Angle drive shaft appears to be too long

[iflights]

I replaced my angle drive, dust cover, and lower cable in hopes of my speedo failure would be solved. Apparently I fall into the 10% of speedo problems not resolved by replacing those. I suspect it is the speedo itself since running a drill on the shaft in the upper cable doesn't move the needle.

Regardless, I hope the speedo can be repaired by some local shop specializing in such things.

The question I have is that the angle drive shaft appears to be about 2mm or3mm too long, and the dust cover is hard to get into a well sealed position. I've ensured its seated into the AD, but still just a bit too long.

Is this a common problem, and if so, any advice?

Thanks
Steve

[Gregadeth]

I haven't done it myself but if the AD shaft is too long I believe you should be able to just grind it down. As for the upper cable not moving the speedo needle, if the needle isn't moving at all, it's possible the cable has gotten disconnected at the speedo end.

[iflights]

I haven't done it myself but if the AD shaft is too long I believe you should be able to just grind it down. As for the upper cable not moving the speedo needle, if the needle isn't moving at all, it's possible the cable has gotten disconnected at the speedo end.

Thought about grinding it down or shearing it off. Didn't know if this was a common problem. Could not find any solution in the forum other than 1 other comment.

Thanks good thought on the possible disconnect. I'll get under the dash this weekend.

[Chris 16409]

This is what I have seen done before. Not an orthodox repair but it seemed to work

53945

[opethmike]

I hate it when my shaft is too long.

[iflights]

I hate it when my shaft is too long.

Honestly, I did give consideration to calling it a rod, but chose shaft instead.

[Shep]

Speedo's busted. Car has momentum, drills do not. Ask me how I know (I did exactly the same thing and demolished my speedo).

Best to replace. Upgrade to higher MPH version while you're at it if you want, but do NOT let a local shop touch it without seeing what they can do first. I've honestly never heard of such a shop as it's an unusual request and also most modern cars are electronic speedos vs. the DeLorean's direct-drive.

If you're okay in taking a "I don't know the real mileage" hit on your title though, GPS speedos do exist. But again, they are not fully accurate (steep inclines especially)

I'm not sure what problems you had before but most speedo issues where the needle bounces are attributed to gear play between the four connection points (angle drive, lambda entrance, lambda exit, speedo). Eliminating the dual cable / lambda counter setup and instead going with a straight-through cable can certainly help. But it also is a sign that the speedo needs some attention.

Once the needle stops moving, stick a fork in it, it's done.

[iflights]

Thanks for the guidance, I suspected as much. If repair is 1/2 the cost of what a 140MPH replica is from DMCH, I'll get it.

This place is one of the best gauge repair shops in the country and not too far away from me. https://www.bobsspeedometer.com

[Shep]

Thanks for the guidance, I suspected as much. If repair is 1/2 the cost of what a 140MPH replica is from DMCH, I'll get it.

This place is one of the best gauge repair shops in the country and not too far away from me. https://www.bobsspeedometer.comNice! :) Always good to have places like that nearby.

There's not many places like his at all around, he's in a dying breed for sure. My point in the last post was more of a "make sure you trust him before throwing caution to the wind and having blind faith". This guy has the track record for fixing the technologies used as well as the orphan cars. The Federal he has on his speedo (https://www.bobsspeedometer.com/1/120/speedometers.asp) page is one they haven't made in decades. (that's NOT a rollback on that page by the way, it's a reset for the restoration. I see it a lot on the older cars, pre-80's era. Essentially, 42,076.1 + 1.4 = actual mileage, it's all well documented in accordance with federal and state laws)

I've seen the DeLorean speedos myself and have given one as a birthday present. It's not mechanically complicated, but more or less just don't let neighbor Joe trade a beer for the speedo is what I'm getting at. There's a few small parts involved even in the speedos alone that can be easily broken as the plastic ages and gets more brittle. This guy clearly knows his stuff, I will see if I can use him for other projects also.

[nkemp]

I've had the bouncing needle problem for years. The heads-up GPS takes my mind off the irritation and keeps me out of trouble. I really like the GPS since it is easy to see compared to the D's speedo.

