| Author | Message | ||
     Mark Chowis Yet to post message Username: markc Post Number: 1 Registered: 07-2020 |
Hi all. There are various problems with the driver's electric window mechanism on my 1967 Corniche (CRH3443). The main issue is that when I got the car the chain had jumped off the sprockets. The tooth pairs on each sprocket form a distinct 'V' shape and I was wondering if that's how they should be or if they've splayed out over the years giving the chain a chance to jump off. I've tried to attach a picture of one of the sprockets - not sure if it's worked. The other sprocket is very similar. The upper sprocket bushing is quite worn so that needs looking at. Are there any tips on adjustment to prevent this happening again? Thanks in advance, Mark | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 3066 Registered: 06-2009 |
The image did not work. Images can be a maximum of 640x640 pixels square. See the Formatting page for the forum and search for the Images, Attachments, and Clipart section. I find using the backslash image option, with the description of the image inside the curly braces following the word "image" to be the easiest way to embed images in my posts. You will be prompted to actually supply the image file(s) when you post, and will get a conventional Windows open dialog to locate them. | ||
| Mark Chowis New User Username: markc Post Number: 2 Registered: 07-2020 |
OK, I'll try again but my browser may not handle it  | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 3067 Registered: 06-2009 |
Unfortunately, I can't tell you whether what the sprockets look like in your photo are normal or not. This is something that apparently changed between the SY1 and SY2 series cars. For comparison, here is the window motor with drive sprocket visible from one of my SY2 cars:  Someone will almost certainly have a photo from a car that's from approximately the same model year as yours is. From what I see in your photo, and what follows is pure, unadulterated speculation, makes me wonder if "sprocket 2" on the underside can be adjusted such that the teeth on it are offset from the teeth on the top one, giving something like the evenly spaced single teeth on the single sprocket on the SY2 cars. But a photo from another car of your era should settle that, or opening up your passenger door and seeing what's what there if all works fine there. Also, and this is a nit-picky aside, but nit-picky is part and parcel of the world of cars from Crewe, what you have is a Shadow Drophead Coupe (DHC). The Corniche (and the name plate for same) was not introduced until 1971, if memory serves. And the DHCs prior to that were far more like one-off cars than their fixed head compatriots, whether coupe or sedan. Brian | ||
| gordon le feuvre Frequent User Username: triumph Post Number: 354 Registered: 07-2012 |
Corniche has Piper motor. Am removing door trim from my 1973 fixed head later next week to attend to sticky micro switch. Will photograph and upload | ||
| John Rowney Experienced User Username: johnrowney Post Number: 86 Registered: 02-2015 |
Gordon is spot on. If you look at the this forum's Small Horsepower section on the topic "Wraith Division Blind Mechanism" you will see descriptions and photos the identical driving mechanism cog wheel in the pre-war cars and others. It is interesting that the same sort of system kept going for so long. | ||
| Mark Chowis New User Username: markc Post Number: 3 Registered: 07-2020 |
That's very helpful, thanks. | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 3068 Registered: 06-2009 |
John Rowney wrote, in part: It is interesting that the same sort of system kept going for so long. Not in a car from Crewe it isn't!! I'm often amazed at how slow they were to make changes that were already "field tested" by many marques and were, unquestionably, superior in functionality to the "tried and true" that they were using. I love my RRs, but having been in this world now for just short of 15 years, I have learned that many engineering choices made by Crewe had nothing to do with what was best at the time the car was built, or at least not necessarily. The number of anachronistic hold-overs in these cars, spanning decades, is jaw-dropping (and many of them were problematic from the outset). Brian, who will be watching here to see more about that Piper motor, which I had not yet seen. Always something more to be learned about these cars! | ||
| Trevor Hodgekinson Experienced User Username: wm20 Post Number: 186 Registered: 11-2006 |
It is a funny sort of mindset First one is backwards compatibility. So the part you are making today will fit something you made 100 years ago, not at all a bad idea. The other thing was the reluctance of management to spend money to purchase new tooling with all of the post WWII tax problems of undistributed profits. There is an amusing story about Edwin Turner's report on Japanese motorcycle production . In it he noted that all of the japanese factories were working 24 / 7 . The consencus of the Chamber of British Motorcycle manufacturers was , " this is good, at that rate they will wear their machines out in no time so will not be able to threaten our superiority and will be unable to maintain supply " |
