Early 67 Telescopic Column Rebuild Help

[Dereck S.]

I bought an early 67 telescopic column nearly 25 years ago. After multiple job moves the column got lost in boxes. I was able to locate it again only recently. When purchased, the guy I bought it from indicated the lower bearing had failed and that he attempted to replace the bearing only to find out it was not available. When I pulled the column apart I confirmed his bubba repair whereby he put a bronze bushing in place of the lower bearing. Not a safe arrangement. The damaged bearing was long gone. The column has the lower round retaining ring which appears to be identical to the early standard column design. It then has a spring seat and spring. I obtained the below pic off the internet. The bearing must have a thin flange that is trapped under a bearing retainer cup that is attached to the end of the main tube housing with three screws. The early standard bearing is available as well as the later tele bearing. However, the early tele bearing does not appear to be available. With the whole column now apart I'm stuck. I ordered an early standard lower bearing hoping I can chuck it in a lathe and machine off part of the flange to allow it to fit under the bearing retainer cup. The end of the main tube housing has the same machined bearing bore as in the early standard columns suggesting the bearings were similar except the standard bearings are not captured inside a retainer cup. I reviewed Jim Shea's papers. They are helpful but they don't offer much information regarding the early tele columns. Bottom line, it appears I'll need to fabricate parts where needed and modify others to be able to rebuild this column. I suspect others have run into this issue before. Any help on the lower bearing would be appreciated. I know there are folks who rebuild these. I may need to send it out. I'd prefer to figure it out and do the work myself. I'll add some pics of my column shortly.
thanks
Dereck

[Keith B.]

Re: Early 67 Telescopic Column Rebuild Help

Not sure if it may help but 67 corvairs shared a lot of the same parts in the column as Corvettes.

[Mike M.]

Re: Early 67 Telescopic Column Rebuild Help

check with page campbell from virginia. he's a frequent poster on the tdb. he's been into columns for years. mike

[Don H.]

Re: Early 67 Telescopic Column Rebuild Help

Dereck
Rich Mozzetta covered his resto of 67 tele column in posts 274-277 in his thread here -->
https://www.forums.ncrs.org/showthre...toration/page6
and he spoke of replacing the lower bearing. You might want to send him a note for some assistance.

[Richard M.]

Re: Early 67 Telescopic Column Rebuild Help

Dereck, Yes I just went through this recently. This one is the "late" column, but your photo looks exactly like the one I have here. Allegedy, both Standard AND Telescopic share the same Early.Late bearings.

Can you post photos of your lower section. Also, what is your lower shaft diameter, at the bearing contact area? Use a caliper for accuracy if possible.

The early bearing is available....I think. if you're certain that's what you have. Allegedly it is the stepped design. I'm not sure of the difference between the internals of the early/Late designs in the lower column tube. Jim's papers(referenced in my post#274 HERE), show the identical bearing image in his parts breakdowns. Maybe the tubes are the same diameter, but the shaft is different.

This is the early bearing.

http://www.zip-corvette.com/63-67-c2/steering-systems/corvette-steering-column/67-standard-or-telescopic/steering-column-components/67e-lower-steering-column-bearing-1st-design.html

sc-417_67.jpg

The later design is shown in my posts Don referenced. That one is not available as exact replacement. The replacement has no inner race and the rollers contact the shaft directly. I don't like it. My vendor and I are working that issue. But your photo in post#1 looks exactly like what I have here, 2nd design. Maybe there are some internal differences in the tube, or the shaft is a different diameter. I can't tell from the vendor bearing pictures.

The 2nd design bearing is shown in my posts. Maybe that's what you have?

I have also rebuilt the 1967 Early Standard column and can show photos of those internals too.

Rich

[Jim S.]

Re: Early 67 Telescopic Column Rebuild Help

I don't know if this will be of help or not.

The early 1967 Corvette steering column lower bearing packages were different between the standard (non-telescoping) columns and the optional telescoping columns.

The standard column had a special bearing with a single row of balls. I think the GM part number was 5698402. The inside diameter of the steering column jacket was machined to accept that lower bearing. The complete lower bearing package consisted of a plastic adjuster, a lower bearing spring, and lower bearing. The lower steering shaft had a single groove machined into it and a round wire snap ring went into that groove and retained a thrust washer. A threaded plastic adjuster was used to take up steering column build tolerance.

