Dr.Ben
Elite Veteran
Location: Richmond, VA, USA
| First you need to heat the existing pinion to pull off the bearing block. If the pinion has been spinning in the lower bearing, that bearing should be replaced anyway. The ratio kits that MA has include the lower bearing which is also of higher grade than stock.
The pinions are installed with high strength loctite, so you'll need to heat the pinion up to the 200-350 degree range to break the loctite bond. The pinion is left hand threaded, so twist the correct way. The pinions are not screwed in that tightly. When the loctite lets go, they come out pretty easily.
Then new pinion should be installed with loctite high strength green (or red in a pinch). Thoroughly clean all parts. Primer is a good idea, too.
If you find you need to replace the other bearings in the block, take note of the following: the two lower bearings must be pressed/punched out from the top to the bottom. There is a step in the block that precludes removal out the top. The top flanged bearing comes out the top, of course. These bearings are installed with green loctite and primer. Expect to use heat to get them out, and expect that they likely won't survive the removal process; i.e., pull the bearings out and have new ones ready to go in in their place. If you completely disassemble the block, I would suggest you put the two lower bearings in first and loctite them to the pinion and clutch shaft, then add the upper bearing and loctite it to the shaft, as well. The is the only way you can get loctite on all the bearings to assure the start shaft won't spin in the bearing inner races. Many builders don't concern themselves with this point. I do it with all of my models, and I have had to replace precious few start shafts. If an assembled bearing block is just slid on the shaft, the lower bearing drags the loctite off, starving the upper bearing of the application. I suppose wicking green could be used on the upper most bearing, but loctite specs (I spoke to the company tech support) really recommend 603 or 640 for bearing to shaft bonding, and those two products are not wicking varieties. I'd sure use the wicking over nothing, though.
Hope this helps.
Ben |