Iflights ... rather than shorten the cable (which is not easily re-lengthened) you may want to drill a hole in the yellow hub to let the cable through. Drill just enough to open a hole, not so much as to round out the square hole that catches the cable.

[QUOTE=Shep;226438]... but most speedo issues where the needle bounces are attributed to gear play between the four connection points (angle drive, lambda entrance, lambda exit, speedo). /QUOTE]

I experience bouncing when installed on the wheel but not when on a drill. That makes me think it is related to the AD interface to the wheel. If it was elsewhere in the chain, it should bounce when on the drill. Some may have problems at the other connections/devices in the chain but if it works well on the drill and not the wheel then those connections seem OK. BTW ... DO NOT run the drill faster than 88MPH!

Attempts to fix:

Multiple ADs - None fixed it
Multiple yellow hubs - None fixed it
The shaft is too short or spinning in hub - No indication of wear and has done so on new yellow hubs and different ADs.
Yellow hub spinning/slipping - Marked it and it had not moved (unless it moved back to the exact spot (unlikely)).
AD cable too long - drilled the yellow hub to let it through if needed. Didn't fix
Cussed, swore and invoked various demons ...no fix


At some point the fun of buying parts trying to fix it lost its luster.

So I'm open to ideas. Maybe there is slippage somewhere in the chain that the drill overcomes but not the wheel ... but that doesn't really make sense.

[Shep]

No just don't run Drills AT ALL! Drills are not a suitable diagnostic tool. Please don't make my mistake, I have learned this from experience the hard way. Here's why:

Drills have next to zero inertia nor momentum compared to a DeLorean at speed, the speedo has been designed to work around the stopping forces of a two thousand pound vehicle, not a ten pound rotary device. 88 MPH to zero in a second and a half -- I don't even know if a Bugatti Veyron is capable of that kind of speed changing. It's certainly not designed to. There is no amount of carefulness in the world that can overcome the problem a drill imposes.

If you absolutely must diagnose issues, leave everything connected and dyno the left front wheel. Use the dyno to change speeds, that's what it's there for (by the way, these are the same powered dynos that often are used by shops to diagnose wheel balancing issues to, so they're out there).

[Josh]

No just don't run Drills AT ALL! Drills are not a suitable diagnostic tool. Please don't make my mistake, I have learned this from experience the hard way. Here's why:

Drills have next to zero inertia nor momentum compared to a DeLorean at speed, the speedo has been designed to work around the stopping forces of a two thousand pound vehicle, not a ten pound rotary device. 88 MPH to zero in a second and a half -- I don't even know if a Bugatti Veyron is capable of that kind of speed changing. It's certainly not designed to. There is no amount of carefulness in the world that can overcome the problem a drill imposes.

If you absolutely must diagnose issues, leave everything connected and dyno the left front wheel. Use the dyno to change speeds, that's what it's there for (by the way, these are the same powered dynos that often are used by shops to diagnose wheel balancing issues to, so they're out there).

54120

My speedometer still functions fine, and I have done this a handful of times.

[Shep]

Which is effectively dynoing the left front wheel -- the brake caliper provides the inertia necessary to avoid damage to the speedometer.

That is the correct way to do what I say is wrong in a manner that is right also :thumbup:

(If that's confusing, drill on bare speedo cables will cause damage. Drill on wheel or brake rotor is basically a makeshift dyno and won't hurt at all)

[Nicholas R]

What? I'm not sure I understand what inertia has to do with the speedometer functionality. As far as I know, rotating the cable just creates a magnetic field that moves the needle. The torque on the speedo cable is irrelevant; all that matters is the speed of rotation.

[David T]

Yes, the speedometer only measures the rotational speed of the cable. 1,000 RPM's = 60 MPH.

[iflights]

Calling Bill Richardson...watched your video on Farrar's angle drive. Exactly how long is the shaft from end to end that you fashioned?

[iflights]

Calling Bill Richardson...watched your video on Farrar's angle drive. Exactly how long is the shaft from end to end that you fashioned?

My mistake, Bill Robertson. Bill Richardson is my neighbor, and he doesn't own a DeLorean.

