[TristanScott]

Hey guys, I am working on replacing the AOC filter, pump, and oil for some preventative maintenance as it's been a good 6 years since it was done and I work that AOC pretty hard. The pinion nut is seriously stuck. It's not corroded or anything, I just think it may have been overtorqued by the indy mechanic that did this job 6 years ago. My HF impact gun can't get it off. Tried heating it up (not too hot though) that didn't help. I made a counterhold tool that uses two bolts threaded into two of the holes on the flange and really cranked on it with the breaker bar and I just bent the tool and the bolts.

In VIDA, they show 9995652 counterhold tool and 9997058 adapter to use as a counter hold. I found the adapter online but can't find the counterhold tool. Called around to some local dealers who were not helpful at all.

Trying to figure out how to proceed. I really don't NEED to do this right now but I already have everything apart and want to just finish up with it. Just wondering what you guys have used in the past as a counterhold or what other solutions you may have thought of?

The first impact socket I used kind of started rounding off the nut because it's such a shallow nut and the socket had kind of a deep chamfer. Found a better socket with a very short chamfer and it is grabbing fine and not slipping.

 

[08XC90V8]

The guide I made when I did this job on my Gen 4 Haldex in my 08 XC90 has what I used as a counterhold. Here's the link: 2006-2008 Volvo P2 XC90 AWD – Gen 3 Haldex/AOC Fluid and Filter Change. But I used this to hold the AOC flange while torquing the nut down. Either way, it worked flawlessly. IDK how much help it would be in your case.

I'd recommend using a (relatively) shallow-welled impact socket. My nut had thread locker on it from the factory, which is why I had some issues with it as well. But for me, my Rigid 1/2" drive impact tore it off within seconds. I think you could just try with a more powerful impact? Have you tried to use penetrating oil on the nut? I let it soak with that stuff for about 2 minutes before I went to town with my impact.

 

[TristanScott]

The guide I made when I did this job on my Gen 4 Haldex in my 08 XC90 has what I used as a counterhold. Here's the link: 2006-2008 Volvo P2 XC90 AWD – Gen 3 Haldex/AOC Fluid and Filter Change. But I used this to hold the AOC flange while torquing the nut down. Either way, it worked flawlessly. IDK how much help it would be in your case.

I'd recommend using a (relatively) shallow-welled impact socket. My nut had thread locker on it from the factory, which is why I had some issues with it as well. But for me, my Rigid 1/2" drive impact tore it off within seconds. I think you could just try with a more powerful impact? Have you tried to use penetrating oil on the nut? I let it soak with that stuff for about 2 minutes before I went to town with my impact.

Thanks for chiming in. That's a great guide you wrote up!

Yeah I've soaked the nut in penetrating oil. The impact socket I have now is holding well and not slipping but the entire nut is just deforming. I'm giving up for now. Hopefully that filter and pump will last the rest of the life of the car. Worst case scenario I cut it off somehow one day. I need this car to be running by Friday so I'm just going to leave it for now.

 

[08XC90V8]

Thanks for chiming in. That's a great guide you wrote up!

Yeah I've soaked the nut in penetrating oil. The impact socket I have now is holding well and not slipping but the entire nut is just deforming. I'm giving up for now. Hopefully that filter and pump will last the rest of the life of the car. Worst case scenario I cut it off somehow one day. I need this car to be running by Friday so I'm just going to leave it for now.

Thanks!

I found this after a quick Google Search:

"If you look at the back of the flange there are 3 extra threaded bolt holes that don't line up with the holes that allen head bolts went into. All you do is screw the bolts into the back and they will push the flange of the shaft right out. "

Found this at this link: 04 XC70 Propshaft Removal [Archive] - Volvo XC Forums

Worth a shot!

 

[TristanScott]

Thanks!

I found this after a quick Google Search:

"If you look at the back of the flange there are 3 extra threaded bolt holes that don't line up with the holes that allen head bolts went into. All you do is screw the bolts into the back and they will push the flange of the shaft right out. "

Found this at this link: 04 XC70 Propshaft Removal [Archive] - Volvo XC Forums

Worth a shot!

Your counterhold tool is basically the same as what I made. I only had aluminum laying around. Shouldn't have even bothered and took the extra half hour to go grab some steel as the aluminum counterhold bent. Bent the stainless steel bolts I had too. Probably will grab some 12.9 M8s next time (if I ever get back to this.)

Yeah the part you're referring to is when you are pressing the driveshaft out of the flange on the AOC. I got that out no problem. That nut is just glued on. I just put everything back together and said F it. I'll get back to it one day when the pump dies if I still have the car at that point!

 

[Hounddogger]

M66 doesn't have a damper on the companion flange-- use a pipe wrench?

 

[TristanScott]

M66 doesn't have a damper on the companion flange-- use a pipe wrench?

Mine does unfortunately.


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[bigtimemcalpine]

Try an electric impact. There have been a couple of times where I’ve had trouble with my pneumatic impact on larger bolts (ex: crank). Switched to my crappy electric impact and it popped right off.


