I have a 66 with 289 and c4 tranny. We have only had this car for about a month, we bought it from a family member who needed money. I thought that I had a tranny leak after cleaning up fluid day after day. I checked the fluid level and it does not appear to have gone down any, Still at full. I then checked power steering fluid and it does not register on dip stick. Ok, this obviously means the leak was comming from power steering pump or lines hard to tell everything is covered under car with thick grease and dirt. I thought that with the excessive leak and the tranny not shifting to 3 that it needed to be rebuilt. Is this still the case or would changing fluid and filter, mod valve help this issue? The car has sat for a long time approximately 6 to 8 years. Any help would be appreciated, Thanks

 

Take it to a diesel truck wash and have them go at it with a warm pressure washer. Then service the trans, check the modulator valve, and the vacuum sorce.
There are plenty of areas for you P.S. to leak from. Having a clean car to inspect makes life much easier.

Good luck,

 

First question has to do with the 1-2 shift

Does it make the 1-2 at what seem to be the proper speed and the proper shift quality.

If so the Modulator etc and the governor is working at that time so no reason to suspect that they do not work properly later.

Now to the 2-3----In order to make the 2-3 two things must happen.

1. The 2-3 shift valve in the valve body must move.

2. Then fluid pressure must apply the High/Reverse clutch at the same time that it releases the Intermediate band by applying pressure to the release side of the Intermediate servo.

Since clutch and release side of the servo are part of the same hydraulic system a leak anywhere in the system will prevent the shift.

My guess would be a leak of the release piston side of the servo--Most likely at the top. Since the vehicle sat for an extended period this chamber could have become empty and resulted in a dry first application and resulting seal damage.

Although there is a procedure for removing the servo piston without dropping the pan I would not recommend trying it so I will not detail it here.

I would recommend dropping the pan. Removing the servo piston. Careful inspection of the release side (Large piston) seal.

If you are confident with that those seals are ok then would be time to check the 2-3 shift valve.

It's been a long time since I worked had one apart so I do not recall it's specific location in the valve body. However I recommend that you go to your library which should have a good collection of manuals and consult it.

If necessary to remove the valve body do it carefully and pay attention to the removal bolts and their lengths. Sometimes there are surprises there. If you remove the screen make sure that you do it carefully. Some valve bodies have rubber ***** or tiny flat rubber valves which can go bouncing away.

At any rate remove the plate holding the 2-3 valve. push it in and out. If it appears stuck remove it then spray the valve and the bore with carb cleaner. Soak it with either trans fluid or coat it with Vasaline and reinstall.

If no problem there it must be a clutch seal- This of course is a job for the knowledgable.

My e-mail don_albasi@yahoo.com if you have a question.

 

what year is your car? in 65 and 66 you could get what they called a green dot trans. in the normal drive position it will only from 2nd to 3rd. in the normal 2nd position it will shift all three gears. i have one in my 66 and i thought the same thing you did. but a old tranny man set me strait. they put them in with the idea that if you are driving on slippery roads you won't spin out as mutch.

 

Scott H. I will look into that I was wondering how I could get all the dirt, gunk and grime removed, Thanks.

DGA, thanks for all the info. I am going to look into it a little deeper but i dont know how comfortable i am going to deep. I may be sending you some emails asking for help!

Speed my car is a 66, how would I know if I had a green dot transmission? If it is by the gear selector This is what I have P, R, N, ., o, L. Does the dot on the selector signify the green dot tranny? If so where should you have selector for normal 1, 2, 3 driving?

Sorry everyone I am new to these cars, Thanks for help

 

try this, put your car in what would normally be 2nd gear and take off from a dead stop. if it shifts 3 times you have a green dot. it sounds like you might have one. check it out and let us know.

 

Checked it out tonight it is a green dot. I feel much better now knowing im not looking at a tranny rebuild right away, Thanks