My experience from a few years ago:
Original post: 4106 starter swap; not all that bad
Reading about 4106 starter swaps is like listening to women swap birthing horror stories. Each one has to one up the other and scare the devil out of those who havenít done it.
This is how I did mine:
1. I securely chocked the wheels and blocked the bus up.
2. I unhooked the batteries.
3. Through the top access hole from the inside I removed the back top mounting nut. (The one closest to the engine block)
4. Crawling under the bus I sat up in the hole that is located ahead of the engine bulkhead.
5. Through the bulkhead cutout I removed the four bolts holding the engine breather on and placed the breather aside. Be sure to stuff a rag in the hole where the breather was on the side of the block.
6. I removed all of the wires to the solenoid and the starter.
7. I removed the bottom nut using a 15/16 boxed wrench cut down to an 8Ē length. (You could use a 15/16 socket if you have a wobble adapter)
8. I then removed the last top nut and slid the starter out onto my lap. (Be careful it is heavy, but not unmanageable)
9. Make sure the new starter is a 12v left hand starter. Check the starter mount to ensure it is the correct one. There are at least three types and the one you will need is the most uncommon. If you have your old one rebuilt it wonít be an issue, but I kept my old starter to use as a spare.
10. If you have an automatic tranny you will need a gasket for the starter mount to bell-housing face.
11. Installation is just reversing the above procedure.
Even though the rebuilt starterís mount looked identical to the one removed, there was enough variation in the casting that I couldnít get my wrench on the bottom mounting nut. I used a socket and managed to get enough bite to tighten it. If I had a wobble adapter I think it wouldnít be an issue. You could also grind the mount in that area (itís plenty thick) to give your wrench clearance room, if you remember to do it before you mount it.
My original starter solenoid was bad and that is the reason for the swap. I wasnít charged a core charge, so I am keeping the starter motor as a spare. I found that even some of the big starter rebuilders donít stock enough of the parts to rebuild a LH starter in one day, so having the spare will be nice. The solenoids are very common and inexpensive, so I donít feel a need to keep one of those on hand.
Conclusion: Itís not as bad as people make it out to be. Unless you are physically not strong enough, this is a DIY job.
I hope this might help the owner of a future 4106 starter swap..