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[TristanScott]

Well, it's one year later and my AOC feed pump has gone out. It is doing what it did when I replaced it last time (maybe 7 years ago?) and taking down the whole CANBUS network.
I ground down a 24mm socket so there is no chamfer on it's ID and threw it on a brand new Makita high torque 1/2 impact wrench and it will not remove the nut. I am so grateful that the mechanic who replaced this feed pump last time did the right thing and used a torque wrench for the pinion nut and didn't just CRANK IT ON AS TIGHT AS HE COULD!

So, I may have dropped the rear diff... 😬 Really not all that bad if your in and out of your rear suspension frequently. Going to take the opportunity to address my rear diff leak. Going to replace all the seals that I can while it's out, rear diff bushings too.

AOC came right out of the rear diff housing with 4 bolts and gentle prying. I have it sitting overnight upright with the nut SUBMERGED in WD-40.

The problem is that there's nothing to counterhold since I have the vibration dampening flange. It looks like there are two holes for some type of spanner which could be an option. Another would be to design and 3D print a Carbon Fiber Nylon 6 counterhold which would be bolted to the flange using the 8 threaded holes on the flange. Could feature a tight fit bore for the 24mm socket so that it can't tilt and further round off the nut. Could also come up with some sort of hold down for the socket so that it couldn't back off the nut either.

I'll update this thread with what I end up doing.

 

[BlkT5]

You could have just unbolted the AOC from the rear diff

 

[TristanScott]

You could have just unbolted the AOC from the rear diff

True. I didn't know how hard it would be to pull it off and I really needed to replace the axle seals on this rear diff so I kinda just dove in head first lol.

Just drew up a counterhold tool to throw in the vise that will use some 12.9 M8x100mm SHCS threaded into the flange that will clamp down on the 24mm socket preventing it from lifting off the nut. Going to print in now.

 

[300+_T5R_855]

What software did you use for your drawing?

 

[TristanScott]

What software did you use for your drawing?

Fusion 360

 

[300+_T5R_855]

Thx. Easier than Solidworks?

 

[TristanScott]

Thx. Easier than Solidworks?

I haven’t used Solidworks. I got into using Fusion a couple years ago just because it’s free for personal use and I had used Inventor in High School. I like it for the most part but it has its downsides too.

 

[TristanScott]

Going to try giving this a shot later today once my 12.9 M8x100 shcs come in.
First print failed 3-1/2 hrs in, was printing too fast and the PID tune for the nozzle heater was way off. Fixed a bunch of small issues and tried again at a slower speed and 10 hrs later I had a successful print.

 

[TristanScott]

So the good news is that my jig is perfect. The M8 shcs needed to be hammered through the holes, meaning it’s a perfectly tight fit, and they all threaded into the flange easily. 😎



I bolt the jig, with the ground down socket in place, to the flange and threw it in my vise. Hit it with the impact gun. Nothing. Back the screws off just a turn to relieve friction on the socket. Nope. Put a bigass breaker bar on it and pushed as hard as I can. Nothing.

I’m glad the socket is at least hold tight to the nut. It’s just unbelievable that this nut is on there so tightly. Letting it sit, submerged, in penetrating oil doesn’t seem to have helped. I’m going to bring it to work and show some of the mechanics if they have time. We have heavier tables and heavier duty buses there so I should be able to put more grunt into it.

I’m also wondering if maybe I should try splitting the nut somehow. With it being so deeply recessed, I’m not sure what would work. Maybe drilling a series of holes in it to weaken it?

 

[300+_T5R_855]

Any chance it's a left hand thread?

Also, based on that photo of a breaker bar. Put a pipe on the end of it. I had to torque the rear hubs and had a 3/4" drive with a bar on it to get it to the torque spec.

 

[TristanScott]

Any chance it's a left hand thread?

Also, based on that photo of a breaker bar. Put a pipe on the end of it. I had to torque the rear hubs and had a 3/4" drive with a bar on it to get it to the torque spec.

I've checked the new nut I have and it is not. I thought the same thing haha.

I'll give it another shot. With a cheater bar. I'm just scared I'm going to round off the nut more and then really be screwed... I was thinking about drilling some holes in the face of the nut, as close to the threads as I can, to weaken it, before trying again.

 

[TristanScott]

So I just tried CRANKING on it earlier today on a nice beefy vise on a nice heavy table and the socket is just digging into the nut.

SO, I'm going to to ahead and try to drill the nut out. I was going to wing it with a punch and a drill press and then I decided to make a jig to prevent myself from accidentally hitting the threads on the pinion.

The four holes in the middle accept some drill bushings from McMaster-Carr. The mounting holes around the perimeter are spaced 18 degrees apart so I can clock the drill guides to the nut properly.

Each of the 4 drill guides is a different distance from where the pinion threads begin, 2.0mm down to 0.5mm.

The drill bushings will be here Wednesday. I'll report back with how it goes.