28 replies to this topic

[n00b]

Hi all!

Well today ive managed to split the gearbox and block which came off easier than expected. Looking at the gearbox;a bunch of syncros and large teeth things, i wouldnt know where to start and id be lying if i knew what it was. Is there anything that stands out in particular and what should i be looking out for in general for signs of abuse and badly worn parts/



Also -
How do i remove the roller caged bearing which sits on the mainshaft on the flywheel side, the one before undoing the large black nut?




And the other; Which is the best way to lock the mainshaft i dont particularly want to wedge a spanner between the layshaft and mainshaft. This is so i can undo the large nut that also sits on the mainshaft but at the opposite side next to the diff housing wheel. Haynes say to select a gear, i do but the two shafts still spin when i try to undo the large nut!



thanks

[AndyMiniMad.]

Hi, firstly can i ask if you are having any particular problem with this gearbox or are you just looking to check every thing over. If it was running fine before then I would suggest you keep it oiled and in a safe dirt free place untill you are ready to put it back onto the engine. Are you wanting to change anything in the box or diff due to engine upgrades? Lots of questions I know, I can help with any questions you may have regarding the splitting and rebuilding of the box as i have just done the same thing myself. But if it aint broke...............

[n00b]

The box is fine, when i say ok it was a pain to select 1st somethimes, dropping to second HAD to be double de clutched, and selecting reverse when oil is warm always ended in a crunch (with Dble de clutch).

Any reply to my question on locking the mainshaft and removing the outer nose bearing>?

thanks

[n00b]

oh forgot . . no mods to be added.

well i say this . .

what improvements do straight cut drop gears have (aoart from that awsome whining noise )

CPU (centre oil pickup) whats wrong with the original design?

how do i figoure out my final drive - by the way its a 998 A standard, stage 1 kit and stage 3 head to add.

[liirge]

Right sounds like you need some Baulk rings! or maybe have a worn 1st/2nd Syncro hub

[n00b]

I did think syncro's initially but to do that i need the mainshaft out first which is why i cant undo the nuts on the shaft.

[AndyMiniMad.]

Does sound like it needs a rebuild. Yes the nose bearing, remove the rollers one at a time, CAREFULLY, as the cage is easy to split, and then remove the cage. this will leave you with the inner race still on the shaft, but your socket for undoing the nut will fit over it. The big nut in the gearbox is "F" tight
150 nmtrs. And the way to get it undone it to select first and fourth gears which locks the box up. then use your deep ball joint socket and a long bar. big heave and job done. the whole box is going to want to turn over as you are doing this so get it jammed under something solid.

[AndyMiniMad.]

Some of the questions you have are covered by a very in depth gearbox rebuild on page one of the engine project page. Its called "Im gonna build a gearbox". Have a read, it might help with what you are about to undertake.

[liirge]

You need to take off the Circlip on the end first to remove the nose bearing.

[n00b]

thank andyminimad il give it a quick bash now. ive been following your rebuild guide along with guess works like the bible but no one has seen to provide a guide to dissmantling the box. To keep the secret knowledge safe?

many thanks

[AndyMiniMad.]

thank andyminimad il give it a quick bash now. ive been following your rebuild guide along with guess works like the bible but no one has seen to provide a guide to dissmantling the box. To keep the secret knowledge safe?

many thanks

Secret knowledge!! Idont know what you mean......... Now has anyone seen the goat!!! LOL. By the way you can use a bearing puller to get that inner race off once the rollers are off. And to lock the box in first and fourth you need to dissengage the selector rod from the selector forks (you can see it through the side as you allready have the diff off) then push the syncro hub towards the main roller bearing to select 1st, and then push the other synchro hub towards the opposite end of the box to select 4th, Carefull you dont push to far just enough to engage the gears. if you push to far you will release the balls and springs (PING)!!!! They will fly out at warp 7, never to be seen again.

[n00b]

How do you select both 1st and 4th with the remote assembly is it a case of using a grip to slide the forks to the selcted gears?

The clip is off and snapped in the prossess so a new one is in order.

Also the reverse shaft isnt held in by anything, i can easily remove it with the box built. Is it ment to be like this?

[liirge]

Its best to replace those balls and springs anyway...guaranteed to give you that 'New gearbox' feel!

[n00b]

you beat me to it! thanks for the info minimad haynes makes it look far too wasy.

[AndyMiniMad.]

Yes the reverse idler will just slide out. well it will now that you have the main bearing holder removed. Centre oil pick up is better because it takes the oil from the mid point of the box, when cornering hard, as you do, the oil tends to slosh from side to side, the original pick up is at the sid of the box by the drain plug. Your final drive ratio is stamped onto the crown wheel, the big cog you took out with the diff. Basicly it tells you how many teeth the cogs have, 59/19 means 59 divided by 19 which is 3.1052 or a final drive of 3.1 to 1



Or maybe you have 62/18 which is 3.44 to 1.

Edited by AndyMiniMad., 12 July 2010 - 10:13 PM.