gearbox and diff install

[atomic]

Hi,
I'm replacing my gearbox and diff and was wondering if anyone could share some tips or give me some advice. Is it a relatively straightforward job or should I take it in to get done professionally?

While I'm at it, I'll be replacing shocks too...

Thanks


Oh, it's an NA

[Bevan]

There are tutorials on www.miata.net/garage I believe.

If there's not one for the gear box, check out the clutch tutorial. They remove and replace the gearbox in that one.

[StanTheMan]

Ask Uncle Arthur...... He can hold up the PPF & gearbox with his teeth. as well as take calls on a mobile but is unable to take pics at the same time. Weak effort.

[manga_blue]

It's doable at home, you need good stands, though a car hoist would be better. You also need to be experienced and reasonably confident with your mechanical work. Good socket set, spanners, torque wrench, trolley jacks and lifting stuff also needed.

The three jobs actually fit together quite well. Taking the diff out means taking out half the things you need to do to remove the gearbox (PPF, exhaust, tailshaft) and also helps with removing rear shocks (rear antiroll bar, upper control arm links).

You should plan for some extra muscle, you really don't want to drop a diff or a gearbox on your face.

If you haven't been through this sort of stuff before then life is short. Take it to MX5Mania, sit back and drink your shiraz and hand over money at the end. I'd guess it's 6-8 hours labour but you get peace of mind (and you don't need to buy the tools, etc)

[Fatty]

i need to do this too. but i'm starting to think i might just take my car to a proffesional to get all this done (bushes , diff, brakes, springs, shocks)

just seems like so much work

[StanTheMan]

Fatty
For the bushes you need to take the shocks & springs out anyway.

the same bench press I have will cost you $90 at supercrap. well worth its weight in Gold. get yourself on a cheap flight to Sydney & watch us do the bushes on Caffeines car. Or drive it up here......

[irwin83r]

are you replacing the whole diff assembly or just the internals? are you changing ring gear and pinion? or going to an different center?

if its a whole different differential housing and internals ie a straight swap its doable at home with minimal tooling. but if your opening the housing and changing center id take it to a shop as you will need to re-do the backlash settings for the ring gear... and if your changing to another ring gear and pinion (to change end ratio) you will need to mesh the gear set too. not much extra tooling.. just a dial indicator and some bearing blue but its a tad more fiddly and not every garage has them.
but if you dont set it up properly you WILL kill your diff

[Fatty]

i'm replacing the whole diff. i'm putting a torsen in to my 1.6, so it's the whole diff, drive shaft and half shafts. also putting 1.8 brakes onto it. as well as the aforementioned bushes, springs and shocks.

have had some of the local crew offer their help by way of a dodgy day but i'll need to sort out a hoist or something i guess. oh yeah , and a bench press, thanks for reminding me about that stan

[AJ]

Ask Uncle Arthur...... He can hold up the PPF & gearbox with his teeth. as well as take calls on a mobile but is unable to take pics at the same time. Weak effort.

stop exaggerating stan.............he was putting the bolts back in with his teeth, he also managed to bite your head off as well

[Craig]

Ask Uncle Arthur...... He can hold up the PPF & gearbox with his teeth. as well as take calls on a mobile but is unable to take pics at the same time. Weak effort.

stop exaggerating stan.............he was putting the bolts back in with his teeth, he also managed to bite your head off as well

Bahahahaha!!!

[StanTheMan]

Ask Uncle Arthur...... He can hold up the PPF & gearbox with his teeth. as well as take calls on a mobile but is unable to take pics at the same time. Weak effort.

stop exaggerating stan.............he was putting the bolts back in with his teeth, he also managed to bite your head off as well

Bahahahaha!!!

ROFLMHO.

I gotta Pay That..

[StanTheMan]

STM.. is that the plans of another dodgy day?

check events....Caff is hosting a dodgy day in mid October.

[Uncle Arthur]

Ask Uncle Arthur...... He can hold up the PPF & gearbox with his teeth. as well as take calls on a mobile but is unable to take pics at the same time. Weak effort.

stop exaggerating stan.............he was putting the bolts back in with his teeth, he also managed to bite your head off as well

Bahahahaha!!!

ROFLMHO.

I gotta Pay That..

KaChing

Here's what I've learned.....

Diff is easy - easy enough to do on your own.

For both jobs you need some good spanners, including a breaker bar. You also need a decent trolley jack, and vehicle stands x 4. You need to be able to get the car about 18 inches off the floor minimum - better if you can get it 2 feet off - you need to be able to lie on your back under the car with enough room to maneuver the gearbox/diff out of and into place.

The diff will drop out by you undoing the PPF bolts in the middle, the drive shaft, and the 2 14mm and 4 12 mm bolts on each end of the diff arms. A good trolley jack will allow you to drop the diff out slowly. It is heavy and you can't lift it yourself, but the jack takes the weight while you remove/install it.

The gearbox is best done with airtools and a long extension bar with a universal joint. They're 17mm bolts - getting the gearbox out is easier than putting it back together. It's not a hard job but it's a biggish job. If you're a newbie to working on your car - do it at dodgy day or pay the $$$

[jules]

If you don't know what you are doing, or are not 100% confident in your tools/ abilities do not do this exercise.

My clutch is due for a change, and unless I have:
a/ height
b/ air tools
c/ ratchet uni joint

I will not be doing it. It's simply not worth the hassle.


Jules

[mossy]

It is definetly a hassle to do and I probably wouldn't do it again, at least by myself anyway but I guess the positive to come out of it is I learned a bit more about working on a car.