| Also known as | MJ 1 1/8 |
| Listed in parts books | Not catalogued by year yet |
MAIN BEARING, BALL (CN)
Ball main bearing for the crankshaft, catalog number 70-1591A, also listed as MJ 1 1/8.
70-1591A is a ball main bearing, listed in the catalog under the drive-side crank grouping. This is one of the bearings that carries the crankshaft in the crankcase, and it's a part you replace when you're rebuilding the bottom end rather than something you check on a running engine.
Read more
Our records on this one are brief - we don't have detailed fitment notes or figure references beyond the bearing listing itself. The alternate number MJ 1 1/8 is worth knowing if you're cross-checking against a bearing supplier's own numbering rather than the Triumph parts book.
Give us a call with your engine details before you order so we can confirm it's the right bearing for your crank.
Sorry if we got something wrong here. If you think this information isn't correct, .