1986 Nissan 720 kingcab how to replace the rear engine seal

[builte]

Are there any other seals or gaskets I will need to replace when I change the rear engine seal and do I need too pull the transmission as an assembly with the engine when I get to working on it 

[datzenmike]

Good question. You can support the transmission in place and separate the engine and lift out. Way easier to work on if the exhaust down pipe isn't rusted to the manifold. Lots of stuff to disconnect and remove the radiator. Then it has to be mated back together. I've only taken the transmission out and it's a bitch, it will not just drop out, then you have cramped work space to get at the seal. If the engine is out you could also replace the hard to get at oil pan gasket just for insurance. Taking them both out involves removing the shifter, draining the transmission, disconnecting the mount and the slave cylinder.

[builte]

So I should just take it separately from the transmission got it. Are there any other seals or anything that will need replaced when doing this? 

[datzenmike]

Nope, it's pretty straight forward. I would replace the throw out or release bearing though. Just a little insurance because if it goes bad in a year or two you'll be pulling the engine again to get at what you can get at now. Gear puller to get it off the housing that holds it and a vice to press it on.

 

Be sure to lightly grease (lithium grease it doesn't melt and run from heat) the input shaft splines, pivot ball that the clutch arm sits on and any surfaces that rubs such as the clutch arm fingers on the release housing. 

[builte]

It was my impression that automatic transmissions didn't have a throw out bearing?

 

[datzenmike]

First I'm hearing that it's an automatic. Well that makes it a lot easier.

[builte]

Lmao I'm sorry I should have included that with that new information can you think of any parts or replacements I should do with it out 

[datzenmike]

Automatics are generally trouble free. If the drive shaft spline area is not wet then leave alone.

[builte]

I will check it out I'll have to refer to a manual to understand what exactly that is first lol 

[builte]

Ok the spline is the gear that connects the engine and transmission right? What would be the issue if it were wet 

[powderfinger]

Mike is referring to the back of the transmission where the driveshaft connects to the transmission. That seal can leak as it ages. If that area isn't wet with fluid then you have nothing to worry about.

[powderfinger]

As Mike mentioned in one of your other posts I would take every step possible to make sure it is indeed the rear engine seal before pulling engine to replace it. Maybe you have already taken these steps but I wanted to state it anyway. I know you replaced the valve cover gasket but these can still leak around the little half circle pieces after replacement if you didn't put a little RTV on the two half circle pieces when installing.

 

One of those half circles is of course on the back of the head and, if leaking, oil will leak down the engine and likely drip off the front of the transmission or rear of oil pan.

[builte]

I replaced the little half circles with new ones also added rubber washers it is bone dry in that area and honestly I believe I'm the only person that has ever done any kind of maintenance to this truck and it has compelled me to want to learn more so even if it isn't needed I would still love to replace it because of the learning experience and added confidence in driving the truck without failure. This website is full of awesome people and I appreciate everyones help if anyone else has anymore tips I would love to hear them including preventive maintenance I could do while the engine is out 😊

[datzenmike]

LOL  I've proven this to myself time and time again. Take something off that works perfectly only to break a bolt off and have to spend more time and money to fix something that was working just fine. I call this "don't fix what isn't broken law".