CV joint removal. Cap head bolts really tight. Tips to remove without rounding out the head?

Any tips on how to remove cap head bolts on CV's?  Working on removing the trans from my Boxster and they are tight, really tight.  I really don't want to strip out the hex in the caps, but I need to undo them.  Any tips?  Should I just risk hitting them with some uggie duggies with the impact, or is that just a recipe for disaster?

The good news is they don't appear at all corroded.  there seems to be enough oil in the area, plus it's more of a nice weather car, that corrosion doesn't appear to be the issue.

Pics courtisy of Pelican Parts showing the area.

One recommendation I've read but haven't had to use myself is to take a sacrificial Torx bit and hammer that into reluctant allen head bolts. Very likely you'll need both a new torx bit and a new bolt afterwards.

Other than that, cleaning up the head really well and ensuring a good fitting allen bit is all the way in should do the job.

If you can grab the outside of the head with vice grips, that can be an option.  On that style of joint, if they're giving me problems I usually just cut the heads off and order new bolts- they can be REALLY stuck.

Set an impact wrench on a low setting and have at it.  It won't be enough to strip them, and may not be enough to loosen them, but the pops of torque will usually get them moving.

A cordless impact gun can usually do the same thing.. .not enough torque to get them off necessarily, but the jiggles will maybe get them started.  Like whacking the lid of a pickle jar with a butter knife to loosen it.

If they round out, I wouldn't stress.  Every time I do one of those with an Allen head (or worse, the VWs with the triple square nonsense) I cut the heads off and use regular 9.8-grade hex-head bolts to replace them, preferably with a flange head if the clearances are tight.

OK, a few Uggie Duggies it is, followed by cutting as needed.

Thx.

The bolts on the G35 were stupid tight and didn't want to come loose using a ratchet. My 3/8" impact popped them out without a issue. 

give each one a couple rattles in the righty tighty direction before hitting them with the lefty loosey.  it works.

Could you use one of those hand held impact drivers that you hit on the end with a hammer? Looks like you would need to use an extension or 2 to reach into the CV bolt area. 

I was just scared to uggie duggie last night.  Yup will hit with lef, right, left, right etc. until either I, or the car, win!

http://www.clarks-garage.com/shop-manual/bolt-01.htm

I've used an air hammer and a pointed punch that fits in the head of the bolt. The shock seems to help. Also some heat applied to the flange the bolts are threaded into can help. Applying that heat and not damaging any surrounding car parts that don't like an open flame can be tricky.

This topic seems fully covered but i want to post these anyway since they seem neat and if i owned one (i dont, yet) it might be one of the things I tried if the normal stuff wasn't working. 

The basic idea

This one for sockets and more torque

Use as new of a socket as you can get, and hammer it in until you know it's bottomed out.

DO NOT USE AN IMPACT GUN.  Crack it loose with a breaker bar.

I had a similar battle with big Torx on a Jeep windshield hinge. Didn't want to strip it out so started with a breaker bar. Got to the sketchy level of torque and switched to a hammer activated impact screwdriver thing and fire, no luck. Friend came over, called me a name, and hit them all with a 1/2 impact and they came out like nothing. Don't fear the impact.

Like Knurled said.  Beat the socket in with a hammer.  Are those Torx, or triple square?  Triple square, you definitely want to beat in with a hammer.  And then use about three feet of extension so you don't rock the socket in the hole.

Take the bit and square it off with a belt sander or a bench grinder.  You will get a better bite with the bit.  then "hammer" it in so it is seated.  Yes they are tight.  That is normal.  I have never broken one.  The biggest thing is to use a bit that is not buggered and give it a tap or three to make sure it is seated.

I have used my small 3/8" impact on these 100s of times on my P cars with no issue.

Knurled. said:

Use as new of a socket as you can get, and hammer it in until you know it's bottomed out.

 

DO NOT USE AN IMPACT GUN.  Crack it loose with a breaker bar.

I know there are arguments not to use the impact on the axle end nut but never heard any issue with using it on the retaing bolts that the OP is having an issue with.  

Streetwiseguy said:

Like Knurled said.  Beat the socket in with a hammer.  Are those Torx, or triple square?  Triple square, you definitely want to beat in with a hammer.  And then use about three feet of extension so you don't rock the socket in the hole.

They are tripple square.  Torx will tend to round off if you try to use them.

These are regular hex, not Torrx or triple square.

I have several sets of these.  I flatten out the end on a grinder so when you tap it in it bites in to the bolt MUCH better.  I would recommend that you get a good sent.  These in the picture were just ones I pulled from the internet.  Not sure of the specific quality of the ones in the photo.  

About the only thing I've learned to never use an impact on are fasteners that go through glass.. 

Everything else is fair game!! lol

dean1484 said:

Knurled. said:

Use as new of a socket as you can get, and hammer it in until you know it's bottomed out.

 

DO NOT USE AN IMPACT GUN.  Crack it loose with a breaker bar.

I know there are arguments not to use the impact on the axle end nut but never heard any issue with using it on the retaing bolts that the OP is having an issue with.  

I have never heard of it on an axle nut.

Using an impact gun on internal-hex (or similar) fasteners that are well and truly MegaTight usually wallows out the hole from the impact action bouncing it around.  Then you WILL have a problem.

Unless it's Torx, in which case it just shatters the tool. 

Using a breaker bar on your 3' extension allows you to put a controlled, smooth torque on it to crack it loose.  THEN you can swap your impact gun on them to zip them out.

I will use an impact to zip MY axles out, because I install them by hand with a 3/8" ratchet, so there will be no bouncing around, just BAP and out.  They're 8mm bolts, they don't need to be stupid tight.

In reply to Knurled. :

If I am ever near Cleveland, I want to meet you for a beer.  It seems you and I respond similarly to many topics. 

In reply to Streetwiseguy :

Thanks.  I'm just some fart who's been doing this for 25 years professionally and made all the mistakes and learned how to avoid them, and I like to pass that knowledge on in case anyone wants to learn the easy way.

And the result is?  Uggie duggies 11 : Car 1. Result under appeal.

So the uggie duggie method does work, and despite the understandable warnings it did not wallow out any  heads. After variable amounts of work, 11 of the bolts came out. The 12th has taken a tremendous punishment but still not given up it's hold. My 25 year 110V Craftsmen impact gun is too hot to hold. I don't want it to die on me so I'll leave it for tonight.   I will let the nice hot bolt soak in penetrating oil overnight and have another go tomorrow.