Early 67 Telescopic Column Rebuild Help

[Richard M.]

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

Jim, I'm understanding it better now, thanks. So, it looks like Dereck's shaft as he pictured is definitely different than the later shaft I pictured. His spacing dimensions are quite different from the later version.

On his, the total length from the left most groove to the end of the shaft is ~7.650". This later shaft totals ~7.805".

But he cannot use the 7800407 bearing, correct? It's 0.580" wide and his mast jacket stepped bore depth is only 0.300" whereas the later is 0.600".

What should he do?

Rich

[Jim S.]

Re: Early 67 Telescopic Column Rebuild Help

Rich,
I'm afraid that I am not going to be of much help. I do have the assembly drawings of most C3 steering columns. These drawings are reduced in size and are not 100% to scale. So I am stuck with visually looking at sections of the drawing(s) for comparisons. I am certainly correct when I say that there are no grooves or round wire rings in the later lower steering shafts. However, I cannot determine if early and late column jackets have different depth of counterbores to accept the lower bearing(s). The later lower column shafts also have some type of stamped collar that is press fit or possibly sweated on the lower strg shaft in place of a groove for a round wire ring.

I am sure that I understand the relationship of the spacers, preload springs, clamps, plastic adjusters, etc. I just am not able to review small differences in dimensions. (Scaling assembly drawings and trying to convert to machining dimensions can really get you into trouble.) I would be happy to review overall concepts with you if you desire.

Jim

[Dereck S.]

Re: Early 67 Telescopic Column Rebuild Help

Thanks guys,
Here is what I feel my available courses of action are:
1. Machine the housing tube bearing bore deeper to allow the use of the integral race late tele bearing currently available. This allows the retainer cup to be used. Use the plastic spacer and clamp from the late tele design. Turn the column into a hybrid late tele.
2. Use the early standard bearing which fits in the current tube bore. This prevents the use of the cup. I studied the bearing and it can't be easily machined to allow the cup to slide over it. Use the plastic spacer and clamp from the late tele design. Turn the column into a hybrid late tele.
3. Search for a replacement shaft that is either for an early or late column. Machine the housing tube bearing bore deeper to allow the use of the integral race late tele bearing currently available. Tele shafts are hard to find.
4. Search for a replacement housing tube with the deeper bearing and find a replacement shaft. Doesn't utilize much of what I have.
5. Exchange this with one of the current restorers such as Magic Mike Denople as being used for parts. Perhaps he can figure out another COA.

The bearing bore in the housing tube remains unexplained. This must be machined deeper to have any chance at using an available bearing. I can accept someone modifying the shaft in some way to get my configuration. That is possible. However, this housing tube appears to be a real tele part that shows no signs of being molested. Curious if there is any pre-production tele columns produced that were hybrids. Someone from Saginaw at the time may be able to comment on that. I've heard stories of creative guys making 67 Corvette tele columns from Corvair or 68 tele column parts. Could this housing tube be from a Corvair? I've never seen a Corvair tele.
Dereck

[Richard M.]

Re: Early 67 Telescopic Column Rebuild Help

Jim, I understand. Thanks for all of the information you've provided. Your documents are a major help.

Dereck,

I would go with #1, machine bore the mast jacket, use the 7800407 bearing, and one step further......I'd go all the way and make it a "Late" column by machining the grooves on the existing shaft for the lockrings based on the Late shaft measurements, and simply acquire the washer, spring and ring retainer and forget about the plastic collar and clamp.

Rich

[Donald O.]

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.

In your photo, there is a soft plastic jacket. Where, how is it attached? Is it for tele only or both? Early or late?
My 67 AIM is missing a couple of pages and it isnt shown in the 66 or 68 so.....

Don

[Jim S.]

Re: Early 67 Telescopic Column Rebuild Help

The thin plastic clamshell cover came from the factory (Saginaw Steering Gear) already assembled over the mesh on the steering column jacket. It basically was to prevent engine compartment noise from coming up the steering column jacket and into the driver compartment. I do not recall if the cover had attachments to hold it in place.
Jim

[Richard M.]

Re: Early 67 Telescopic Column Rebuild Help

Jim I think he was talking about the yellowish/white piece in that pic? If so, that's inside and between the mesh jackets and is a plastic bushing for the shaft to ride on, correct?

