-
Hi Guest!
You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
There are some perks with a member upgrade!**Upgrade Now**
(PS: Subscribers don't see this gawd-aweful banner
Hey - did you know if you click on the title of a thread it will take you to the first unread post since you last visited that thread?
but were afraid to ask: 
STOP!! Never post your email address in open forums. Bots can "harvest" your email! If you must share your email use a Private Message or use the 
smilie in place of the real @
Pretty Please - add it to our Events forum(s) and add to the calendar! >> 
Overdrive rebuild
- Thread starter 77v8
- Start date
Share this page
tony barnhill
Great Pumpkin - R.I.P
Offline
Jim - pulling the OD off the mainshaft isn't too hard a deal.....I don't know if Hap does overdrives but he's where I'd start.
Steve_S
Yoda
Offline
Consider shipping it up to Quantum Mechanics. I shipped a complete transmission plus an extra OD unit from So Cal for $72. Quantum are considered the best.
https://www.quantumechanics.com
https://www.quantumechanics.com
Hello Jim,
removal is easy but replacement takes care and patience (well certainly an 'A' type does).
This is because there are two internally splined components one behind the other deep in th overdrive unit. The rearmost must be lined up exactly with the front one or the unit will not go on to the output shaft. I have found it can take several goes to mate the overdrive with the gearbox. If the two nuts that pull the overdrive on go tight, don't keep tightening as you will crack the adapter plate.
You will also need to wire the pump piston down and ensure the cam is at zero lift to get the piston onto the cam or it will foul as you try and slide the overdrive on.
Alec
removal is easy but replacement takes care and patience (well certainly an 'A' type does).
This is because there are two internally splined components one behind the other deep in th overdrive unit. The rearmost must be lined up exactly with the front one or the unit will not go on to the output shaft. I have found it can take several goes to mate the overdrive with the gearbox. If the two nuts that pull the overdrive on go tight, don't keep tightening as you will crack the adapter plate.
You will also need to wire the pump piston down and ensure the cam is at zero lift to get the piston onto the cam or it will foul as you try and slide the overdrive on.
Alec
Update on o/d
Drained 1 quart of the 20/50 oil, added 1 quart of atf( this was recomended to help clean out ports )took the car for a drive ( 20 miles )in 4th gear, selected the o/d switch and could not feel it engage.tried this several times, but the same result, but when I coasted the car ( foot off of the gas )and turn off the o/d I could feel the car down shift, this is first time it would do that.When coasting again I would engage the switch and the car would slowly drop in rpm's.Maybe a rebuild is do soon, I am going to run this car that way for another 2 months and see what happens. Jim
Drained 1 quart of the 20/50 oil, added 1 quart of atf( this was recomended to help clean out ports )took the car for a drive ( 20 miles )in 4th gear, selected the o/d switch and could not feel it engage.tried this several times, but the same result, but when I coasted the car ( foot off of the gas )and turn off the o/d I could feel the car down shift, this is first time it would do that.When coasting again I would engage the switch and the car would slowly drop in rpm's.Maybe a rebuild is do soon, I am going to run this car that way for another 2 months and see what happens. Jim
tony barnhill
Great Pumpkin - R.I.P
Offline
Have you checked the little ball in the solenoid housing to see if its properly greased....gonna almost bet that when you remove the solenoid & clean everything them properly grease it, it'll work!
Steve_S
Yoda
Offline
While driving along, engage overdrive. Then force the shift lever left and right and see if it makes a difference. If so, the inhibitor switch may need adjustment.
To elaborate on what Tony is talking about, sometimes it helps to do the following:
1 Remove the solenoid cover plate
2 Remove the solenoid, plunger and ball
3 Put a small dab of grease on the ball and stick it to the end of a punch
4 use the punch to put the ball up in its seat and lightly tap with a hammer
5 Reassemble the unit
This procedure sometimes helps free up a "sticky" OD. Good luck!
To elaborate on what Tony is talking about, sometimes it helps to do the following:
1 Remove the solenoid cover plate
2 Remove the solenoid, plunger and ball
3 Put a small dab of grease on the ball and stick it to the end of a punch
4 use the punch to put the ball up in its seat and lightly tap with a hammer
5 Reassemble the unit
This procedure sometimes helps free up a "sticky" OD. Good luck!