First issue real issue with the 55 and some ?'s
- Thread starter ChuckB
- Start date
ChuckB said:
I would not be intimidated by the drilling and tapping. In Hawaii, there may not be any spare knuckles available. That would make the choice pretty simple. I did the drill and tap in about 15 minutes total, so it isn't a big job. I did use my drill press, but that's optional. The tapping part of it goes surprisingly well. You really have NOTHING to loose, if you think about it.
Go to your local ACE Hardware. Ask for a 1/2 FINE thread tap. That's about $10. The package will tell you what size to drill through first. Buy that drill bit($6). Buy a 1/2 drill bit as well($6), to drill the ear in the caliper. That's really all it takes. At most you are out $22. A new knuckle from Toyota is $$$$. I don't know how much, but figure 10X the cost of drilling and tapping as a start.
I have never helicoiled anything, but that may work as well, but since it's your brakes, you want to be really sure about it!
And yes, this is an excellent time to do the full front axle rebuild.
Where are you in Hawaii? I'll be there in January and I'll even help.
cpg
Adventurer
AndrewP said:
Heli coil / Perm Coil is drilling and tapping with a special tap that will return the threads to better then new after the insert is screwed in. The only down side is that it will cost a little more for the kit then the 1/2 tap you are talking about. It can be easily done with a hand drill. The advantage is you can use your stock fastener and not worry about the odd inch wrench.
http://www.amazon.com/Perma-Coil-12MM-1-25-Thread-Repair/dp/B0002KL3ZO
DaveInDenver
Middle Income Semi-Redneck
If you are considering replacing it, why not go ahead and try to re-tap it? If you ruin it (which you won't), you're not out anything. No time like the present to give it a try!ChuckB said:
Yup.
ChuckB
Expedition Leader
AndrewP said:
Andrew and Dave,
I appreciate the encouragement. Thanks!
Andrew,
I may take you up on that offer. I am on Oahu, about 20-25 min west of Honolulu. When and where are you going to be? I'll pick you up from the airport if we can work it out, plus :beer: & :chowtime:
I think I'll give this drill/tap a whirl :elkgrin:
cruiser guy
Explorer
Normally I'd drill and tap it as well and in your case if a replacement knuckle is not available then you don't have many choices but I would be watching for the right parts to return it to stock as soon as possible being that it is brakes. See if you can get the helicoil with the correct thread size as it will save drilling, and thus ruining, the caliper.
The last thing you need is for that new bolt to snap when you need it most and end up killing someone. The lawyers would be all over you if it's modified in any way. Just read what folks who offer the disc brake upgrade kits say. Almost every one says it's for off road use only at the buyers risk!
Whatever bolt you use make sure it is a high grade bolt not your run of the mill lumberstore bolt. Ask for a grade 8 or better.
The knuckle is, or should be the same as a Toyota solid axle pickup or any disk brake LandCruiser. You may have steering arm bolt pattern differences though so watch that.
If you do a birfield repack get the seals from Marlin Crawler. They are supposed to be better than stock.
The last thing you need is for that new bolt to snap when you need it most and end up killing someone. The lawyers would be all over you if it's modified in any way. Just read what folks who offer the disc brake upgrade kits say. Almost every one says it's for off road use only at the buyers risk!
Whatever bolt you use make sure it is a high grade bolt not your run of the mill lumberstore bolt. Ask for a grade 8 or better.
The knuckle is, or should be the same as a Toyota solid axle pickup or any disk brake LandCruiser. You may have steering arm bolt pattern differences though so watch that.
If you do a birfield repack get the seals from Marlin Crawler. They are supposed to be better than stock.
DaveInDenver
Middle Income Semi-Redneck
The inner axle seal is definitely an improvement, even over stock. It's worth investing in that. The rest of his axle kit will be OEM or equivalent, but he's got a special seal that greatly reduces the chance of gear lube and knuckle grease from mixing due to seal failure or knuckle shim alignment issues. It's one of those 'Well, duh' things. Toyota's seal is just fine quality wise, but requires a very good alignment of the axle. This is possible when the front end is manufactured, but when you replace the king pin bearings on the knuckle the alignment may not be nearly as good as the initial build. Marlin's seal allows the axle to come through at a slight angle and still seal. Friggin' brilliant and surprising no one thought of in the, oh, almost 50 years Toyota's been making 4WD trucks...cruiser guy said:
cruiseroutfit
Well-known member
If you end up replacing the knuckle... give me a ring... I've got both varieties in stock. We've heli-coiled plenty of stripped caliper bolts, seems to be happening more & more often lately. I'd bet you could find a local service shop that is comfortable doing it, I'd figure they wouldn't charge more than say $20 to do the labor. The heli-coil can be $10-15+
If you do want to swap the knuckle, measure your steering arm pattern:
http://www.cruiseroutfitters.com/tech_front_axle.html
Good luck!
If you do want to swap the knuckle, measure your steering arm pattern:
http://www.cruiseroutfitters.com/tech_front_axle.html
Good luck!
cruiser guy said:
I think a 1/2 inch grade 8 bolt is far stronger in shear than a stock 12mm bolt, but still, your point is well taken.
Chuck-I'm going to be on the Big Island, so it won't work.
And incidentally, I did the drill and tap to keep rolling, and swapped it around a year later when I got a good knuckle. The tapped one is still in my spares box in the 40. The helicoil thing sounds good. I don't know how strong it is, but if Kurt gives the thumbs up, it's probably just fine.
