Archive for the 'Drivetrain' Category

Rear axle is done!

Saturday, August 22nd, 2009

Phew! It’s been a year since the first parts of the rear suspension was taken off the car, and today the rear axle and suspension renovation was finally done. I mean, completely done. The brakes were bled (which took a long time since the entire circuit rear of the proportioning valve was empty) and the wheels were put back on, and then it was time for a quick shakedown in the neighbourhood. The handbrake needs some more adjusting since it doesn’t hold the car even the slightest, but that’s all so far. No strange noises, no leaks and no surprises. The 35 mm drop in ride height looks quite good compared to gas shocks on original springs too.

Once the car was down on its wheels, I tightened the nuts at the front and rear of the trailing arms. Front 110 Nm and rear 120 Nm.

I parked the car the other way around in the garage so it’ll be a little more room to manoeuver with the front suspension. That job is starting right away. The engine is very rough after sitting for so long, so it’s not much fun driving anyway. One small thing I noticed is that the alternator has too little amperage on idle making the alimentazione telltale light up. Might be a slack in the belt, but I’ll look into that later.

Tomorrow it’s time to start on the front suspension!


Axle shafts are ready!

Friday, July 24th, 2009

The rear wheel bearings arrived in the mail today, just four days after I ordered them. Classic Alfa delivers really fast on smaller items. The larger items tend to get stuck in customs, something Richard Norris apparently is painfully aware of. With the bearings came new oil seals for the axle tubes, which was a nice surprise. I had actually forgotten all about these oil seals, but now I got to replace them as well. I took an oblong, square piece of wood and chipped away the corners to use as a driver, and the removal was done with a brake pad puller. After that was done, I mounted the new bearings on the shafts. I didn’t have a long PVC tube handy, so I used the inner race from the old bearing and hammered the new bearing in place with a flat piece of wood; two strokes on one side and two more strokes 180 degrees from the first two. In the end, I used a flashlight/torch to check that the bearing had seated properly.

Note: the left and right handbrake assembly plates aren’t interchangeable. Firstly because of the left/right threading on the wheel studs, secondly  because of the draining groove in the bearing seat which must face down when the axle is mounted, and third because the caliper mounting ears should face backwards. The drain groove is clearly visible in the fourth picture.

After the threaded ring nuts were back on the shaft, I used some universal, non-hardening sealant (Biltema # 36-2404) and sealed the back of the handbrake shoe retaining pins. The workshop manual suggests using Minnesota EC 5305 sealing compund to avoid foreign matters entering the handbrake assembly, but that particular sealant probably isn’t on the market anymore. I wonder if you lose concours points over this? 😛

Axle shaft ready to be mountedBiltema universal sealant, 36-2404img_5712.jpgimg_5713.jpg

The Classic Alfa GB035 oil seal didn’t fit the Montreal differential. I called up Richard Norris and he told me had the right oil seal in stock. Probably a slip-up by someone since I asked before ordering if the seal would fit. I’m sending it back to have it replaced. The correct oil seal has a 48 mm inner diameter, an 80 mm outer diameter and a 12 mm depth. I managed to ruin the part number when removing the seal, but the manufacturer’s name is Goetze. I’ll see if I can patch the seal back together and make out the number. By the way, SKF has a nice manual mounting guide for rotary shaft seals.

Update: the oil seal is a Goetze 827 SRD 48-80-12 and has Montreal part number (TAV. 57). According to Bruce Taylor, the 48-80-12 is difficult to find and is usually replaced with a 48-80-10 seal driven flush with the differential housing. Here’s how the original 12 mm seal looks like behind the slinger:

A Goetze 827 SRD 48-80-12 on a Montreal differential

Removing rear wheel bearings

Friday, July 17th, 2009

Yesterday and today was spent removing the bearings from the rear axles. It seemed like a good idea to replace them since I had new bearings on the shelf and everything was taken apart, but as usual when there’s bearings involved, the good-idea feeling quickly fades away when faced with reality 😉 Yes, they were of course impossibly stuck, and the special tool A.5.0120 to remove the ring nuts is not in my collection of tools. As a matter of fact it’s in nobody’s collection of tools, at least those who either can lend it to me or do the job. Yes, I asked around.


Mounting propshaft and handbrake cable

Saturday, July 11th, 2009

The front propshaft is now mounted back on the car. It was a fairly easy job because the centre support acted as my third arm, leaving the second arm free to hold the 17 mm spanner 😉 The chassis bolts securing the support got a serving of copper grease, new nuts and washers. According to the workshop manual, the guibo bolts should be oiled before inserting them through the bushings in the guibo, and I can certainly attest to the usefulness of that. It’s a really tight fit! I can only imagine what happens if the bolt sets against the bushing and suddenly decides to snap into place when you’re driving. Once everything was into place, the nuts and underside of the centre support got a fresh layer of spray undercoating. The latter is Biltema’s general purpose body coating (part number 36-2413) which I’ve used several places to repair damaged coating.

The bearing was actually the wrong type for the support, although the dimensions are an exact fit. The new one didn’t have seals on it, but I transfered the seals from the old one after packing it with regular, all purpose wheel bearing grease. I’ll just have to see if this is good enough or not.I used the same grease to pack the bearings in the dynamo.

Another thing done today was the handbrake cable. That was another rather easy job, but I suspect the adjustment won’t be so easy. The handbrake assembly on the rear wheels will be completely rebuilt once I have the rear wheel bearings removed.

New bearing on the left, old on the rightnew_centre_support.jpgView from under the spare wheel well