[Nicholas R]

Which is effectively dynoing the left front wheel -- the brake caliper provides the inertia necessary to avoid damage to the speedometer.

That is the correct way to do what I say is wrong in a manner that is right also :thumbup:

(If that's confusing, drill on bare speedo cables will cause damage. Drill on wheel or brake rotor is basically a makeshift dyno and won't hurt at all)

Just a point of note, the photo shown doesn't show the drill turning the brake rotor; it shows the drill connected directly to the angle drive shaft. The only way to spin the angle drive via the brake rotor is if you rotate the rotor by hand, and have the angle drive cap in place (thereby linking the rotor and angle drive).

[Shep]

Exactly how long is the shaft from end to end that you fashioned?
Lay out old next to new, leave Lambda counter connected, use the total as reference. If it fits now, match it. Simple :)


What? I'm not sure I understand what inertia has to do with the speedometer functionality. As far as I know, rotating the cable just creates a magnetic field that moves the needle. The torque on the speedo cable is irrelevant; all that matters is the speed of rotation.Okay, I'm learning a bit as I go here, this was my understanding, correct any mistakes:

In the scenario where you take the end of a speedo cable, which is connected to a speedo, and attach it directly to the drill like this:

Drill --> Cable --> Speedo

With nothing in between, it's not hard at all to simply pull the drill to full speed immediately and have the speedo jump from 0 to 100 MPH in a quarter of a second. It's this very action I am cautioning against. A brake rotor or some other type of flywheel will slow the acceleration enough to not to not be an issue. As far as what those issues, are, well, this was how it was explained to me:

There is a peg on the speedo that prevents the needle moving past about 90 MPH stock. If the needle is forced against this quickly, it can become offset, so everything reads a certain amount "off". I want to say this one corrects, I don't have a speedo handy to look at currently, but I believe there was a peg on the backside that cuts off at 0 MPH to prevent reversing from showing on the speedo. Which honestly was another angle I couldn't figure out as the same guy said reversing lowers your mileage. He really knows his stuff, but this sounded a bit :8ball: to me.

The second part is that it "wears out" quicker. Given that it's a magnetometer, I would assume that means it demagnetizes itself, I thought it was some kind of gearing and it added "tooth play" when I addressed this earlier (which, by the way, is the problem angle drives tend to have. Tooth play + time = failure).

The other components however are still prone to failure. The cables can unwind, the lambda counter can snap, but generally they don't do much more than add a little bit of flex into a system that could use a slight bit more anyways. Downstream of the angle drive, of course, there's really no easy way to replace it and bypass all the shenanigans. Some guys have, but again, no "easy" way exists.


Just a point of note, the photo shown doesn't show the drill turning the brake rotor; it shows the drill connected directly to the angle drive shaft. The only way to spin the angle drive via the brake rotor is if you rotate the rotor by hand, and have the angle drive cap in place (thereby linking the rotor and angle drive).Oh god good catch, yeah I need to redact that earlier statement that using a drill as pictured was correct, that will prematurely kill the angle drive if it wasn't dead already. Baby steps on that spot, the gears in the angle drives are hypersensitive!!! Slow and steady wins the race, don't overdo it!

[Nicholas R]

There is a peg on the speedo that prevents the needle moving past about 90 MPH stock. If the needle is forced against this quickly, it can become offset, so everything reads a certain amount "off". I want to say this one corrects, I don't have a speedo handy to look at currently, but I believe there was a peg on the backside that cuts off at 0 MPH to prevent reversing from showing on the speedo. Which honestly was another angle I couldn't figure out as the same guy said reversing lowers your mileage. He really knows his stuff, but this sounded a bit :8ball: to me.


When you replace the trip reset shaft, I believe one of the steps is to remove the needle from the center stud. I remember doing this when I installed my 140mph speedo. It's definitely important that the needle goes back at the right angle otherwise you will indeed always read incorrectly. I'm not sure if driving the needle into the stop while driving could cause it to slip, but I suppose if you were to rotate the speedo cable at the equivalent speed of say, 200mph on an 85mph speedometer, you could feasibly create enough torque on the shaft to slip the needle; especially if the needle was slightly loose on the shaft to begin with.