15-03-2018, 07:36 PM
To be honest Simon I'm hesitant to venture a view as there are so many unknowns here. However if only to give following contributors something to snipe at...
You don't specify how far you have gone with stripping down - for example are the camshaft, oil pump, fuel pump still in place? Or is it simply a crank suspended between 2(?) main bearings?
What type of bearings do you have at each end? Sounds like a roller rear, but several configurations have been tried by various people over the years.
I don't think movement in the rear bearing should be perceptible. If it is you probably need a new rear bearing. But 'perceptible' is slightly open to interpretation...
Are you saying the crankshaft wobbles when spun when it's only supported by the front bearings? (i.e. with the rear main outer removed?) A certain amount of looseness is to be expected in the fronts if they've put in some service. How much? Well a lot of people would tell you to fit new ones regardless once you've stripped to this point, as it's so much work and inconvenience to strip it again later. There are ways to take up a touch of slack, which are covered in the A7 companion.
If we're talking about an original crank you might be well advised to get it checked for straightness and also for cracks. Might consider checking balance too. A competent specialist is the best call for these things, though there are DIY routes.
Sorry, I'm not sure how helpful the above is, and I don't want to teach you to suck eggs, at least we got the thread started!
btw if you don't already have the A7 companion I'd strongly recommend acquiring a copy
You don't specify how far you have gone with stripping down - for example are the camshaft, oil pump, fuel pump still in place? Or is it simply a crank suspended between 2(?) main bearings?
What type of bearings do you have at each end? Sounds like a roller rear, but several configurations have been tried by various people over the years.
I don't think movement in the rear bearing should be perceptible. If it is you probably need a new rear bearing. But 'perceptible' is slightly open to interpretation...
Are you saying the crankshaft wobbles when spun when it's only supported by the front bearings? (i.e. with the rear main outer removed?) A certain amount of looseness is to be expected in the fronts if they've put in some service. How much? Well a lot of people would tell you to fit new ones regardless once you've stripped to this point, as it's so much work and inconvenience to strip it again later. There are ways to take up a touch of slack, which are covered in the A7 companion.
If we're talking about an original crank you might be well advised to get it checked for straightness and also for cracks. Might consider checking balance too. A competent specialist is the best call for these things, though there are DIY routes.
Sorry, I'm not sure how helpful the above is, and I don't want to teach you to suck eggs, at least we got the thread started!
btw if you don't already have the A7 companion I'd strongly recommend acquiring a copy