Removing Timing Cover?

[Trav]

Do I need to drop the oil pan to remove the timing cover? I don’t know why this is such a head scratcher for me?
1970 1600

[JT68]

Yes, there are 4 studs that pass through the oil pan.

[Bwk2000]

This may help you visualize the position of the studs JT mentioned.

6B16667C-164A-42F9-93E4-4055EAA8111E.jpeg

[23yrRebuild]

I removed the 4 studs on the timing covers of my old 3-main, and current stroker R16, a long time ago, and replaced them with using 4 more oil pan bolts. I've never had a problem with this, and it's so much easier to r & r the oil pan, OR the timing cover, if need be,... but I DID have challenges with the original studs. At the time I replaced them on the first engine, I thought to myself, "why did Nissan use studs instead of bolts? "....

[Bwk2000]

I removed the 4 studs on the timing covers of my old 3-main, and current stroker R16, a long time ago, and replaced them with using 4 more oil pan bolts. I've never had a problem with this, and it's so much easier to r & r the oil pan, OR the timing cover, if need be,... but I DID have challenges with the original studs. At the time I replaced them on the first engine, I thought to myself, "why did Nissan use studs instead of bolts? "....

That’s a very good idea. I’ll have to remember that next time mine comes off.

[JT68]

Studs in aluminum are the better method, no question.

[23yrRebuild]

I TOTALLY agree JT....fortunately, it seems, there should be no worries concerning oil pan bolts, specifically,.... as excessive tightening is not going to improve gasket sealing anyway...that was my logic when I first considered doing it....and by the way, I'm pretty sure I had come across someone else doing that first....not my idea originally...

[Bwk2000]

For high temperature/pressure applications (aluminum heads on a steel block, exhaust manifold to an aluminum block, etc), I would agree. But on a simple cover plate? That just sounds like a design hiccup, or maybe they just wanted guides to help attach the oil pan, who knows … Why else would they put studs there when they are also using a dozen other bolts to hold the timing plate on and a dozen and a half more for the oil pan? Good quality bolts, some anti seize, that sounds to me like an easy solution to fix an otherwise annoying issue.

[JT68]

I TOTALLY agree JT....fortunately, it seems, there should be no worries concerning oil pan bolts, specifically,.... as excessive tightening is not going to improve gasket sealing anyway...that was my logic when I first considered doing it....and by the way, I'm pretty sure I had come across someone else doing that first....not my idea originally...

It's not a mechanical stress issue, it is a "mechanic skill" and service issue.

Definitely correct, excessive tightening won't help the gasket, but it will strip the cover.

Threaded holes into AL with bolts tend to get cross threaded and or stripped out for one reason or another.

The studs never will unless over-torqued.

Structurally and strength wise, bolts are fine, that's for certain.

Of course, if someone does strip out one of those holes on an engine in the car, that will really ruin the after noon (trying to do a perpendicular 6mm helicoil on your back with oil dripping in your face....(not to mention the crossmember is in the way)

Studs are just the better option for many reasons. Nissan did it on all of these engines, it wasn't a mistake.

Also, of course, cross threading would also more likely occur trying to replace the pan in the car, through a semi-aligned gasket covered with gooo. It is much, much harder to dork-up the stud.

Anyway you slice it, it's way easier to install a nut on the stud if the engine is in the car! Stay with the studs, there isn't a good reason to use bolts, but several reasons not to.

Notice NIssan used bolts for all the positions into the iron block, they used the 4 studs only in the AL-that was intentional.

[Gregs672000]

Since they are studs, they can be carefully removed as an option over pulling the pan (small stud remover or double nut if long enough... I've removed plenty of studs this way). But in the long run it may just be easier to remove the pan!

[JT68]

Studs or bolts for the cover is no big deal either way, but yeah, it takes 5-10 minutes to drop the pan, so that is definitely the easy route. Then you can (gently) pry and tap the front cover forward from underneath. (it has small alignment dowels, so it has to go straight forward to clear the dowels)

Putting the pan back on (if the engine is in the car) is definitely easier with studs on the front cover since everything is self-aligning.

Hope this helps!