Iain's 1970 MG BGT

Pictures of the Main Bolts Issue

Click here for the full text of the thread about this problem on the MGB BBS.

The catalogues said that bolts could be used as a direct replacement for studs, but it was found that the un-threaded section of bolts was too long, and as a result the thread was binding.

The replacement bolt and original stud, shown with main bearing 2 cap.

And side by side.

That's about 2 washers of clearance!! Some of the thread does go into the hole, so measurements show that two washers will give the required clearance.

Distance from underside of the bolt head to the block face is 1.636 inches.

With one washer (on the left) the thickness is 1.647 inches. With two washers (right) the total is 1.724 inches. All measurements were taken with the venire gauge you can see in the background.

In the end I had two options. Replace the bolts with the original studs, or use two washers. I went for two washer as I couldn't get hold of the studs quickly.