Saturday morning Alastair and Rita ducked to Polokwane so I was left to myself to fix the gearbox leak. I first had to remove the starter/bellhousing/gearbox combo from the engine which was fairly easy, but to remove the bellhousing from the gearbox was a real mission. This was (as I found out later) the thread used on the cap screws supplied by Birkin is not the same as the thread that is in the gearbox. When I first attached the bell housing to the box I used the impact wrench and did not feel any resistance. This time I started to unscrew it manually and quickly gave up. I had to use an impact wrench all the way out. There was something funny going on here....
I removed the clutch actuator, undid the bellhousing/gearbox cap screws and examined the bearing retainer/input shaft cover closely to see where the leak might be coming from. As it happens, when I replaced the input shaft bearing the new bearing sits a little too proud of the gearbox face and seating the shaft cover on it leaves about a half a mil of clearance which the gasket cannot seal off. The proper engineering solution is to mill the cover recess deeper to accept the larger bearing and its thicker retaining ring. In the end I adopted an easier solution and installed a thicker gasket, supplemented by copious amounts of silicon sealer.
I then filled the gearbox with the correct gear oil and let it sit while I went to the shops to search for the correct bolts for the gearbox/bellhousing joint. My reasoning was as follows that the car was built in metric with metric threads. Any "fine" thread should therefore be a metric fine. Right? (well I hoped so)
I arrived at Struck and Schulz with the offending capscrew and asked for a similar capscrew in metric fine. OK they sez we don't have it in a capscrew we have it in a bolt and not that length either. OK sez I the bolt can be about 10mm shorter and it doesn't HAVE to be a capscrew, a bolt is fine. We eventually settle on something that looks workable and off I go and try it out. The bolt glides into its thread in the box with no problems at all, so I am thinking Birkin supplied a UNF or some other funny thread, that was nearly metric fine but just not quite. Problem solved!
Actually after checking out the spec sheets there are TWO metric fine specs M12x1.25 and a M12x1.50. So Birkin must have supplied the wrong one.
As a bonus while I have been away at the shops the gearbox has decided to play ball and not leak. Yippee!
While the box is on the workbench I remove the selector fork and install the little brass saddle on the fork. I have to bend the tabs a bit to get it to stay on the fork. Install the quick shift Quaife gear lever, test the gears 1-5 and reverse, everything is looking good.
So the box goes back on the engine, on goes the starter and everything is back to where it was. 3 hours spent sorting out that little lot.
The family come back from Polokwane and with Alastair available to help we remove the radiator and start fastening up the front suspension dampers, and installing the brake hoses, remembering to install the mounting brackets at the hard line/hose connections. Incidentally we could not get braided hoses as was mentioned before. Too expensive!!!
We move to the rear and first thing I want to do is connect the brake hoses to the hard lines below the diff. The right hand side was pretty difficult but it was impossible to do the left hand side - we just could not get our fingers in, never mind the spanners.
In the end we undo 4 of the 6 diff bolts and lift her up (pivoting on the diff front mounting) and hold it in the elevated position with some rope and a steel bar. This gave us the necessary space to get in and attach the hard lines to the snouts of the brake hoses.
After we drop the diff and insert the bolts we move on to attaching the rear hubs and brake calipers to the suspension. The only missing element is the shocks as the bottom of the shock fouls the wishbone. The shocks will be off to the engineering works to get ground down.
I grease up the ball joints, splines and threads and with no problem the hubs are installed, the nuts torqued up and the R clips installed. Fitting the rear brake calipers presented no problem either. As a final touch the handbrake cables were also hooked up although they cannot be adjusted at this point.
The rear brake discs are still not available so the brake calipers will need to come off again. The reason I attached everything up is to seal off the hydraulic system from dust. The bleed nipple setup on the rear brake calipers looks a bit dodgy.
In short we accomplished:
Front suspension and brakes completed.
Gearbox leak, and the nagging bolt thread problem sorted
Rear suspension and brakes completed, apart from the shocks
Tyres mounted on rims and balanced.
We are getting closer and closer to dropping the chassis onto its wheels, the only holdback is the rear shocks.
No comments:
Post a Comment