Guys, the great day dawned when, various repairs having been completed on Madame's vehicles, I could start the work of removing my gearbox in order to replace it with a new one. This is because a vibration I have been chasing for about 2 years seems to stem from the gearbox. Obviously we will find out if it was so caused once the new one is installed!
To say this was a daunting task is an understatement, but having gathered together all the necessary tools over the last few months, I was at last ready to start. My courage was much bolstered by advice from Grant on the France/Australia scrambler hotline. Here is a list of what is done so far, and I am in a position when I restart on Monday, to actually undo the bellhousing bolts and remove the box. Below the list are a few snaps of the work. I have a lift, but providing you can safely raise the car 3 feet off the ground, there is no reason the work cannot be done without one. What is essential is to have a very good friend called Michel (see photos) to help.

1. Remove battery done
   
2. Partially syphon coolant done
   
3. Drain gearbox done
   
4. Undo shock absorbers from hubs done
   
5. Undo top hoses from radiator done
   
6. Undo crank beather hoses (not necessary with OEM breather) done
   
7. Undo heater feed hose from tap end done
   
8. Remove cold start solenoid to give access to B bank lifting eye (not necessary with OEM AAV) done
   
9. Undo wing bracers done
   
10. Install engine beam chains on rear eyes and just take weight
    
11. Undo steering rack/column joint done
    
12. Loosen six shots done
    
13. Undo downpipe joins and undo over-axle pipe joins and remove exhaust central section done
    
14. Remove selector cable from box done
    
15. Remove speedo transducer loom and kickdown loom from gearbox done
    
16. Remove modulator vac pipe done
    
17. Undo gearbox mounting (beam is supporting the motor) done
    
18. Undo and remove propshaft done
    
19. Undo the rear subframe V mount nuts (remember that the weight of the engine and subframe is taken by the beam across the engine).
    
20. The plan is to lower the entire engine, subframe and gearbox asembly, as a single unit, using the six shot bolts as a fulcrum. Carefully undo the threaded adjusting screws on the beam and lower the engine/subframe assembly allowing the gearbox, engine and subframe to swing down on the six shots. This will give access to the top bellhousing bolts. This plan worked fine, BUT the exhaust downpipes just fouled the rear corner of the subframe V mounts once the lot was lowered a couple of inches or so. About ¼ inch was ground off the corner of the V mount to allow clearance done
    
21. CHECK BRAKE FLEXIBLES are not stressed while lowering subframe done
    
22. Undo the flexplate black pressed metal cover from under the flexplate (flywheel) and gearbox front end done
    
23. Before the gearbox bellhousing nuts are undone, the flexplate (autobox equivalent of the flywheel on a manual car) bolts that hold it to the torque converter must be undone. This is possible in a number of ways, but I used the following method: The bolts are 15mm, and they are just accessible if each bolt is at the 6 o'clock position, providing the engine sump centre-rear fixing bolt is removed. To undo each bolt, the engine was turned using a socket on the crank pulley bolt. Remember the engine must only be turned CLOCKWISE facing the engine from the front. Once each flexplate bolt is at the bottom position, a short 15mm socket can just be placed on it, but it cannot be turned by a ratchet owing to lack of space. To overcome this problem two flats were ground on the socket to take a 17mm spanner. Then each bolt was removed in turn done
    

 

Wasn't sure if I missed, it, but have the transmission cooler lines been undone from the radiator? Starter wire and earth straps removed?

While you have the lump out, consider replacing the starter motor. It's a devil to do in the car. It took me 2 days to get it out, and I had the car on a hoist.

 

The steel cooler lines will be undone from the gearbox, they are easily accessible now the box has been lowered, as shown in the third from last photo. The flexibles to the actual cooler do not need to be undone.
The battery has been removed, the starter will just stay in place, more or less, when its bolts are undone. The earth flexibles and the main power line to the starter have plenty of extra length to accommodate the lowering.
I am not replacing the starter, so I hope I do not regret it later!

 

Well done Greg.

Michel has a smile, he luvs YOUR V12 mate.

I will toast the progress later.

 

All fine so far, Greg, but...

The torque convertor bolts are supposed to be undone from the ooening behind the oil filter mounting point. And the bolts are imperial

 

I did know but it was easier for me to do it as described. I thought the bolts were imperial too, but only the 15mm socket fitted properly.

 

Normally the lower cover would still be attached, so I guess you're right in this case.

Is your TC the original one? As said, mine were no issue. Just removed the TC and tranny again yesterday to take apart and make two bad ones into one good one...

 

Congratulations!

 

Greg,

Great work! And I love the checklist description and pics!

