R32 GTR actuator leak...

[Jjtxaz24]

Recently did a clutch install and noticed a leak that seems to be coming from the rear of that transmission where the actuator is. 

I can tell it's not my transmission fluid because I used the redline shockproof and that was a thicker, more pinkish color. I filled the transfer case with ATF and that is bright red. That seems to be the fluid I am leaking. 

My question is, would I be able to use RTV to help make the seal on the actuator? I know these actuators have a built in lip that act as a gasket/oring and considering the cars 30+ and I had to remove it on and off a few times it might be due for a new one (hopefully it's not).

Prior to the clutch job, there was no leaks from. 

I'm waiting for some replacement hoses to change out the lines for the ATTESSA canister in the trunk leading to the actuator and address another leak that I've had from there for a little bit. 

Appreciate your advice and thanks in advance guys!

[Duncan]

Yeah the line into the back of the transfer case is for the ATTESSA actuation, it is fed from the reservoir in the boot. It is unlikely to be coming from the transfer case itself (same fluid but separate areas) and won't be gearbox fluid back there.

There are 2 common leak points:

1. Where the actuator connects to the transfer case, it is a flange with 2 bolts (from memory) and a gasket. This could leak, if so remove the actuator, replace the gasket, tighten to spec and it should be fine.

2. More common the threaded fitting and angled seat is leaking. Sounds like you have been undoing the line there so that is most likely the issue, I'd remove it again, clean both the threads and actuator with brake clean then retighten. No point adding thread tape / teflon sealer there as the sealing is in the flange not the thread.

90% I'd guess it is #2, and an easy fix. You might have to bleed the ATTESSA afterwards.

[Jjtxaz24]

59 minutes ago, Duncan said:

Yeah the line into the back of the transfer case is for the ATTESSA actuation, it is fed from the reservoir in the boot. It is unlikely to be coming from the transfer case itself (same fluid but separate areas) and won't be gearbox fluid back there.

There are 2 common leak points:

1. Where the actuator connects to the transfer case, it is a flange with 2 bolts (from memory) and a gasket. This could leak, if so remove the actuator, replace the gasket, tighten to spec and it should be fine.

2. More common the threaded fitting and angled seat is leaking. Sounds like you have been undoing the line there so that is most likely the issue, I'd remove it again, clean both the threads and actuator with brake clean then retighten. No point adding thread tape / teflon sealer there as the sealing is in the flange not the thread.

90% I'd guess it is #2, and an easy fix. You might have to bleed the ATTESSA afterwards.

As always Duncan, thanks man. You always come in clutch.

Ok so I removed and reinstalled #1 a few times. After looking through the service manual I found out this was the actuator that is fed from the reservoir in the boot as you mentioned through a few hoses and a high pressure one. When I removed it, there was no gasket. Once I looked into it and through the forums I saw the actuator has a built in gasket in the actuator itself. 

Side question: the metal rod in there. Is there a specific way it goes? It's rounded on both sides and I'm sure it's what the actuator pushes on to engage the transfer case to transfer the torque to the front wheels.

In regards to #2, the threaded fitting and angle seat. Which is this? Is this what connects to the actuator itself? If it is a line that connects to the actuator, I never undid it but I can double check it's tight, it could have come loose when I unbolted the 2 bolts off the actuator that connects it to the transfer case those couple times. 

You are right, luckily both are accessible and don't require me to drop the trans  or anything crazy. I need to make some time this weekend to knock it out.

Again I appreciate the help.

[Duncan]

Right, that makes sense. Yes you can just remove the line from the actuator instead of removing the whole actuator. That has the downside of losing your boot ATTESSA fluid and having to rebleed (unless you can block it some how) but the benefit you've found of not stuffing with the actuator gasket.

I can't find anything in the manual about Actuator re-assembly, so I'd make a gasket from paper and add some of that dark brown gasket harder stuff, then re-assemble. If there is an old gasket stuck to the actuator flange, definitely remove that

[Jjtxaz24]

16 minutes ago, Duncan said:

Right, that makes sense. Yes you can just remove the line from the actuator instead of removing the whole actuator. That has the downside of losing your boot ATTESSA fluid and having to rebleed (unless you can block it some how) but the benefit you've found of not stuffing with the actuator gasket.

