Ideas removing broken DEM / Haldex bots off - 2005 XC70

[kef]

Greetings All,

I have a 2005 Volvo XC70 at ~260 k miles. Recently, I lost AWD function; I noticed that the rear wheels were not spinning driving in snow. I followed XEMODEX's diagnostic flow chart which pointed the problem to the DEM.

I tried to slowly remove the two 4 mm allen bolts - moving them back and forth, but they eventually broke off anyway. I read https://www.volvoxc.com/forums/showt...highlight=1A64 and VTL had showed a method of removing the top bolt off by cutting a channel (I get that). My problem is that I don't have a lot of room to make a cut on the housing as the whole unit is still attached to the car.

If you look at the picture, the bottom broken bolt has plenty of stud to grab on to, the top one just a little.

I would appreciate ideas to remove the studs. [Minus welding a nut]

Thanks!
-Kef

[FirstVolvo]

Greetings All,

I have a 2005 Volvo XC70 at ~260 k miles. Recently, I lost AWD function; I noticed that the rear wheels were not spinning driving in snow. I followed XEMODEX's diagnostic flow chart which pointed the problem to the DEM.

I tried to slowly remove the two 4 mm allen bolts - moving them back and forth, but they eventually broke off anyway. I read https://www.volvoxc.com/forums/showt...highlight=1A64 and VTL had showed a method of removing the top bolt off by cutting a channel (I get that). My problem is that I don't have a lot of room to make a cut on the housing as the whole unit is still attached to the car.

If you look at the picture, the bottom broken bolt has plenty of stud to grab on to, the top one just a little.

I would appreciate ideas to remove the studs. [Minus welding a nut]

Thanks!
-Kef

I've had been saved more than once using bolt extractors. You hammer them on to get a good bite and they really dig into the rounded bolt head and then you wrench them off. I can't tell from the photo if you room for a hammer to pound them on but if you do these extractors work very well. The pounding is also good for shocking the corroded and stuck threads and no matter what you use to twist these bolts out you should heat them and rap the bolts with a hammer to first loosen the stuck threads.

Sizing is important so measure the diameter and get the best fit for your bolts. I'm not recommending any brand just want to show you what these bolt extractors look like. They do work very well if you have room to use them.

THINKWORK Bolt Extractor Set, 18 Pieces Impact Bolt & Nut Remover Set, Stripped Lug Nut Remover, Extraction Socket Set for Removing Damaged, Frozen, Rusted, Rounded-Off Bolts, Nuts & Screws - Amazon.com

[kef]

Thanks for the input, FirstVolvo.

I attempted to remove the bottom longer stud with similar idea but with a vise grip. I gave it a lot of heat, hammered well, but the bolt simply broke off. Next attempt will be to just drill them off and re-tap if needed. Still waiting for the repaired DEM to return from XEMODEX, so got some time.

[kef]

Closing this thread:

I managed to drill out the old stuck screws and tapping them for new screws. The DEM is finally back on the car. I used a 4.2mm drill bit and and an m5x0.8 tap: Got the combo from here: https://www.amazon.com/dp/B072FBTP4H...05?starsLeft=1

For the top, I used a 90 deg drill attachment to my cordless drill.


I started drilling with a smaller drill bit after marking the center with a punch tool. I progressed with larger bits until I used the 4.2 mm drill bit. Then finished off with a tap (photo).


Repeat for the bottom, easier access bolt. [Drilled straight this time]

Snow forecast for Tuesday, so it will be a good time to test the AWD.

Cheers!

[vtl]

Another approach is to remove the AOC (only 4 bolts, easy to do) and cut the slot along the stuck bolt. Degrease, screw in a new bolt, use JB Weld.

[kef]

I did mention your old post at the beginning of my post. But thanks!