distributor belt replacement - thread collection
05-05-2005, 12:28 AM
#1
Rennlist Member
Thread Starter
distributor belt replacement - thread collection
Here is a collection of some useful threads/references on distributor belt replacement, followed by some commentary:
Brian Smith's writeup with pictures, on p-car.com in the DIY section (technique includes removing the secondary shaft) -
http://p-car.com/diy/dualbelt/
Alan911SC's thread explaining the technique of drifting one of the alignment pins instead of removing the secondary shaft (titled "Distributor Belt Replacement Tips (long)") -
https://rennlist.com/forums/964-forum/108648-distributor-belt-replacement-tips-long.html
Duncan's thread with lots of nice photos (dunasso, titled "DIST. BELT REPLACEMENT SEQUENCE PHOTOS") -
https://rennlist.com/forums/showthre...ht=distributor
Discussion of washer sequence & orientation along the primary shaft, plus a listing of part numbers - (Dave R.'s thread, titled "Uh-oh! I replaced the distributor belt, but..."
https://rennlist.com/forums/964-forum/201361-uh-oh-i-replaced-the-distributor-belt-but.html
Discussion of solid pin vs. roll pin, plus several hints re aligning the distributor rotors and knocking out/drifting one of the locating pins rather than removing the secondary shaft (Dave R.'s thread, titled "Roll pin for distributor shaft gear") -
https://rennlist.com/forums/showthre...ht=distributor
Last but not least, Adrian Streather's fine book.
Repair sequence in a blow-by-blow nutshell:
1. remove blower, blower tube, and belt tension sensor to provide access
2. disconnect the Hall sensor on the distributor from the engine wiring harness, and detach the vent tube from the distributor
3. remove distributor caps (OK to leave the plug wires attached)
4. mark the position of the primary rotor (ink, white-out, carve nick in housing with a blade, ...)
5. unbolt and remove the distributor (some folks have needed to apply a pry bar) - and don't allow the engine crankshaft to move until the distributor is properly re-installed
6. mark the new position of the primary rotor (it will have moved slightly as the helical gear moves out of the crankcase)
7. remove the distributor rotors
8. remove the black plastic caps under the rotors
9. gently pull out the black Hall sensor connector
10. remove the translucent plug insert from the black Hall sensor connector, e.g. with needlenose pliers
11. unscrew the three philips head screws inside the main distributor that fasten the Hall sensor mounting plate to the distributor housing
12. push the translucent plug insert & attached Hall sensor wires back throught the hole into the distributor so they won't catch when the primary shaft comes out
13. drill the pin retaining the helical drive gear (trivia note, the end of the pin with three radial marks at the outer circumference was the larger end before the pin was originally staked in place)
14. remove the helical drive gear (if there are burrs you may need to apply a gear puller) and the spacer washers between the helical drive gear and the first sealed bearing
15. pull the primary shaft assembly up and out of the distributor
16. remove the primary belt gear/cog and the washers underneath it (between the primary belt gear/cog and the second sealed bearing)
17. remove the five allen-head bolts holding the upper and lower distributor case halves together
18. identify the locating pin on the outer edge of the housing near the secondary distributor
19. look inside the secondary distributor and rotate the secondary shaft so that when the locating pin comes up into the housing, it won't bump anything
20. tap the bottom end of the locating pin to drift it up into the upper housing far enough to clear the lower housing
21. separate the case halves (the secondary shaft assembly will continue to link them loosely together)
22. rotate the upper case half with respect to the lower case half, remove the distributor belt
23. install the new belt, don't crimp it
24. reinstall the five allen-head bolts
25. drift the locating pin back into position (half in the upper housing, half in the lower housing, loosen the five allen-head bolts if you need to, then re-tighten when the locating pin is back in position)
