|double click on the picture
Rebuilding the overdrive transmission
A picture of the transmission
as it was taken out of the car.It will require a clean up, a tear down and powder coated..
Tearing the transmission apart and
making a list of replacment parts needed.
We decided to purchase a new gear
(#7113). It was difficult to find one with the right tooth count (29-25-19-15).The transmission had been torn down before
because some snap rings and washers were not correct. We replaced the bearings,and was cautious about ordering the right kits.
After rounding up all the parts needed we started re-assembling the tranmission.
More numbers on the transmission
case.The powder coated case looks nice.
Putting the many bearings in the
cone and using grease to keep them in place.
A picture of a dummy shaft holding
the bearings in place.
We purchased a new shaft
so we shorten the old one to fit in the case and used it as a pilot in order to keep the bearing in place.Here we are driving
the pilot shaft out with the new one. It is almost impossible to put the shaft through the bearings without the dummy shaft.
Getting it back together.
About to the end of this project.Everything
checks out ok.We'll put the electrical parts back on and mount it on the engine .
The motor is taken off
the engine stand and mounted on a cart to assemble the clutch
and transmission.The cart will be converted with a radiator
and gauages to test and break
in the engine.
Speedometer / Overdrive Problem
restoration is now completed, I've put 40 miles on the car and the OD isn't working. After pulling the Gov I discovered
it had no gear on the end. There was no Gov gear in my transmission parts but I had another OD transmission from a 57
Ford wagon so I used that gear. After driving the car a few miles the OD still didn't work and now neither did the speedometer.
When ever I have a problem I can't solve I go to the Thunderbird chat room. After a few suggestions Wade Taylor said the
speedometer drive gear on the OD output shaft may be bad. This gear drives the Gov and also the speedometer cable gear. He
had this problem years ago and the drive gear was very hard to find.
The gear on the
left is from the 57 wagon, the center one is the correct one and the right gear is for the speedometer cable. Click on the
picture to enlarge it and you can see the left gear is a right hand helix, and the other 2 are left hand gears. Putting the
right hand wagon gear on the Gov chewed up the speedometer output shaft drive gear. All three gears should be left handed
so they mesh together.
right hand gear on the Gov ruined the speedometer drive gear and the transmision has to be removed. The gear is in the
tail shaft area but it can't be removed in the car. After finishing the restoration I didn't want to remove the engine
so I concetrated on the transmission. This picture shows the clutch cover removed and to jack up the rear of the engine to
remove the transmission mount, a board was placed on the bottom ledge of the bell housing. The oil pan is not a good place
to jack on.
After spending a day
trying to get the transmission out I finality gave up and pulled the engine. I could see no way to remove the transmission
unless maybe sliding the motor ahead a few inches to drop the clutch. I wasn't happy about this decision but took steps
not to mar the paint.
|click on the picture
shows the Gov location and if you look in you can see the speedometer driver gear is stripped. In order to get the tail shaft
off, pop the brass plug on top of the transmission and remove the snap ring. On the opposite side of the case the
dowell pin on the OD shift lever needs to be removed from the bottom up to pull the lever out. Remove the tail shaft bolts
and slide the shaft off.
After calling all the T-Bird
suppliers I could think of and going down the list in Hemmings (about 20 calls), I finally found the transmission driver gear
# MC-17285-A at North West Transmission Parts. The phone # is 1-800-327-1955 and ask for John. According to the Ford text
manual this is a nylon L.H. helix gear but John tells me orginally they were steel, used in other applications and when they
replaced them with nylon they changed the number. John has a good supply of steel gears and also machines the nylon replacments.
I found John to be old school, easy to talk to and very helpful in getting the right 3 gear combination. Just don't call
before noon EST.
I waited to make sure I could get the part before disassembling the transmission
and we thought this transmission would have the nylon gear so that was ordered. In the picture is the new nylon gear which
is an exact duplicate of the old steel gear sitting on the output shaft.
Wayne is a retired
mechanic and helps with difficult problems. When pulling the tail shaft the bearing also slid and he is preparing the output
shaft for the speedometer gear. It is held in place by 2 snap rings. I've already started on my next project seen in the
Notice the grease container.
When pulling the tail shaft the small bearings can come out of their holder. Grease is used to keep them in place for
assembly. Getting it back together.
Since I have the
engine and transmission out I also wanted to go over the OD wiring as it is easy to get at. I also can't thank John Sailors
enough for his patience to my simple questions.
I purchased this car
in 1980 from a Michigan TARTA member. The gear shift switch was installed in the 50/60 era. The previous owner has passed
away and was an active member in the 70's. If anyone in Michigan has any infomation about the history of this car I would
appreciate hearing from you.
was operated by the gear shift switch and the Gov. was taken out of the wiring loop. There was no OD reverse but by operating
the switch you could run through 6 forward gears. For street driving only 5 were practical, first with second and third
high and low. I liked driving the car this way especially using second high for intown driving. Since the OD was set up this
way I don't think there was a gear on the Gov. for 50 years and this instigated my OD gear problem.
John told me there
were 2 ways to hook up the gear shift switch. I could break the white wire from the Gov. with the gear shift wires as
the drawing shows. This would let the kick down switch operate as orginal with the option to over ride with the gear shift
The second way is to unhook the wire from the gear shift switch to the Gov. and ground it
to the case. This eliminates the Gov. and lets you control it with the gear shift switch only.
And of course the third way is to eliminate the gear shift switch wires and it would operate as designed. I now have
the car re assembled and with patience no paint damage.