Front end changeover in progress..., 8/8- Alignment woes Options

[jk76.914]

I'm finally getting rid of the 4-to-5 lug adapters and doing a real Porsche 5 lug front suspension. Contrary to normal practice, which is normal for me, I guess, I'm installing real 914/6 struts with new Bilstein inserts. I bought the parts about 5 years ago on eBay, and the kit was all-inclusive, with freshly painted struts and new ball joints, bearings, rotors, pads, and brake hardware, and rebuilt M calipers. My excuse is I didn't know any better at the time, or I'd have looked for a later 911 set with the later bearing type, but alas, I own it now and everything is in real nice shape.

I think I'm good to go on parts and tools, but I'm trying to find out the torque requirement for the lock bolt for the ball joint. It's an M10 x 30mm x 1.5mm pitch, going into steel threads in the strut; presumably the lower part of the strut, below the tube, is forged.

Looks like an M10 grade 12.9 bolt is good for 50 ft-lbs, but I don't want to chance stripping out the threads. Nor do I want the BJ to pop because it's too loose. Does anyone know the torque spec? Thanks! Picture below-

PS- any tips for installing this type of strut? Thanks!

[ArtechnikA]

I think I'm good to go on parts and tools, but I'm trying to find out the torque requirement for the lock bolt for the ball joint. It's an M10 x 30mm x 1.5mm pitch, going into steel threads in the strut; presumably the lower part of the strut, below the tube, is forged.

Looks like an M10 grade 12.9 bolt is good for 50 ft-lbs, but I don't want to chance stripping out the threads. Nor do I want the BJ to pop because it's too loose.

The early 911 Spec Book calls for 6,5 mkp on the M10x30 ball joint bolt.

Since the bolt positively retains the ball joint as long as it is there, you don't really have to worry about it coming adrift. (You have the 'Old Style' ball joints with the round 'notch' - yes?)

The big problem with the pinchbolt ball joints is that the hole at the bottom of the strut wears and the fit gets sloppy; there is no fix for this other than new struts. So MAKE SURE you have a good tight fit.

(I have always thought it should be possible to ream the hole and install a sleeve, but this never materialized in the marketplace, so I have to conclude it was always cheaper to replace the struts than machine the sleeves.)

[jk76.914]

I think I'm good to go on parts and tools, but I'm trying to find out the torque requirement for the lock bolt for the ball joint. It's an M10 x 30mm x 1.5mm pitch, going into steel threads in the strut; presumably the lower part of the strut, below the tube, is forged.

Looks like an M10 grade 12.9 bolt is good for 50 ft-lbs, but I don't want to chance stripping out the threads. Nor do I want the BJ to pop because it's too loose.

The early 911 Spec Book calls for 6,5 mkp on the M10x30 ball joint bolt.

Since the bolt positively retains the ball joint as long as it is there, you don't really have to worry about it coming adrift. (You have the 'Old Style' ball joints with the round 'notch' - yes?)

The big problem with the pinchbolt ball joints is that the hole at the bottom of the strut wears and the fit gets sloppy; there is no fix for this other than new struts. So MAKE SURE you have a good tight fit.

(I have always thought it should be possible to ream the hole and install a sleeve, but this never materialized in the marketplace, so I have to conclude it was always cheaper to replace the struts than machine the sleeves.)

THANKS!! 6.5 mkp works out to 47 ft-lbs, which is pretty close to the 51-56 ft-lbs recommended for a 10.9 grad fastener. This means that the bolt is at least a 10.9 grade, which generically rates at 51-56 ft-lbs in steel. An 8.8 is only rated for 34-38 ft-lbs. (I said 12.9 originally, but I think I fat-fingered it.)

I have the right ball joints, and they're a smooth snug fit into the bore, which itself looks to be very clean and smooth, so I think I'm OK.


Thanks again!! Jim

[ArtechnikA]

...This means that the bolt is at least a 10.9 grade...

The bolt is specified as a 10,9 - check the headstamp.

[jk76.914]

...This means that the bolt is at least a 10.9 grade...

The bolt is specified as a 10,9 - check the headstamp.

That's more good information! I actually don't have the bolts. I bought the setup from someone who was going to do a 5-lug conversion (or maybe he was restoring a 914/6?) and must've changed his mind. But anyway these bolts were the only parts missing.
Thanks again! Jim