4AGE 100kW Dizzy Oil Leak Guide

[Talasas]

AE93 Distributor Oil Seal Replacement Guide
by Talasas

Does your 4AGE powered car leave nasty oil stains on driveways? Is your air conditioner compressor (and just about everything under the dizzy) covered in oil? Has some crazy mechanic/sparky quoted you $100 to do the job? Has Toyota told you the only fix is to replace the dizzy with a new $800 (!) one?

Well here's your answer! With a little common sense and some elbow grease (these can't be purchased so don't go to Supercheap Auto looking for these items) you can fix it yourself!

Okay, to the serious part. Before you go attempting this there are some things you will need.

- I'm assuming you have half-decent mechanic skills and know how to use tools and have proper equipment. Generally this job can be done without any special tools however one thing you WILL need is a press (or a vice might do the trick but you will have to be creative).

Parts List:


1 - “Outer” O-ring. Toyota part no. 9009914091 – Costs around $6
2 - “Inner” U-seal. Specs: 20mm OD, 10mm ID, and anywhere from 5 to 7 mm Wide. This has no Toyota part no. and Toyota do not sell it whatsoever. You will have to source this part yourself by whatever means you can. It’s not overly hard to find however as it is a standard seal size so call around and see where you can get it from. A good place to start is someone like Motor Traders. These cost anywhere between 50 cents to $2.50. Don’t bother starting the job until you have this part.

STEP 1: Diagnose the problem.

Even though 99% of the time the first oil leak to happen on a 4AGE is the dizzy to leak, it may be something else. I found out after fixing this on my car that oil was also leaking from the crankshaft seal. It’s also common to have oil leaking from the cam covers so check that this isn’t the cause beforehand! (Signs are oil in the spark plug valley or baked on the side of the head).

So two good telltale signs for a dizzy leak are:

1) Feel underneath the dizzy (near the heat shield), there is a small hole that has been put there to stop leaking oil from filling your dizzy cap. This will be wet with oil.

2) If your car has Air Con and/or Power Steering, look at the AC compressor and/or Power Steering pump underneath the dizzy, the top of both too should be covered in oil. (See picture below).

Sometimes it is handy to degrease and wash your engine beforehand and then run it for a little while to get some fresh oil leaks. Watch out for hot engine oil!

PIC 1: The oily dizzy cap and heat shield.



PIC 2: The oily power steering pump



STEP 2: Remove the dizzy cap.

There are two retaining screws holding the dizzy cap, remove these and lift off the cap. There may or may not be a large O-ring between the cap and the dizzy housing. This is there to help stop moisture getting into the cap but it’s not critical to have one. If there was one there you can just reuse that one if it’s not totally trashed.

Check the inside of the cap, if the leak is pretty bad there may be oil near the electrodes, this can cause some arcing to occur (yes it’s true engine oil doesn’t conduct electricity very well but dirty engine oil has impurities which do make it conduct better, especially at the voltages that pass through the ignition system of a car).

PIC 3: Oily dizzy cap inside



STEP 3: Set piston 1 to TDC and mark reference points

THIS STEP IS IMPORTANT. Set the engine to Top Dead Centre by rotating the crankshaft pulley clockwise with a spanner until the rotor arm of the dizzy is pointing towards the electrode which corresponds to the No. 1 cylinder. TDC is not critical but I wouldn’t leave it out in case something goes wrong and you’re stuck having to set the timing all over again (which is a massive pain). Once you’ve got TDC set you can pull off the rotor arm and plastic cover which will expose the electronics.


To be able to reassemble everything you’ll need two main sets of reference points.

1) DIZZY WITH RESPECT TO HEAD
Mark the distributor where it meets the head (mark both the dizzy and the head) in a couple of places. This is to help you put it back exactly where it was once you are done. Again if you forget this you will have to set the timing all over again. I chose to mark it on the top and on either side where the dizzy retaining bolts are (the ones you undo to set the timing). This way you’ll know if it’s crooked.

2) SHAFT WITH RESPECT TO DIZZY
Repeat this for the inside, except this time you will be marking the shaft’s position with respect to the dizzy housing. This is the only way to ensure that the gear on the shaft goes back onto the correct tooth otherwise your timing will be way off.

PIC 4: Marking reference points



It’s also a good idea to take lots of photos if you have a digital camera. This way you can double check in case you forgot something.

In the pic below you can see that the “lobe” or “point” of the cam embossed with the letter “E” points to edge of the part which looks like a magnet sandwiched between two metal pieces. This is again a good reference point. Don’t be afraid to draw diagrams to help you remember better. Once you’ve got enough reference marks (triple check everything) you can remove the dizzy retaining bolts.

PIC 5: Shaft reference points



STEP 4: Remove heat shield

This is a pretty straightforward step. There are two 8mm bolts holding the heat shield on. Spin the dizzy around so you can get to it easier. It is possible to remove this before you undo the dizzy but it’s just a lot easier this way (since you’re already gonna remove the dizzy).

PIC 6: Removing the dizzy heat shield



STEP 5: Remove the dizzy from the head

Unplug the wire that runs into the side of the dizzy at the connector not far down. Gently pull the dizzy out until it’s free from the head. It should slide out fairly easily, be careful not to drop it or hit/grind the gear on the head on the way out. You should now have in your hand what you see in the pic below:

PIC 7: The dizzy



And if you’re diagnostics were correct, the hole for the shaft in the side of the head will look like this:

PIC 8: Eeeew, nasty oil leak



STEP 6: Dismantle inner dizzy: Remove front support plate

Clean the oil from all parts of the dizzy with a rag so you have a nice clean part to work with. Remove the two retaining screws from the front support plate and you can now fold back the plate. You don’t have to remove any wires so just leave them as they are. You should now see what looks like a trigger gear. Each time a tip of this gear goes near the electrode it produces a signal.

