So I started work on the Croma on Friday. Unfortunately there were a couple of unexpected issues. First was the inboard offside brake pad was completely worn out I'd checked the visible (outboard) pads earlier and they had at least 3/4 thickness left. Obviously a stuck calliper. There is a pad wear warning but it's on the nearside inboard pad which was fine. So off to ECP for new pads and disks. Next was the gearbox oil. When drained only 1 litre came out. there should have been 2.2 litres!
This raises the possibility that my thrumming noise could be a gearbox issue. Original symptoms did not support this as it was road speed related regardless of gear in use at stopped with steering input applied. Could be a differential issue, but that is the last item in the gearbox to lose lubrication.
The driveshaft to hub nut is 32mm but I used a 11/4" (31.75mm) socket as I had one and it was good tight fit. You don't have to have a thin wall or deep socket. A breaker bar is essential though. Good news is that you don't have to split the lower arm or steering ball joints to extract the outboard end of the drive shafts. I loosened the lower two upright to hub bolts before undoing the upright to strut bolts and pushing out the driveshaft ends with a 6" 3 leg gear puller. To loosen the last (top) upright to hub bolts I put a steel bar through one of the upright to strut bolt holes to provide leverage. The offside hub was very difficult to remove from the upright due to corrosion between the steel hub and alloy upright. The ABS sensor stayed in the upright and had to knocked out separately. All the corrosion products had to be cleaned off. A coating of LPS-3 before fitting the new hub should stop new corrosion. Next problem was that I could not withdraw the offside driveshaft from the centre support and gearbox. The centre support has hollow dowels so I could not tell were the hang-up is. As the driveshaft tulips were not giving trouble (yet) and there is the possibility of gearbox trouble I decided to leave the drive shafts as they are.
Then we had an unexpected guest so the afternoon was wasted. Sunday I started on the offside brake. Stripped and cleaned the calliper and re-lubricated the pins. Went to fit the new pads and found I bought the wrong ones Doh! There are two different brake systems fitted to the Croma (and Vectra) Teves and Lucas. I have the Lucas system but had clicked on the wrong item when I ordered the pads.
Back to ECP, but Cambridge did not have the correct pads so had to go to Peterborough. With the right pads it all went back together fine. I use Ceratec brake grease rather than copper based grease which I've never liked especially near aluminium components. Drop link replaced as well (Lemforder) due to rattles over rough surfaces.
I then did the nearside which went a lot quicker. Wheels back on and only the gearbox oil to refill when I packed up for the night (just before torrential rain). Gearbox oil was this morning's job. I took the battery box out for better access to the filler plug on top of the gearbox. Just as well as it was VERY tight. the plug had a 8mm hex recess but a standard L allen key would not budge it. It took a 1/2" socket fitting key and a 3 foot breaker bar to loosen it. 2.2 litres of oil (SAE 75-85 GL4. I used Morris Lubricants) added using a small (4") funnel, a 10" length of 1" waste pipe and a measuring jug. I did check and it not possible to "dip" the oil level from the top of the gearbox.
A road test showed brakes fine, no rattles on rough surfaces and most importantly, no thrumming noise. The off-side bearing showed the slightest, intermittent roughness when rotated by hand. Hopefully that was the cause and the gearbox is OK. The thermostat will have to wait for another day. The hard to remove hub, stuck driveshaft, guest and runs to ECP took up too much time. The weather is now not looking good for working outside.
Robert G8RPI.