ChuckB
Expedition Leader
Thanks for all the input you all have been really helpful!!
As soon as I get more time I'm going to take a look at it some more. I need to start compiling a list of parts/materials that I need to do the birfield repack. Anything else I should do while I have this all apart?
Kurt I'll probably be getting in touch with you really soon.
As soon as I get more time I'm going to take a look at it some more. I need to start compiling a list of parts/materials that I need to do the birfield repack. Anything else I should do while I have this all apart?
Kurt I'll probably be getting in touch with you really soon.
cruiser guy
Explorer
AndrewP said:
1/2" = 12.7mm so I doubt that the 1/2" is that much stronger! I can't say for sure but I'd bet the OEM caliper bolts are not just "run of the mill" bolts either. The OEM shop manual calls for 73-108 ft/lbs torque so they cannot be too wimpy.
Chuck, if you're ordering stuff from Kurt I'd get him to send out a knuckle too then you KNOW you're good to go.
ChuckB
Expedition Leader
cruiser guy said:
I bought the replacement OEM bolt from the dealer. Which also reminds me, I need to get a torque wrench!!
I'm contemplating having Kurt send me everything that I need to freshen up the front axle. But, I'll be in well over my head if I do that. I guess you have to start somewhere!!!
Grim Reaper
Expedition Leader
AndrewP said:
a little over 1/2 a mm is all that is different. There are bolts stronger then grade 8 and the factory bolts are that variety.
A 12.9 Metric bolt is stronger then Grade 8. A grade 8 Proof load is rated 120,000 PSI and 12.9 Metric is rated 140,686 PSI. A 10.8 is 120.381Psi 8.8 is 87,022.
http://www.boltdepot.com/fastener-information/Materials-and-Grades/Bolt-Grade-Chart.aspx
There are US bolts stronger then Grade 8 as well but not listed on that chart.
ntsqd
Heretic Car Camper
What folks forget or don't know about G8's is that they tend to be more brittle than better bolts of similar strength. So instead of yielding or bending a little they snap off.
If you want/need quality SAE type bolts buy the F911's. Stronger and more Ductile than a G8.
Also, there is no control over what gets marked as a Grade 8. Any unscrupulous overseas mfg can make any danged bolt they want & call it a Grade 8. Even the Fed Gumbement has had trouble with counterfeit bolts working their way into the procurement system.
Then there's that mixing SAE into a metric vehicle. That just rubs me wrong. If you can't get them locally, mcmaster.com sells metric bolts.
Elevententh the drill it yourself. The caliper's hole should make a pretty good guide for getting the new hole square. If there's room put a wrap of duct tape on the drill so that the flute edges don't dig into the caliper hole.
If you want/need quality SAE type bolts buy the F911's. Stronger and more Ductile than a G8.
Also, there is no control over what gets marked as a Grade 8. Any unscrupulous overseas mfg can make any danged bolt they want & call it a Grade 8. Even the Fed Gumbement has had trouble with counterfeit bolts working their way into the procurement system.
Then there's that mixing SAE into a metric vehicle. That just rubs me wrong. If you can't get them locally, mcmaster.com sells metric bolts.
Elevententh the drill it yourself. The caliper's hole should make a pretty good guide for getting the new hole square. If there's room put a wrap of duct tape on the drill so that the flute edges don't dig into the caliper hole.
DaveInDenver
Middle Income Semi-Redneck
Yeah, that brittle thing.
My estimation is this, take with a grain of salt. A grade 8 is technically a more brittle bolt than a grade 5 by way of it's heat treating. But, a grade 8 is still rated for 150 ksi UTS and 130 ksi YS, while a grade 5 is 120 ksi ultimate and 92 ksi yield. Please, materials people correct my errors.
A 1/2-20, 3A-thread bolt has a minor diameter of 0.4387 and so an area of .1512 sq-in. So strengths:
Grade 8 in tension:
Yield at 19,656 lbf
Fail at 22,680 lbf
Grade 5 in tension:
Yield at 13,910 lbf
Fail at 18,144 lbf
So a grade 8 bolt is more brittle (i.e. the bolt's ultimate tensile and yield points are closer) but it still remains plastic at a higher stress than the failure of a grade 5. Have I always been wrong to say grade 8 is always preferred? BTW, after reading NASA-RP-1228, I've always taken 60% of the strength in tension to find shear, but I'm certainly no expert here.
My estimation is this, take with a grain of salt. A grade 8 is technically a more brittle bolt than a grade 5 by way of it's heat treating. But, a grade 8 is still rated for 150 ksi UTS and 130 ksi YS, while a grade 5 is 120 ksi ultimate and 92 ksi yield. Please, materials people correct my errors.
A 1/2-20, 3A-thread bolt has a minor diameter of 0.4387 and so an area of .1512 sq-in. So strengths:
Grade 8 in tension:
Yield at 19,656 lbf
Fail at 22,680 lbf
Grade 5 in tension:
Yield at 13,910 lbf
Fail at 18,144 lbf
So a grade 8 bolt is more brittle (i.e. the bolt's ultimate tensile and yield points are closer) but it still remains plastic at a higher stress than the failure of a grade 5. Have I always been wrong to say grade 8 is always preferred? BTW, after reading NASA-RP-1228, I've always taken 60% of the strength in tension to find shear, but I'm certainly no expert here.
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