Author Topic: 59 A7SS Tappet Grubscew confusion  (Read 180 times)

Offline Peter Gee

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59 A7SS Tappet Grubscew confusion
« on: 29.03. 2019 10:33 »
My 59 A7SS is a thin flange.

I possess 4 tappet groubscrews in 3 different types.

The hole depth of the tappet grub screw 67-0276, with ball in place, is about 12.56mm deep.

From left to right in the pic, I have two screws not fully threaded & with domed head, length 12.06mm

One screw with thick  protrusion,full thread 14.07mm long OA

One screw with thinner protrusion, 16.21mm long OA.

Which ones are/is  67-0276  Top Grub Screw and which are 67-0299, side groubscrews x 2 ?

Why  is one longer screw (14.07mm) have a "fatter" and shorter protrusion than the other?

Dont dare build the top end and then discover something is wrong. Help appreciated

Online Greybeard

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Re: 59 A7SS Tappet Grubscew confusion
« Reply #1 on: 29.03. 2019 11:45 »
My memory tells me that the central screw, that has a ball beneath it to lock the cam follower alignment piece is shorter than the two outer screws that have a pin on the end to, (stop the followers from dropping out before they are assembled onto the camshaft?) locate the slot in the cam follower. Someone else will confirm or deny this soon.

Offline Peter Gee

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Re: 59 A7SS Tappet Grubscew confusion
« Reply #2 on: 29.03. 2019 11:55 »
My memory tells me that the central screw, that has a ball beneath it to lock the cam follower alignment piece is shorter than the two outer screws that have a pin on the end to, (stop the followers from dropping out before they are assembled onto the camshaft?) locate the slot in the cam follower. Someone else will confirm or deny this soon.

Thanks Grey..looking at images from parts stores, all their various barrel grub screws, if for the slotted followers or the alignment piece, have a pin on one end. But none give the OA lengths.




Online berger

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Re: 59 A7SS Tappet Grubscew confusion
« Reply #3 on: 29.03. 2019 12:23 »
peter just looked at my A7 jobby and the screw that holds the ball is 14mm long and sits flush with the barrel flange with pin and ball in place , the shorter ones hold the followers. EDIT - you want the one at the right in your picture. DOUBLE EDIT if the one with the thinner end protrudes above the barrel flange with the pin and ball in place it is for the thick flange road rocket so try the other long one with the thicker end, but the short ones go in the sides to stop followers falling out----- I am going to the pub!!

Online JulianS

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Re: 59 A7SS Tappet Grubscew confusion
« Reply #4 on: 29.03. 2019 12:39 »
Look at the ends of the pins, the centre screw, unless new, will have an indentation where it bears on the small ball. If you have indentations on the 2 on the right of your photo then the short one is for thin flange barrel and the long one is for A10 thick flange barrel.


Offline Peter Gee

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Re: 59 A7SS Tappet Grubscew confusion
« Reply #5 on: 29.03. 2019 15:03 »
peter just looked at my A7 jobby and the screw that holds the ball is 14mm long and sits flush with the barrel flange with pin and ball in place , the shorter ones hold the followers. EDIT - you want the one at the right in your picture. DOUBLE EDIT if the one with the thinner end protrudes above the barrel flange with the pin and ball in place it is for the thick flange road rocket so try the other long one with the thicker end, but the short ones go in the sides to stop followers falling out----- I am going to the pub!!

Thanks very much. I suspected  like you say, the longest screw was for a thick-fin barrel

I have tried the 14mm one in the flange centre to lock the pin-and-ball. However it sits proud a few threads of the flange. The short 12.06mm ones seem to do fine in the side.