Toyota Corolla AE101 GTZ Levin Buildup

Crank angle sensor seal replacement

A common problem with the 4AGE series motors is the seals for the distributor/CAS (depending if you've got coilpack ignition or not) wear and leak oil all over the side of the engine.
After flushing the old oil and using a thin synthetic, my engine started leaking oil at a rather substantial rate.
This is how I fixed it...

Parts you will need to complete this mod:

• Plain encased seal, 10x20x7TC. Part no: TC12379VI from CBC bearings. This is the high temp 'Viton' version, it's a reddish colour.
• Rubber O-ring. Part no: BS217 from CBC Bearings, or part no: 9009914091 from Toyota if you want to pay double for the same part....

Tools you will need:

• Screwdrivers
• Hydraulic Press
• Scribe
• Drift
• Socket set
• Feeler Gauges
• Hammer

Step 01

First thing is to find top dead centre. I didn't go to extreme lengths to do this, I simply took the cover off the CAS and turned the crank until the internals were lined up as in the picture.

You can see where the bump on the rotating section is lined up with the bottom sensor bit. As long as the CAS is reinstalled exactly like this, and the engine doesn't rotate at all, it'll be fine.
Using the scribe, mark the position of the CAS in regards to the engine block. You'll need to reinstall it in the same position to ensure your timing is correct.

Step 02

Unbolt and unplug the CAS and remove from the engine. You will end up with something like the picture below.

Wipe it all down with a clean rag, and put a clean rag into the hole in the engine to stop dirt and junk getting in.
You will notice that the oil has stained the metal it has been in contact with. We will use this to correctly relocate the gear once we have replaced the seals.
Measure the distance from the rotor to the sensors and note down. You'll have to reset them once you've replaced the seal. Remove all the internal electronics and carefully place aside.

Step 03

Using the scribe, mark the position of the gear on the shaft, so the rotation will be spot on.
Using the press, press the gear off the shaft. You will notice the gear has an indent that has made the same shape on the shaft. You have to line this up so your timing isn't out when you reinstall it all.

You can see the old seal here, using a drift, carefully knock it out of the housing. Don't scratch the inside, or you will end up with a permanent oil leak...

Give it all a good clean, and carefully tap the new seal in, be careful to reinstall the new seal with the same orientation as the old one.
Remove the old O-ring and carefully roll the new one into position.

Here the old oil seal has been removed and the housing cleaned, ready for the new seal.

Step 04

Here is the shaft, you can see the clean section on the far right from the gear, with the clean section from the seal in the middle.

Give it a good clean and slide back into place. Line up the gear and press back onto the shaft.
Reinstall the electronics and using the feeler guage, make sure the sensors are the correct distance from the rotor and all equal.
Now you're ready to reinstall it to the engine.

Step 05

Wipe a thin smear of oil inside the hole where the CAS inserts. This will help it slide in without binding.
Make sure the rotor is aligned as per the top photo, the same position it was when you pulled it out, and slide into place.
Tighten everything up and reconnect the electronics. Make sure the body is lined up to the marks you made on the engine block.
Start the engine and check timing, adjust if nessecary and reassemble everything if all is well.