Here's the deal. I have 2 gaskets that are shaped exactly the same. They have differing materials. One is "fiber", the other feels a bit more like felt. They go around the brake ring of the Overdrive unit. But which one goes where? I read somewhere the gaskets are not interchangable. The original gaskets are long scraped off.
You will have to give us more information about car and/or make of overdrive unit.
I have just looked at the exploded diagram of the Laycock unit fitted to Triumphs, and can't see anywhere where there are two gaskets exactly the same shape.
Jim
Thats the cast iron "ring/sandwich" in the OD unit. They have two gaskets which are the same shape but these are the same thin material thickness in the Triumph etc, Laycock OD units both Mk1 and 2.
As above - re Jim - more info please to reference.
rm
My guess from the title is it's a Laycock overdrive - aren't they "Laycock de Normanville" or something equally exotic?
I have a service manual to the Laycock unit fitted to Vauxhall Victors, I'll see if I can find it tonight.
Mike.
Mike Edwards ( snipped-for-privacy@test.com) gurgled happily, sounding much like they were saying :
Indeed they were.
I'd also hazard a guess from the OP's moniker (S1500) that it may be for a Spitfire 1500...?
S1500 realised it was Thu, 08 Mar 2007
00:03:36 -0600 and decided it was time to write:
I'm certainly no expert on OD's, never having taken one apart, but I'm willing to learn and help.
As far as I can see from the pictures, there's one gasket NKC87 that goes between the rear housing and the brake ring and another gasket NKC86 that goes between the brake ring and the main housing.
I would think that the gasket on the front of the main housing (31H1901) would logically be made of the same material as the one at the rear. If you have the front gasket, that may be the answer. You could also call Rimmers or Canley Classics and just ask them nicely. I'd be surprised if they wouldn't help you.
They look the same but the OP said they were of different materials and thickness.
There are 2 - NKC86 (Ft) & NKC87 (Rr) gaskets which are the same shape and go both sides of that ring (NKC10). The 37H1901 joins to the main box, thickness is not relevant.
In the workshop manual they stress, that these gaskets are different. (Can't locate my parts book at present to see what that has to say which is which.)
With the brake ring /clutch / cone distance, thickness of the gasket, may make a difference in the spring tension/clearance. The problem is that its slow to fully engage OD.
Another point, make sure you replace ALL the O rings.
You illustrated the J OD unit (late) and they had slippage problems if they were not assembled correctly.
Both the early and late types work exactly the same way. The latter being beefed up in size.
r
(original poster here, postin' from work)
Gotcha. I can always order another one of the 2 gaskets, seeing as that my shortsighted self forgot to order 2 other gaskets(around the gearbox itself) so I'm stuck for the time being. That's okay.
The car in question is a USA model '79 Spitfire. I abbreviated it LdN as not to go overboard on the subject line.
Eh, about 1.5 seconds and it engages. I was happy with it. Either way, I've replaced most of the O-rings in mine. None of them looked the least bit damaged.
I swear 99% of this transmisison rebuild is part polishing. I dared not try to do the bearing replacement at the annulus. There's no way I could get those circlips off.
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