Belltech Disc Conversion Spindle Issue

[R.S.S.]

I'm currently working on installing a Belltech 952SP (4/5) kit on a 69 gmc. I'm having some issues in regards to the upper ball joints. I've search the forum and contacted Belltech and still haven't had my question answered.

The kit comes with spindle part #3121 which requires me to upgrade to 71-72 brakes which is no issue. However when I go to bolt the spindle on the upper ball joint it will not seat as the outer diameter is to small. The top of the spindle just binds on the control arm. Considering these are conversion spindles I would have expected these to bolt directly onto the standard 69 ball joints. This does not seam to be the case.

Dose anyone know what the OD measurements are at the top and bottom of the tapper for a 71-72 upper ball joint as well as 73-87? The spindle has the following measurements for the upper ball joint:
Large opening: 0.710"
Small opening: 0.531"

Thanks

[lolife99]

Belltech 3121 is the correct spindle to convert a 63-70 drum brake truck to disc brakes.
I don't have balljoint numbers,... But the 71-72 and 73-87 trucks share the same LOWER ball joint. The uppers are different as are the outer tie rods.
Any chance your balljoints have been changed?
I assume you are converting a drum brake truck,... And not just adding DROP spindles to a 63-70 truck already converted to discs?

Any pics would be helpful,..

[R.S.S.]

Lolife99, thanks for the input. the truck originally had drum brakes and I am in the process of converting to disc.

the lower seems to seat perfect on what I would assume to be a stock replacement ball joint. The truck has had its ball joints replaced at some point as the rivets have been knocked off the uppers.

At this point I can only assume that stock replacement ball joints were used as the drum spindle was still on the truck until yesterday. I will try to get some pics tonight for reference.

[R.S.S.]

I will post some pics tomorrow to show the issue i currently have. I've gone to NAPA and picked up one of each series of ball joints and this is what I have discovered.

63-70: stock replacement (currently on the truck), stud is far to long, cotter pin hole is miles away from the castle nut, seems to operate normally with a jack under the control arm. once the control arm is at full droop the upper control arm contacts the spindle causing a bind ie. it is very difficult to move the spindle.

63-70: New, bench test only. This ball joint seems to fit very well and the cotter pin hole does line up well. I will have to install this ball joint and install the spindle to see if there is the same bind at full droop as the existing ball joint.

71-72: The stud and taper is much to small. This is a definite no go.

73-87: The taper seems to mate ok but perhaps not as well as the new 63-70 upper ball joint. The stud is also to long and the cotter pin hole is to far from the castle nut on this ball joint as well.

Has anyone experienced this bind issue between the front lip of the upper control arm and the spindle before? Could a little clearance via a grinder be the answer? I don't think it would need much and the bind is only at full droop. However i don't see why i should have to clearance anything if this spindle was made for the purpose in which i am using it. I will try the other ball joint and see if this resolves the issue.

On another note, the outer tie rod ends do not fit either. I had gotten new outer tie rods for a 69 but the taper and stud is much smaller than the taper in the spindle. does anyone know if i need a 71-72 or 73-87?

Thanks.

[R.S.S.]

First pic shows the lower ball joint. this seems to be seated well with no obvious issues.

Pic 2 shows the stock replacement ball joint currently on the truck. note the excessive length of the stud.

Pic 3 shows the bind in question it is touching the spindle making it very difficult to move. Note: this is at full droop.

Pic 4 shows the bind again from the side (looking towards the front of the truck).

Pic 5 shows the stock replacement ball joint on the bench.

[R.S.S.]

Pic 1 shows another view of the stock replacement ball joint (off the truck).

Pic 2 shows the NEW replacement ball joint (63-70) test fit on the bench.

Pic 3 shows another view of the NEW replacement ball joint (63-70) test fit on the bench.

Pic 4 shows the 73-87 replacement ball joint test fit on the bench. Note the excessive stud length.

[lolife99]

I would try a new 63-70 upper ball joint.
The 73-87 version looks wrong.

[R.S.S.]

Installed new upper ball joints but this did not rectify the bind issue. So out came the grinder. The casting needed a radius to clear the upper control arm to allow it to rotate at full droop.

[N9nefingers]

I know this is an old thread but I couldn't find anything else anywhere on the interwebs...I've just installed the same drop spindles and found that my new outer tie rod ends also don't fit these. The ends I bought are for a 70 C10 which Belltech says are the ones but the hole is way to big in the spindle. Anyone have this issue, solve it, know anything about it? Thanks for any help

[SCOTI]

Originally Posted by N9nefingers

I know this is an old thread but I couldn't find anything else anywhere on the interwebs...I've just installed the same drop spindles and found that my new outer tie rod ends also don't fit these. The ends I bought are for a 70 C10 which Belltech says are the ones but the hole is way to big in the spindle. Anyone have this issue, solve it, know anything about it? Thanks for any help

Try a 71-87 TRE & see if that works.