Footloose was still equipped with the original MCI speedometer
that was driven from the left front wheel. This instrument appeared to work
OK but it did not have an odometer or trip odometer. I am an engineer by trade
and an absolute maniac about keeping accurate maintenance records on my vehicles.
This had to go.
I located a company in Arizona that had custom replacement instruments available
for my coach but they were programmable and would not work with the front
wheel driven generator system unless I modified the drum by adding more bolts
to provide more pulses to the speedometer head. As an alternate, I could drive
it from my Allison HT 740 automatic transmission if it was equipped with a
drive gear.
In order to determine this, I had to crawl up under the coach and sit up in
a hole that was just large enough for my torso, then remove a cap bolt in
the tailpiece on the transmission. The bad news was that this hole, and everything
else under there, was covered with 10 years worth of accumulated diesel grime
mixed with dirt and I had to head for shower when I finished. The drive gear
was in there and I decided to go with the transmission driven generator
since the front wheel thing sounded like a takeoff on the old magnet-on-the-driveshaft
approach which I have never had reliable success with.
An additional benefit of this approach was the new speedometer's ability to provide an output signal for my KC-2500 King Cruise Control so I ordered the parts.
All of the parts arrived and I pulled the supplied 2 wire
shielded cable from front to back using a run of 1/2 inch PVC conduit that
was installed by the original converter. Boy was that nice!.
I installed the new speedometer in the MCI dash board in place of the original
and connected it up to the mating connector on cable above and switched 12
VDC.
As
a side note here, I had to go to a 12 VDC instrument in order to get the features
that I needed which required that I create a new ignition switched 12 VDC
source up front. This was done by using a 30 Ampere 24 VDC relay that was
driven by the switched ignition power source in the front junction box and
switching 12 VDC from house battery with the contacts. I fused the input line
to the relay at 20 Amperes in the event anything inadvertently got grounded.
I also
had to locate a pencil gear and bushing for the Allison transmission to drive
the supplied generator. I managed to find a used one from USA
Parts. Very nice folks and prompt service.
I finally had everything ready to assemble on the transmission and crawled
back into the "Black Hole" again and had the wife hand me parts.
The pencil gear and busing went into transmission very easily but when I attempted
to install the supplied 30 pulse generator it would not thread on to the bushing
because the body was too large to clear a flange on the transmission tailpiece.
After some not so kind comments, I pulled everything out, crawled out and
headed for shower.
The next day, I called the supplier and they indicated that this was unusual problem but that they had an 8 pulse generator that would work. A comment was made that the head was not specified to work with this generator but that they had tried it and it worked fine. I should have called the whole thing off then and there!
A week later, I finally received the smaller 8 pulse generator and crawled back into the "Black Hole" again to install it. Everything fit OK mechanically and I thought I finally had a solution. WRONG!
On May 18, we took our maiden voyage in the coach and I immediately
noticed that the speedometer was anywhere from 4 to 5 MPH slow as compared
to my GPS receiver that I was using for reference. Also, after we got to our
destination which was approximately 82 miles from home, the odometer only
registered 35 miles. I called the supplier from a pay phone to request some
new switch settings for the head to correct this and was told to call back
in about 15 minutes since they would have to look up my records.
When I called back, I was informed that the setup I had would not provide
accurate odometer readings but that the speedometer readings would be close.
Basically, they goofed and then gave me two choices:
1. Accept the system as it was and live with the slow speedometer and lousy odometer.
2. Use the original 30 pulse generator with an extension(which they originally recommended that I avoid because of vibration problems and damage).
#1 was not even acceptable since that would be worse than
the original MCI speedometer so I requested that the 30 pulse generator be
returned to me with an extension and they indicated that this would be done
as soon as they received it back.
Another side note: They will only ship UPS and it takes EVERYTHING
at least a week to get to me from Arizona. I shipped the 30 pulse generator
back to them via US Priority Mail and they received it in 3 days but they
refused to use this method because they would have to go to the post office.
I called back to check on receipt and return of the 30 pulse
generator and was informed that it had been shipped but that they do not supply
extensions and I would have to go to a speedometer shop to get one of these.
After some heated discussion, the individual I was talking to finally agreed
to "see if he could find one".
The next day I called Powls Speedometer Service
in Pa. and described the situation to them. They indicated that a 1 to 1 ratio
adapter would work and agreed to build one and send it to me that day. I called
the original supplier back and told them not to worry about locating one.
