Thread: Tips on rebuilding a 3 bolt steering box

Originally Posted by 85 county

Rubbish

the selector shaft wheel is BELOW the worm not above it. Dougal its been to many years since you had your box out,

Suggest you take another look. My memory is clear.

It is definitely above, because I have never taken my box out. I've changed sector shafts in-situ and this would not be possible if they went in from below.

Originally Posted by 85 county

well i know no one who has broken a 3 bolt but know of a few with broken 4 bolts.

3 bolts wear out, 4 bolts break. i have seen 2 with broken selector shafts, where the wheel attaches.

As I said, I have seen (more) broken 3-bolts than 4-bolts. Which renders your statement incorrect. The only person I know who has broken a 4-bolt is RangierRover on here - in a 120 that works VERY hard.

3-bolts were manufactured for ~15 years, and fitted to 2 vehicle types (at a time when a large percentage of vehicles were sold without PAS). 4-bolts have been manufactured for ~27 years currently, and sold in far greater numbers than the 3-bolt ever was. So even if 4-bolt shafts were breaking in larger numbers, it probably wouldn't be statistically significant.

My 3 bolt skipped a notch in a high stress situation, that was near-enough broken for me to replace it asap. Prior to that the vehicle hadn't been very well maintained, and I hadn't adjusted the box since I bought it so no idea if it was well adjusted or not, so granted it may have happened to any box that hadn't been cared for.

My last box in the D2, the sector shaft actually twisted after being t-boned. Bent panhard rod and track rod, drag link stayed straight by some miracle and the drop arm bent (very slightly but was out by comparison to the new one)and the shaft twisted below the wheel.

Either way, the shaft must come out from above through the lid. Doesn't the worm on the input shaft act on the wheel? And in so doing means the worm is level with the wheel (input shaft centreline level with centre of wheel). The sector shaft needs to be removed before removing the input shaft.

Unless referring to the assistance gear which is below the wheel on the sector shaft.

Originally Posted by clubagreenie

My last box in the D2, the sector shaft actually twisted after being t-boned. Bent panhard rod and track rod, drag link stayed straight by some miracle and the drop arm bent (very slightly but was out by comparison to the new one)and the shaft twisted below the wheel.

Either way, the shaft must come out from above through the lid. Doesn't the worm on the input shaft act on the wheel? And in so doing means the worm is level with the wheel (input shaft centreline level with centre of wheel). The sector shaft needs to be removed before removing the input shaft.

Unless referring to the assistance gear which is below the wheel on the sector shaft.

Same thing happened to mine. But it was driven into a bridge and I wasn't driving. Sector shaft was slightly bent, but mostly twisted. Steering wheel was about 90 deg to drive straight.

The wheel on the sector shaft is just a bit higher than the worm, it meshes down from above and that top bolt is the free-play meshing adjustment. The assistance gear (or piston or rack, whatever you want to call it) doesn't get any adjustment.