The better of two evils... (loctite fix question)

Inksta · Postby **Inksta** » Mon Aug 20, 2018 10:40 am

Good people, I'm hoping for some advice:
Should I undo my crankshaft loctite fix in order to change the crank seal...
OR should I let sleeping dogs lie, and leave it all as-is?

Long version: Some years ago, I discovered the crankshaft keyway had become worn due to an incorrectly fitted woodruff key. Thankfully, slathering the keyway, key, crank nose and pulley with hard-setting loctite fixed it, and I've been all good since. Now it's time to change the timing belt, and it looks to me like the front crank seal is weeping a little - nothing major, but there's a bit of oil in the area around the pulley. Normally I'd change the seal, but I have two concerns: 1) apparently the loctite is a real mongrel to loosen, and the timing pulley promises to be a pain to remove. 2) If I do go through with it, there's no guaranteeing that the loctite fix will work a second time (I feel lucky enough having had it work once).

The engine has 360,000ks on it, and I'm changing everything else while I'm down there (water pump, belts, cam seals etc etc).

Postby **NitroDann** » Mon Aug 20, 2018 11:39 am

Remove the pulley with heat, 2-300c gets loctite soft and replace the pulley if you ruin it removing it.

Loctite it again, it's all good.

Dann

hks_kansei · Postby **hks_kansei** » Mon Aug 20, 2018 11:48 am

As above, loctite releases with heat, how much heat depends on the specific sealer used (blue softens at a far lower temp than red for example)

It will be a good opportunity to inspect the keyway while it's cleared, and make sure it hasnt continued to get flogged out.

edit:
also just double check the front seal IS actually leaking, and it's not just cam seals weeping and collecting at the bottom.

Inksta · Postby **Inksta** » Mon Aug 20, 2018 12:04 pm

Awesome, thanks guys.

I'll need to buy a blowtorch of some sort - any idea how powerful it will need to be? I'm guessing the one I use for cooking isn't going to cut it.

Supercheap sell these little propane ones: https://www.supercheapauto.com.au/p/hot ... 40617.html

hks_kansei · Postby **hks_kansei** » Mon Aug 20, 2018 12:48 pm

Is the cooking one like that?

if so, it will probably do the job, just be a bit slower than a propane one.

The propane ones arent really that powerful anyway, they're fine for working thinner metal, and heating bolts/nuts to shock cool but not a huge amount more.

If you're going to be buying a torch for use around the garage, heating metal for shaping, or brazing, then you're better to spend the extra on a MAPP torch.
Hotter and more useful than a straight propane, but nowhere near as costly as an oxy/acetylene setup.

But, for your job of just heating the keyway area up, they kitchen one should do, provided you have enough access to direct the flame directly over the loctited area.

Inksta · Postby **Inksta** » Mon Aug 20, 2018 1:04 pm

Brilliant. I'll give it a go and see what happens - and spring for the MAPP torch if needed.
Thanks heaps for the info.

I can't see the image/link you put up, but this is what I've got:
https://www.homewaresdirect.com.au/mast ... -17cm.html

hks_kansei · Postby **hks_kansei** » Mon Aug 20, 2018 1:32 pm

Bugger about the pic.

But yeah, the one I posted is similar to what you have.

Is the flame adjustable? so long as you can turn the flame flat out and get a good inch or two of flame with a nice blue burn, it should eb enough.
But yeah, you'll want to try and focus it right on the area the loctite is.
and probably have a spare gas refill handy, since you'll likely use up a good amount of the gas getting it hot enough.

also, I just looked up the price of MAPP torches, the gas is similarly priced to propane, but it looks like they dont do the cheaper manual igniton heads anymore, looks like all they do for MAPP is the electronic start ones which cost more.

Inksta · Postby **Inksta** » Mon Aug 20, 2018 1:47 pm

Yep the flame is adjustable, hopefully it does the job. I had a look at the Loctite spec sheet, which says heat to at least 250ºC. Fingers crossed.

Shame about the MAPP cost but I suppose the electronic ignition ones are safer.

Will report back with results.

project.r.racing · Postby **project.r.racing** » Mon Aug 20, 2018 3:45 pm

I see no reason why the little blowtorch wont work. You are only heating a 20mm area.

Postby **NitroDann** » Mon Aug 20, 2018 3:51 pm

IMO even map gas will struggle. Youre warming the front of a 100kg block of steel.

Dann

hks_kansei · Postby **hks_kansei** » Mon Aug 20, 2018 5:18 pm

NitroDann wrote:IMO even map gas will struggle. Youre warming the front of a 100kg block of steel.

Dann

Yeah, but you only need to get the loctite hot, as long as you can get that area hot it should do it.
You wont get it cherry red, and the steel/iron will be somewhat of a big arse heat sink, but even so, the area directly under the flame will still get plenty hot.

Of that 100kg block you only need to get a keyway and the crank bolt hot, and since they sit proud they dont have a huge surface area contacting the block to disspate heat.

Mr Morlock · Postby **Mr Morlock** » Mon Aug 20, 2018 6:04 pm

you could do nothing. Perhaps do a comp check and see if its worth the effort.

bruce · Postby **bruce** » Mon Aug 20, 2018 8:33 pm

I would do nothing. A possible tiny oil leak is not worth worrying about.

Inksta · Postby **Inksta** » Mon Sep 10, 2018 2:10 pm

Alright, so it turns out that the little masterchef blowtorch was enough to loosen things up. Turns out most of the loctite wasn't the hard-setting stuff after all, but the heat was necessary regardless.

New oil seal is in, fingers crossed that's done the job for another 5 years or so

Cheers for the advice!