I can't find anything in the manual about Actuator re-assembly, so I'd make a gasket from paper and add some of that dark brown gasket harder stuff, then re-assemble. If there is an old gasket stuck to the actuator flange, definitely remove that

I'm not worried about the fluid in the reservoir. It's pretty low that a flush is required anyways and when I change those hoses out for new ones I'm sure I'll loose the rest. I'll have to refill and bleed it anyways. 

Ok so I'll make a paper gasket and use some RTV to help seal it. Got both on hand. I was curious about that as well. 

[GTSBoy]

1 hour ago, Jjtxaz24 said:

use some RTV

RTV is not for sealing gaskets. Use a proper gasket compound.

[Jjtxaz24]

39 minutes ago, GTSBoy said:

RTV is not for sealing gaskets. Use a proper gasket compound.

Noted. I'll look one up and see what the local parts store got, otherwise I'll order it. Don't plan on working on it until the weekend. 

Edit: this is the one I got. Would this not work? It's what came up when I googled "gasket compound". 

Edited June 27, 2023 by Jjtxaz24
Added picture

[GTSBoy]

That's a "gasket maker", which you would use in place of a gasket. Examples would include sump or cam cover flanges, in metal to metal contact, where no paper gasket was intended to be used.

That will likely work on the ATTESA actuator, if the metal to metal contact surfaces are really nice and the insertion depth is not critical. If the insertion depth is dependent on the thickness of a gasket, then it is better to use the correct gasket.

Note I am not all that familiar with the actuator.

[Jjtxaz24]

12 minutes ago, GTSBoy said:

That's a "gasket maker", which you would use in place of a gasket. Examples would include sump or cam cover flanges, in metal to metal contact, where no paper gasket was intended to be used.

That will likely work on the ATTESA actuator, if the metal to metal contact surfaces are really nice and the insertion depth is not critical. If the insertion depth is dependent on the thickness of a gasket, then it is better to use the correct gasket.

Note I am not all that familiar with the actuator.

I can say with confidence that the actuator is a metal on metal surface and flat with no indentation to run a seam. I don't believe depth is critical. It sits flush against the back of the transfer case and then it gets torqued down to like 50 ftlbs (can't remember off the top of my head at the moment)

Here's a picture of it. 

Edited June 27, 2023 by Jjtxaz24

[Duncan]

Yep, it is not designed for silicone / rtv etc, that is why I suggested making a gasket and adding a sealant as you've had trouble in the past.

I meant stuff like this which you apply to a paper gasket:

https://www.permatex.com/products/gasketing/gasket-sealants/permatex-high-tack-gasket-sealant-16-oz/

I'm not a sealant specialist but I understand locktite 515 and equivalent products might be a more modern option which replace a paper gasket

https://www.blackwoods.com.au/adhesives-sealants-fillers/thread-sealants-and-threadlockers/henkel-loctite-515-flange-sealants/master-gasket-flex-loctite-515-300ml/p/05894512

[Jjtxaz24]

Awesome. Thanks guys. 

[joshuaho96]

AFAIK the OEM sealant is actually Loctite 518, listed as p/n C133531X25 if you buy it from Nissan. Checking online I do not see any paper gasket or anything like that for the actuator: https://nissan.epc-data.com/skyline/bcnr33/3935-rb26dett/trans/333/30570X/

[Jjtxaz24]

5 hours ago, joshuaho96 said:

AFAIK the OEM sealant is actually Loctite 518, listed as p/n C133531X25 if you buy it from Nissan. Checking online I do not see any paper gasket or anything like that for the actuator: https://nissan.epc-data.com/skyline/bcnr33/3935-rb26dett/trans/333/30570X/

Sounds good. I'd assume like Duncan suggested that loctite would be very similar if not better to the nissan flavor. I also searched and didn't see a gasket required

[joshuaho96]

8 hours ago, Jjtxaz24 said:

Sounds good. I'd assume like Duncan suggested that loctite would be very similar if not better to the nissan flavor. I also searched and didn't see a gasket required

When I searched up that part number it was literally a tube of Loctite 518 in a Nissan box. I'm just not sure what the difference is between 515 and 518. Both are anaerobic sealants with similar methacrylate base. As far as I can tell it's just a color difference and 515 needs a longer cure time.

