air chisel recommends

[lifespeed]

I think I need an air chisel for a particularly vexing car disassembly job. I have a 2004 Mercury Marauder (like a Crown Vic) with the transmission crossmember press fit into two C-channel brackets on the side frame rails. It is notoriously difficult to remove. The factory installation apparently involves pressing it up into the C-channels (towards the floor pan of the car). The provision for removal is non-existant. Prying too hard will bend things.

I am thinking a wide air chisel in between the edge of the C-channel and the crossmember would be the least destructive way to loosen and spread slightly to get this out. Of course I have already used penetrating oil.

What is a good bang-for-the-buck tool to consider? I see that air hammers are rated from 5X to 9X, although I have no idea what this means - I am assuming 9X is more powerful. I don't know that I need the best or most powerful, but I also know better than to buy an inadequate tool.

Other uses might be chiseling of ball joint rivets, etc.

Thanks!

 

[engineer2]

What a crappy design! A quick search of the crown vic forum:

"Here is my solution should you have only jackstands.

Take a loop of chain and go over the crossmember on one side, then under a floor jack (I am using a 6 ton model.) Make sure the floor jack is positioned to lift against the frame and not the crossmember area, as that will bend. Jack up the car a bit and the crossmember broke free for me.

Take the car's tire jack and raise the now dropped side back to horizontal-ish. Then go over to the other side and repeat the chain floor jack dance, and the crossmember will pop loose.

I wasn't able to get the cross member to break out of the second side until I brought it back to horizontal with the second jack. After that it went super quick."

To put it back in, you apparently support both ends and jack each end into place with the weight of the car assisting you.

 

[lifespeed]

What a crappy design!

Yes, but it results in a very stiff chassis. Which is enjoyable except when transmission work is needed.

I thought of the pulling approach in the context of a fabricated tool with acme threads to pull the crossmember, but I like the jack and chain approach better.

 

[gdocktor3]

Air "rivet guns" are rated with the 4x 5x etc with higher numbers being stronger. These are recommended over air hammers because of the variable trigger. In addition to the variable trigger you can use an adjustable pressure regulator at the air inlet for even more control. When it comes to things like this, I say stronger is better. The only thing to take in to consideration is the size of the tool. With air hammers you can choose short, medium or long barrel designs, with the longer the barrel the harder the hits.

 

[theoldwizard1]

Any one that uses 0.498 chisels.

 

[lifespeed]

Take a loop of chain and go over the crossmember on one side, then under a floor jack (I am using a 6 ton model.) Make sure the floor jack is positioned to lift against the frame and not the crossmember area, as that will bend. Jack up the car a bit and the crossmember broke free for me.

Seemed like a clever idea. $45 worth of chain and hooks later, it moved 1/16" of an inch before the frame started to flex. I'm not going to jack on it any harder. No doubt every car is a little different. Mine is not rusted, but that crossmember sure is pressed in there tight. Air chisel it is . . .

Any one that uses 0.498 chisels.

How about the Atlas Copco RRH10P-TS? They are available used under $200, and as far as I can tell are fairly powerful. One can always use less power at the trigger.

The spec sheet states "Rivet set shank 0.5 inch", which I think you are saying is the 1/2" size provides good strength and tool options?

 

[lifespeed]

So I bought a used Atlas Copco RRH10P-TS, it looks like a quality tool. I also learned every air rivet/chisel/hammer manufacturer on the planet uses a different style bit! What a PITA. I ordered a modest selection of Ajax bits 4 days ago, but of course they aren't here yet. The only bits available locally are the round 0.4", which I suspect is more common among the cheaper air hammers.

Project is dead in the water waiting for tools. Sigh . . .

 

[Packard V8]

Going to be interesting if a relatively small, light air hammer can move what a powerful hydraulic jack can't move.

Have you given thought to putting the jack and chain back in there and using all the pressure you are comfortable applying and then hitting it with the air hammer? That way, neither process has to supply all the force necessary.

jack vines

 

[md21722]

So I bought a used Atlas Copco RRH10P-TS, it looks like a quality tool. I also learned every air rivet/chisel/hammer manufacturer on the planet uses a different style bit! What a PITA. I ordered a modest selection of Ajax bits 4 days ago, but of course they aren't here yet. The only bits available locally are the round 0.4", which I suspect is more common among the cheaper air hammers.

Project is dead in the water waiting for tools. Sigh . . .

The Atlas is designed as a rivet gun.

