Quote:
Originally Posted by Bored&Stroked
We all know the feeling! I tend to start "collecting parts" long before I do the rebuilds. The parts that I pay the most attention too are the mainshaft and the cluster shaft - I try to find the best ones I can. If I have to install a used mainshaft, then I make sure there is very little wear on the bearing surface - hopefully none.
I do believe that having a precision fitment on second gear (bushing to main shaft clearance) is one of the important "tricks" to helping 2nd gear stay in gear, but that is a hunch that Charlie NY and I share. Most of the guys on the site share information - we are all trying to rebuild the best transmissions in the best ways possible and nobody can claim to know all the secrets.  |
**Edit: I should have read all of Dale's post. As usual, he's spot on and covers my comments.
I am no expert, but after having many chats with MacVP, I also think the backlash setting of the cluster is also a crucial measurement. Too much and the cluster wants to thrust upward. When you let off the gas, the cluster then drops causing the synchro to move.
This movement, which the synchro is under load, pushes/forces it "pop" out of gear.
When this happens, no fix except a hook on the dash for the stick will keep it in second gear under deacceleration.
Good thing Mac sells shims off various thicknesses to get this measurement spot on. This measurement is a by product of wear to the thrust surfaces fore and aft in the case.
Too much movement also can grenade the clusters since they will makes contact with one another. Reason why many hi-po or OHV swaps cause a blow out of the transmissions.
Finding the best case you can is also an important part of the rebuilding process.