51 replies to this topic

[Dennis]

Is there a problem with using Locktite? What happens?

Dennis

[Keith Novak]

I missed the information "on the old site" about RTV vs Locktite on the flywheel bolts. What's that all about? I've always used blue Loctite on the flywheel bolts and never had a problem. I just checked my Mazda manual and it says to use "sealant" which means gasket sealer which = RTV. Guess I haven't been paying attention. Anybody......?

Dennis

Dennis,
Since the bolt holes on the crank go all the way through, the only thing other than the bolt keeping the oil in is the locktite or RTV/sealant gunk. You can get a good fluid tight seal with blue locktite, but RTV or a thicker gunk like in a thread sealant tends to be a bit more reliable to create a foolproof seal.
Keith

[Tom Hampton]

It isn't necessarily oil proof of good at making a seal. Glad it hasn't leaked for you, yet. But, that isn't what it is designed to do.

[FTodaro]

I just used blue locktite. Is that a problem?

[dstevens]

Over time blue might give out. Loctite 515 is a gasket former, much like RTV. The higher you go up in the various grades of Loctite, the better the seal.

[Keith Novak]

I just used blue locktite. Is that a problem?

Not unless it leaks. It's a better threadlocker than a thread sealant. It's pretty thin viscosity so it's just not as reliable to seal it up as well as a goopy substance that sits on the threads like a paste. You're not talking about a major oil leak though. I've had a slight dribble of oil that I don't think even hit the friction surface when I used blue but didn't get a good seal. Now I use Permatex high temp thread sealant which is kind of like the equivalent of teflon tape in a tube. I find lots of it in the threads when I pull the bolts out so there are some nooks and crannies to fill.

[FTodaro]

Not unless it leaks. It's a better threadlocker than a thread sealant. It's pretty thin viscosity so it's just not as reliable to seal it up as well as a goopy substance that sits on the threads like a paste. You're not talking about a major oil leak though. I've had a slight dribble of oil that I don't think even hit the friction surface when I used blue but didn't get a good seal. Now I use Permatex high temp thread sealant which is kind of like the equivalent of teflon tape in a tube. I find lots of it in the threads when I pull the bolts out so there are some nooks and crannies to fill.

Are we on the same page? I was talking about the bolts that hold the flywheel on the crank.?

[Tom Hampton]

Are we on the same page? I was talking about the bolts that hold the flywheel on the crank.?

Yes. Those bolts penetrate into the crank case.

[FTodaro]

Yes. Those bolts penetrate into the crank case.

Are you referring to the RED sealant? So that is what is preferred and it gets enough of a grip to prevent the bolts from backing out. That was my big concern. Thanks for the heads up. I learn things event when I think I already new it.

[Keith Novak]

Are you referring to the RED sealant? So that is what is preferred and it gets enough of a grip to prevent the bolts from backing out. That was my big concern. Thanks for the heads up. I learn things event when I think I already new it.

If you're talking about red locktite, I wouldn't use that stuff. You're not trying to keep the bolts from backing out, just keeping them fluid tight. Red requires heat to break loose which is more of a pain than you need to cause yourself.

[Tom Hampton]

Local machine shop says: $51 for a two-step turn. Open 9am - 6pm, Saturday...If I can get it in tomorrow afternoon he will turn it while I wait.

-tch

[dstevens]

Open Sat, while you wait? I do live in the wrong place... NAPA says one day turnaround on stuff like flywheels and rotors. Of the three most trusted machine shops in the valley two of them have race programs, off road and circle track. The big money maker for these guys are taxi rebuilds. At any given time there could be a dozen or two various cores for service.

[Tom Hampton]

That was just the first place I called. Also, the closest...a good 15 minutes from my property. Didn't bother working down the list... Yeah, Dallas doesn't have a lot of Taxis.

PS: You know, Dave....your Avatar scares the hell out me. Between being a "Peeler" in "Vegas Baby" and that....I'm very afraid.

[Sphinx]

Here's a pictorial guide to the whole process. I've followed it before and it works well: http://www.miata.net...utch/index.html

I always replace the rear transmission seal, and the front cover seal during a trans drop if I don't know the history of the current seals. I also replace the rear crankshaft seal if I haven't done so previously since I have the flywheel off anyway.

[FTodaro]

If you're talking about red locktite, I wouldn't use that stuff. You're not trying to keep the bolts from backing out, just keeping them fluid tight. Red requires heat to break loose which is more of a pain than you need to cause yourself.

No I was talking about the red silicone sealant. I did use the blue locktight, I guess I will know if it leaks why it leaks.

[Brendan O]

I'm about to bolt my flywheel to my new engine and am leaning towards RTV Black oil resistant silicone sealant instead of blue locktite. RTV package says good to 500 deg F.
Are there any more thoughts on this? The shop manual is useless in this regard: it just says "use sealant".

thanks
Brendan

[Dennis]

When Mazda manual says "use sealant" I assume they mean the stuff they sell "Silicone, Tube (Gray)" pn 8527-77-739. I use that for all the sealant applications in engine assembly, the tube says "Silicone Sealant SH780M". It's RTV-like.

Dennis

[Keith Novak]

I use Permatex thread sealant. It's a white liquid that dries to a soft chalky texture. If I remember, the Mazda grey silicone is $30 a tube.

[Brendan O]

ok - i'll try find the Permatex thread sealant (or the Mazda sealant)

thanks!!

[Brendan O]

http://www.permatex....ad_sealants.htm

Do i want the Permatex "high performance" or "high temp" product?

thanks