How To: 3.0 Camshaft Syncro Replacement

Ok, this is extremely easy, maybe a 3 on a level from 1-10. Took about 45 minutes.

PERFORM AT OWN RISK.

Things needed:

A drop light
10MM Socket
Socket Extensions
5.5MM Socket (I think)
Clean Motor oil
New Syncro
Syncro Alignment tool

NOTE: All photos will be shown so that the bottom of the photo points to the front of the engine.

Anyways to start, you need to get the new part first.


Now, the Synchro is on the passenger side rear of the engine, all the way in the back. To make it easier, remove the spark plug wires from the coil pack going to the drivers side of the engine, label them for quick easy installation when your done.


This is what the top of it looks like, thats the sensor on top, I believe they are 5.5MM, I dont remember which one I grabbed. Remove both bolts then remove the sensor.


With the sensor removed, you can see the cutout in the window for the sensor to be seated. Keep note of where this is. Also notice the Slightly curved pin sticking up from the shaft, that is what lets the sensor know what cylinder is where. Also keep note of where this pin is. IT IS EXTREMELY IMPORTANT THAT EVERYTHING IS PUT IN THE SAME LOCATION, OTHERWISE THE TIMING WILL BE INCORRECT AND YOUR ENGINE WILL NOT RUN CORRECTLY.


Now put your alignment tool onto the top of the syncro, it will slide in with the pin, and the arrow on top will allow you to easily align the new syncro with the old. I found a picture was the best way to keep an Idea where the old syncro was


Now, Remove the 10MM bolt that holds the camshaft syncro in place on the engine.


(Dirty Engine, I know)

Now, it may be a little difficult to remove the syncro, Just twist the top portion (what holds the sensor to the syncro) and it should pop right out.

Installation is the reverse of the above, EXCEPT, do not tighten the bolt until the sensor is properly aligned and in the same orientation as the original!

It may take one or two tries to get the sensor in there right, but it will go how it used to.

After I finished mine, reconnected everything and she started right up. I noticed that the truck Idles much smoother and also has a little bit more pick up.

I will edit this and add a few arrows to the pictures soon.

 

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Probably one of the many things that is still wrong with my truck. Haha. Nice write up man

 

I dont think the SOHC 4.0's Have these, there only on the 3.0/4.0 OHV because they were pushrod engines, and were originally distributor instead of ignition modules.

These are on these engines because they would have had to redesign the engine to get rid of the distributor, and find a new way to drive the oil pump (a shaft attatches to the bottom of the syncro that goes into the oil pump to turn it), so instead, they put this in, and slapped a sensor on it to the computer always could know how to time its ignition.

 

Good writeup! Glad it worked for you.

 

nice job, but I have a question, after the sensor is removed it all looks mechanical, so what was wrong with the lower part ? cant you just replace the sensor part and be good ?.....does the gear strip out ? or like I said why not just replace the sensor on top ?

 

The sensor is not the problem.

Through research I've found out that unlike the distributors that were used in these engines, the bearings the inner shaft rides on like to give out prematurely. When that happens, you get more play in the shaft, and the pin that the sensor uses basically gets stuck on the sensor, stopping the shaft, which either strips the gear on the syncro if it was nylon (apparently earlier models had nylon gears?) or it would just shear the pin that held the gear onto the shaft. If you recall I was saying that this syncro drives the oil pump. Once the syncro is seized, the oil pump isnt turning, and at highway speeds, if you dont notice it immediately you have no oil psi, your engine is ****ed, and even sometimes you do notice it, its too late. Thats why you cant just get away with replacing the sensor.

 

Okay then, looks like I learned something new today! Haha

 

I learned something too, thanks