Pinch Bolt Removal (new method)

Below is the mcmaster.com part number for the hardened-steel hex coupling used in the original info base write-up. On my 2003 Passat V6 FWD ATQ, the pinch bolt is 10mm dia (M10) size. So this is the hex coupling that will fit the M10 bolt:

Part # 93020A782

Also, here's the part number for hardened-steel "fixturing" washers that will help if you put these under the hex coupling (you should grease these up too). These are actually SAE (american) 3/8" washers, but they fit better (less play) than the metric M10 washers and have a larger OD too.

98029A046


btw, a lot of people said they tried the method in the info base, but instead of using the hex coupling they used the nut that was originally on the pinch bolt, and that the nut/bolt stripped out. Others have already pointed out the importance that using the hex coupling engages a lot more threads to prevent stripping, and also that its better because the coupling is of hardened steel. So you really should use the hardened steel hex coupling and grease everything up good!

Pinch Bolt Success !!

Today I was finally able to get the pinch bolt out ! And in one piece no less.

What finally worked was getting the bigger air hammer gun from Harbor Freight. They sell two models, and it was the larger "Super Duty" gun (for only $15) that worked. Definitely one of the best bargains in tools!

You have to use a combination of two techniques with this air hammer gun:

First, as Jay and PZ mentioned in other posts, you have to use the flat chisel bit inside the spaces (cracks, recesses) of the housing sleeve. But first you have to blunt the chisel edge, using a grind stone, so that you don't cut into the pinch bolt. I also formed a U-shaped notch at the tip, as was suggested. (this is so that the bit will conform the the pinch bolt and not cut into it or deform it too much) I also ground down the thickness of the chisel so that it did not expand the spaces of the housing too much, otherwise you can crack the housing (again, thanks for the great advice!)

The goal is to get the blunt chisel tip to hit against the bolt and vibrate it to loosen the rust and get it unseized. You keep hitting it with penetrating oil too (in the housing slots) as you are doing this, and the vibration apparently helps work the penetrating oil in. Don't just go straight in horizontally; you also have to rotate the gun to hit it from the top and bottom, and all the possible angles in between. Just be careful not to f-up the rubber boots. Also, with the penetrating oil, you should try to get it inside the top of the slots. There's a little cavity at the back top of the slots that the oil can pool in.

Secondly, you also have to use the air hammer on the end of the bolt as well. In order to do this, you use the pointed chisel bit (bull point). I also blunted this tip with the grind stone so that it didn't cut into the bolt metal. You need to keep the nut on about half way to create a "pocket" to keep the chisel tip riding centered on the tip of the bolt. Actually, at first I did not use the nut because I bought the 10mm (M10) hex coupling from mcmaster.com noted above. (see part number in posts above) This coupling gives you a deeper "pocket" to keep the bit centered. Just be sure that the tip of the bit is contacting the tip of the bolt. You don't want the bit to be riding on the ID of the coupling. Then later, as the bolt is finally coming out, you will need to switch to the nut because the coupling will eventually bottom out. Its also good to have this coupling on hand in case you want to use the method in the info base.

btw, you also turn the car's steering wheel all the way to the left or right, depending on whether you are hitting the housing slots versus the end of the bolt.

Just keep alternating between hitting the housing slots versus the end of the bolt. I'd say a good 5 minutes on one, then switch. Alternate every 5 minutes or so.

I was about to give up and then, like a miracle, I noticed that the bolt head had finally moved about 1/8" ! I knew right then that it was "all over" for that pinch bolt !

Then I would tap the bolt head back in using a regular hammer (because you cannot access the bolt head end with the air hammer), and then hit the other end with the air hammer again; this way working the bolt back and forth, and hitting it with penetrating oil all along. Then I was finally able to turn the bolt head using a six-point socket and a 3 inch extension. You have to be careful not to snap the bolt head off. Then using a box wrench, I worked the bolt head back and forth quickly, hitting the bolt with penetrating oil through the housing slots and at the bolt ends as well. It kept getting more freed up as I did this.

