Gearbox removal

[jimzzr]

Hi,

I've got the well reported 5th gear popout probs. I tried the quick fix by swapping a hub from another good (probably - well at least the hub wasn't worn when I removed it so most likely didn't have issues) gearbox I have. This worked for a while but problems have returned.

I figure my best bet now is to buy a new hub and then fit my replacement gearbox, particularly as the one on the car has a sheared bolt from the 5th gear housing. It'll also be able to check the clutch as the cars done nearly 150k.

I have the Toyota manual but does anyone have any tips on removal? Can I get away without draining the coolant/removing thermostat? How high do I need to raise the car? I'm wondering if rigging some sort of engine support beam would make removal/refitting easier rather than trying to balance things on jacks.

Cheers

Jim

[LimeyMk1]

Getting it out is the easy bit, getting it back in is the ball ache if you don't have lifting gear (hoist or 2 buddies and a pole + rope).

Thermostat housing just unbolts from the top of the gearbox and can be left hanging about, so need to drain the coolant. I'd drain the gearbox oil, although not necessary due to the lovely MK1 driveshafts it makes it a couple of kg lighter.

Jack the car up as high enough that the box will slide out from underneath.

Otherwise a bit of grease on the splines of the box helps it engage with the clutch and if you have a couple of M8 fine thread studs handy use them in place of the bolts for the clutch slave cylinder, makes putting it back on a lot easier (thank you Mr Jinxy).

[PW@Woodsport]

I wonder who gave Jinxy that little tip

[elbon50]

Getting it out is the easy bit, getting it back in is the ball ache if you don't have lifting gear (hoist or 2 buddies and a pole + rope).

Thermostat housing just unbolts from the top of the gearbox and can be left hanging about, so need to drain the coolant. I'd drain the gearbox oil, although not necessary due to the lovely MK1 driveshafts it makes it a couple of kg lighter.

Jack the car up as high enough that the box will slide out from underneath.

Otherwise a bit of grease on the splines of the box helps it engage with the clutch and if you have a couple of M8 fine thread studs handy use them in place of the bolts for the clutch slave cylinder, makes putting it back on a lot easier (thank you Mr Jinxy).

I've put mine back on two occasions on my own using two trolley jacks (one under the engine)

No big problems

The last time I had it out it took a bit of shifting off the dowels where it joins the engine

I've got those well copper greased now, ready for next time

[DNOS808]

I have changed quite a few gearboxes single handed and I find it easier to have the box suspended from a crane or winch rather than using jacks. The ability to swing the box toward the engine when it is suspended us useful.

Whenever I dismantle parts I am a great one for greasing threads before reassembly A useful tip I was given by an engineer in the aero industry was that copper grease should not be used with aluminium alloys since the copper and aluminium together can cause corrosion due to galvanic effects. These days I use a special corrosion block grease that is used in the aerospace industry.

[PW@Woodsport]

I use this stuff on brakes, gearbox dowels, splines, release bearing trumpet etc, i don't use Copper slip anywhere.

http://www.wurth.co.uk/technical-chemic ... 1100-1000g

[jimzzr]

Cheers for the advice. Looking around on the net I found one set of instructions that are slightly different to those in the BGB.

www.mr2mk1club.com/old/repairsp90.html

On the face of it they look more complicated, requiring removing the track control arm mount and driveshaft on the LHS. I guess it may come down to not having to tilt the engine so much to get clearance to withdraw the box from the engine?

One last thing, is there any reason why I wouldn't want to use a ramp on the RHS and an axel stand on the LHS?

Jim

[LimeyMk1]

I've never removed any part of the suspension when doing a MK1 gearbox, just disconnect the drive shafts from the gearbox and then secure them up out of the way with summat like a bungee cord.

I'd stick with a pair of axle stands, keep it simple.

[kaiowas]

Same as Chris, no need to be taking the suspension apart.

I do sometimes undo the hub nuts and knock the driveshafts out in order to keep them out of the way but it's not really necessary and I only do it because I know my car has been apart frequently enough that nothing will be stuck and the few minutes it takes to remove the shafts is worthwhile to keep them out of the way.

I also use a pair of ramps because I find it gives me more room underneath the car for jacks, engine crane legs etc

If the weather plays ball I should be doing a gearbox over the weekend hopefully.

[elbon50]

I have changed quite a few gearboxes single handed and I find it easier to have the box suspended from a crane or winch rather than using jacks. The ability to swing the box toward the engine when it is suspended us useful

Good system IF one has engine crane or block & tackle on hand

Will keep a lookout for any unalike metals galvanic corrosion on the bell housing

Nevertheless, the alloy has been in constant contact with an unalike metal from day 1 (the dowels)

[jimzzr]

Getting it out is the easy bit, getting it back in is the ball ache if you don't have lifting gear (hoist or 2 buddies and a pole + rope).

Thermostat housing just unbolts from the top of the gearbox and can be left hanging about, so need to drain the coolant. I'd drain the gearbox oil, although not necessary due to the lovely MK1 driveshafts it makes it a couple of kg lighter.

Jack the car up as high enough that the box will slide out from underneath.

Otherwise a bit of grease on the splines of the box helps it engage with the clutch and if you have a couple of M8 fine thread studs handy use them in place of the bolts for the clutch slave cylinder, makes putting it back on a lot easier (thank you Mr Jinxy).

I've put mine back on two occasions on my own using two trolley jacks (one under the engine)

No big problems

The last time I had it out it took a bit of shifting off the dowels where it joins the engine

I've got those well copper greased now, ready for next time

Well that's a job I don't wish to do again in a hurry. Fashioned a support beam out of wood, which I think made getting it back in pretty straight forward. However, getting it out was another matter.

Too a bit of shifting is an understatement - ended up needing a club hammer, a selection of pry bars and a crow bar.

Then to compound my problems I discovered the threads for the clutch slave mount were stripped on the replacement box, which would have been easy to fix with the gearbox out of the car- another lesson learned the hard way. Managed to find some 1/4 inch longer bolts which seemed to torque up OK and that will have to do for now.

Still all seems to be working OK now. Very small amount of movement on fifth gear, but nowhere near popping out so hopefully will last a while.

Jim

[boondougal]

I have this to do.. really not looking forward too it.

[stenky]

I did it 2 weeks ago. Didn't put it back on yet
I also wasn't looking forward to doing it at all so I ended up buying an engine crane to ease up the task a bit.