Author |
Message |
   
Nigel Johnson
Prolific User Username: nigel_johnson
Post Number: 165 Registered: 12-2008
| Posted on Monday, 30 October, 2017 - 08:57: |    |
Hi Everyone I have just started to renew the exhaust manifold gaskets on my friends 1988 Silver Spirit. I would like to ask who thought it was a good idea to fit locking tabs to the manifold bolts? I spent all afternoon trying to bend them back. Regards, Nigel. |
   
David Gore
Moderator Username: david_gore
Post Number: 2713 Registered: 4-2003
| Posted on Monday, 30 October, 2017 - 12:44: |    |
Nigel, Quick answer........... Every owner who whined about the inevitable service bill item "check and retorque exhaust manifold bolts". As I understand, blown exhaust gaskets and warped/cracked exhaust manifolds associated with the bolts coming loose over time were common before the lock tabs were added during the early Cloud/Shadow V8 era. |
   
Mark Aldridge
Grand Master Username: mark_aldridge
Post Number: 466 Registered: 10-2008
| Posted on Monday, 30 October, 2017 - 19:34: |    |
The lock tabs are a PITA to remove, and did not prevent the gaskets leaking on Jackie's 1988 Bentley8. I have changed these on my Shadow also. It seems the nearside exhaust manifold and downpipe clamp are more prone to loosening.On the Bentley, we drilled the bolt heads and lockwired them together; looks nice but doubt that it will solve the loosening as I suspect this is partly due to heating and cooling. Mark |
   
Paul Yorke
Grand Master Username: paul_yorke
Post Number: 1931 Registered: 6-2006
| Posted on Monday, 30 October, 2017 - 19:52: |    |
Quicker answer. Not me! Cars with lock tabs are blowing gaskets anyway. I'd prefer to nip them up at service. Price of tabs and extra time negates my annual 'nip up' charge by a long shot. :D It's odd that 99% of time it is only the left hand 2 bolts that loosen on each manifold. Half moon spanner is good for A bank 4 cyl bottom bolt. Forget that "quicker answer" comment I started with! lol. Also manifold faces are rusting away so 50% of the time the manifolds need skimming to ensure the new gaskets have enough surface to last. (Don't forget to add a washer or use shorter bolts). |
   
Nigel Johnson
Prolific User Username: nigel_johnson
Post Number: 166 Registered: 12-2008
| Posted on Tuesday, 31 October, 2017 - 08:41: |    |
I enjoyed your replies gentlemen it was like the old RRBEW website we all used to frequent. As David said the factory thought they had to do something and lock tabs were it.Thats all well and good when you have the engine on its subframe before being fitted, but as Mark pointed out a right PITA for maintenance afterwards. Thanks for the tip about half moon spanners Paul and shorter bolts and washers.It is the near side I'm working on.On my 1980 Spirit I lapped the manifold back on a flat steel plate. That worked the heart muscle a bit I can tell you. Kindest regards, Nigel. |