Then I was finally able to "go in for the kill" with the air hammer at the bolt end. Then the nut bottoms out and you have to remove it and use a punch or another bolt and tap it out the rest of the way using a regular hammer.

Afterwards, my ABS trouble-light was on. But luckily, I read here that the same thing happened to someone else, and its just a matter of pushing the ABS sensor back in. (The vibration from the air hammer allowed it to pop out a little.) I cleaned the ABS sensor up, as well as the sensor's well/socket. And then wiped the sensor down with WD-40 before pushing it back in. You rotate it back and forth using slight 1/4 turns as you push it in. When it bottoms out, you back it out about the thickness of a sheet of paper by rotating a 1/4 turn, and back again, as you apply a slight pulling force. You don't want to pull it out too much. Its just so that the axle inside does not rub against the end of the sensor as the axle rotates. But the end of the sensor needs to stay close enough to the axle inside in order to sense the axle's movement.

Thanks again to all the great advice here. There's no way I would have been able to do this without having learned from all the great tips on this board.

Someone said in another post that removing a siezed pinch bolt is like a "right of passage" for the B5 owner. I couldn't agree more. Anyone I told about this (friends, family, co-workers) would say "all that trouble to remove a bolt" ?? But its comforting to know there are many here who understand the signifinace of finally "bagging" the pinch bolt !

penetrant and hammers and clamps and torches, oh my....

this pinch bolt story has a succesful ending:
I pre-read all the posts on pinch bolt removal pain, and after much back and forth with wrenches, and much kroil and much pb blaster, and some attempts to press the bolt out with slave nut and clamp, and blow torch and mankinds second greatest invention: the hammer and yes, even mankinds greatest invention, the bigger hammer: I opted to try the dremel cut method.

This was not the path to success. I cut through the head side slot and the head came out instantly as hoped. The tail however wouldn't budge, even using lubricated washers and oiled threads on the coupler nut, the bold snapped cleanly off at the base of the threads. Not twisted, snapped. Do you like folks to us emoticons in posts? the one where I have a baffled and sad look would be right at this point.

So I took out a drill and a small cobalt drill bit and a center punch and carefully drilled a hole through the center of the bolt. I bought some replacement pinch bolts and nuts, and cut one the bolts off cleanly below the threads to use as a driver. Then I drilled increasing larger holes as deep as I could for a couple of hours (did I say carefully?), trying between each bit to lubricate the remains and whack at it with the driver bolt and a hammer.

At one point, about 60% of the diameter, I used the dremel to make a through cut an the thread end pinch slot. The short piece then came loose and I was able to pull it out. The longer center piece was stuck though and I continued to enlarge the drill bit size until I broke through the wall of the bolt. The remains drove out with little effort, and I am left with a perfect 2 inch long C shaped crescent of bolt. The outside of it is almost clean, with tiny corrosion spots only, but they were enough to freeze it in place forever. the next time I go to replace the upper control arms, I will start with the Dremel cut and pull method, but plan to again drill the bolt out.

Glad it worked out for you. And definitely -- never seez !

It does seem that its the center section of the bolt (between the two pinch slots) that gets jammed up. I was reluctant to try the dremel cut method because I did hear of the bolt snapping off in some cases.

I'm convinced (per suggestions of Jay and PZ, and from my experience of doing the 1st pinch bolt last weekend) that its incessant vibration thats needed, switching between all different angles.

Tomorrow I'm taking the day off from work and going to try doing the 2nd pinch bolt using the air hammer method again. But this time I'm also going to add a new twist to the mix:

It would have been good to have been able to get an impact wrench on the end of the bolt and, with low to medium torque, cycle back and forth between forward and reverse. But the space was just a little too tight to fit the impact wrench. I do have an air ratchet, but if the bolt head does not turn, then the air ratchet just freezes up (does not have any "impact" action).

