around Easter i fully stripped and rebuilt a 3 speed GM400 auto gearbox for my 1989 V12 XJS
this was extensively covered on this site and shouldn't be hard to find, and at the beginning of December i SORN's the XJS , got her up on jacks etc and started the removal process of my faulty gearbox, this has been covered in another thread, but not easy to find , so to surmise below
car is now 1 mtr in the air on axle stands and ramps with several other axle stands ready to ' catch ' if required, rather that than be squashed
so with the car in the air, the front wheels are off , everything looks really good with some very minor bits to paint black to keep on top of things
the full exhaust system has been removed from the collector pipes backwards, the heat shield is out from under the middle and the prop shaft has been undone from the diff end ,
next will be to support the gearbox, and remove the gearbox mount, then the prop shaft will come out, i have a brand new prop shaft from jaguar to refit
then remove all attachments to the gearbox ( vac pipe , kick down switch connector, selector cable and fill pipe tube along with the oil cooler pipe connections ,
then the front torque converter cover to allow access to the flywheel attachment bolts ,
only spending a couple of hours each evening taking it slowly and methodically
so , i now have the sensor and sensor mounting plate ( marelli ) removed from in front of the gearbox
the gear selector cable, the kick down switch connection , a heat shield , module vac pipe and drained the transmission fluid and removed all of the sump bolts , to allow the maximum amount of fluid to drain...
the transmission cooler pipes need to be undone from the box ,
next will be to remove the starter motor and get a jack under the gearbox ( with sump refitted ) and remove the gearbox support , i will also have to place a jack or axle stand under the back of the engine to stop it rocking backwards once the gearbox mount is removed
getting there slowly
gearbox is now supported on a low scissor gearbox jack, and the engine is supported on a beam ,
the rear gearbox support has been removed , and then the prop shaft ,
the starter motor is out and the bolts for the torque converter have been removed using a 15mm socket on a short knuckle bar and turning the fly wheel with a large screwdriver on the teeth against the case , very fiddly and time consuming.....
talking of the starter motor, as she is a 1989 car she has as standard the gear reduction starter motor fitted, the top bolt is different from the bottom bolt, and you need a 12 point 7/16 socket to be able to remove it , while on your back, looking over the gearbox in a cold garage, still, its cheaper than paying someone else to get cold doing the work.....
one thing i did find to my horror was the rear gearbox to prop shaft flange bolts were all loose !! , there are nylon nuts on each bolt , but each bolt was not tight by 1mm or so , resulting in a sloppy fitting prop shaft that would knock when picking up the drive , especially reverse, but worse than that the fixing bolt holes have become elongated ( by 1mm or slightly less ) rendering the flanges useless, luckily i have a brand new prop shaft, and my rebuilt transmission has a perfectly good flange plate , so no panics , but i will need four new bolts , and they are a fiver each....ah well
all thats left now is to remove the gearbox to engine block bolts and remove from the car
and today i have successfully removed the gearbox from the engine and out from under the car
this went fairly easy but did have a few fiddly bits to contend with , firstly the top oil cooler pipe, the dip stick gets in the way , but is a pig to get to the fixings and pull from the sump , that provided better access to the top cooler union which thankfully came undone very easily , then i was onto the bell housing bolts holding the transmission to the block
there are 8 bolts, all 9/16 , i had to use every 3/8 extension bar i could find to make a tool around 1mtr long, pass this over the whole length of the transmission and use the ' force ' to locate the bolt head and undo each one blind, took about 45 mins, the transmission was supported on a scissor jack and strapped to it for safety , the bell housing was then wiggled away from the block with a gentle pry , and off the locating pegs she popped, and a controlled lowering to the ground on the jack
thats that stage done, i will take some pics later but not a lot to show and its very tight down there for working
on the whole i am very pleased with the way it has gone so far, very little corrosion ( nothing really ) to deal with and other than the loose drive plate flange no damage either, so a quick clean up and the replacement box should pop in without trouble , but with a big dose of the force to find the bolt holes, lol
wish me luck
BB
