Repro Speedo Cable Problem

[Patrick B.]

When I restored the instrument cluster and interior of my 67, I replaced the old shabby speedometer cable and case with a Paragon repro. You wouldn't think that aftermarket an speedo cable would be a big deal; replacement cables were common long before the reproduction parts industry for old Corvettes existed. The cable didn't look as robust as the original and it was a little longer, but it is not a part that shows so having a new cable seemed good from an operational standpoint.

However, the cable is not driving the speedo. When I remove the cable at the transmission and turn it with my fingers, I can get the speedometer to move. If I rotate the rear wheels, the plastic driven gear rotates. It seems like the cable is not entering the plastic gear far enough to cause the gear to turn the cable. Have any of you seen this problem with repro cables? Did you have any solution short of putting the old cable back on?

[Harry S.]

Re: Repro Speedo Cable Problem

Patrick, is the inner cable the same length as your original? If not swap the inner cable.

[Patrick B.]

Re: Repro Speedo Cable Problem

Patrick, is the inner cable the same length as your original? If not swap the inner cable.

[Harry S.]

Re: Repro Speedo Cable Problem

Using DORMAN kit 03368 can you build a new cable the same length as the original?

[Patrick B.]

[Edward D.]

Re: Repro Speedo Cable Problem

Patrick, try replacing the plastic pencil gear in the trans. The center of these is what turns the end of the speedo cable that slips into them. Its only plastic, it can round out. Ensure solid cable end enters the plastic pencil gear and the collar nut is tight. Make sure there is no binding between your cable and cable sleeve. Lastly, if this is an NCRS car, you are better off with a functional ugly original than a shiny new repro cable. The crimps on the ends are different.

[Donald O.]

Re: Repro Speedo Cable Problem

When I restored the instrument cluster and interior of my 67, I replaced the old shabby speedometer cable and case with a Paragon repro. You wouldn't think that aftermarket an speedo cable would be a big deal; replacement cables were common long before the reproduction parts industry for old Corvettes existed. The cable didn't look as robust as the original and it was a little longer, but it is not a part that shows so having a new cable seemed good from an operational standpoint.

However, the cable is not driving the speedo. When I remove the cable at the transmission and turn it with my fingers, I can get the speedometer to move. If I rotate the rear wheels, the plastic driven gear rotates. It seems like the cable is not entering the plastic gear far enough to cause the gear to turn the cable. Have any of you seen this problem with repro cables? Did you have any solution short of putting the old cable back on?

Patrick
Read my posting on this same issue, also from the same vendor
The actual problem is that when before you install the cable the cable looks good, the inner cable is visible at both ends BUT when the cable is routed around the car from the speedometer to the transmission on the passenger side, the cable retreats into the sheath and will no longer make contact with the NEW plastic drive gear.
https://www.forums.ncrs.org/showthre...ight=Big+shout.

Don

[Patrick B.]

Re: Repro Speedo Cable Problem

Patrick, try replacing the plastic pencil gear in the trans. The center of these is what turns the end of the speedo cable that slips into them. Its only plastic, it can round out. Ensure solid cable end enters the plastic pencil gear and the collar nut is tight. Make sure there is no binding between your cable and cable sleeve. Lastly, if this is an NCRS car, you are better off with a functional ugly original than a shiny new repro cable. The crimps on the ends are different.

I don't think the square hole in the plastic gear is rounded out. I stuck it on the speedo cable for a handle when I spun the cable with my fingers to observe speedometer movement, but the very end could be a little beat up. The driven gear for a 4.56 rear is steel instead of plastic. I have one of those I could try as a test since I'm sure it is not rounded out.

I am sorry I didn't just wipe off the original cable housing and reuse it. I installed the repro when the steering column, gauge cluster and seats were out and I might have added some tie wraps under the dash to keep the the cable away from the wiper mechanism. I'm not anxious to remove those things to squeeze myself under the dash again.

You are right about how different the repros are in appearance. I actually removed the new repro tach cable and replaced the old original because the repro was so cheap looking and the nut was hard to start threading on the distributor. But that was easy because it was before the steering column and seats were in.

[Patrick B.]

Re: Repro Speedo Cable Problem

Patrick
Read my posting on this same issue, also from the same vendor
The actual problem is that when before you install the cable the cable looks good, the inner cable is visible at both ends BUT when the cable is routed around the car from the speedometer to the transmission on the passenger side, the cable retreats into the sheath and will no longer make contact with the NEW plastic drive gear.
https://www.forums.ncrs.org/showthre...ight=Big+shout.

Don

[Joe L.]

Re: Repro Speedo Cable Problem

Thanks, Harry. If my repro cable is no longer than 72” I could make a slightly longer cable with the Dorman kit.

Patrick------


What is the length of the original casing?

[Joe L.]

Re: Repro Speedo Cable Problem

Using DORMAN kit 03368 can you build a new cable the same length as the original?

Harry-------


This kit only replaces the drive cable of the original assembly. The way I understood it, at least, I think that Patrick wants to replace the entire casing/cable assembly.

[Patrick B.]

Re: Repro Speedo Cable Problem

Harry-------


This kit only replaces the drive cable of the original assembly. The way I understood it, at least, I think that Patrick wants to replace the entire casing/cable assembly.

Actually, it would be easier to leave the Paragon casing in place and insert a slightly longer cable. I will rig up an empty tail shaft with a driven speedo gear, attach the car's cable and see if the gear in engaged as a test of the theory that the cable is too short.

[Larry M.]

Re: Repro Speedo Cable Problem

Pat:

Awhile back Don Olson had similar issues with a speedometer cable for his 67 car. He found a source that will fabricate an exact replacement, made in USA. It worked out well for him.

Name is John Rulio, Deluxe Speedometer Service, Denver, Colorado. Phone # 303-629-6958 or 888-907-6505.

Thread is titled: Shout Out for a Job Well Done, by Don Olson, September 20, 2019.

You might want to followup on this.

Larry

EDIT: Joe Ray was also involved in this issue with Don.

[Joe L.]

Re: Repro Speedo Cable Problem

Actually, it would be easier to leave the Paragon casing in place and insert a slightly longer cable. I will rig up an empty tail shaft with a driven speedo gear, attach the car's cable and see if the gear in engaged as a test of the theory that the cable is too short.

Patrick------


Do you still have the original casing? That's the one that I'd be interested in knowing the length of.

As far as the reproduction casing goes, the internal shaft ("cable") should be about 1-1/16" longer than the length of the casing.

[Patrick B.]

Re: Repro Speedo Cable Problem

Patrick------


What is the length of the original casing?