Grade of Loctite for flywheel bolts?

I'm installing a Zoom aftermarket clutch kit on a 1992 XJ Laredo. I'm asking this in OEM tech because the flywheel torque specs to be used are the OEM specs. The clutch kit incuded a new flywheel. I have removed the old one, and have the new one positioned exactly as the old one was removed and held in place by two of the bolts for now, but in the instructions, I quote "Be sure to use a thread locking compound on the on all flywheel-to-crankshaft and cover assembly-to-flywheel bolts. (e.g. Loctite Threadlocker #262 or equivalent.)" Ok, that's fine, supposedly explicit and useful direction to use a specific grade of Loctite. Only problem is, there is no such part number.

Here are my options:

22200--low strength (purple)
24200--medium strenth (blue)
26240--permanent strength (red)
27100--high strength (red)
27200--high temperature (red)
27740--large diameter (red)
29000--penetrating grade (green)

Kind of seems like they maybe meant the permanent grade. I used a 3/8" impact wrench to loosen these and they came out easily. Maybe the clutch was replaced before I got it (seems pretty likely since I got it at 170K yet the flywheel shows almost no wear at all) and the installer failed to add thread locking compound. Seems like it should have been more difficult to remove if there was permanent grade loctite on the bolts. I had used PB Blaster to presoak, but not for very long, maybe 15-20 minutes.

Does anyone know what grade of loctite I should be using? I'd like to finish the clutch install this afternoon, but don't want to use the wrong formulation.

Thanks!

--waving pine

I would personally use blue on something like this. If you ever had to take it back off for any reason, the red (permanent) would be a pain since usually a torch is required to reverse it.

Couple of things I've noticed. . .

First, I noticed that no one sells Loctite. I was looking at Permatex thread locking compounds.

Second, that Permatex compounds seem to be numbered in a copycat fashion similar to the Loctite. However, I'm quite certain that whatever if anything was on the flywheel bolts before was definitely not the high strength material, simply based on how easy it was to remove with a small impact driver.

I'm going to take your advice BIGSLVRXJ and use the medium strength blue Permatex stuff. There was no evidence of any bolts getting ready to walk themselves out and the clutch disc was almost completely worn down to the rivets, with some of the radial grooves near the center worn flat. Clearly it was on there for a while. Oddly, the flywheel itself had an almost impercepticble wear on it. The pressure plate fingers were heavily worn also, though--about a quarter inch lower than the new unit.

I'm hoping to not have to crack this open again. I shouldn't have been so cheap when I replaced the internal slave cylinder and just done the clutch then. . . Live and learn.

--wp11

LocTite = Permatex - same outfit.

I use 242 on flywheel screws, have for years. Don't have any trouble. New flywheel screws (which I recommend using) purchased as flywheel screws will likely have threadlocker already applied.

The "stock" part number for LocTite are, as you already noted, five digits. The first three are what type of locker (222/242/262/&c.) and the second two usually indicate the size (small tube, largish bottle, semisolid stick, &c.) So, the various sizes of, say, "blue" LocTite would all have P/N 242xx.

And "permanent" LocTite is just that - it's a sleeve retainer, and it's burning Hell to get back out. Don't use that stuff unless you mean it, and you know you're not going to take it apart for any reason whatever later. Use the blue (242,) since it can be broken loose with levereage and maybe a bit of heat.

ACE hardware sells it for sure, I just picked up a tube of blue for the intake/exhaust bolts I needed to replace on the TJ today.
I'd go with blue.

RichP said:

ACE hardware sells it for sure, I just picked up a tube of blue for the intake/exhaust bolts I needed to replace on the TJ today.
I'd go with blue.

Click to expand...

Rich - for combination manifold screws, you want #272. Anything else will fail under the heat, and won't do you any good at all. If you can't get #272 (last time I got it, I had to go to an MRO shop to find the stuff...) don't bother using anything.