[Jjtxaz24]

6 hours ago, joshuaho96 said:

When I searched up that part number it was literally a tube of Loctite 518 in a Nissan box. I'm just not sure what the difference is between 515 and 518. Both are anaerobic sealants with similar methacrylate base. As far as I can tell it's just a color difference and 515 needs a longer cure time.

That's good to know. Ordered the 515 should be here Thursday so I'll get it done this weekend. Then I'll wait for the next problem to come up...

Anyone on here know how to tune with NISTune by any chance? Lol. 

[BK]

Sounds like there is a tear in the actuator boot. Use 518 not 515. There is no gasket between the Attesa actuator and transfer case, it relies on the boot of the actuator itself to seal with just an oil film or 518 usually. Failing that, Threebond the mf'er in with 1207C.

 

 

[Jjtxaz24]

On 7/1/2023 at 4:16 AM, BK said:

Sounds like there is a tear in the actuator boot. Use 518 not 515. There is no gasket between the Attesa actuator and transfer case, it relies on the boot of the actuator itself to seal with just an oil film or 518 usually. Failing that, Threebond the mf'er in with 1207C.

 

 

Saw this post after I ordered the 515. I've already drained the transfer case, and ran a bead to let it cure. Did it Friday and went out of town so hopefully when I get back I can fill it and top off the ATTESSA reservoir in the trunk and bleed the system. Also replaced those hoses. 

I took off the shifter boot and replaced it with a new one. What if that was where it was leaking from too? Boot was torn and worn out. The new one fits snug and I put a zip tie around the bottom to hopefully keep it secure and the ATF fluid in.

[joshuaho96]

10 hours ago, Jjtxaz24 said:

Saw this post after I ordered the 515. I've already drained the transfer case, and ran a bead to let it cure. Did it Friday and went out of town so hopefully when I get back I can fill it and top off the ATTESSA reservoir in the trunk and bleed the system. Also replaced those hoses. 

I took off the shifter boot and replaced it with a new one. What if that was where it was leaking from too? Boot was torn and worn out. The new one fits snug and I put a zip tie around the bottom to hopefully keep it secure and the ATF fluid in.

I took the time to stare at the technical data sheets more carefully, Loctite 518 is more tolerant of bad machining. Both are supposedly fine with a 0.25mm gap but 518 has a lot more shear strength than 515 in that scenario. Both have comparable engine oil tolerance but only 518 is specifically tested for ATF tolerance. 518 actually has less shear strength at 100C than 515 assuming you have that 0.05mm maximum gap. If the 515 fails to seal I would try the 518 and see if that improves anything.

[Duncan]

3 minutes ago, joshuaho96 said:

I took the time to stare at the technical data sheets more carefully, Loctite 518 is more tolerant of bad machining. Both are supposedly fine with a 0.25mm gap but 518 has a lot more shear strength than 515 in that scenario. Both have comparable engine oil tolerance but only 518 is specifically tested for ATF tolerance. 518 actually has less shear strength at 100C than 515 assuming you have that 0.05mm maximum gap. If the 515 fails to seal I would try the 518 and see if that improves anything.

Excellent information, particularly re ATF resistance since that is what the xfer case and actuator both run.

[Jjtxaz24]

33 minutes ago, joshuaho96 said:

I took the time to stare at the technical data sheets more carefully, Loctite 518 is more tolerant of bad machining. Both are supposedly fine with a 0.25mm gap but 518 has a lot more shear strength than 515 in that scenario. Both have comparable engine oil tolerance but only 518 is specifically tested for ATF tolerance. 518 actually has less shear strength at 100C than 515 assuming you have that 0.05mm maximum gap. If the 515 fails to seal I would try the 518 and see if that improves anything.

This is excellent information to have  I will report back if the leak is still persistent. 

28 minutes ago, Duncan said:

Excellent information, particularly re ATF resistance since that is what the xfer case and actuator both run.

Agreed. Our boy Josh doing the dirty work.