Well done. Looking forward to hearing the update.

Paul

 

If readers refer to post 1, above, they can see that I had got as far as unbolting the torque converter from the flexplate. This post describes the next few steps I have taken today:

1. Install trans jack done
2. Undo gearbox oil cooler pipes done
3. Blow out cooler lines done
4. Undo the 9 of the 10 bellhousing bolts, note these 9 bolts have 9/16ths inch hex heads. The tenth bolt is the one fastening the topside of the starter motor; this bolt is NOT a normal hex headed bolt, it has 12 points on the bolt head and you MUST use a 7/16ths inch 12 point (ie double hex) socket to undo it.. done
5. The gearbox can now be easily pulled back from the engine done
6. If a new flexplate is to be fitted, proceed as follows: Undo the 10 flexplate to crank flange bolts having knocked back the locking tabs, but VERY carefully ensure the engine cannot turn when the bolts are being undone, by inserting a rod into the flexplate hole reacting against the block bottom corner (see photo). To remove the flexplate it is first necessary to pull out the locating dowels using socket as a reaction tube and threading a UNF bolt into the dowels, thus pulling out the dowels. Carefully keep the reinforcing ring which is beneath the locking ring and the dowels. It is best to use a new locking ring when reinstalling the flexplate.
7. If a new flexplate is to be fitted (I did) proceed as follows: Undo the 10 flexplate to crank flange bolts having knocked back the locking tabs, but VERY carefully ensure the engine cannot turn when the bolts are being undone, by inserting a rod into a flexplate hole reacting against the block bottom corner (see photo). Having undone the bolts (which are UNF threads turned by 19mm hexs on the bolts!) to actually remove the flexplate it is first necessary to pull out the locating dowels using a socket as a reaction tube and threading a UNF bolt into the dowels, thus pulling out the dowels. Carefully keep the reinforcing ring which is beneath the locking ring and the dowels to reuse it. It is best to use a new locking ring when reinstalling the flexplate.
8. If a new flexplate is being fitted pull the dowels into the new flexplate using a socket and bolt as used above to remove the dowels done
9. Place the reinforcing ring and the locking ring in positon on the flexplate and screw in the 10 locating bolts to the crank flange done
   
10. Do up the 10 flexplate to crank bolts to 66 Ft. Llbs (90 NM) torque done

Rather amusingly, we miscounted the bellhousing bolts and wondered why the 'box would not come away. In the end we found numbers 9 and 10 were still attached, and once they were removed the box just floated off perfectly on the tranny jack! The entire process was pretty straightforward, and in fact the actual removal was far less work than the preparation stages to get to the stage we could undo the bellhousing. Alert readers will notice that the Gearbox Swap Team has increased to three. My heartfelt thanks to Frederique, who with his Father Michel, helped me today.

 

Greg,

Well done, as I said on the Batphone.

BUT

MAAAAAATE

Typo, and I know you are TIRED, but you have typed 7/8 for the starter top bolt instead of 7/16.

Enjoy the afternoon off, I am off to bed, see ya.

 

I have just re-read it, it looks like 7/16ths to me.... (as in thanks Matey, I have just fixed it)! At least one person has read it!!

 

Daim
The flexplate to TC bolts ARE Imperial threads, but they also ARE 15mm hex headed. The flexplate to crank flange bolts ARE UNF but they ARE 19mm hex headed. My belief is that when the UK went metric in the mid 1970s, Jaguar converted all their assembly tools to metric, and ordered up metric-hexed UNF and UNC bolts, so as not to have to re-make/convert all their machine tools that produced the threaded holes in the block etc etc.

 

19mm is 3/4", so likely imperial threads. What are the bolt head markings on the TC bolts? Metric and imperial bolts have different markings

 

Nice write up Greg. Well done.

 

nice job! great write up

 

JB, They are definitely 19mm, not 3/4, with a socket on them the difference is noticeable.

 

I'm surprised, the ones on my Daimler are 3/4" and it has the TH400 as well.

 

Same in my 89. That is why I was a little confused.

 

Greg, I feel your thread is not getting the love it should be.

What you have done is quite amazing, I think the fact is that there are very few of us who would even attempt such a job.
I am one that NORMALLY would give anything a go, but this has scared me. So impressed, which means if you can... I can but most likely would run for the tree's.
UNTIL.. I took home the quote. And that is where "Hi Greg howz it going" post will happen.
So I am following this and enjoying your work, please keep the posts coming because they are excellent and this post needs to be pined... to the main page.
We need as much info you can give.

Solute to "give it a go from me!"
Too Greg the Cool!