TA-31 and FE oil pan questions

[lippy]

So far so good. I don't think it leaks. I used studs and Right Stuff, per my prior post. I retorqued it several times (once after each of the first few heat cycles, and then once per week), but the nuts still seem to get a little looser and tighten up by about 1/8 turn each time I retorque. By now they should've settled and the gaskets should be fully compressed by now.

So my question is: anything wrong with using double nuts on each stud to keep things tight? Or is it the studs themselves and not the nuts that might be loosening?

[Bernica]

Just don't crush 'em!!

[lippy]

Originally Posted by Bernica

Just don't crush 'em!!

Crush the gaskets? I would hold the inner nuts in place with a box wrench and tighten the nuts on top of them, so the clamping force on the gaskets would remain as is.

[Tim7139]

Remember, using the Right Stuff, ideally you need to get a feel for this . You do not want to keep screwing with it after application.
I tightened everything on the pan and left them overnight. About a week later, I just checked tightness and maybe 2 or 3 nuts snugged up a slight bit........then leave them alone unless something seeps.

[lippy]

Originally Posted by Tim7139

Remember, using the Right Stuff, ideally you need to get a feel for this . You do not want to keep screwing with it after application.
I tightened everything on the pan and left them overnight. About a week later, I just checked tightness and maybe 2 or 3 nuts snugged up a slight bit........then leave them alone unless something seeps.

But if I check them and they are all loose 1/8 of a turn, then I have to tighten them back to spec torque, right? That is what is happening. I checked the torque 4-5 times and each time they had loosened. I fear that if I just leave them I will develop leaks.

[Bernica]

And therein lies the conundrum...
It's not leaking now, but should I just give it one more torque? Then another??
I do not have the answer, but if it's not leaking I would let things be IMHO.

[lippy]

Originally Posted by Bernica

And therein lies the conundrum...
It's not leaking now, but should I just give it one more torque? Then another??
I do not have the answer, but if it's not leaking I would let things be IMHO.

Right! So I was thinking I would double up on the nuts without changing the torque of the first set, ensuring they don't loosen.

[Bernica]

Originally Posted by lippy

Right! So I was thinking I would double up on the nuts without changing the torque of the first set, ensuring they don't loosen.

Good, and I would do that. However, maybe just dab a bit of paint on each bolt to you know if it has moved at all? Just a thought....

[Tim7139]

Originally Posted by lippy

But if I check them and they are all loose 1/8 of a turn, then I have to tighten them back to spec torque, right? That is what is happening. I checked the torque 4-5 times and each time they had loosened. I fear that if I just leave them I will develop leaks.

I think the issue is that you are probably a little light on the initial torque. This is where the feel part comes in. Initially as you tighten, if you used proper amount( remember it's real easy to overdo this) you tighten until you just see it begin to extrude out the edge.
A major issue with this stuff is the propensity to use too much. A nice continuous bead about 1/4" is about right. This and a slight smear around any stud holes so there's no voids.
I believe the major reason for nuts backing off may be excess material leading to the pan moving slightly or vibrating, etc.
I also pull all the studs, clean them with brake cleaner and put them back so you nut them on nice clean dry studs.
This is what I've learned in working with this stuff on cars and high vibration vintage motorcycles.

[lippy]

Originally Posted by Tim7139

I think the issue is that you are probably a little light on the initial torque. This is where the feel part comes in. Initially as you tighten, if you used proper amount( remember it's real easy to overdo this) you tighten until you just see it begin to extrude out the edge.
A major issue with this stuff is the propensity to use too much. A nice continuous bead about 1/4" is about right. This and a slight smear around any stud holes so there's no voids.
I believe the major reason for nuts backing off may be excess material leading to the pan moving slightly or vibrating, etc.
I also pull all the studs, clean them with brake cleaner and put them back so you nut them on nice clean dry studs.
This is what I've learned in working with this stuff on cars and high vibration vintage motorcycles.

The studs were new and clean. I used Permetex Hi-Tack between the gaskets and windage tray, and then a bead of Right Stuff between the gasket/pan, and gasket/block, probably about an 1/8" bead, and around all bolt holes. I can get a torque wrench on all the studs but one, and tightened to 90 in-lb, which is 7.5 ft-lb. That *should* be good, and I don't want to distort the pan. Do you think I need a bit more torque?

[DanEC]

Maybe I'm all wet on this but I don't think your nuts or studs are backing off - I think the relaxing of tension on the studs is from the gasket taking a set which relieves the expansive forces or rebound forces acting on the pan and fastener tension. Re-tightnig the nuts compresses the gasket slightly further, again restoring the expansive forces acting between the pan and the block. At some point after a couple cycles of this, the gasket is compressed to where it's density increases to a point the fasteners can't be tightened any further without exceeding torque standards and possibly distorting the pan, etc. I don't think double nutting your studs will do anything except make it a little more difficult to snug up the fasteners any further. I would think after 2 or 3 cycles of that you are probably near the point of diminishing returns.

That's my theory or understanding anyway - right or wrong.

[Tim7139]

Originally Posted by lippy

The studs were new and clean. I used Permetex Hi-Tack between the gaskets and windage tray, and then a bead of Right Stuff between the gasket/pan, and gasket/block, probably about an 1/8" bead, and around all bolt holes. I can get a torque wrench on all the studs but one, and tightened to 90 in-lb, which is 7.5 ft-lb. That *should* be good, and I don't want to distort the pan. Do you think I need a bit more torque?

I use Right Stuff silver on all surfaces.

[lovehamr]

I'd just take the washers out and let the serrated nuts do their job.

Edit: Besides, once the Right Stuff is solid you could probably remove all of the nuts and that pan wouldn't be going anywhere.