OK, I took the unanimous advice here and got the new flywheel, clutch disc, and pressure plate assembled with the 242 blue thread locker. I've had a nagging problem with the clutch not fully disengaging for a while now, which was fixed in the short term first by replacing the clutch master cylinder, then the slave cylinder. There's nothing left to replace now, and given the excessive wear noted on the old clutch disc and the spring fingers of the pressure plate, I think this problem should finally be licked. Unfortunately, I'm waiting on u-joints for the rear drive shaft to really find out, since I discovered when I removed it that not one, but both of the u-joints were unservicably damaged. Guess that explains the excessive vibration that had crept into the system a few months back!

back to topic, though, I was thinking that the permanent grade was a little on the overkill side myself. I wonder why it was recommended by Zoom. . . I rechecked the original bolts and they definitely had no thread compound on them at all--neither the flywheel bolts nor the pressure plate bolts. This is one of the reasons why I lay on my back in the driveway and spend my time doing this work. Not only can I afford to keep up two cars that way, but I also know exactly what has been done or not done for any given job. If I mess something up, I know exactly where to point the finger.

Thanks to everyone who chipped in with their advice!

wavingpine11 said:

OK, I took the unanimous advice here and got the new flywheel, clutch disc, and pressure plate assembled with the 242 blue thread locker. I've had a nagging problem with the clutch not fully disengaging for a while now, which was fixed in the short term first by replacing the clutch master cylinder, then the slave cylinder. There's nothing left to replace now, and given the excessive wear noted on the old clutch disc and the spring fingers of the pressure plate, I think this problem should finally be licked. Unfortunately, I'm waiting on u-joints for the rear drive shaft to really find out, since I discovered when I removed it that not one, but both of the u-joints were unservicably damaged. Guess that explains the excessive vibration that had crept into the system a few months back!

back to topic, though, I was thinking that the permanent grade was a little on the overkill side myself. I wonder why it was recommended by Zoom. . . I rechecked the original bolts and they definitely had no thread compound on them at all--neither the flywheel bolts nor the pressure plate bolts. This is one of the reasons why I lay on my back in the driveway and spend my time doing this work. Not only can I afford to keep up two cars that way, but I also know exactly what has been done or not done for any given job. If I mess something up, I know exactly where to point the finger.

Thanks to everyone who chipped in with their advice!

Click to expand...

While it's not required, I'll put #242 on the cover screws anyhow.

I also replace the OEM cover screws with 3/8"-16x3/4" (or was it 1"? I forget at the moment...) socket head capscrews - they're stronger, and I like them. I'll also use socket heads anywhere a reduced hex head is called for (like on axle yokes - D30/D35 take a 1/4"-28 x 1" for the U-joint straps. Buy 'em by the box and replace them every time you take them out - it's cheap insurance...)

5-90 said:

Rich - for combination manifold screws, you want #272. Anything else will fail under the heat, and won't do you any good at all. If you can't get #272 (last time I got it, I had to go to an MRO shop to find the stuff...) don't bother using anything.

Click to expand...

Did not know the blue came in various numbers, the 242 says 300F, I'll check it in a few days and will look for 272 blue.

RichP said:

Did not know the blue came in various numbers, the 242 says 300F, I'll check it in a few days and will look for 272 blue.

Click to expand...

I don't recall what colour the #272 is offhand - I don't refer to the various grades by colour (as you've probably noted already...)

The #272 is rougly equivalent in strength to the #242, but it's formulated for much higher temperatures - specifically for exhaust hardware, as it turns out.

5-90: do you ever have trouble with stripping the heads on the hex head cap bolts? I would worry that having them locked in place with, essentially, super glue, would make them more prone to stripping out since the contact area to apply torque to is even smaller than the reduced head bolts'. I've had trouble getting old torx bolts to come back out of body panels. I know--much smaller and weaker grade bolts, but that's my only experience to comare this idea to. Are you talking about the black oxide coated hex head cap screws that are easily had at any good hardware store?

