Speedometer stripping out dust sheilds

[bruscreen]

As spring approaches, I'm realizing I need to get the speedometer working in #5316.

When I bought the car, it had no dust shield and a seized angle drive. I bought a new angle drive and dust shield from delorean.com, and that lasted a couple of years. Then the speedometer became intermittent, low-speed only, then nothing. I lubricated the cables. The lambda counter is still hooked up with the cable, with the wire disconnected by a previous owner. I've pulled it out and tested it, but it doesn't appear to be slipping. With everything hooked back up, I pulled the dust cap and tested the cable with fingers (turns freely) and a drill (reads highway speeds, easy). I suspected the dust cap was spinning against the wheel, but gluing it on with lock-tite didn't help (I got about half a mile out of that). So I pried it off, bought a new dust cap, and that fixed it for a couple of months before the problem came back.

I suspect that the square hole in the dust cap that accepts the speedometer cable is rounding out, and the only thing I can think to do for it is to fill it with JB Weld and try to mold it to the cable without effectively gluing it on. Before I go to those extremes, what else should I try? Is there a better dust cap on the market? Am I missing some other component to test?

[SS Spoiler]

Head on down to ace hardware and look for a square brass
tube that fits over the angle drive. Fit it into the dust cap and
enjoy a working speedo. I did this 23 years ago, no problems......

[David T]

Head on down to ace hardware and look for a square brass
tube that fits over the angle drive. Fit it into the dust cap and
enjoy a working speedo. I did this 23 years ago, no problems......

One car I worked on was "eating" angle drives and dust caps. I pulled the speedo head out and opened it up. One of the plastic posts had broken off and still had the steel clip on it. It was moving around inside until the magnet in the speedo mechanism attracted it and jammed the works. All that resistance was the problem. If you are having similar problems you may have the same cause. Might be time to pull that head and examine it's innards.

[sdg3205]

The lambda counter is going to add resistance no matter what, but not so much as to kill a dust shield.

I solved this problem by completely cleaning all the 35 year old grease out of the lambda counter, regreasing the mechanisms and installing tin shims in the dust cap itself. This was Toby's idea and it's practically free. You cut thin tin strips from a can to fit the 4 walls of the dust cap. This provides a tighter fit and does the trick.

[PJ Grady Inc.]

FWIW I'd like to let the group know we have made up this part using a stronger urethane resin because many people have experienced fit issues and/or failures of the commonly available replacement.
Rob

[bruscreen]

Thanks for all the advice guys, I knew I'd find some experts here! This should keep me busy experimenting for a weekend, and if it doesn't work out I'll turn to the upgraded dust cap.

[David T]

Thanks for all the advice guys, I knew I'd find some experts here! This should keep me busy experimenting for a weekend, and if it doesn't work out I'll turn to the upgraded dust cap.

That dust cap is like a mechanical "fusible link". It breaks before other, more expensive and harder to replace parts break, like the angle drive. Making the dust cap more robust may not be the thing you want to do.

[PJ Grady Inc.]

That dust cap is like a mechanical "fusible link". It breaks before other, more expensive and harder to replace parts break, like the angle drive. Making the dust cap more robust may not be the thing you want to do.

We made the dustcap as strong as the original because many people had repeated failures with the currently available replacement. It's like using a 10 Amp fuse when the current draw is 20! They also are often too big to fit in the hub and need modification to fit. We made these adaptor cups only because we felt a need for a more durable part. David if you prefer to replace your dustcap every few times you drive your car I can understand your desire to preserve your angle drive at all costs but it's unnecessary. We also have a one piece cable that eliminates the extra drag of the lambda counter. As for angle drives I prefer reconditioned Smiths Instrument units as opposed to the inaccurate Chinese/Indian units currently available. We offer a kit with all three of the above for those who want to fix their speedo woes once and for all.
Rob

[David T]

We made the dustcap as strong as the original because many people had repeated failures with the currently available replacement. It's like using a 10 Amp fuse when the current draw is 20! They also are often too big to fit in the hub and need modification to fit. We made these adaptor cups only because we felt a need for a more durable part. David if you prefer to replace your dustcap every few times you drive your car I can understand your desire to preserve your angle drive at all costs but it's unnecessary. We also have a one piece cable that eliminates the extra drag of the lambda counter. As for angle drives I prefer reconditioned Smiths Instrument units as opposed to the inaccurate Chinese/Indian units currently available. We offer a kit with all three of the above for those who want to fix their speedo woes once and for all.
Rob

My car has the original dust cap, angle drive, speedo cables, Lambda counter, and head. I lube everything once a year and it all works fine. The original parts can be reliable if everything is working as it should and you keep it all lubricated.