The good news: I received the
ratio adapter before I received the 30 pulse generator back.
The bad news: It had the wrong key on generator
end and would not mate with same.
I called Powls back and they indicated that all generators were normally supplied
with an assortment of keys or adapters. They assumed that I had received these
but would send me one that day.
On Memorial Day weekend I finally had everything I needed to crawl back in the "Black Hole" and try again. I reassembled the 30 pulse generator to the transmission using 1 to 1 ratio adapter and everything appears to be pretty solid. It extends the generator up about 2 inches above the bushing but the whole assembly is still pretty well sheltered by surrounding structures and I don't anticipate any damage.
When I reprogramed the head for a 8 pulse generator it didn't
occur to me to write the old switch settings down because I did not expect
to need them again. The supplier preprogrammed the head and did not supply
any programming instructions for same. To date, I have called them twice for
the old switch settings and they keep telling me that they will have to look
up their notes.
I finally got the original settings from supplier on 5/31/2000 and reinstalled
the head. Guess I will find out if it works the next time I have the bus out.
June 17, 2000
I decided that I would take the bus out for a short drive this weekend just
to insure that the speedometer worked.
Guess What? It didn't. Oh Well! Back in the Black
Hole again.
I took the whole generator/ratio convertor assembly loose from transmission
and hooked a battery operated drill up to it and was able to get the speedometer
to work OK.
I then took the pencil gear out of transmission and examined it again and
could find nothing wrong. I put it back in and stuck a flat blade screwdriver
in the slot that drive key normally goes in. It had a slight amount of play
in gears but appeared to mesh fine and I could not turn it. I had run out
of options and finally gave up on it.
June 21, 2000
I had the bus at Bernards Bus Service in Quakertown Pa. for other work and
ask Bernie to check the speedometer hookup. It took his mechanic about 3 minutes
to find the problem.
This is where I discovered that Allison makes, or made, pencil gears with
two different sizes of sleeve that interfaces with the generator, one that
requires a smaller drive key and another one that takes a larger one. My pencil
gear required the larger key and the interface was supplied with smaller key
thus it was not engaging the pencil gear. He swapped keys with me and the
speedometer started working.
This is the only thing that I did not try simply because it never occurred
to me that there could be two different sizes of mechanical interface between
the pencil gear and generator.
Another funny thing here was the fact that the 8 pulse generator worked erratically
for about 80 miles or so with the same smaller key size then essentially quit
working altogether. I can only assume that it had a burr or something on the
small stamped indentation on the side that is inserted in a slot in the pencil
gear or that it was slightly larger. Who Knows?
If anyone else out there attempts any of this, I suggest that you measure
the outside diameter of the hole in pencil gear and insure that you get the
right drive key for it.
June 25, 2000
I had a good opportunity to try everything out on my 270 mile trip back from
Pa. The speedometer worked but the programming requires changing since odometer
is about 96% of actual measured mileage using interstate mile markers and
the trip odometer is erratic and mostly nonfunctional.
Another problem I had noted earlier was a tendency for the
speedometer to fog up immediately after the engine was started. When I started
my trip home on June 25th, both the speedometer and the tachometer fogged
up and this did not dissipate for at least a 100 miles. I suspect this is
due to the lamps used to illuminate the instruments and the fact that I have
both of them wired to ignition on 12 VDC source which means they are on when
ignition is on.
I did this in order to avoid creating a 12 VDC switched source for them when
headlamps or parking lamps were on but I suspect that the bulbs are heating
up the interior of the housings and drawing moisture when they cool off. Since
I do not plan to do a lot of night driving, I intend to change this by either
replacing the bulbs with 24 VDC equivalent and wiring them to dash lamp circuit,
or creating a new witched 12 VDC circuit for same.
June 27, 2000
Had to remove the speedometer and send it back for repair or replacement
because of trip odometer problem. This means that my cruise control is also
dead until I get it back. I am having second thoughts about trying to do too
many things with too little equipment.
If I had this to do over again, I would have probably dealt with Powls from the start because of the competence, or lack of, related to the supplier in Arizona and the turnaround time from same. If you deal with this supplier, I suggest that specify exactly what you want and insure that you get all installation and programming instructions up front and supplied as hard copy also.
July 26, 2000
Received the spedometer head back earlier this month and finally had
a chance to check it out. We only put 75 miles on coach but the calibration
agrees with my GPS and both odometer's appear to be working OK.