rotor reverse threaded? 1975 860GT

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rjk40
Diana
Posts: 57
Joined: Thu Dec 05, 2013 10:54 am

rotor reverse threaded? 1975 860GT

Post by rjk40 » Tue Mar 07, 2017 9:58 am

After getting the ignition rotor/gear assembly off of the crankshaft, it appears that the six flat head hex screws holding the assembly together are revers threaded, looking from the backside; not easy to tell.

Anyone been here?

Thanks in advance.

Regards,
Richard
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ducadini
750 GT
Posts: 155
Joined: Sat Jul 31, 2004 8:54 am
Location: Antwerpen

Re: rotor reverse threaded? 1975 860GT

Post by ducadini » Wed Mar 08, 2017 1:27 am

Nope, ordinary bolts, nothing fancy

ciao
ducadini
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rjk40
Diana
Posts: 57
Joined: Thu Dec 05, 2013 10:54 am

Re: rotor reverse threaded? 1975 860GT

Post by rjk40 » Wed Mar 08, 2017 7:42 am

Thanks for the reply; after further review, I found three replacement screws in the Sachse ignition kit, and had I had any forethought I would have found them, and seen that they are "regular" threads. Getting new ones with the kit is great, as the original ones are seriously "hogged" to where the hex wrench wobbles.

Regards,
Richard

ducadini
750 GT
Posts: 155
Joined: Sat Jul 31, 2004 8:54 am
Location: Antwerpen

Re: rotor reverse threaded? 1975 860GT

Post by ducadini » Thu Mar 09, 2017 2:15 am

You've gotten them out ?
Lucky You, I've been drilling a few to get those out .

ciao
ducadini
Nego i ricordi peggiori
Richiamo i migliori pensieri

rjk40
Diana
Posts: 57
Joined: Thu Dec 05, 2013 10:54 am

Re: rotor reverse threaded? 1975 860GT

Post by rjk40 » Sat Mar 11, 2017 11:57 am

Yeah, no surprise at that. The hex holes in the heads were damaged, either from the factory or by the dealer that replaced a bad stator many years ago. I was able to get the durned things loose by pushing hard on the hex wrench whilst applying brute force counter-clockwise.
I consider myself lucky (for a change). I too would have had to drill the beasts out, as the next step. Good thing that Sachse provides replacement screws; they even fit (whoopee!).

Next challenge: getting the last pin out of the crankshaft gear, so that the new timing rotor from Sachse will seat properly on it. So far, broke two 3/32 pin punches.
Regards,
Richard

rjk40
Diana
Posts: 57
Joined: Thu Dec 05, 2013 10:54 am

Re: rotor reverse threaded? 1975 860GT

Post by rjk40 » Thu Mar 23, 2017 8:20 am

Finally had to resort to drilling and Dremeling the last stubborn pin out.
Even though the parts manual shows it as a pin, it seems like it is welded in.
Biggest challenge will be to grind enough out to maintain a fairly good balance on the gear.

Anyone else had this issue?

ducadini
750 GT
Posts: 155
Joined: Sat Jul 31, 2004 8:54 am
Location: Antwerpen

Re: rotor reverse threaded? 1975 860GT

Post by ducadini » Mon Mar 27, 2017 7:24 am

There seem to be holes at the back of the pins, couldn't You punch them out ?
Nothing welded, but Loctite is possible.
As long as You get both out, do not worry about balancing

ciao
ducadini
Nego i ricordi peggiori
Richiamo i migliori pensieri

rjk40
Diana
Posts: 57
Joined: Thu Dec 05, 2013 10:54 am

Re: rotor reverse threaded? 1975 860GT

Post by rjk40 » Tue Mar 28, 2017 1:13 pm

Yeah, I got the first one out by punching from the backside into the small hole, and it eventually came out, but the second one refused, so I drilled and dremeled it out. used about 6 pin punches and one Dremel tungsten carbide cutter. Phew!

Judging by the 860GT parts manual, the crankshaft gear, flywheel and six screws are all one part number, and likely were never thought to be available separately, as they are balanced as a unit (per holes in the rotor...).

Then, along comes Sachse et al.

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