[PJ Grady Inc.]

My car has the original dust cap, angle drive, speedo cables, Lambda counter, and head. I lube everything once a year and it all works fine. The original parts can be reliable if everything is working as it should and you keep it all lubricated.

You also only drive your car about once a year! Ok a few times a year. Btw the original adaptor cup was fine. I'm referring to the current repro's unless they were recently improved?
Rob

[bruscreen]

I took the wheel off last night. Found a human error that kept the cable from turning. The upper cable wasn't lined up properly to the lambda counter. Unfortunately I think I've had that apart since the speedo last quit so I can't prove it's the source of the problem.

The root of the alignment problem seems to have been the way my footwell was arranged. My wiper controller mount has been hanging since I bought the car, and I think some of the wires were pulling on the speedometer cable. I just found where the mount belongs in another thread and I'm working to clean it all up.

[David T]

You also only drive your car about once a year! Ok a few times a year. Btw the original adaptor cup was fine. I'm referring to the current repro's unless they were recently improved?
Rob

While it is a low mileage car it goes out to cruise nights, car shows, and some paid engagements. My point is, a properly taken care of speedometer system can work well on original parts. Over designing one part to compensate for deficiencies in other parts of a system is not always the best way to 'fix" a problem. Oftentimes it just moves the failure point.

[opethmike]

While it is a low mileage car it goes out to cruise nights, car shows, and some paid engagements. My point is, a properly taken care of speedometer system can work well on original parts. Over designing one part to compensate for deficiencies in other parts of a system is not always the best way to 'fix" a problem. Oftentimes it just moves the failure point.

Start driving your car and we'll see how long that speedo system works.

[sdg3205]

+1 with Mike. I think we can all agree the original DMC speedometer system is one of the most failure prone issues with the car.

[David T]

Actually the worst (IMHO) system is the electrical system. It tends to be the root of most of the problems with the car. Next would be the fuel system but in most cases it is because of stale fuel and aging of the parts, not because of inherent design defects.

[PJ Grady Inc.]

While it is a low mileage car it goes out to cruise nights, car shows, and some paid engagements. My point is, a properly taken care of speedometer system can work well on original parts. Over designing one part to compensate for deficiencies in other parts of a system is not always the best way to 'fix" a problem. Oftentimes it just moves the failure point.

You're not listening to what I said David. We made the cup more equivalent to the strength of the original because we saw repeated failures of the repro part commonly available. To use the prior analogy we replaced a 20A "fuse" with another 20A instead of a 10A. That is not over engineering but rather just common sense engineering. If you don't understand my point now then I give up. As usual you can have the last word. Carry on.
Rob

[opethmike]

All I know is I'm far more inclined to listen to advice from someone who actually drives their car, or the guy who has been working on DeLoreans on a daily basis for nearly forty years.

Practical, real world knowledge versus book "knowledge".

[David T]

I will always defer to Rob Grady's advice. He speaks from years of "Hands On" experience and if he hasn't seen it all, he has seen more than any of us. That said, I also have a lot of years of experience working on, looking at, and speaking to many owners and other Deloreans. While my advice on Deloreans cannot ever be as good as Rob's, it still has a lot of credibility. IMHO there is no better authority on Deloreans than Rob. That includes all of the people at DMCH because Rob has been at it since the beginning. PJ Grady was an original dealer and the only surviving one. No one else can make that claim. Not only does he work on the cars himself, he gets parts made to reproduce or replace the original service parts. As for the dust cap, if it is made to the same specs as the original it HAS to be better if only because the originals are so old and brittle. Getting deeper into the speedometer drive system, it has a LOT of problems. The design of the dust cap, the cable through the spindle is wound the wrong way, the angle drive is an engineering and design mess, the original cables were the wrong length, there was no support bracket for the lower cable originally, no one EVER lubes the cable or the angle drive, etc.With all of that said, it can still be made to work in its original configuration. Getting back to the original specs for the dust cap is a good place to start.

