I am rebuilding both the transmission and transfer in my 97. Things are going relatively well, but there are a few main case threads giving me some trouble, specifically the 10-mm and 12-mm bolts both at 1.25-mm pitch. I don’t understand why Toyota went with that fine 1.25-mm pitch anyway, but the aluminum in contact with steel bolts over the 25+ years has corroded. I was able to get the original bolts out, which I guess I should be thankful about, but now what.
At this point, I have; Soaked the holes with various cleaners; Brushed the threads with various brushes; Attempted to use thread chasers, which only thread in about 1/4”; And finally, verified that new bolts will not even start to thread in.
I have a set of taps arriving soon and I think my last option is to clean those threads out with taps. I know that is not ideal, and I am sure others have faced this same problem, so I wanted to ask if there is any other option.
At this point, I have; Soaked the holes with various cleaners; Brushed the threads with various brushes; Attempted to use thread chasers, which only thread in about 1/4”; And finally, verified that new bolts will not even start to thread in.
I have a set of taps arriving soon and I think my last option is to clean those threads out with taps. I know that is not ideal, and I am sure others have faced this same problem, so I wanted to ask if there is any other option.