So at Harbor Freight I just picked up a compact, palm-sized "butterfly" impact wrench for $25 minus 20% coupon. I can't wait to use this thing tomorrow. The butterfly lever will make it so easy to cycle back and forth between forward and reverse. I think this, together with the air hammer/chisel, is really going to break down the corrosion quickly.

I'm also going back first thing tomorrow morning to get the "air hammer quick release chisel holder" for $6. This is needed for two reasons: First, the HF "Super Duty" air hammer (more powerful than the standard model) actually ends up dislocating the chisel retainer spring. I think this in turn causes the gun to stop working and just blow air (which does happen, but not sure if these are related). This quick change holder replaces that retaining spring altogether, and will hopefully also stop the tool from "hanging up". The second reason is that this quick release holder will make it so much easier to change back and forth between the bull nose point bit and the flat chisel bit.

Another thing that occured to me is that when I was doing the first inch bolt last weekend, its possible that the upper control arm pins may have been lifting up and catching on the bolt. So tomorrow I'm going to make sure that these two pins remain fully seated. I guess I'll just push down on them now and then, or maybe tap them down with a hammer. If it appears that they are in fact lifting up and catching on the bolt, then I may have to strap them down to the lower control arms, using something like ratcheting tie-down straps.

Will report back ...

HERE'S THE BOTTOM LINE ON WHAT WORKS WITHOUT USING HEAT (BUT HEAT IS INDEED RECOMMENDED AS LONG AS YOU ARE NOT TRYING TO SAVE THE UPPER CONTROL ARMS).

Today I removed the second pinch bolt and it only took 20 minutes this time ! It was definitely as rusted in as the first one I did last weekend (that took 6 hours of experimentation to finally remove). These bolts had been exposed to 8 years of winter salt in PA and NJ.

HERE'S WHAT YOU NEED TO HAVE:

1) Air compressor capable of at least 4cfm at 90 psi.

2) Air Hammer/Chisel Gun (get the "Super Duty" one at Harbor Freight for $15 and it comes with all the chisel bits you will need. Also get the "Chisel Quick Change Holder" that is a $6 accessory designed to be used with this gun. It turns this "okay" air hammer into an "incredible" tool.

3) The hardened steel, 10mm hex coupling from mcmaster.com for $4. See part # above.

4) A 16mm or 5/8" box wrench (or at least an adjustable wrench). btw, 16mm and 5/8" are about the same size; that's why you can use either.

5) Some kind of penetrating oil. I made my own using a 50/50 mix of ATF (automatic transmission fluid) and mineral spirits. I also added a little acetone, MEK, and marvel mystery oil, but those ingredients are optional, and the acetone and MEK can harm paint and rubber. Pretty much any penetrating oil like Liquid Wrench should do fine.

HERE'S WHAT YOU NEED TO DO:

Pre-treat the pinch bolt between the pinch slots. Start doing every day for a week prior, if possible. Otherwise, just start applying the penetrating oil now. Also hit the ends of the bolt with the penetrating oil, but getting in the pinch slots is more critical, especially at the TOP of the slots so that the oil gets to the back of the bolt too. Throughout the procedure below, you keep hitting the area with penetrating oil about every minute or so.

After the car is jacked up and the wheel is off, you take the nut off the pinch bolt.

You are first going to use the air hammer with the flat chisel. But first you have to blunt/flatten the tip of the chisel using a grind stone. This is so that the chisel does not cut into the pinch bolt. Now, put this flat chisel bit into the air gun and lube the flats of the chisel tip. You are going to chisel into the pinch slots with this flat bit so that you SLIGHLTY expand the pinch slots back to their normal relaxed position. If you use the flat chisel bit thats supplied with the Harbor Freight air hammer, it will be the perfect thickness after you blunt the tip. Without too much trouble, the chisel tip will then contact (hit against) the pinch bolt, which is exactly what you want to happen. This way, the chisel tip will vibrate against the bolt and help break it free. You do this in both of the pinch slots. And as you do this, you hit it from all angles (not just coming in horizontally, but also from the sides, top and bottom).

