Gearbox Complexity??

[Adam.Findlay]

Hey Just a thought has anyone ever cracked their manual gearbox open?? as i am looking at cryo treating the gears, i dont know if it s worth it yet as im still researching but my main concern is can i dis-assemble and re-assemble the gearbox my self or is it horrendously complicated?? My thought is make the driveline strong so if i can somehow afford driveline smashing power it wont break. any feedback would be much appreciated :)

[Nick Mann]

Except for the output end of the box it is very much like any other FWD manual box.

Nothing outrageously comlicated.

[Nutter_John]

Yeah not that hard , as long as you know how to pre-load the thing before shimming you will be fine

[Adam.Findlay]

Yeah not that hard , as long as you know how to pre-load the thing before shimming you will be fine
Righto Pre load and shimming. unknown to me so. Im only 18 so havn't had much experiance. I have never cracked a gearbox before. done plenty head gaskets and swapped my entire engine out myself (just having help seperating the pull clutch and lifting it into place) sounds like i have a bit of research to do on the matter then. haha i just don want to risk ruining a good gearbox to save on labour costs haha if i can do it myself i will ;)

[Subaru ETA]

as said above - pretty easy. mike and i have one apart at the mo that we are going to replace all the bearings in. the only thing - as said above - is setting up the shims and preload etc. its prbably best to pull the gear set out of the box and take it somewhere to be pulled apart and put back together if you dont know about preloading etc.

I have done heaps of mazda boxes (bounty, mx5, rx8 etc) but have havent actually completly stripped and rebuilt a vr4 one.

[Adam.Findlay]

sweet well i still have to research the pros and cons of cryo treating, I know it strengthens but theres no point if it makes the gears more brittle. ill look up how to do the preloading and setting up of shims on the net, doubt ill find anything but im definatly giving the entire box a wicked clean out next time i have it out as last oil change the old oil was a sick grey colour :thinking: that wont be until im flatting next year tho.. if anyone has a link to a site explaining the preloading etc please post.

[Adam.Findlay]

just while im at it do u think you could please send through a few images of the gearbox apart??

[Turbo_Steve]

Just out of interest, how much power were you thinking of running to need a cryo-treated gearset? It's not that different to the Evo stuff, so it's reasonably strong, and if you're really worried about abusing it, then an Evo gearset is probably the way to go...stronger and better ratios.

[Nutter_John]

You can get an uprated EVO gearbox with longer 4th and 5th for around £1000

[bradc]

As Steve said, the gears are very strong and aren't going to cause you many problems. The 3rd, 4th and 5th gears are shared with EVO's and are very strong, I haven't seen anyone break 1st or 2nd either, so I don't think those are any weaker.

If you want to rebuild it the main things would be the bearings on the shafts, in particular the input shaft bearing, as well as the syncro's. The gears themselves are fine.

[zentac]

I thought about cryo treating my gearbox but after talking it over which a couple of metalagsts, one who studied cyrotreatment said it wasnt worth doing on an old box, Im sure people selling the treatment would tell you different.

[Adam.Findlay]

Oh i did not know that the evo gearset and vr4 gearset were interchangeable. but I do know one guy local to me who has smashed 1st form launching hard and he has slaughtered a few AYC diffs and a SAYC diff too.

[Kenneth]

If you do a bit of a search, you can find a thread where Brad (bradc) got a couple of evo gear sets and I put them into VR-4 gearboxes.

Am currently running an evo set in mine, and so is Brad.

[bradc]

If someone has damaged that much stuff they would have probably damaged it regardless of whether things had be cryo treated or not

[scott.mohekey]

http://www.fishpond.co.nz/Books/Nonfiction/Transport/Automotive/Repair_Maintenance/product_info/2644345/?cf=3&rid=138267248&i=76&keywords=motorbooks

Might be worth a look.