The black tube gets heat welded to itself. I show a photo of the welds in one of my photos earlier. I needed one a few years ago on a early '67 Std column, and come to find outthere are many in junkyards as the Jeeps and some other Mopaas used the same part. Not available in reproduction at this time.

Rich

[Donald O.]

Re: Early 67 Telescopic Column Rebuild Help

The thin plastic clamshell cover came from the factory (Saginaw Steering Gear) already assembled over the mesh on the steering column jacket. It basically was to prevent engine compartment noise from coming up the steering column jacket and into the driver compartment. I do not recall if the cover had attachments to hold it in place.
Jim

Jim I think he was talking about the yellowish/white piece in that pic? If so, that's inside and between the mesh jackets and is a plastic bushing for the shaft to ride on, correct?

The black tube gets heat welded to itself. I show a photo of the welds in one of my photos earlier. I needed one a few years ago on a early '67 Std column, and come to find outthere are many in junkyards as the Jeeps and some other Mopaas used the same part. Not available in reproduction at this time.

Rich

Thanks Jim. That explains why it wasn't shown in an AIM.

Rich, I did mean the black tube.

I have the tube, but is is split along a length seam and had been held in place with black electrical tape and a black zip tie. I guess I'll use the electrical tape. Most of the junk yards around here are scrap yards and most only deal with the late model wrecks. Oh well.
I wonder if super glue might work, either the thin or gel type. Maybe even an epoxy with tape to hold it in place until it cures.

Thanks guys. I appreciate the transfer of knowledge.

Don

[Richard M.]

Re: Early 67 Telescopic Column Rebuild Help

Ooops, my bad. Sorry.

So, I needed one a few years ago and a fellow member said he had a few and I got one from him. If you'd like I can try to find who it was. he's a regular here on the TDB.

Rich

[Jim S.]

Re: Early 67 Telescopic Column Rebuild Help

You have one other problem in trying to come up with a plastic cover for your Vette strg column. The jacket diameter for the Corvette (and also the Corvair) steering columns is smaller in diameter than any other Saginaw mesh type steering column. The mesh type steering column was only used for two years on GM passenger cars (1967 and 1968). So all the other GM passenger car covers will be designed to fit the larger diameter column jackets.

Just for you info, here are pictures of the two different types of energy absorbing and telescoping steering column jackets.
MESH TYPE ENERGY ABSORBING JACKET (1967 & 1968 only)

BALL ENERGY ABSORBING JACKET ASSEMBLY (1969 and later)

[Richard M.]

Re: Early 67 Telescopic Column Rebuild Help

Great info Jim, Thanks.

This is the plastic cover that came from a Jeep.

P3180030.jpgP3180036.jpgP3180037.jpg

[Donald O.]

Re: Early 67 Telescopic Column Rebuild Help

Great info Jim, Thanks.

This is the plastic cover that came from a Jeep.

[ATTACH=CONFIG]67732[/ATTACH][ATTACH=CONFIG]67733[/ATTACH][ATTACH=CONFIG]67734[/ATTACH]

Rich, that looks just like my cover, I'll measure for length a bit later. It looks like you are using the black electrical tape method for retention on the mast.
Don

[Richard M.]

Re: Early 67 Telescopic Column Rebuild Help

Yes I used tape. At that time I wasn't that learn'ed. I found out later it was plastic welded.

[Donald O.]

Re: Early 67 Telescopic Column Rebuild Help

My original (as far as I know) is about 10.45" in length.
Don

[Dereck S.]

Re: Early 67 Telescopic Column Rebuild Help

Finally received the late tele replacement bearing. The OD is 0.010" bigger than the early standard column bearing. My bore in the housing tube is not only shallower 0.3" vs 0.6" but the diameter would result in a very high press fit. My bore ID and depth are clearly intended for a completely different bearing. Interestingly, the early standard bearing would fit perfectly in the housing tube. This is not an option with the retention cup. I have no choice but to machine the housing tube bore to accept the late tele replacement bearing. There must have been a version of the bearing that is no longer available. Regarding the mesh cover I typically see 2-3 local areas whereby a heat gun type device is used by the supplier to locally melt the overlap area together. Once broken one way I've used to reattach this overlap is to line the melt marks back up and directly beneath them add silicon. Temporarily tape the overlap together until the silicon cures. This provides the factory look.