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1275 A Series Engine Back Plate Clutch Cover Flywheel bolts

Posted: Fri Sep 05, 2014 8:46 pm
by jonclancy
Hi Folks,

Seeing as this information is not readily available on the net in one place, I'll publish it here (so the next person won't have to dismantle a spare engine to check!).

Backplate (not including gearbox housing bolts)

5/16" x 7/8" UNF (7 no) with spring washer - torque around 20 lbf ft

Clutch cover

5/16" x 3/4" UNF (6 no) with spring washer - torque 20 lbf ft

Flywheel

3/8" x 7/8" (6 no) with single compound lock washer - torque 40 lbf ft

Sump bolts

1/4" x 1/2" (14 no) with spring and oval load-spreading flat washers - torque 6 lbf ft

Oil Pick Up pipe bracket bolts

1/4" x 3/8" (2 no) with star washer. Torque around 8 lbf ft

If anyone can list the gearbox mounting bolts, that'll be most helpful!!

Cheers

Jon

Text for the googlebot:

1275 A Series back plate clutch cover flywheel bolts bolt size UNF thread length engine spring washer

Re: 1275 A Series Engine Back Plate Clutch Cover Flywheel bo

Posted: Tue Sep 23, 2014 1:32 pm
by jonclancy
For info:

The depth of the bellhousing-to-backplate threads in the block are 26mm (including the backplate itself which is around 8.2mm).

The width of the flange on the bellhousing is 12mm. So a total of 38mm (minus the spring washer). That's pretty much 1 1/2".

So, it looks like 1 1/4" 5/16 UNF is what I need (bottom bolts run through and are nyloc-nutted). Torque assume standard 20 lbf ft.

If anyone can be so kind as to whizz one out of their car to check, I'd be most grateful!!

Cheers

Jon

ETA: On second thoughts, 1 1/2" might be a better choice. The spring washer will stop any bottoming out, and the full depth of the block thread will be used.

Re: 1275 A Series Engine Back Plate Clutch Cover Flywheel bo

Posted: Wed Sep 24, 2014 3:46 pm
by Westfield 129
Just make sure that you use Grade 8 or better (Aircraft AN) fasteners.

Re: 1275 A Series Engine Back Plate Clutch Cover Flywheel bo

Posted: Wed Sep 24, 2014 5:35 pm
by erictharg
What's wrong with the bolts you took out Jon?

Re: 1275 A Series Engine Back Plate Clutch Cover Flywheel bo

Posted: Wed Sep 24, 2014 7:14 pm
by jonclancy
A troop of gorillas with a box of hand grenades came through my garage. And my house. :D

Not finding the original bolts isn't too much of a drag, though. The backplate, clutch cover etc look great with new fasteners, even though not visible when fitted.

Hopefully help with the sale as soon as I can get it finished and on the market. :shock:

Re: 1275 A Series Engine Back Plate Clutch Cover Flywheel bo

Posted: Sat Oct 04, 2014 3:02 pm
by jonclancy
Update:

Four of the bellhousing bolts have lost around 1/8" to ensure they do not bottom out in the block. Rest as per above.

Water pump bolts

5/16" UNF x 1 7/8", 2 no, plus plain and spring washers (17 lbf ft)

5/16" UNF x 1 1/4", 2 no, plus plain and spring washers (17 lbf ft)

W11 water pump pulley bolts

1/4" UNF x 3/4", 4 no, plus plain and spring washers (8 lbf ft)

In other news, sump is on. Waterpump and head about to go on. Might get it done before Xmas!