While removing the harmonic damper in order to access the timing chains I noticed that the bolt seemed to require rather more force than I thought should be necessary to remove it. I broke it loose with a breaker bar using a 3' section of pipe to increase the leverage, then I switched to a 1/2" ratchet wrench but it still required the use of the pipe to back the bolt out until it was almost completely removed. Now that I am reinstalling the damper I can't turn the bolt in more than two revolutions by hand and only another revolution or so with a ratchet until it starts to rotate the motor. This does not allow the split sleeve to be compressed tightly enough to prevent the crank from turning. The threads on the bolt look undamaged as do the threads on the bolt I removed. Does anyone happen to know what the thread size and pitch of the damper bolt is so that I can get a tap to chase the threads?

I have heard that it is not recommended to turn the motor in one direction because it could possibly bind up the timing chains. Facing the front of the motor which direction is it that I should not turn the motor? I have rotated the motor about 90 degrees in both directions trying to install and then remove the bolt. Should this cause an issue and how could I determine if it has?

Thanks for any help you can offer.

 

The torque specs on that are insane. That said, I wouldn't be surprised if there was some old loctite left in there.

Also, are you reinstalling the original damper? There was a TSB that prescribed an "upgraded" part (AJ81330) that's less prone to coming loose, but it's obnoxiously expensive. You can probably guess how I found out.

 

I suspect that there is some of the old threadlocker embedded in the threads. When I stick my pinky finger in there I can feel some roughness and was able to dislodge a few particles of some kind of debris.
I am installing the original damper. The rubber compound between the inner and outer diameters still looks good and smooth and I am in no way interested in paying the $1700 USD on the new style damper unless or until I absolutely have to. I think I'd go the rebuild route if it came to that.

We have a lot of metric taps at my place of employment so I could just go in and match it up but it would give me a bit more peace of mind if I knew the spec before hand.
I was able to borrow a calibrated torque wrench from work that tops out at 600 ft.lbs. so reaching that insane torque spec should not be an issue once I get things to lock up.

 

I had the same thing happen when I worked at the dealer over a dozen years ago. The car was in factor warranty so I called Jaguar Tech Hotline and they wanted me to put a crankshaft in the engine!!!

I told them that I was not wanting to do that and that it would be easier to put a reman engine in it!!!

I thought about it for a while so I decided to make a TAP from the old bolt. I cleaned the bolt and cut 4 grooves with a cutoff wheel and retapped the crank threads working slowly back and forth, in and out until all the threads were clean and the tap turned easily.

I got a new bolt from the parts dept and put everything back together!!!!

There are ways around a seemingly disastrous situation.

bob

 

Thank you for the tip. I'll give that a try.

 

I sized the bolt at work this morning and it is an M16X2. I now have a good sharp bottom tap in hand so I should be good to go. Thanks for the tip on slotting the old bolt though, it was my last line of defense.

 

I chased the threads with the M16X2 tap and now the bolt threads in freely. All that came out was a black powder which I assume was caked on threadlocker. Now to finish reassembly.....