[PJ Grady Inc.]

I will always defer to Rob Grady's advice. He speaks from years of "Hands On" experience and if he hasn't seen it all, he has seen more than any of us. That said, I also have a lot of years of experience working on, looking at, and speaking to many owners and other Deloreans. While my advice on Deloreans cannot ever be as good as Rob's, it still has a lot of credibility. IMHO there is no better authority on Deloreans than Rob. That includes all of the people at DMCH because Rob has been at it since the beginning. PJ Grady was an original dealer and the only surviving one. No one else can make that claim. Not only does he work on the cars himself, he gets parts made to reproduce or replace the original service parts. As for the dust cap, if it is made to the same specs as the original it HAS to be better if only because the originals are so old and brittle. Getting deeper into the speedometer drive system, it has a LOT of problems. The design of the dust cap, the cable through the spindle is wound the wrong way, the angle drive is an engineering and design mess, the original cables were the wrong length, there was no support bracket for the lower cable originally, no one EVER lubes the cable or the angle drive, etc.With all of that said, it can still be made to work in its original configuration. Getting back to the original specs for the dust cap is a good place to start.
Thank you David for your confidence in my competence. Over the last 36 years of my Delorean experience it might be fair to say I've managed to forget more than many people know about the cars ! Is that a good thing....maybe?

You are correct that the original speedometer system can be made to last a long time with the proper lubrication of the drive and cables. Lubing the gears with 90wt gear oil from a pump bottle and the cable in the stub axle with a good spray grease will assure the longest life possible. We do this at every oil change for our service customers and it minimises the reliability issues. Making sure you update the lower cable and bracket to the better design used after VIN #005179 is also important. Our rebuilt angle drives with a properly wound, thicker, cable better initial lubrication also have an excellent track record. We can also make the axle cable a double square for easy removal and servicing if someone wants that feature. Finally for the non-purist eliminating the lambda counter and using a one piece cable takes an additional load off the system and simplifies it. Ours are made in America and the core is servicable unlike the Chinese copy. (Please note I am not anti-Chinese but the quality varies greatly from supplier to supplier and verification of specifcations is much easier when you use more local supply sources). Failures most often occur on the parts exposed to the elements but even the upper cable benefits from lubrication if you have your binnacle removed for any other reason. I think that covers it from top to bottom but in the reverse order.
Rob

[opethmike]

Dave still owes me a hug.,

[David T]

Dave still owes me a hug.,

You're going to have to wait a LONG time for THAT!

[opethmike]

You're going to have to wait a LONG time for THAT!

Uh, dude, we all drive time machines. Duh.

[Drive Stainless]

You're going to have to wait a LONG time for THAT!

What does the workshop manual say about hugs?

[PJ Grady Inc.]

what does the workshop manual say about hugs?

"verboten!!!"

[David T]

"verboten!!!"

There is no torque spec listed. I suppose you could use the standard torque for that size once you can determine the size.

[PJ Grady Inc.]

There is no torque spec listed. I suppose you could use the standard torque for that size once you can determine the size.

Mike only gives the biggest hugs David so I would start with a torque spec of 150LB's and go from there.

[bruscreen]

I'm trying to listen to all of the advice I've received - at once - even where it conflicts!

I have removed the binnacle and pulled out the speedometer. The cable was stuck in the back of the speedometer, but I was able to wiggle it free. There's nothing out of place in the speedometer itself, but the plastic gears for the odometer are very dry. I have some graphite that I was going to use on the cable, should I apply some to those gears and inside the hole where the cable goes? Or is there a "better" option for lubricating the speedometer head?

[David T]

You can use 3-in-one oil sparingly.