Cold blooded overdrive...

[99ZoomR]

Hi folks.

I have a Series 2 with overdrive. Ever since I've had the car, if the temperatures are below around 50 or 60 degrees the overdrive will many times not engage until after about 15 or 20 minutes of driving. After it's warmed up, it will go into overdrive just fine. When I first got my Alpine it had 90w oil in the transmission, so I figured that was why it took awhile before the overdrive would kick in, since that was the incorrect lubricant. I replaced the 90w with a non-detergent 30w, drove the car for a few hundred miles, then drained the transmission and put in fresh 30w again. I wanted to get all the gear lube out of the transmission since I thought that might be why it wouldn't kick into o/d right away. Does anyone have any ideas or other reasons why my o/d needs to warm up before it will kick in? Should I try a detergent 30w for awhile and see if that helps?
Thanks!

Len

 

[RootesRacer]

90w trans oil is not unlike 30w engine oil.

You need to determine if your problem is electrical, mechanical or hydrolic.

Mechanical is tough to determine, but we can eliminate electrical and hydrolic.

With the cold condition, in a garage where you can jack and safely support the car, put the car in 3rd or 4th and with the ignition on (but not running), select the OD lever.

Do you hear the clunk of the solenoid?

Yes, the problem is not electrical. Problem is probably a sticking valve or other hydrolic related issue.

No, get under the car and put a voltmeter on the wire going to the solenoid (to the chassis for ground) and see if you have 12v. If yes, connect the solenoid wire to the solenoid (try to keep the voltmeter on it too) and see if you see minor sparks and here a bit of noise from the solenoid.
If yes, again its not electrical (but it could be the solenoid).

The solenoid has 2 coils, a BIG powerful one and a lighter holding coil that reduces current after actuation.
The smaller coil doesnt have enough power to engage the solenoid from the disengaged position so if the engagement coil or its points are bad, the OD will not engage.
Now there are a set of points at the end of the solenoids stroke that are actuated by the movement of the solenoid armature. When it reaches the end of its stroke, it opens the points for the engagement coil.
It is critical that the solenoids op rod be adjusted so that the points open JUST at the end of stroke (see manual) and if the points open too early, it will not engage the op valve in the OD unit.

Lastly, if both tests seem to pass and you here a clunk going into OD, you will need to make an adapter to measure the operating pressure on the OD when its engaged and running (wheels off the ground) to verify that you dont have internal oil pressure losses or a gummed up filter (you should replace filter for good measure if you dont know it to be new).


HTH

 

[crs]

RR has provided excellent diagnostic guidance, so my comments merely pass on my experience with my Series II overdrive.

IIRC, Upon buying the car used, I read the manual thoroughly and then took it to the Dallas dealer (who shall remain unnamed) to have all fluids drained and refilled so that I would know exactly what was in the car. I stood by and watched every step of the process and had to intervene to keep the person doing the work ( not a mechanic) from putting transmission fluid in the overdrive. He argued with me until I showed him the manual where it said what weight oil to use. He then did it correctly. There were never any problems with the overdrive on that car.
After that, I did all the fluid changes on that car and on my wife's Series IV.

Some things are best done yourself or with your informed supervision.

 

[99ZoomR]

Thanks for the info!

Len