Removing a manual gearbox
On Saturday, after months of deliberation and discussion, my friend Steve and I decided to bite the bullet and remove the manual gearbox from his Stag so that it can be reconditioned. For the last 12 months there has been a very loud howling noise from his gearbox which gets worse with speed. There was also a rattle at idle which was diagnosed as the clutch release bearing.
We both have office jobs and fall into the enthusiastic amateur category of Stag owner. We started at 9.00am on Saturday and with plenty of teabreaks and head scratching had the gearbox out at 7.00pm (that’s about 16 man hours – we won’t be giving up the day jobs anytime soon!). The following points may help others who are thinking about doing this job:
1. The manual recommends draining the coolant and removing the heater hoses and then removing both exhaust downpipes. We had also been advised to remove the distributor. However we just removed the coil and took the distributer cap off which gave sufficient access at the top of the engine. There was sufficient flex in the heater hoses which meant that we could work around them without draining the coolant. We removed the passenger side downpipe and managed to break 1 stud in the process. The driver’s side exhaust manifold studs were locked solid and so we decided to leave well alone.
2. There are 18 bellhousing bolts of which about 10 need to be removed in the engine bay. There is no access for sockets. We used a selection of thin ½” and 13mm spanners but access was still very difficult. The best tool we used was a 13mm ratchet spanner – I definitely recommend getting one of these. It took both of us to remove each bolt – one to hold a spanner on the bolt to stop it moving and the other to undo the nut.
3. Removing the gearstick is well documented in the manual and was straightforward.
4. We then raised the car as high as possible onto the ramps. We removed all the clamps holding the centre sections of the exhausts.We tried separating the exhaust at the balancing pipe but even with a scissor jack it wouldn’t budge.
5. We then painted a reference point on both ends of the propshaft and removed the bolts – again needing 2 of us to stop the bolt heads moving. Those at the diff end were very tight and fiddly to get at. With a bit of levering on the exhausts with wood blocks we were able to draw the propshaft out from the diff end.
6. We drained the gearbox oil and found a 1 inch high stack of iron fillings on the magnetic drain plug – perhaps an indication of the poor health of the gearbox.
7. Steve had bought a Dirty Pro gearbox cradle for £30 which was mounted on a trolley jack and then attached to the gearbox. We then removed the remaining bellhousing bolts and the rear bracket – this was also very fiddly.
8. We then tried separating the gearbox from the engine but it wouldn’t budge. Eventually we forced a screwdriver between engine and gearbox followed by further levering with larger screwdrivers, a crowbar and then blocks of wood. We then reached the end of travel in the transmission tunnel but weren’t sure whether the gearbox main shaft had separated from the engine. We tentatively lowered the rear end of the gearbox down and then moved a few inches further backwards and then it was obviously clear of the clutch housing. Having the driver’s side downpipe still in place wasn’t a problem when manoeuvring the gearbox.
The gearbox has now gone to be reconditioned and should be back in about 10 days. For those that have done this job before, do you have any hints or tips which might help us put it all back together?
Thanks
Chris
We both have office jobs and fall into the enthusiastic amateur category of Stag owner. We started at 9.00am on Saturday and with plenty of teabreaks and head scratching had the gearbox out at 7.00pm (that’s about 16 man hours – we won’t be giving up the day jobs anytime soon!). The following points may help others who are thinking about doing this job:
1. The manual recommends draining the coolant and removing the heater hoses and then removing both exhaust downpipes. We had also been advised to remove the distributor. However we just removed the coil and took the distributer cap off which gave sufficient access at the top of the engine. There was sufficient flex in the heater hoses which meant that we could work around them without draining the coolant. We removed the passenger side downpipe and managed to break 1 stud in the process. The driver’s side exhaust manifold studs were locked solid and so we decided to leave well alone.
2. There are 18 bellhousing bolts of which about 10 need to be removed in the engine bay. There is no access for sockets. We used a selection of thin ½” and 13mm spanners but access was still very difficult. The best tool we used was a 13mm ratchet spanner – I definitely recommend getting one of these. It took both of us to remove each bolt – one to hold a spanner on the bolt to stop it moving and the other to undo the nut.
3. Removing the gearstick is well documented in the manual and was straightforward.
4. We then raised the car as high as possible onto the ramps. We removed all the clamps holding the centre sections of the exhausts.We tried separating the exhaust at the balancing pipe but even with a scissor jack it wouldn’t budge.
5. We then painted a reference point on both ends of the propshaft and removed the bolts – again needing 2 of us to stop the bolt heads moving. Those at the diff end were very tight and fiddly to get at. With a bit of levering on the exhausts with wood blocks we were able to draw the propshaft out from the diff end.
6. We drained the gearbox oil and found a 1 inch high stack of iron fillings on the magnetic drain plug – perhaps an indication of the poor health of the gearbox.
7. Steve had bought a Dirty Pro gearbox cradle for £30 which was mounted on a trolley jack and then attached to the gearbox. We then removed the remaining bellhousing bolts and the rear bracket – this was also very fiddly.
8. We then tried separating the gearbox from the engine but it wouldn’t budge. Eventually we forced a screwdriver between engine and gearbox followed by further levering with larger screwdrivers, a crowbar and then blocks of wood. We then reached the end of travel in the transmission tunnel but weren’t sure whether the gearbox main shaft had separated from the engine. We tentatively lowered the rear end of the gearbox down and then moved a few inches further backwards and then it was obviously clear of the clutch housing. Having the driver’s side downpipe still in place wasn’t a problem when manoeuvring the gearbox.
The gearbox has now gone to be reconditioned and should be back in about 10 days. For those that have done this job before, do you have any hints or tips which might help us put it all back together?
Thanks
Chris
so "simply" had to remove the box again"
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