26. place the washers and the primary belt cog on the primary upper bearing (order - cog, curved washer, flat washer, bearing OR cog, flat washer, curved washer with convex side facing bearing!, bearing)
27. adjust belt cog so that the distributor rotors will be properly aligned relative to each other (there are two small nubs or bumps on the distributor housing, one for each distributor just to the right of one of the bolt holes that holds the distributor caps in place - when the rotors point simultaneously to the nubs, they are properly aligned with each other - in dunasso's thread in the first picture, the nubs are visible, they are several millimeters wide)
28. insert the primary shaft assembly
29. place the spacer washers and the helical drive gear on the end of the primary shaft
30. squeeze the primary shaft and the helical drive gear together (e.g. with a 12" clamp or vise) until the hole in the primary shaft and the helical drive gear line up
31. insert replacement retaining pin (and then remove the clamp)
32. mushroom or stake the retaining pin (e.g. use a vise to squeeze the ends of the pin together, I used the flat hexagonal shaft faces of two drift punches between the pin ends and the vise jaws)
33. feed the translucent Hall sensor connector back through the aperture of the housing
34. rotate the Hall sensor mounting plate into position and re-fasten with the three screws (e.g. hold screwdriver with tip straight up, place screw on tip, turn distributor upside down and feed screws straight up to start)
35. insert the translucent Hall connector into the black connector and snap the black connector back into place
36. install black plastic caps in the distributors
37. install the distributor rotors
38. replace the distributor O-ring
39. rotate the rotors to the position they were in just after you removed the distributor from the engine block
40. insert the distributor into the block (you may need to help it into place because of the new O-ring, e.g. by tapping with a mallet and a shaft such as a large socket extension)
41. verify that the rotors are in the position you marked just before you removed the distributor
42. bolt the distributor to the block
43. re-install the distributor caps
44. re-install the belt tension sensor
45. re-install the blower and blower tube and corresponding connections (power plug to the blower, resistor/sensor to the tube, tube vent to the tail lights and tube vent to the distibutor)
46. reconnect the Hall sensor to the engine wiring harness
Review, doublecheck, etc... then fire it up.
Any comments or other good threads?
Brian Smith's writeup with pictures, on p-car.com in the DIY section (technique includes removing the secondary shaft) -
http://p-car.com/diy/dualbelt/
Alan911SC's thread explaining the technique of drifting one of the alignment pins instead of removing the secondary shaft (titled "Distributor Belt Replacement Tips (long)") -
https://rennlist.com/forums/964-forum/108648-distributor-belt-replacement-tips-long.html
Duncan's thread with lots of nice photos (dunasso, titled "DIST. BELT REPLACEMENT SEQUENCE PHOTOS") -
https://rennlist.com/forums/showthre...ht=distributor
Discussion of washer sequence & orientation along the primary shaft, plus a listing of part numbers - (Dave R.'s thread, titled "Uh-oh! I replaced the distributor belt, but..."
https://rennlist.com/forums/964-forum/201361-uh-oh-i-replaced-the-distributor-belt-but.html
Discussion of solid pin vs. roll pin, plus several hints re aligning the distributor rotors and knocking out/drifting one of the locating pins rather than removing the secondary shaft (Dave R.'s thread, titled "Roll pin for distributor shaft gear") -
https://rennlist.com/forums/showthre...ht=distributor
Last but not least, Adrian Streather's fine book.
Repair sequence in a blow-by-blow nutshell:
1. remove blower, blower tube, and belt tension sensor to provide access
2. disconnect the Hall sensor on the distributor from the engine wiring harness, and detach the vent tube from the distributor
3. remove distributor caps (OK to leave the plug wires attached)
4. mark the position of the primary rotor (ink, white-out, carve nick in housing with a blade, ...)
