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rotor reverse threaded? 1975 860GT

Posted: Tue Mar 07, 2017 9:58 am
by rjk40
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

Re: rotor reverse threaded? 1975 860GT

Posted: Wed Mar 08, 2017 1:27 am
by ducadini
Nope, ordinary bolts, nothing fancy

ciao
ducadini

Re: rotor reverse threaded? 1975 860GT

Posted: Wed Mar 08, 2017 7:42 am
by rjk40
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

Re: rotor reverse threaded? 1975 860GT

Posted: Thu Mar 09, 2017 2:15 am
by ducadini
You've gotten them out ?
Lucky You, I've been drilling a few to get those out .

ciao
ducadini

Re: rotor reverse threaded? 1975 860GT

Posted: Sat Mar 11, 2017 11:57 am
by rjk40
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

Re: rotor reverse threaded? 1975 860GT

Posted: Thu Mar 23, 2017 9:20 am
by rjk40
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?

Re: rotor reverse threaded? 1975 860GT

Posted: Mon Mar 27, 2017 8:24 am
by ducadini
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

Re: rotor reverse threaded? 1975 860GT

Posted: Tue Mar 28, 2017 2:13 pm
by rjk40
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.