klm wrote:Thanks Declan for your response and the information on the seal used on the rear damper. I note it is a single lip oil seal recommended for a push rod application. I have some questions.
Has this seal been successful in eliminating leaks through the shaft?
Are you presently using the overhauled damper?
Did you notice any score marks on the shaft where the original metal ring and rubber washers were in contact?
If the shaft was scored did you machine it to remove the score marks before fitting the seal?
Thanks
Yes the lip seal has proved quite successful-it's a lovely fit on the shaft but the outside diameter of the seal needs a few thou taken off the metal to prevent it splitting the housing. The repaired damper has been tested over the last few weeks on Hans Dieter's car and there are no signs of any leaks. There were no score marks on the shaft and there was no machining done just a straight replacement.
Regards
Declan
Thanks Declan for the response. I will first check if a suitable oil seal can be sourced locally here in Australia before ordering through eBay. Thanks again.
Regarding the rear springs, the original 7 leaf springs for saloons and convertibles have 7/32" thick leaves and they have the part number ACA5016Y stamped on the bottom leaf. The traveller springs have a different part number ACA5066 quoted in the Parts List and it is not clear what the differences are. The BMC Workshop Manual gives specification for the 7 leaf 7/32" thick rear springs in terms of a free camber and working camber. Does anyone know more about this subject?
1960 Morris Minor 1000 Convertible
1984 Ford Laser KB Ghia
1997 BMW Z3 1.9
1999 Holden Astra 1.8 CD
Did you use Fork Oil 30 or engine oil? Fork oil contains the same additives as hydraulic oil but if engine oil was used it is likely to breakdown after some time. Hydraulic oil is not available in SAE30 but Fork oil is, for use in motor cycles. It is a matter of peference on what viscosity of oil to use, and I found the movement of the arm to be smooth with SAE20 hydraulic oil compared to more viscous oil. Also the grade recommended by BMC was SAE20 which I guess the damping rate for the torsion bars and springs are set at.
Regards
klm
1960 Morris Minor 1000 Convertible
1984 Ford Laser KB Ghia
1997 BMW Z3 1.9
1999 Holden Astra 1.8 CD
Engine oil has even more additives than 'hydraulic' oil - it will last even longer! SAE 20 was the standard oil - the dampers work much better with 30, and better still with 40 ! I've only seen 'fork oil' in SAE 10 and 20 - but it may well be available in other grades in small cans - which could make it a more economic proposal.
KLM Ref spring types.
The original springs fitted to Series MMs to car 680463 were 7 leaf x 7/32 in. (5.56mm) These were replaced on the saloon and convertible by 5 leaf x 1/4 in. (6.35mm). The Traveller was fitted with 7 leaf by 1/4 in. Total spring thickness in mm = 38.92, 31.75 and 44.45.
It is a common mistake to fit the 7 leaf Traveller springs to Series MMs which results in less predictable handling, a harder ride and a jacked up rear end, particularly noticable with the high cut wheel arches.
Thank you Mike for the information on springs. My car is a 1960 Convertible Chassis number 877700 series assembled in Cowley and it is fitted with 7 leaf springs. Were the cars for export continued to be fitted with 7 leaf springs while the UK cars had 5 leaf springs? It appears not much information is available on the specification of springs.
1960 Morris Minor 1000 Convertible
1984 Ford Laser KB Ghia
1997 BMW Z3 1.9
1999 Holden Astra 1.8 CD
In last week's Classic Car Buyer Kim Henson recommends using proper hydraulic oil in dampers rather than engine oil, which he reckons can rot the dampers' seals. I hadn't heard this before - has anyone else? I'm topping mine up using up an old can of Duckhams Q found in a property I bought. The viscosity looks OK, it smells like only unused Duckhams Q did, but I wouldn't chance it in an engine due to its age.
The dampers are still fine too.