Shortly after 1967 Corvette production began, the lower bearing package was redesigned and replaced. The groove in the lower steering shaft and the round wire ring were eliminated and replaced by a clamp, nut, bolt, and a plastic spacer. The bearing was replaced by 7800407. This bearing package was also used on the telescoping column as well.

Jim

[Dereck S.]

Re: Early 67 Telescopic Column Rebuild Help

Here are some pics of my early tele column exploded on the bench. My tele appears the same as Rich's column. As I indicated my lower bearing area was modified for a bronze bearing. I believe I'm also missing parts. Focusing on the lower bearing area I have a machined bore in the lower end of the column tube for accepting a press-fit bearing. My shaft has the round cross-section c-clip at the lower end. I'm missing the spring and spring seat. I ordered 18-25B spring and 18-26B seat from LIC. They are for the late tele. Not sure if they are correct for the early column. I also have another groove above the c-clip groove to trap the bearing and keep the shaft from moving axially. Not sure if this is correct. Jim's paper suggests a collar that is part of the shaft. Cutting grooves in the shaft is not typically done due to causing a stress riser. I've attached pics for consumption.
- Rich, do you have the upper groove in the lower portion of the shaft or do you have another means of capturing the bearing?
Dereck

[Dereck S.]

Re: Early 67 Telescopic Column Rebuild Help

Pics attached. I also added a pic off the net of an unrestored early tele showing a felt covering the spring. I ordered this from Doc rebuild. Again, not sure if it is correct. Not many tele parts reproduced.

[Dereck S.]

Re: Early 67 Telescopic Column Rebuild Help

Sorry,
The first pic was one of Rich's parts that I had down loaded.
Dereck

[Dereck S.]

Re: Early 67 Telescopic Column Rebuild Help

Here's some questions I'm struggling with:
1. Is the upper snap ring groove design intent or was this added? If incorrect, there must be another means of trapping the shaft against the lower bearing. What does the "collar" referenced in Jim's paper look like?
2. Are the LIC parts applicable (spring and spring retainer)? I suspect the spring is but the retainer may be unique to this application and may need to be fabricated.
3. Is the Doc Rebuild felt correct for covering the spring? Part number 6521133.
4. Will the late tele lower bearing work? The tube has a machined bore that would need to accept the bearing (press-fit). My caliper battery died so I can't measure the shaft OD. The late lower tele bearing is clearly integral race. Meaning, it runs right on the shaft (no separate inner race).
Dereck

[Dereck S.]

Re: Early 67 Telescopic Column Rebuild Help

More pics of the upper end of the shaft and lower end of my shaft.
Dereck

[Richard M.]

Re: Early 67 Telescopic Column Rebuild Help

Jim, Thanks for that information. Here are some (before) photos of a early Std Column I restored a few years ago showing the stepped bearing and the other items mentioned. BTW, your excellent papers helped me then too.

P3140001.jpgP3140002.jpgP3140007.jpgP3140008.jpgP3140009.jpgP3140010.jpgP3140011.jpgP3140012.jpgP3140013.jpgP3140016.jpg

So I just dug into this late Tele column and took some reference measurements. I just checked some part numbers in Group 6.521 of my P&A books.

Derek, After seeing your photos, I think all you need is the lower bearing. Below you'll see this Later unit is very similar in assembly except the Early machined area is shallower based on your photos. This one is 0.600" deep. The bearing is apx 0.580" and it's edge is lipped to stop at the end of the column tube as shown. It is then held by the spring, special inner edge lipped washer, then retaining ring. You shaft looks correct to me except it's designed for that earlier bearing, which is now to me, clearly thinner than this later bearing.

P1030001.jpgP1030002.jpgP1030003.jpgP1030004.jpgP1030005.jpgP1030006.jpgP1030007.jpgP1030008.jpgP1030009.jpgP1030010.jpgP1030011.jpgP1030012.jpgP1030013.jpgP1030014.jpgP1030015.jpgP1030016.jpgP1030017.jpgP1030018.jpgP1030019.jpg

I think the spring and special washer you ordered will work as the end of the bearing sits in the same place as the later type bearing.