5. unbolt and remove the distributor (some folks have needed to apply a pry bar) - and don't allow the engine crankshaft to move until the distributor is properly re-installed
6. mark the new position of the primary rotor (it will have moved slightly as the helical gear moves out of the crankcase)
7. remove the distributor rotors
8. remove the black plastic caps under the rotors
9. gently pull out the black Hall sensor connector
10. remove the translucent plug insert from the black Hall sensor connector, e.g. with needlenose pliers
11. unscrew the three philips head screws inside the main distributor that fasten the Hall sensor mounting plate to the distributor housing
12. push the translucent plug insert & attached Hall sensor wires back throught the hole into the distributor so they won't catch when the primary shaft comes out
13. drill the pin retaining the helical drive gear (trivia note, the end of the pin with three radial marks at the outer circumference was the larger end before the pin was originally staked in place)
14. remove the helical drive gear (if there are burrs you may need to apply a gear puller) and the spacer washers between the helical drive gear and the first sealed bearing
15. pull the primary shaft assembly up and out of the distributor
16. remove the primary belt gear/cog and the washers underneath it (between the primary belt gear/cog and the second sealed bearing)
17. remove the five allen-head bolts holding the upper and lower distributor case halves together
18. identify the locating pin on the outer edge of the housing near the secondary distributor
19. look inside the secondary distributor and rotate the secondary shaft so that when the locating pin comes up into the housing, it won't bump anything
20. tap the bottom end of the locating pin to drift it up into the upper housing far enough to clear the lower housing
21. separate the case halves (the secondary shaft assembly will continue to link them loosely together)
22. rotate the upper case half with respect to the lower case half, remove the distributor belt
23. install the new belt, don't crimp it
24. reinstall the five allen-head bolts
25. drift the locating pin back into position (half in the upper housing, half in the lower housing, loosen the five allen-head bolts if you need to, then re-tighten when the locating pin is back in position)
26. place the washers and the primary belt cog on the primary upper bearing (order - cog, curved washer, flat washer, bearing OR cog, flat washer, curved washer with convex side facing bearing!, bearing)
27. adjust belt cog so that the distributor rotors will be properly aligned relative to each other (there are two small nubs or bumps on the distributor housing, one for each distributor just to the right of one of the bolt holes that holds the distributor caps in place - when the rotors point simultaneously to the nubs, they are properly aligned with each other - in dunasso's thread in the first picture, the nubs are visible, they are several millimeters wide)
28. insert the primary shaft assembly
29. place the spacer washers and the helical drive gear on the end of the primary shaft
30. squeeze the primary shaft and the helical drive gear together (e.g. with a 12" clamp or vise) until the hole in the primary shaft and the helical drive gear line up
31. insert replacement retaining pin (and then remove the clamp)
32. mushroom or stake the retaining pin (e.g. use a vise to squeeze the ends of the pin together, I used the flat hexagonal shaft faces of two drift punches between the pin ends and the vise jaws)
33. feed the translucent Hall sensor connector back through the aperture of the housing
34. rotate the Hall sensor mounting plate into position and re-fasten with the three screws (e.g. hold screwdriver with tip straight up, place screw on tip, turn distributor upside down and feed screws straight up to start)
35. insert the translucent Hall connector into the black connector and snap the black connector back into place
36. install black plastic caps in the distributors
37. install the distributor rotors
38. replace the distributor O-ring
39. rotate the rotors to the position they were in just after you removed the distributor from the engine block
40. insert the distributor into the block (you may need to help it into place because of the new O-ring, e.g. by tapping with a mallet and a shaft such as a large socket extension)
41. verify that the rotors are in the position you marked just before you removed the distributor
42. bolt the distributor to the block
43. re-install the distributor caps
44. re-install the belt tension sensor
45. re-install the blower and blower tube and corresponding connections (power plug to the blower, resistor/sensor to the tube, tube vent to the tail lights and tube vent to the distibutor)
46. reconnect the Hall sensor to the engine wiring harness
Review, doublecheck, etc... then fire it up.
Any comments or other good threads?
05-05-2005, 09:00 AM
#2
Rennlist Member
Man I wish I'd seen that JasonAndreas post about not having to remove the shaft to get the belt out. That was a real PITA. To anyone who's planning on doing this in the future, use Jason's tips. Getting that stupid cap off and all those ring clips, washers, compressing the shaft to get it all back on.....nightmare.
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