for the bearing. It has two screws and i used the propane torch to pull it out.








Input shaft seal, bell housing side.

Bell is the two dowel pins you punch out.













New diff bearings
















pressing on the diff bearings.







 removing the ring gear













Use rubber hammers only. Clean ring gear!!!
No metal fragments.


Last time i did the diff bearings i used a speak holder. So that there was no pressure on the diff bearings. This time i didn't have a choice so i sat the bearings in the bearing race and proceeded to tap on the other bearing. I did it on a wood surface hoping to absorb and pressure. I used a socket and washer as well as a special bearing/seal tool made out of aluminium.

4 comments:

  1. hi i have just read ur post, that is brilliant. i am from sydney. I think i got the input shaft bearing worn off as well , and would like to have your opinion as if i need to overhaul my gearbox immediately? or it will last for another year with the noise there. Do you also know the price for changing the input shaft bearing ?? i have quoted around aud $1200 to 1600

    ReplyDelete
    Replies
    1. It shouldn't cost that much to change. U can buy the part, maybe $60
      I would do a lsd at the same time to save money.
      Gearbox always makes noise, I would just ignore it.
      I been racing mine for years without issues. So I can't see how a person could break it as a daily driver.

      Delete
  2. That would be a great help if i can get some opinion from you

    ReplyDelete
    Replies
    1. Unless it's driving bad, I would ignore noises, but that's just me.
      Idle bearing and input shaft bearing noise while idling is annoying but fine.
      Seems to do it when people change different clutch.

      Delete