Perkins Locking Tab Kit, how important is it?

[jfharper]

Rebuilding my ad3.152 and my locking tabs for the crank caps, flywheel, idler gear and cam are shot. Anyone leave these out and been ok with the omission? Or have you seen these torqued bolts back off. Other engines don't use locking tabs like these, like a 289 ford small block I'm rebuilding too. I'm wondering why these are needed for a motor that doesn't rev past 2500 rpm and hp at 40. These tab kits are hard to find in the USA and shipping from the UK makes the price much higher.

 

[ptfarmer]

Some had the locking tabs, some didn't, never heard of the ones without the locking tabs coming loose. I do use Loctite the flywheel bolts, as long as they are torqued correctly never had any back out. I also go over, and check the torque on everything three times to make sure none were missed.

 

[FBH44]

Really don't know, BUT Perkins AD3.152 has a reputation for one of the best of the best. I bet the Perkins design engineers knew what they were doing, and I wouldn't skimp on the rebuild. Just me.

 

[DavidP, South Wales]

Hello,
It does pose the question as to why the tabwashers were originally fitted. I have never
seen any tabbed or not coming loose. As far as tightening is concerned the target figure
for tabbed bolts is 110lb.ft. The figure now for untabbed bolts is 115lb.ft. MF recommended
the extra 5lb.ft of torque to compensate for the removal of the tabs. A thorough cleaning
and a spot of Loctite should be satisfactory on the lesser bolts. If you still want to use
tabs get in touch with PV Dobson in Kendal in England. I don't know if any of the non-
genuine suppliers offer kits but as far as I know the main tabs are no longer available
from MF. They will be able to help you.
DavidP, South Wales

 

[jfharper]

Thank you. My manual specifies 90-95 ft lbs for the main caps...are those figures you provided revised? If so, do you know where I can get a copy of this updated list? I'm also curios about revised head bolt torque.