Steering Gear Sector Shaft roller won't roll

[Richard M.]

I wouldn't be concerned with the sector. It's not a high speed application.

Rich

[Ian G.]

Just as an update. I disassembled the rollers. You can see the guts below. There is no shim, but there is a clip that holds the two halves of the inner race in place. I took measurements of the roller itself vs the original and they appear very close, but it's a bit tough to do due to the shape. The inner races of old and new are identically thick. I mic'd the clips and found the original one is slightly smaller as seen in the pics. I reassembled the new roller using the smaller original clip, and the two races almost touch now, but still a tiny gap and it still seizes up when put in a clamp sadly, and won't roll when installed the sector shaft.

I've emailed CHS and waiting to see if they respond. Looking at the sector shaft with the roller loosely held in it I can tell that it doesn't perfectly align. I know the car was in a front end collision so I'm wondering if the sector shaft receiver ears are tweaked somehow, and may be adding to the problem. I don't have a known good one to compare.

Given the old races and roller seems to work, I decided to buy an NOS 53-54 sector shaft and roller on eBay for around $135 and waiting for that to be delivered. I'll then try using the NOS sector shaft & inner races with the new roller and cross my fingers. I know I cannot use the NOS sector shaft assembly in full, as it has different roller geometry.

if anyone's interested part numbers below:

3703611 chevy sector shaft/roller
3707787 corvette sector shaft/roller

[Richard M.]

Ian, Good diagnosis.

I hope it's solved with the new sector shaft. Is it the identical part number to the Corvette application?

[Ian G.]

The casting number on top of the sector is the same: 5660218
I understand from other sources on the web that the sectors are the same. I know the roller will will have a different number of turns on the worm though. So I'll need to switch out the roller for sure.

[Richard M.]

Ian, I looked up the sector part # information. It appears that it was only available as a sector/roller bearing assembly. Hopefully the shaft itself is identical to both applications. I understand that the casting number is identical, but I'm hopeful that the finished machining is identical too.

Rich
SectorShaft.jpg

[Ian G.]

Thanks Rich, this post on corvette forum by our own Tom Parsons leads me to believe they are the same in that respect. Anyway It's paid for now, so I'll find out soon enough

https://www.corvetteforum.com/forums...post1601335830

[Gary B.]

Ian,

What do you make of this statement in the Corvette Forum thread:

“…BEWARE of the rebuild kit - there is an issue with one of the bearings…“

Gary

[Ian G.]

Hey Gary, I have a feeling he's referring to the topic below that Rich also mentioned in his post #10:
https://www.forums.ncrs.org/forum/te...ring-worm-gear

In short, the CHS repro worm gear is not machined to the same tolerance as the original and the "center" is not usually in the exact center of the worm. So there are specialized adjustments needed that aren't covered in the ST-12.

The original, fascinating Corvette Forum thread can be found here, but I think the doc "As the Worm Turns" covers most of it:
https://www.corvetteforum.com/forums...problem-5.html

[Gary B.]

Ian,

After reading those threads, it’s still not clear to me that having an issue with “one of the bearings” is the same as the challenge of finding the center. But I’m way over my head on this topic, so I could easily be wrong..

Gary

[Ian G.]

I'm happy to report that I got the NOS Chevy sector shaft delivered and after checking measurements, my "frankenroller" works like a charm. I assembled the NOS inner races and ball bearings with the CHS roller and it installs into the original sector shaft with the pin and turns just fine with finger pressure. Since I now have an NOS sector shaft, I think I'll prep it and use that one though.

If someone needs to do this in the future, I basically followed Joe Calcagno's instructions for the bearing assembly from his article in the restorer (and the Corvette Cenytral kit). It took about 3 tries to get the bearing clamped and spinning OK, as the clip has a tendency to crush a bit in the vice, and I had to pull it and adjust the clip. A comparison pic of the chevy and corvette rollers and finished product below.

[Ian G.]

The finished product if anyone's interested. Lash is set and it seems to pull a little pull harder in one direction than the other, it's in spec both directions (7/8 to 1 7/8 lb or 16-32 ozs). All oiled up, though I did not fill it. I plan to use 85-140 gear oil and put in a felt washer to help keep any oil from riding up the column. My original gearbox did not appear to have paint underneath the grease buildup. So I'm going with the cast appearance. I used boiled linseed oil to darken and protect it. I probably could have done a better job derusting it, and I'll need to blacken the blue sealant for judging I imagine.

One thing of note is the roller on the NOS sector shaft would not roll by hand at all, which surprised me. I'm sure the grease was 60 years old though. Once I pulled the NOS roller it spun fine. My finished sector shaft roller would only roll with firm finger pressure. In the end it seems OK, and I could see it rolling through the high point of the worm with the sector shaft fully in, before I put the cover on.