PIC 9: Removing the front support plate



STEP 7: Remove back support plate

Now you can undo the two screws holding the inner support plate. Now all the electronics should come out in one piece. There will be two screws left over still inside the dizzy housing. You can now remove these. You should be faced with a bare dizzy and shaft now.

[Talasas]

PIC 10: Two inner screws


PIC 11: Bare inner dizzy ready for the press


STEP 8: Mark drive gear reference and press gear off shaft

Now comes the delicate part. Mark the drive gear’s position on the shaft in a couple of places (a line above and below should do). Also note there is a groove and a bump on the faces of the gear, this is a reference marker put there by factory, it’s a backup in case you forget to mark the gear’s position. I do stress that you MUST know where to put the gear back because if it’s out in any way your timing will be stuffed. The gear MUST go back to the exact same position on the shaft it was when you removed it.

Once you’ve marked the gear use your press (or whatever other device you’ve conjured up) to press the gear off the shaft. It’s important to apply an even force on the face of the gear (on opposite sides) so that the gear is moving up the shaft and not trying to “twist” while it’s moving up the shaft. Once it gets moving it should come off without too much force but again, if you have a press this won’t be an issue.

Once the gear is off you can pull the shaft through the dizzy housing. You’ve now got an empty dizzy housing.

PIC 12: Reference marking for gear wrt. Shaft


Here you can see the dizzy drive gear. Unlike the popular assumption that there is a notch on the shaft to aid putting the gear back on, we can see that it actually doesn’t have any marker apart from the little bump/groove on that one tooth. (The bump visible in the photo). You can see the shaft in the background.

PIC 13: The dizzy drive gear
IMAGE MISSING - will upload again later


From left to right along the shaft we see the cam, trigger gear and bearing. At this point it may be a good idea to examine the bearing to see if it’s spinning nicely. Mine was perfectly fine so I didn’t have to replace it but if you decide to replace it, you can now press it off. Be gentle when fitting a new bearing.


PIC 14: The dizzy shaft and gear.


PIC 15: Checking the bearing for good operation



STEP 9: Remove the U-Seal

Now if you peer inside the dizzy housing you will see the U-Ring that has been the cause of all the oil coming out of your dizzy. You can remove the U-Seal using a flathead and tapping it with a hammer carefully from behind. I do mean carefully, if you slip and score the side of the dizzy you will be the cause of your own irrepairable oil leak. Once you’ve knocked the little bugger out you can stare for a few seconds in amazement at how rock hard it is compared to the new one. Once you pick your jaw off the ground, you can fit the new seal, take note of orienatation!

Once the seal is fitted everything can be wiped clean and reassembled in reverse order.

PIC 16: The troublemaker


STEP 10: Replace O-ring

Before you fit the dizzy back don’t forget to change the O-ring as well. The old one is probably dried up as well so cutting it off is probably the best option, again careful not to score the dizzy housing. The new one should be elastic enough to roll on.

PIC 17: The O-ring



That's it. Refit the dizzy making sure all the alignment marks are correct and if everything went smoothly the car should fire up no worries. Check for oil leak from the dizzy and smile!

[c2888]

Awesome how to guide
Massive reps from EVERYONE
this is how to do a how to guide, well not really, cos it's a how to fix oil leak guide

Dan

[kingmick]

I thought this was a thread about a dizzy leaking! not an essay about changing orings! Simple. align cam and main pullt marks with dissy mark, undo dizzy bolt, pull dizzy, change orings and put dizzy and bolt back ! hahahahahahhahaah
For god sakes dont right an essay on how to rebuild an engine properly, it will take 300+ pages
well done but it could do with a bit of trimming

[Talasas]

Apologies to all who find it too long. Many people tell me that they hate the other guide because they don't understand it and that it's not specific enough. This was a guide targeted at those people (including myself who needed some more detail). If this is too long for you then you are too gun!

[kingmick]

dont apologies at all, its sensational, just trim it next time you do it i cant wait for the next one because this one is good! mine is just a taking the piss pointer

[turbo ke20]

mate that is a awsome thread. love the close up shots
top work

[Cynic]

Thanks!

This is one job that I need to do.

[Grega]

gold. well done.

[30psi 4agte]

top stuff m8 + rep

[takai]

Aye good work.

[GTI-TRD]

I too need to repair my dizzy seals... I have everything ckaed in sticky black oil scum and its got to the point where its dripping on the ground from the undertray

a gret guide indeed for those less confident such as myself. big ups

[BigWorm]

Nice work, and interesting to note the small differences between the bigport & small port dizzys.
So there's is nothing but the tight fit stopping the gear on the shaft from slipping?
The bigport gear has a rivet/staked pin going through part of it that needs to be drilled out & then replaced, so anyone looking to do the same on a bigport needs to be prepared for that. Drill of the staked head, knock it out with a pin punch, then I used a solid alloy rivet to replace it when it all went back together.
Apart from that it's just the one less sensor inside, and the 2 sensors are also adjustable, so you need to get the gap between the sensor & tooth right.

[finney]

great thread talasas - would have been handy for my old 16v if it was still in my car

[bmak]

Has anyone had success with the kbox dizzy kits?