The 3857184 bolt from Volvo Penta is still inexplicably on back order with "vendor issues" After much discussion with Volvo Penta the bolt is described .375 - 16 4.125" Grade 8. Although Volvo Penta provided another document that said it was 4.4” (or 4 13/32”) or just a hair over 4 3/8”.
However, part number 3857184 is on back ordered with Volvo Penta saying they cannot predict when it will become available. We can wait until they come in and we will ship them off to you or if you would like, I can provide you with an aftermarket version.
The aftermarket ones are exactly the same with the same rating. They are available in 4” (actual measurement is about 3 29/32”) or 4.5” (actual measurement 4 27/64”). Otherwise all measurements (head, thread, thread length) are the same and the grade rating is the same as well.
One reason that Volvo Penta is having issues with suppling the 3857184 may be this length issue. When we had them in here some measured 4.096", some measured, some measured 4.125”, some measured 4.25" (which is what the drawing says is should be), and some measured 4.5" and a couple were a strange inbetween length.
If you want to go with the aftermarket ones, you should measure your existing bolt (measure the shank only – bottom of the head to the bottom of the bolt) and let us know.
If you don’t have the bolt to measure, I think I would go with the 4” version as a default.Tags: 3857184, Flange Screw, Volvo Penta