waypoint
Member
Some project notes for anybody else undertaking a timing chain replacement, with the caveat that this is for informational purposes only and should not be taken as authoritative:
-I soaked the new chains in clean motor oil prior to mounting them, to allow oil to soak into the pins & bushings. Also applied a light coat of engine assembly grease to the sprocket teeth, guide rails, and tensioner sliders as prelube. No dry new parts during initial startup.
-I removed the two threaded studs from the block at the lower side of the timing cover to allow more up/down movement of the cover during installation. They threaded back into the block easily after the cover was in place.
-Triple-check the oil pump drive alignment *before* applying FIPG to the timing cover. The service manual provides a drawing showing the oil pump center gear at about 1 o'clock, with the crank at #1 TDC.
-Do a few dry runs installing the timing cover without sealant and before the oil pump o-ring is installed. Build muscle memory for the process, it's a complex operation getting the oil pump, pickup o-ring, FIPG bead, and block dowels aligned in one smooth motion.
-I also left the crank seal out during timing cover installation, to allow more up/down movement of the cover. The new seal drove in easily after the cover was bolted up...seal drives in until flush with the timing cover surface, no more and no less. Leaving the seal out also allows for visual inspection of the oil pump center gear and drive, and wiggling the oil pump center gear to get it aligned during assembly if needed.
-The timing cover was most easily installed by placing the bottom of the cover onto the oil pan surface first, at a slight angle with the top of the cover away from the engine, and then tilting the cover onto the engine while gently pushing the lower cover onto the oil pump drive and the 2 block dowel pins. Again, do a few dry runs before installing the o-rings and applying FIPG sealant.
-Permatex "aviation" sealant did a nice job of holding the oil pump o-ring in place during timing cover installation. Light coat in the o-ring groove, light coat on one side of the o-ring, let both tack up for ~5 minutes, then press the o-ring into place. I used a large plastic carpenter's clamp and a plastic spatula-type scraper to apply light & uniform pressure to the o-ring while the sealant cured.
-Light coat of motor oil on the o-ring and oil pan surface it seals allows the o-ring to slide across smoothly during timing cover installation.
-The shop manual calls for removing the oil pan for this, I didn't. After the cover was in place and a few front bolts loosely threaded, I torqued the 4 bolts attaching the oil pan front to the timing cover bottom first. Goal was to compress the oil pump o-ring and ensure sealing. First pass at 7 N*m, then second pass at 14 N*m then final pass at 23 N*m. Then I torqued the front bolts in same 3 steps, starting at the center and doing figure-8 sequence outward. It's a lot of work doing all the bolts 3x gradually, but the thing's aluminum and avoiding warpage is worth the effort.
-FIPG sealant: The shop manual calls for 2 different FIPGs: one for the water pump passages, and a different one for the cover's main sealing surfaces. I used the Toyota specified expensive FIPG for the water pump surfaces, not sure if this was absolutely necessary but it wasn't worth risking re-doing the project to save $40. The #103 FIPG specified for the cover's main sealing surface was only $15 at the dealership, but the $40 water pump passage FIPG was special order.
-Prior to initial startup of the engine, I removed the fuel pump fuse and used the starter to build oil pressure until the oil pressure warning light went out. Three short cranks of a few seconds each was all it took, and probably helped pressurize the new #2 chain tensioners which don't have ratchets like the #1 chain tensioner. When I reinstalled the fuel pump fuse and started the engine, it was quiet.
-I soaked the new chains in clean motor oil prior to mounting them, to allow oil to soak into the pins & bushings. Also applied a light coat of engine assembly grease to the sprocket teeth, guide rails, and tensioner sliders as prelube. No dry new parts during initial startup.
-I removed the two threaded studs from the block at the lower side of the timing cover to allow more up/down movement of the cover during installation. They threaded back into the block easily after the cover was in place.
-Triple-check the oil pump drive alignment *before* applying FIPG to the timing cover. The service manual provides a drawing showing the oil pump center gear at about 1 o'clock, with the crank at #1 TDC.
-Do a few dry runs installing the timing cover without sealant and before the oil pump o-ring is installed. Build muscle memory for the process, it's a complex operation getting the oil pump, pickup o-ring, FIPG bead, and block dowels aligned in one smooth motion.
-I also left the crank seal out during timing cover installation, to allow more up/down movement of the cover. The new seal drove in easily after the cover was bolted up...seal drives in until flush with the timing cover surface, no more and no less. Leaving the seal out also allows for visual inspection of the oil pump center gear and drive, and wiggling the oil pump center gear to get it aligned during assembly if needed.
-The timing cover was most easily installed by placing the bottom of the cover onto the oil pan surface first, at a slight angle with the top of the cover away from the engine, and then tilting the cover onto the engine while gently pushing the lower cover onto the oil pump drive and the 2 block dowel pins. Again, do a few dry runs before installing the o-rings and applying FIPG sealant.
-Permatex "aviation" sealant did a nice job of holding the oil pump o-ring in place during timing cover installation. Light coat in the o-ring groove, light coat on one side of the o-ring, let both tack up for ~5 minutes, then press the o-ring into place. I used a large plastic carpenter's clamp and a plastic spatula-type scraper to apply light & uniform pressure to the o-ring while the sealant cured.
-Light coat of motor oil on the o-ring and oil pan surface it seals allows the o-ring to slide across smoothly during timing cover installation.
-The shop manual calls for removing the oil pan for this, I didn't. After the cover was in place and a few front bolts loosely threaded, I torqued the 4 bolts attaching the oil pan front to the timing cover bottom first. Goal was to compress the oil pump o-ring and ensure sealing. First pass at 7 N*m, then second pass at 14 N*m then final pass at 23 N*m. Then I torqued the front bolts in same 3 steps, starting at the center and doing figure-8 sequence outward. It's a lot of work doing all the bolts 3x gradually, but the thing's aluminum and avoiding warpage is worth the effort.
-FIPG sealant: The shop manual calls for 2 different FIPGs: one for the water pump passages, and a different one for the cover's main sealing surfaces. I used the Toyota specified expensive FIPG for the water pump surfaces, not sure if this was absolutely necessary but it wasn't worth risking re-doing the project to save $40. The #103 FIPG specified for the cover's main sealing surface was only $15 at the dealership, but the $40 water pump passage FIPG was special order.
-Prior to initial startup of the engine, I removed the fuel pump fuse and used the starter to build oil pressure until the oil pressure warning light went out. Three short cranks of a few seconds each was all it took, and probably helped pressurize the new #2 chain tensioners which don't have ratchets like the #1 chain tensioner. When I reinstalled the fuel pump fuse and started the engine, it was quiet.
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