RRH10P-TS (5X) and up use .498 Parker shank bits

RRH8P-TS (4X) and down use .401 Parker shank bits

Most air hammers use .401 Parker shank bits

The Astro 4980 and CP717 (and any others that size) use .498 Parker shank bits

Its not a matter of "cheaper" its a matter of how much power you are looking for.

 

[lifespeed]

Going to be interesting if a relatively small, light air hammer can move what a powerful hydraulic jack can't move.

Have you given thought to putting the jack and chain back in there and using all the pressure you are comfortable applying and then hitting it with the air hammer? That way, neither process has to supply all the force necessary.

jack vines

The thought has crossed my mind. The press fit between cross member and frame is into a C-channel bracket in the frame. So spreading it slightly with a weld descaling chisel seems pretty reasonable, and an acquaintance with the same car has used this approach successfully. I will definitely proceed with care, I want to make the car better, not tweak the frame or crossmember.

The Atlas is designed as a rivet gun.

RRH10P-TS (5X) and up use .498 Parker shank bits

RRH8P-TS (4X) and down use .401 Parker shank bits

Most air hammers use .401 Parker shank bits

The Astro 4980 and CP717 (and any others that size) use .498 Parker shank bits

Its not a matter of "cheaper" its a matter of how much power you are looking for.

Good info, and nice to have the name "Parker shank" to put with the bit. There were some recommends here to go with the larger bit size and err on the side of more power and rivet gun configuration due to adjustable trigger. I guess you can always turn the power down, but not up.

You would think I could find these bits locally in the San Francisco Bay area, but I struck out. Guess I'll just wait a few more days.

 

[md21722]

You would think I could find these bits locally in the San Francisco Bay area, but I struck out. Guess I'll just wait a few more days.

Doesn't Amazon have same day delivery in the Bay Area? .498 bits are not that common in automotive repair today.

 

[lifespeed]

Doesn't Amazon have same day delivery in the Bay Area? .498 bits are not that common in automotive repair today.

The only 0.498" bits I found on Amazon are round shank. Ajax shows a square shank for the Atlas Copco. Or perhaps the round shank can be used if it is OK for the tool to spin in the rivet gun?

 

[Pipe]

Funny question but can you cut the cross member our then weld it back in?

Sent from my 0PJA2 using Tapatalk

 

[Krician]

***** I didn't see this thread earlier :/ let me tell you my story on rivet guns and bits... A month ago I also bought the rrh10pts on eBay. supposedly its specs on paper meet the CP717. I bought it to go against my boss' cp717 which is also used as the shop gun. First day of using it, it wouldn't hammer out a ball joint when the cp717 did right after. I quickly returned it and did more research for another gun. The gun I was looking for was the rrh12p ts but no one had one for sale... So I searched deeper and ended up with a fresh rebuilt CP 4447 RUTAB which is a 7x hammer. Also ordered all my Ajax bits through Western state tools in Hayward CA which is 10 mins away from me they hit up Ajax and was told that my bits would take about 3 days to source/make except their ball joint forks which took a week to make. Received everything and went for a spin, the hammer blew off BOTH sides and ALL arms of a w220 front suspension in under 10 minutes!! Everyone here says the cp717 is a beast, but now I will challenge anyone against my CP 4447. The gun was purchased from eairtool1.

 

[lifespeed]

The CP4447 is impressive indeed, double the force of the RRH10P-TS and priced accordingly. I can only hope the RRH10P-TS will be adequate for my needs. I just do my hotrod hobby, don't work at a shop.

I heard of Western Tool, but at this point I have Ajax bits on order. Although the slow boat via UPS won't help.

Can I use a more readily-available 0.498" round shank bit in this hammer?

 

[lifespeed]

Funny question but can you cut the cross member our then weld it back in?

No, it isn't welded in now - just jammed in really good. I've made this car better, I won't hack on it.

 

[md21722]

I don't have a RRH10P-TS in front of me to compare but I don't recall anything other than Atlas listed the bit size as 0.500. If you're in a hurry, I would buy one of the bits off Amazon and if it doesn't fit, return it. A mechanism to keep the bits from turning would be nice. As long as your 10 can deform the metal it's big enough.

 

[lifespeed]

Did this job a couple weeks ago. RRH10p-ts was adequate for the job, I did use max power. Have to allow time to special-order the bits.

 

[md21722]

Did you use round or hex shank bits?

 

[lifespeed]

I used a round shank because it arrived first. The hex shanks arrived after I finished, but look like a more gradual chisel edge. And of course don't turn, which wasn't in issue in this case.

Wish I had waited for the double-edged no-turn chisels, probably would have been a bit gentler on the frame.