flange bolts for drive axle

tightened a flange bolt on the drive axle to hard and broke it, where can I get replacements. 1996 Passat tdi?

Hardware store. It doesn't need to be a triple square head. Standard hex head will be fine.

How tight were you torquing it, to snap it...?

-Todd

if its the 8mm 12pt on the inner flange of axle/trans arent they hardened? allen is much weaker of a head, will a std hex head bolt work here? but i do believe it calls for a hardened bolt. try 10.9? if you snapped it are flange threads ok?

ive been using standard allen heads on my VW cv axles for years now.

I had an axle's bolts walk out on me once a few years ago (im sure it was my own fault) so I use a dab of blue locktite on mine also. the head can strip out sometimes if i use a ball end hex or worn out hex bit. Then I'll have to tap a spline bit in there with a hammer or my small air chisel and then crack em loose. usually 1 or 2 of the 12 will strip if i use locktite.

keep those washer plate things to spread the pressure of the bolt across the flange instead of just immediately around the bolt hole.

i dont think there is enough clearance for the socket if you use regular hex headed bolts, but ive never tried it.

From my understanding, all metric socket cap screws are 10.9 or harder.

I believe 10.9 is somewhat equivalent to SAE 8.8.

-Todd

thats a no todd, you go down to your local or chain hardware store you will find std metric fasteners of 8.8grade. thats a 5sae it ll hold basic fastening stuff. the big chain stuff being even cheaper, prob from china more likely. check the drawers std will be sae5, metric 8.8grade. unless marked otherwise. some now stock 10.9 certainly not as much variety as the lower grade.
other than not being a fan of the allen cheese heads, the book value (33 iirc) is again low, not surprising. id say 42-45 for tightness, not much more, dont want to strip the flange, breaking off a bolt isnt much better. and to say thats not all at once, i go around the axle at least twice, and a third time for consistency, youd be surprised.

I bought M8x45mm grade 12.9 6mm Allen bolts from Home Despot and used them in place of the ridiculous OE special bolts. Checked a few weeks later and unlike OE, they were still tight.

Tighten them gradually and in a star pattern (not going around the circle).

iluvmydiesels said:

and to say thats not all at once, i go around the axle at least twice, and a third time for consistency, youd be surprised.

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moroza said:

Tighten them gradually and in a star pattern (not going around the circle).

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even if you tighten all 6 bolts in a star pattern just one time, your still going around twice, thats minimum, check again it wants more *even tightness/torque, and more advice start with a different bolt than you first did, and even then do you do that in a star pattern? yea go around 2 more times,,min.

iluvmydiesels said:

thats a no todd, you go down to your local or chain hardware store you will find std metric fasteners of 8.8grade.

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Is that typical a hex head or socket cap, as I stated?

Moroza found 12.9 socket caps at HD. I think that pretty much counts as a chain hardware store.

ToddA1 said:

From my understanding, all metric socket cap screws are 10.9 or harder.

I believe 10.9 is somewhat equivalent to SAE 8.8.

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I just saw a typo... should have typed SAE 8. I should have mentioned SS is excluded. I don't think any SS is graded.

-Todd

i dont know what a socket head is doing (for the most part) hardened, its a pretty weak design. thats why torques or 12pt. much stronger. i do believe the 'special' allens on the balancer/pulley are hardened, they are already special and arent high torque. other than that.
and how many other specialty fasteners do you expect mom&pop (stores) to carry. F* HD(and other chains) considering more than just fasteners. rather cheap and high volume. not much there. although i do find stuff, and often cave in and get certain hardware there. what choice do i have.

ToddA1 said:

Moroza found 12.9 socket caps at HD. I think that pretty much counts as a chain hardware store.

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isnt 12.9 going to be (much) harder than an axle flange if not other uses(we have) imagine what that does. im not 100% sure; but either you get the right bolt there, or perhaps 10.9 will do.
i think metric SS fasteners are 8.8. thats a grade.

Long story short, a socket cap can handle the torque requirement of the CV. Why 12.9 is available is a moot point.... they're available. Going higher in strength for an application may not be needed, but it won't hurt.

If your shopping choices are limited, they're also limiting you. You mentioned chain stores and now you're dismissing them. If "mom and pops" don't have them, but chain stores do.... well, the choice is yours.

Honestly, I don't buy fasteners too often. If I do, it's because I'm being lazy and don't feel like sifting through (2) 5 gallon buckets, filled with metric hardware.

I looked up metric SS fastener grade; seems what's readily available is going to be A-2, at a minimum. Specs are pretty low.

https://www.boltdepot.com/fastener-information/materials-and-grades/bolt-grade-chart.aspx

FWIW, I've only ruined one or two of the CV bolts, when I first got into VWs. I didn't realize it was a triple square and was hammering an Allen in there.

Now, I tap the bit in with an extension and hammer, then blow it off with a 3/8 impact. I do the same to reinstall, with quick blips of the trigger. I don't mess around with going around in a star pattern, torque wrenches or multiple passes. It works for me...

-Todd

I reuse them all the time and never have had any back out ever. I don't even bother with locktite.

You can replace if you want but I don't think it's necessary. The only time I've used new ones is when a boot kit included them and IIRC that's not very often.

I torque in circular fashion and at least twice around, I use a breaker bar and long extension.

Steve

Steve Addy said:

I use a breaker bar and long extension.

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huuhh?? its only 33ftlbs thats book value. even if 42-45 works.

iluvmydiesels said:

huuhh?? its only 33ftlbs thats book value. even if 42-45 works.

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When it comes to drive flange bolts I don't follow the recommendation for torque.

Steve