Then you switch to the bull-point chisel. But first you also blunt the point of this bit so that it will not cut into the bolt. Also, first grease the threaded portion of the pinch bolt. And then put on the 10mm hex coupling. Thread this coupling on all the way (but not tight). Then place the tip of the bit on the threaded end/tip of the bolt, and unscrew the hex coupling until it just starts to lift the bit off of the end of the bolt. Then screw the hex coupling back on about 1/2 turn or so. This is so that you are using the hex coupling to keep the bit centerted on the end of the bolt, but you do not want the hex coupling taking the brunt of the vibrations. Thats why you back it off about a 1/2 turn. Then you go at it with the air hammer for about a minute or so.

Then repeat hitting the pinch slots with the flat chisel and hitting the end of the bolt with the point chisel. Keep alternating between these two methods and using plently of penetrating oil.

Now here is a truly "new" method that seemed to really get the job done:

You screw the hex coupling all the way onto the threaded end of the bolt. Then, using the box wrench or an adjustable wrench, you tighten the hex coupling and then loosen it. You keep doing this with 1/2 turns back and forth. What this does is it works the right side of the pincher back and forth and it is breaking down the corrosion. Keep hitting with penetrating oil. Just don't over do it with too much torque (up to 30 ft lbs at most).

Then lossen the coupling and hit the end of the bolt and the pinch slots again with the air hammer one more time. Did I mention more p oil ?

Now, you keep the flat point chisel wedged into the pinch slot that is closest to the threaded end of the bolt. (Or you can shove a thick washer in there. The slots are about 1/8" or 3mm wide.) The intention is that you are wedging something in there to keep the pinch slot from closing during this next step:

After you have the chisel or washer wedged in the slot, you screw the hex coupling all the way on the threaded end of the bolt. Then, using the box wrench or an adjustable wrench again, you continue to tighten the hex coupling and then loosen it. You keep doing this with 1/2 turns back and forth. What this does is it works the bolt free at the center of the pinch sleeve where it is the most seized. You see, in the previous step you freed up the pincher near the threaded end of the bolt. Now, by wedging something in the crack, the force is transmitted to the center portion of the pinch housing sleeve. And you can go a lot tigher too (more torque) on the bolt because the pinch slot is being prevented from closing (flexing) too much.

Continue to do this back and forth for a few minutes and using lots of p oil.

Now, loosen the hex coupling and use the air hammer again on the slots and then on the end of the bolt again. More p oil.

You should now miraculously see a small gap appear between the head of the bolt and the seating surface. In other words, the bolt will start to move ever so slightly.

Keep oiling and keep at it with the chisel. Of course, when the hex coupling bottoms out, you will have to take it off and you can use the original nut to keep the chisel bit centered until that nut bottoms out as well. Then just use a hammer and a punch (or a thinner bolt) to tap the bolt out the rest of the way.

As mentioned, use never-seez on the new pinch bolts.

Just to add my recent experience: I used the "Cut the bolt head off" method. I didn't have the special coupler, so used a nut. Nut went on with spacer washers. Tightened and tightened until, lo and behold, the end of the bolt snapped off. Now I had a bolt with both ends missing. Hammered for another hour with a drift on the bolt. Nothing happened. Went to Harbor Freight and bought 2 sets of air hammer chisels. Went to work on the bolt from the end using the pointy chisel that came in the set (I ground the point off). Vibrated the thing with the split chisel. Went back and forth with each tool while squirting more and more penetrating oil. It worked!!! Kept driving it til the air hammer tool didn't fit , then used a drift and hammer, then finished with a hardened bolt. Took about 45 minutes. One trick I have to add: when using the split chisel on the joint, round off the corners of the chisel. It WILL slip off the fitting and hit your rubber bushings. Original Chisel:

Chisel after Grinding