According to the chart I reproduced at the top of the thread, the 27200 is also red. I actually was hoping to get that, as I noticed on the chart that they had very similar strength characteristics yet the 272 had a higher breakdown temperature, and I reasoned that the clutch being a frictional creature might enjoy the added heat resistant thread locker, but after stopping at 1) Pep Boys, 2) Advance Auto, 3) National Auto, 4) Ace Hardware, then finally 5) Sears Hardware, the lesson I learned was that at least in my area, you can spend a lot of gas and time running around, but not one of these stores carried anything but the blue 242 and the red 271 varieties. No kidding, I went to all of the mentioned places yesterday. I'm hoping my clutch never reaches exhaust temperatures anyway, but I did like the idea of the extra thermal stability.

On another note, now that I have a few heavy hitters subscribed to this thread, do you guys know if the 92 NP231 transfer case is vacuum actuated? I ended up with an extra thick wall maybe 3/8" OD hose hanging down when I put everything back together. It routes up to the top of the firewall (driver's side) to a metal connector near the clutch master cylinder.

There is a similar hose that comes from the transfer case and terminatesh at a metal tube that is tab mounted to the passenger side E5 (star head) clutch housing to engine block bolt. I was thinking that this was a breather hose, and I noted its level so I wouldn't do any water crossings anywhere near that height. It looked like the tube didn't really have a clean end, so no strong evidence that a hose had recently popped off of it when I pulled the tranny out of the way, but the hose that's just hanging there had a tear in it like it had come off of something and also the ID of the torn part of the hose was stretched out enough so that it very well could have come off of that very tube.

I finished putting everything back together except for the drive shafts (waiting for those U-joints to come still) and started the Jeep up and it idled smoothly enough and then checked to see if there was suction at the mystery hose. No noticeable suction at all. To me, this means one of two things. 1) This is not a vacuum hose. Or 2) It was a vacuum hose that maybe came off who knows when and subsequently vacuumed up road debris and became clogged.

If the latter were true, I would expect to have no 4wd capability now, which I can't check yet, but I can definitely say that I have had working 4wd as far back as a month or so ago, when I was up in central PA last. Maybe it's like a vestigial vacuum hose, something like an appendix in your stromach, that had a use on an older model and was still hooked up but not needed. The Haynes manual mentioned something about a vacuum line for the T-case, and this would be the only good candidate as there are no other hoses going to the transfer case. I thought I had read somewhere in the tech forums that XJ's don't use vacuum to actuate the 4wd, but I guess reading it doesn't make it true.

If the former were true, and this is simply not a vacuum hose, then I guess the TC has a breather hose like the axles and I'll just extend it up higher for my peace of fording mind, and I have a mystery hose that I don't know where to connect that remains a problem. If I knew how to post pics, I would. Sorry to replace them with a thousand words!

Oh, perhaps it would be prudent to mention that the engine is supposedly a rebuilt job, so it seems likely that the engine and transmission/TC are not a correct year match.

What do you guys think? I'm thinking myself in circles. . .

wavingpine11 said:

5-90: do you ever have trouble with stripping the heads on the hex head cap bolts? I would worry that having them locked in place with, essentially, super glue, would make them more prone to stripping out since the contact area to apply torque to is even smaller than the reduced head bolts'. I've had trouble getting old torx bolts to come back out of body panels. I know--much smaller and weaker grade bolts, but that's my only experience to comare this idea to. Are you talking about the black oxide coated hex head cap screws that are easily had at any good hardware store?

Click to expand...

"Brain strain leads to brain pain."

Yes, the socket heads at the hardware store (black oxide finish) are routinely H&T to SAE Grade 8 or ISO PC 10.9. I've not had trouble with the socket stripping out - internally-wrenching head screws tend to be able to take more than externally-wrenching head screws anyhow, from what I've seen. Just make sure you get the wrench solidly in the socket - or it will be like not having the wrench all the way on the hex head, and stripping it won't be the fault of the screw or the wrench. Merely operator error. But, I've been replacing hex heads with socket heads for years (either in an application where a reduced head is needed, or where internal wrenching is desired - they're also useful in limited-clearance applications,) and they've all been four-O so far. I trust them, as long as they're not Chinese crap (Hong Kong or Taiwan are somewhat better, Japanese or European are quite good. I tested a batch of assorted screws - all identical, except for country of manufacture. The Chinese SAE8 screws tested out to about an SAE4-5, while the rest made a nice little scatter plot right around SAE8 spec. Screws were 1/4"-20 and 1/2-13, tested in tension and shear. Made a nice "extra credit" project in Materials & Processes, and was otherwise quite instructive.)

