Driveshaft coupling removal DIY, AIR TOOL version

So, this is the 2nd time I've removed my driveshaft from its press-fit coupling. The first time I did it, I used this same general method, however, used only hand tools. It took all day- glacial speed- and left me with blistered hands and a lot of frustration. I vowed to NEVER do it again. "Sawzall next time- I'm just cutting it in half and buying a new one if I EVER have to do this again".

If this is the first post you've seen on removing a press-fit coupling from an inboard driveshaft, the basic concept is to use longer bolts or threaded rod with nuts in order to press the coupling halves together while keeping a spacer of some sort between the halves in order to press out the shaft from the coupling. This is the turbo version.

I was ready to order a new driveshaft, knowing I'd saw this one, when I started chatting about it with Timmy (TRBenj). I get the feeling Tim's a bit more frugal than I am- he fixes stuff generally only when it's broken and always has some clever shortcut or crazy cost-saving measure to get things done (well, most of the time). He casually threw out that an impact gun would probably speed the job up of removing the driveshaft coupling. That hit me like a wrecking ball- Impact Gun + "Socket" Press-out method- a match made in heaven!

Couple things to consider using the impact method: I would need clear access to the head of the bolt at all times- that throws out using long bolts with nuts on each side or threaded rod. Also, as with the hand method, there is not much clearance between the trans output flange and the trans, so as the shaft got pressed out, slack in the bolts would have to be taken up on the head side with washers.

Another gotcha is that, at least in my case, my thick-walled impact sockets did not have the clearance to get around the head of the bolts due to interference with the side of the coupling. Had to use my standard chrome/vlad hand socket with the impact. Didn't seem to hurt the socket one bit.

Went to Ace this morning and got (4) 3/8 Grade 5 2" bolts and (4) of the same thing in a 3" length. Also got an entire box of 3/8" washers (If I was Tim, I'd probably have returned the box after this job, but I tore the box opening it- damn). I had used a lower grade of bolt the first time I did this, and stripped 2 of them. Grade 5 seemed to handle this just fine.

My little compact 1/2" impact from Harbor Freight was perfect for this job. It's not overly powerful, and even has a low setting to make it even more benign. It's light, and really small. Perfect for this application, where I did not want to overdo it with the torque.

With the impact method, this job took 30 minutes. Absolute walk in the park. 1 second with the impact, rotate, 1 second, rotate, add washers as necessary. Repeat over and over. So, so awesome.



Closeup showing washers taking up the slack


Box of washers and longer bolts


Compact impact gun, flawless


Washers taking up more slack


Longer bolts in place, and yes those are stacked sockets inside.


Somewhat unrelated but neat- you can see where the double-lip seal has burnished its own little sealing surface (bottom 2 lines) on the shaft. Probably a bit wider due to hull flex- neat!

Oh, yeah, also, the v-drive coupling is 3 1/2 inches. I couldn't even get a thin walled socket on the bolt heads. Used open end wrenches all the way.

30 minute walk in the park! I'm so jealous!

Excellent pictures by the way.

Levin,
You put a spacer just under the shaft diameter between the shaft and the trans shaft. A deep socket can be used. Then when the space between the coupling halves is drawn up, the spacer pushes the shaft out of the coupling.

As far as bracing the shaft against the impact's rotation- that's the beauty of the impact's hammering action- no bracing other than a spanner on the nut required.

eric lavine wrote: a little neverseize on the threads goes along way also

It sure does! It goes even further when used on puller threads.

rfarkash wrote: Recently pulled the coupler on mine a few weeks ago, and found the best way was a steering wheel puller. Basically 2 bolts hold the puller to the flange, Ron

Ron,
Bad idea! You are pulling the flange at only 2 points so you chances of warping the flange are twice over using four bolts. Before you put the shaft back in, I suggest you press the coupling on the shaft, chuck the shaft up in the lathe and take a face cut on the coupling. DO NOT just chuck the coupling up in the lathe on it's OD. You must machine the face true to the bore so a expanding mandral is an alternate.

Since you have the shaft out, make sure it's straight. It should nor run out more than .003"

Joel,
A lathe isn't needed but V blocks or a decent flat surface like a surface plate is. What are your kitchen counter tops? Stone? You could try to roll it there and use a feeler gauge. However, that will only tell you if it's straight from the strut forward. Many times if you take a prop hit, the shaft will bend aft of the strut. Measuring runout on the taper is where you really need the dial indicator.

and, besides antiseize on the bolts, when using bolts as a pulling force, you always use fine thread because of thread angle, a fine thread has less slope allowing more force

having trouble wrapping my brain around the need for the washers

Why are you using coarse thread bolts????