Overdrive Gearbox - A saga of many parts

We left the story with the car off the road, well although I haven't posted any updates I continued working on the car until it was roadworthy; essentially I packed the gearbox away from the crossmember with more washers and longer bolts.  I fitted the propshaft and the speedo cable, both of which fitted like gloves, I checked the wiring and shaped a steel plate to go over the hole in the transmission tunnel.  Next a trip to see our MOT tester to see what he thought.  I was expecting a fail on something, but he passed it!.  


The first test was the following August Bank Holiday (2006) weekend as I had booked a space on the Morris Marina Owners Club (MMOC) stand at the Knebworth Classic Car Show, lining her up with a number of other Marinas and Itals.  She drove OK, there were one or two groans from the mountings, but she ran.  On the way down the overdrive packed up and it wasn't until the following weekend that I had time to check her out - it was just a loose earth wire.  I tightened a few bolts etc. then I noticed a rather large pool of gearbox oil collecting on the garage floor.


So once again up on the ramps and to keep her level I put the back axle up on axle stands.  The gearbox and the underside of the transmission tunnel was awash with fresh gearbox oil, it was getting onto the propshaft, which was spinning it out like a farm muck spreader.  I suspected everything from a cracked overdrive housing to the rear seal.  I thought that one of the long fixing bolts was leaking round the thread.  In the end after washing everything down to find the source - no joy, so I topped up the gearbox and left her alone to bath in her pool of oil.


Since then I have driven to various shows, up to the Lake District for the MMOC National Show 2007, more shows and always with my own oil bath.  I found that parking on grass hid the oil leak.  All in all about 2,500 miles - worth it - definitely.  Much more relaxed cruising and it felt so different on the motorway drive up to the Lakes and a little more economical into the bargain.


It's also worth noting that the gearbox itself was straight out of the box from its' rebuild and it has benefited from the workout as it was a little notchy to begin with, now the change is much smoother.  Finally, after 4 litres of gearbox oil, I have found the leak - would you believe that I had never fully tightened the solenoid into its housing, it looked fine but you could wiggle it about - once tight - no more leaks.


One of my goals has been to find a better gearbox cross member.  Between the bottom of the gearbox mounting brackets on the tunnel and the bottom surface of the gearbox mounting bush, all the rubber and washers amounted to a drop of 40mm.  I have been looking round for a suitable transverse gearbox carrier, when I saw this on EBay listed as a Dolomite Sprint gearbox member - it isn't, I have one and the Dolly one isn't deep enough.


This by comparison had possibilities - it cost me all of 0.99 plus postage - I was the only bidder.  Those of you of a Ford persuasion will probably recognise it as what I believe is a Sierra cross member.  If I am wrong can you let me know.


As you can see it has a rubber bush riveted into the centre, but two minutes with an angle grinder fixed that.  Lined up side by side the BL Marina/Ital Dolomite/SD1 bush on the left is very similar to the Ford item on the right




What I have done is to slot the rivet holes slightly so that I can fit the BL bush, here's a shot of the Marina bracket and the Sierra bracket.  You can clearly see the difference in height in these upside down shots.  The height differential on the Sierra crossmember is 43mm by my measurement - so this should be close to ideal.  Also the bush is offset in the bracket, which means that I can do away with all the packing washers that I was using to align everything horizontally.


At the time of writing this in Spring 2008, the car is off at Paul Mondey's having the bodywork done (separate story to come), so I can play around a little with the engine and gearbox.  The plan is to trial fit the new cross member when the car comes back and see what I can see.  All the new crossmember needs now is a coat of satin black paint and I think that we are in business.



As a little bonus, it occurred to me that should I ever want to go down the Ford Type 9 five speed box route then I am already on the way.  A friend in the MMOC has sent me a plan for a spacer to fit between the Marina bellhousing and a long-nose Sierra gearbox - who knows?  The thing that I like about the overdrive conversion is that it's one that BL could have done to the standard car instead of just a few rally cars.  Fitting a blue oval gearbox seems a bit disloyal somehow or am I being silly?


Watch this space for the end to the story.  Will the new bracket fit?  Will it be smiles all round?  Will I pursue the Ford gearbox option?