I have a automatic transmission (C4)in my 64.5 mustang 289 and it goes from 1 gear to second just fine. I do not think it is kicking into 3rd gear at all. Is there anything that I should look at to see what may be happening?

1964 had a different valve body and shift pattern.

The first drive position down from neutral has 2 gears, 2nd & 3rd.

The next position has all three gears.

That is known as the "green dot" transmission.

Even when I have it in the big green dot and manual shift it to the small green dot while driving at 40 mph it does not shift.

It should shift to 3rd no matter what drive position you are in, other than Low.

Check vacuum at the modulator and kd linkage.

But chances are very good if it has never been opened or serviced the internal seals are hard and shrunk.

Just so we are all on the same page, this is a VMFer I brought over with me to this forum. He's already triple checked his green dot C4 shifting pattern as well as replaced the vacuum modulator (with negative results may I add). He has also verified his vacuum line is not leaking and checked his kickdown cable for binding. My guess from the start was the intermediate servo, but I thought the experts here could guide him better than a newb like me. Thanks, Carlos.

The more the merrier.

The intermediate servo is used for second gear only and as he has second that rules it out.

The direct (front) clutch is needed for 3rd and reverse.

Even though reverse may work it is because of the higher pressure needed to apply vs direct.

I was thinking about the servo not releasing and thus the direct hub not applying, but maybe that doesn't make sense. I haven't been around transmissions long enough to know if that is possible. What else could it be then? A valvebody issue?

Hey guys thanks so much for tring to help me with my problem. Just to make sure tomorrow I will try the big dot again and lesson and feel for the car to shift. There was work done to the tranny in 1989. However not may miles where put on it since then.

Thanks
Jon

Soory guys it is raining. I will have to try it tomorrow.

Are we talking about a transmission that has had the valve body down recently and done any air checks ? Was it working properly when parked after the work in 89? I ask these because in the mid 80's a buddy built a C 4 and when he was air checking it he applied air to the govenor and it stuck it .Wored fine but just would not shift to 3 rd as you are discribing. Just another learning experiance.

I did not do the tranny work. The guy who had it before got it done. The only air checks that I did was the vacuum check before the vacuum mod. and there was good vacuum there. It may just be me. What RPM's should it ran at around 40-50 mph? I am guessing the rpm's are around 3,000.

Ok guys here is what is happening. When I start the car up is idles very high. I put it into reverse and it shifts a little bit hard. I start out in "L" and click up to the big"O" and it shifts very smooth. When I shift up from that to the little "o" nothing changes. When I stopped I but it back to the big"O" and started to go and it shifted around 25mph and at 40mph it felt like it needed to shift again but nothing happened. So am I missing 1st gear or 3rd gear. I am think 3rd because at 40 mph I would guess my rpm's are about 3,000.

Thanks
Jon

I am going to try some Lucas Trans Fix. We will see what happens.

If it shfted at 25 and 40 that's all there is.

There ain't no mo.
Does it shift once in the small Ö"?

"There ain't no mo."

HAHAHAHA


Jon you need to go out and buy a cheap tach. Leave it in the small "o" and note the rpms at which it shifts. Likewise for the big "o." Also, a tach will be a more accurate visual to see exactly how many shifts you have. A good transmission (not a racing one) will shift gears on you and you won't even know it!!! Remember these cars don't have overdrive and who knows what rear gear you may have, so maybe you are getting all three shifts and you don't even know it. A tach will answer how many shifts you have as the RPMS will decrease slightly after each shift.

Moreover, you should not have a shift from switching between the big and small "o" as this does not control 2nd or 3rd gear. It only controls if 1st comes in or not.

What kind or type should I buy. I am not very good at this car stuff as you can tell.

You can do this two ways. One is to get a "sun" brand mini tach at autozone. The other is to get a multimeter dwell/volt/tach at autozone. Both around 20-30 probably cheaper to get the multimeter and IMO better in the long run in case you need to diagnose an electrical issue later on or set dwell when you are tunning the car.

I have a multimeter what do I need to do to hook it up? Also what setting on multimeter does it need to be on?

No it shifts at 25 and sounds like it should shift again at 40 but it does not.

OK I got a tach and it runs about 2500 when I have the gas pressed at 40-60 mph

Can you measure the size of your tire from the ground to the top? I need to plug it in to the RPM calculator. I am going to assume you have a stock gear of 2.80

EDIT: Here try it yourself... http://www.csgnetwork.com/multirpmcalc.html use 3.00 for gear ratio, 1.00 for final dive, and measure your tire size. I think you are fine... I would only be worried if you were in the 3000's.

OK the RPM's are ok. I think I had a few things going on. I thought at the higher speed it should shift once more. I also think that the green dot sopt was not going into 1st gear. I used the Lucas Tranny Fix and the Tranny problem is NO MO!!! Thanks for all of your help guys.

Can to much fluid in the tranny cause this problem?