Koni 8610 - 1437 with GC coilover and camber kit strut housing sectioning questions

[thunderz]

I have read a few write ups and the instructions from GC on installation for a 240Z. Needless to say I am confused. I was wondering if there is a write up with clear measurements on cutting the strut housing tubes and the spacers? I also read that they need Koni gland nuts? Thanks.

[71Ugarte]

Did you see this one?

HOW TO:

The most current version of my how-to is always here:

http://www.betamotor...Sectioning.html

The text is copied and pasted below:

SECTIONING DATSUN 240Z STRUTS

For Koni 8610-1437RACE Inserts

General

Remove stock lower spring perch from all the struts and remove the brake line brackets from the front struts. Use a cutoff wheel to remove all the spring perches and brackets above the welds and then grind the welds off the strut tube. Get it smooth but be careful not to grind off too much of the tube itself and thin it.

Front

From the dished bottom center of the strut to the top lip the overall length should be between 12.875" and 12.938", measured from the inside using a tape measure. The threaded collar weld-on ring height (assuming 10" tall springs and 5" tall threaded collars) measured from the top of the spindle casting (opposite spindle) is 5.250". The strut tube is cut at about 6.5" up from the top of the spindle casting to put the welded section under the threaded collar. From 1 to 2" is cut from the bottom of the top half of the strut tube but you must measure first to be sure of the exact length as specified above. The most important measurement is the overall length of the strut tube (12.875" to 12.938").

Rear

From the dished bottom center of the strut to the top lip the overall length should be between 14.938" and 15", measured from the inside using a tape measure. The threaded collar weld-on ring height (assuming 10" tall springs and 5" tall threaded collars) measured from the top of the hub casting (opposite hub) is 7.250". The strut tube is cut at 8.5" up from the top of the spindle casting to put the welded section under the threaded collar. From 1 to 2" is cut from the bottom of the top half of the strut tube but measure first to be sure of the exact length as specified above. The most important measurement is the overall length of the strut tube (14.938" to 15").

Process

Preparation

The Koni 8610 inserts are a very tight fit inside the strut tube. The inserts typically have an OD of 1.725 and the strut tubes typically have an ID of 1.730. All cuts must be precise and perpendicular to the strut tube centerline. Use a lathe or a tubing/pipe cutter. Bevel both cut edges at 45 to 60 degrees leaving a flat of .030 to .060 at the bottom of each bevel. This bevel is important to ensure proper weld penetration.

Physically remove all paint and chemically clean (with Acetone) 3" to either side of the weld area. The strut tubes must be clamped into a large piece of angle and a tube (simulating the insert) of 1.720 diameter and 18" in length should be inserted into the assembly to help ensure straightness. Its critically important that the strut tubes are welded square.

Welding the Strut Tubes

Tack weld the assembly in at least 6 places making sure the inserted tube still slides in and out easily. After tack welding, alternate 1" beads back-stepping around the circumference. Make sure no weld bead extends inside the strut tube and frequently check to be sure the inserted tube moves easily. Be careful not to weld the inserted tube to the strut tube. You'll also need to lightly grind down he weld to allow the threaded collar to slide over it.

Weld-on Rings

Fabricate the lower threaded collar weld-on ring from 2" schedule 40 plumbing pipe (2" pipe nipple 6 or 12" long). Cut four .75" rings from the pipe and slide over the strut tube. They should fit over the tube but if not, cut a slot in the ring. A gap in the ring supporting the threaded collar is not an issue.

Slide the threaded collar weld-on ring over the strut and tack weld it to the strut tube on the underside of the perch. This tack weld should be on the back of the strut with the top of the perch 5.250" from the top of the spindle casting on the fronts and 7.250" from the top of the hub casting for the rears.

Measure down from the top of the strut tube to 3 places on the top of the weld-on ring. Make sure the ring is perpendicular to the strut tube. Tap the ring into position with a hammer before adding 3 more tack welds. After tack welding, alternate 1" beads back-stepping around the circumference on the underside of the ring.

Insert Installation

Try installing the inserts into each strut tube. They should slide all the way in with nothing more then a light push. Most likely they won't. Using any or all of the following, clean out and open up the ID of the strut tube:

36 grit 1.750" diameter flap sander

36 grit 1.5" diameter drum sander

Christmas tree shaped carbide bit

1.735" diameter reamer

1.750" diameter wire wheel

You can also sand the paint off the Koni insert and you will probably have to slightly grid down the weld at the bottom of the insert.

When you can easily slide the insert into the strut all the way to the bottom, make two spacers for the rear struts that are approximately 1 to 2" tall and 1.5" in diameter out of .120 wall steel or aluminum (6061 T6) tube. Drop in and center these in the bottom of the rear strut tubes and install the inserts. Measure to make sure the inserts sit at the correct height. You'll probably have to shave a bit off the spacers. Once the spacers are correct, pour a little synthetic oil into the tube, install the spacers and the inserts, tighten the gland nut down, and torque to spec.

The Koni gland nut for the 240Z strut tubes and 8610 inserts is part number 73.25.01.003.1 (M48 x 1.5p). For 280Z strut tubes (which are physically larger in OD and wall thickness) the Koni gland nut part nubmer is: 73.25.01.007.1 (M51 x 1.5p). You can get these from Truechoice but be sure to give them the part numbers.

You will need a wrench for the Koni gland nut and spring perch. Both can be sourced from McMaster-Carr with the gland nut as part number 5480A13 (1.5" span, 7/32" pins, 5.5" long). The spring perch wrench style will depend on what type of adjustable lower spring perch you bought with your coil over kit.

[thunderz]

Thanks, I did see that one. It was the conflicting information that Ground Control sent me that was confusing me. There are write ups out there that say the GC instructions were originally written for the Tokico struts. GC does not specify that in their instructions which has led to more than one person sectioning their struts wrong.:stupid:

[71Ugarte]

I'm trying to decide if I want to section my strut housings or not,but probably will. From what I understand you can do it anyway you want as long as your inside length allows for the strut and gland nut. So basically , you just measure the insert and remove enough from the housing to allow the insert to fit in the housing with gland nut on.

[John Coffey]

From what I understand you can do it anyway you want as long as your inside length allows for the strut and gland nut. So basically , you just measure the insert and remove enough from the housing to allow the insert to fit in the housing with gland nut on.

And if you did that in back you would completely screw yourself. Read the entire strut thread in the faq on hybridz.

[71Ugarte]

There's a lot of good information there. I'll read through it a few times.

Thanks