rebuilding your own gearbox

[STEEV888]

soo with my shitbox car i like to practise doing things to it i recently rebuild the engine because i was bored and the gearbox doesnt select gears as smooth as it used to 100,000 km's ago so i was thinking of rebuilding the gearbox.

so my questions are as follows:
1. can it be done by a backyard mechanic ?
2. do i need any special machines to remove/put back together parts ?
3. besides the basics on how they work i know nothing of gearboxes and have never seen inside one so is it quite a large job.
4. would the whole inards come appart or are they a throw away item for eg, 3rd gear is shit so would i just be able to replace the sincro or would i have to replace the whole 3rd gear assembly ?

and any other relative information you could provide would be nice to hear it thanks.

car is 97 excel.

[noddys VP]

Basically its the same as the motor, Take note when taking it apart and put it back together in the reverse form. i have series 3 excel 5 speed gearboxes apart before there bit of a prick when it comes to getting the diff out and apart from the main assembly, by all means give it a try but give very special attention to everything, slight pitting or wear can go un noticed but is very bad for a manual box. When you do it i recommend doing bearings and syncros. that should be everything that general wears out.

[304runner]

IMO, Gearboxes are like women..... Hard to understand and hard to put together when they fall apart......Run away my friend....RUN AWAY!

[wraith]

Gearboxes are one thing you don't want to do without some knowledge. Auto's are even worse.

[nemesis_adrasteia]

have a crack at it, worst thing you can do is #### it and have to buy another one from ebay for #### all.

[Calaber]

The problem with dismantling and reassembling trannies is the possibility of special tools and presses being needed to do the job. Bearings and gears are sometimes pressed onto shafts, mongrel circlips buried inside synchro cones, plenty of traps for the inexperienced.

Before you start, get a workshop manual for the car and read the transmission section thoroughly. Make sure the trans can be pulled apart and rebuilt with the tools you have or can get your hands on. Otherwise, give it a big miss.

[vkberlina]

I have rebuilt Aussie 4 speeds, T5s & the horrid MC6 & M76 transmissions, you really need a rebuild manual to do a gearbox, you need to check tolerances end float etc to do them properly else your gearbox might not be as smooth as it should. the main thing is to take your time & be accurate, I have needed a few special tools some I have bought some I have made.
We usually pack the bearings with mobil waxrex (aka industrial vasaline) once the gearbox is installed we prewarm the oil to be installed to around 50dec C, it will be notchy untill properly warmed up. We take the car for a good run 50km will do the waxrex will melt at temperature, once you return back home/workshop remove the oil right away, this will drain all the waxrex out and then refill with oil.

scott

[STEEV888]

thanks for the tips and well wishing.

I will definitely give it a shot soon, hopefully work will slow down to at least less than 50 hours a week so i will have some free time, last week i brought a daewoo lanos for $100 it needs a starter motor a tyre and the doors reset, god knows how it got the same crushings on each side.. so ill have another shitter for when i get it all apart and forget how to put it back together then swear for a while.