So I think all you need now is to locate the proper lower, shallower lower bearing. If you can get the depth of the machined area it will help to locate it. My parts book does not differentiate Early/Late so it's very confusing. There may be a typo in it's description, but it may be part# 7801324.

edit.....I'm wondering if this is it? It looks similar, but used on Std column but Jim said they were different. I think it has the same ID.
18-30CR

same as

SC-417
sc-417_67.jpg




Rich

[Dereck S.]

Re: Early 67 Telescopic Column Rebuild Help

Rich,
Thanks much for the effort you put into documenting your information in an easy way to understand. I'm going to guess that you are an engineer like myself. Following your approach I'm attaching dimensions on my tele shaft. The pic shows two shafts. The upper shaft is from an early standard column I've had forever. It's from a collapsed column from an accident car. The lower shaft is my tele shaft. First, note that the length of the spline and the location of the first c-ring groove relative to the end of the shaft are identical on both shafts. 1.70" and approximately 4.60" respectively. Both are different than your dimensions. Secondly, the second snap ring groove is 1.35" from the first groove. This is longer than yours. Finally, the depth of the machined bore in the housing tube is 0.30" which is shallower than yours and is consistent with the early standard bearing width of 0.27" which I purchased and is laying next to the tube end in the pic. Regarding the lower bearing it suggests that my column used a different version of lower bearing than what is currently available. A short bearing pilot like the early standard bearing with a thin flange that is trapped under the cup when installed would make sense. The differences in my shaft dimensions and yours are a head scratcher. Many more questions. Sure looks like a bit of a hybrid column. I'm not yet convinced that this column represents a work of art and creativity from someone. However, it is possible. There is no evidence that the housing tube has any modifications. The spot welds on the under dash mount bracket are factory. The shaft dimensional differences and the shallow lower bearing bore in the housing tube remain unexplained. Therefore, the way forward remains unclear.
Dereck

[Richard M.]

Re: Early 67 Telescopic Column Rebuild Help

Dereck, Yes, retired from 30 years in Electronics engineering 10 years ago. However during that time I was a part time Corvette restorer nights and weekends......much needed therapy from feeling like a cinder. I guess my early career habits are hard to hide.

So again I just tried to find the original part number for the early column bearing. The P&A books are vague. I'm away from my books but just found this from the online 1980 P&A, which is similar to my 1970 P&A in it's confusing description of the 2 lower bearings. Nowhere does it mention early or late.
It simply lists the 7800407 and the 7801324(if that is in fact a lower bearing) with meaningless descriptions, at least to me.

http://www.gmpartswiki.com/getpage?pageid=84969

80PA14-395.jpg

However, if you scroll down to Group 6.524 SHAFT, there are some clues in Note 1 regarding the SHAFT when being replaced from the "single row ball bearing" type.

I think we need a parts expert. I suggest that you send a PM to Joe Lucia and ask if he could investigate the part# for the bearing.

Rich

[Jim S.]

Re: Early 67 Telescopic Column Rebuild Help

I have the assembly drawings of the early and late 1967 Corvette telescoping columns. The late column definately uses the 7800407 lower column bearing that has a double row of balls. It is called out on the assembly drawing. The problem is that the early column assembly drawing does not call out the lower bearing seperately. The bearings look the same between early and late columns. The difference is in the lower steering shaft.

The early shaft had round wire rings that installed into grooves that were machined into the lower shaft. One ring seated the lower bearing and prevented it from migrating up the steering shaft toward the steering wheel. The other ring seated the plastic threaded adjuster and prevented movement toward the steering gear.

The later shafts eliminated the machined grooves in the lower steering shaft. The steering wheel side of the lower steering shaft has a small collar that seated the bearing and prevented it from moving up toward the steering wheel. The steering gear side of the steering shaft has a clamp, nut, bolt, and a plastic spacer.

Now the standard column definately had two different bearings. A single ball bearing in the early column where the lower steering shaft had only one groove for a round wire retaining ring.

The later standard columns used the same 7800407 bearing as the telescoping column. There were no grooves in the lower steering shaft. There is a collar on the steering wheel side of the bearing and the clamp, nut, bolt, and a slightly different plastic spacer.

Jim