Thanks, 5-90 for the info on the bolts. I'll keep that in mind. How do you know where the bolts originate from in any given store, though?

Any thoughts on that wayward hose?

It's mainly you check the packaging at the store - it will say something like "Contents from one or more of the following:" and a list of countries. There are also "maker's marks" on the heads, and you can look those up.

For fasteners you use often (like U-joint strap screws and the like - stuff you replace every time you take them out, or very common sizes,) I'd suggest you go to an MRO supply house. You can probably find one locally to you - being in Philly - if you can't, I suggest you Google MSC Direct, J&L Industrial, or something like that. They'll usually have a breakdown in their catalogue - a "premium brand" (like SPS/Unbrako - excellent screws!) followed by "domestic", followed by "import" - or something similar. Gimme a minute...

Here's a good example - this link should give you an assortment of 3/8"-16 x 3/4" socket head capscrews at MSC Direct - http://www1.mscdirect.com/CGI/N2DRVSH?PACACHE=000000068250219. Note the variations in manufacturer ("Import"/"Made in USA"/"Holo-Krome"/"Camcar-Textron"/et al.) All of the brand names are good - they also make AN/NAS hardware (aeronautical use - each screw can be tracked back to which spadeful of dirt the iron came from...) and it's solid. The "Nylon patch" screws mean there is a Nylon button somewhere in the threads, and it "locks" the threads by the same principle as the Nylon collar locknut (and should be replaced every time as well.) And, there are different head heights ("standard" or "low" head,) different materials (alloy/carbon steel or CRES - note that CRES is typically H&T to about an SAE6 or SAE7 - not quite as strong as SAE8, but close,) and the like. In fact, I suggest to everyone that you order their catalogue - it's free for the asking, it's about 4400 pages, and it can really save your arse on some projects! It's worth having just for specialty fasteners, but there's also some tooling and supply in there you'll find useful as well. I've got a list of catalogues that all fabricators and project men should have listed on my site, and I try to review and add to it from time to time...

That "wayward hose" is likely precisely what you think it is - a vent for heat/vapours. It can be extended and/or rerouted at will, and you should have the one for the transfer case, one for the front axle, one for the rear axle, and possibly one for the transmission (I know it's on the AW4, I think it's on the BA-10, and I think it's on the AX-15.) Use fuel hose or power steering hose to replace the line, and run it to a convenient point somewhere well over the anticipated waterline.

I followed the metal line on the wayward hose, and it went to the gas tank. Then I realized that the charcoal cannister was sporting a naked hose barb. Not sure how long it's been that way, but I put the hose back where it belonged after cutting off the damaged end. I think the Jeep is idling more smoothly now after the hose reconnect. Is there vacuum going to the charcoal cannister?

As for the TC vent line, well, at least I know at what height the vent tube ends. I'm definitely going to put an extension on it. I don't know how the vent is routed on the AW4, but for anyone running this era of AX15, I think it's safe to say that if you run through water higher than the transmission tunnel, you have a good chance of introducing water into the transmission oil.

Finally, I swapped out the u-joints today, then reattached the drive shafts. Then I reassembled the interior console and shifter stuff and took it for a test drive. It's better than it was, but still grinds a little in reverse. I'm hoping that it just needs to be bled out a little better. I have a "power bleeder", and am looking for the cap to my spare master cylinder to install a hose barb in so I can pressure bleed the system and rule out any residual air in the line from the traditional two person bleed job that was done for the test drive. I would be very, very bummed if I had to replace the slave cylinder again, given that this one is less than a year old, but worst of all, it's the inside the clutch housing version. I guess it is what it is. . .