Finally started...transmission slipping?

[1966stangkid]

I just got my 66 i6 automatic to start.. some of you may know that i bought it two months ago when she wouldnt start for anyone. the guy i bought it from told me the car hadnt been driving well before he parked it and let it sit for two years. .......now two years and two months later it cost me 60 bucks to put a new batt. in and put in feash gas. anyway she starts right up now and sounds really good. the problem is when i put into any gear and press the gas the moter revs for a little and then she jerks foward and starts moving. but if i take my foot back off the car stops and i have to repeat the process again. does anyone know if this is the transmission or the rear-end slipping. and if you could tell me how to go about fxing it. thanks guys.

[stanger66]

I had mine do the same thing when I got mine 3yrs ago. I checked the fluid and there was none so I added about 3-4 quarts and it drove alright and then did a trans filter kit and cleaned the hell out the valvebody as I could without taking it off and drove it about 400 miles and did it again. Its running ever since and I have the cruise-o-matic c4 I-6 in mine but I have had a fuel problem since I have had it. Try that and then go from there. But yes it sounds like the trans.

[1966stangkid]

Thanks, ill try that and post back with what happens. one other thing i thats a little weird about this mustang is that there are alot of wires hanging from under the dash. most of them are conected to themselves with wire caps and all sorts of relays. i was wondering if this is what normal wiring looks like when its falling out of the dash or if the last owner thought he was some sort of electrision and in the end just made things very complicated?

[stanger66]

To tell you the truth mine has the same thing because my friend that owned the car before me tried to fix all the wiring and didnt finish and now Im trying to find a wiring diagram to repair them or Im going to have to buy a actual harness.

[1966stangkid]

put new fluids in works good now. it stopped slipping and runs good. well atleast in and out of my driveway. it was leeking most of its fluids right back out again but then i put leak stopper in and its stopped for now. will the leak stopper hold up or sould i try and rebuild the trans?

[stanger66]

Where do the fluid leak from? Because you might be able to replace a gasket or something. If it is the transpan gasket or the output shaft you can replace it but if coming from the front seal or other have it rebuilt.

[1966stangkid]

They leak from the tray. but im not sure if its the drain cap or the gasket, also i took it out on the road yesterday i opened it up to about 40 and then felt it shift into second then i hit 65 and saw a cop and slowed back down. it felt like it took to long to shift or is this normal. is this just because she hasnt run for 3 years? and if so can i do any damage by openin he up like this or should i go slower.

[Gearhead999]

Don't be so judgmental of the transmission. First it's an old car and it has been layed up. Take it easy and drive it locally working with the shifts. Maybe it will straighten out when it gets all up to operating temperture and the fluid gets flowing through out everything. Then decide if it needs to come out or what.

As for "Stop Leak" .....it's crap. It doesn't "Fix" anything and any benefit you have now, won't last. It is usually ATF with some brake fluid type fluid added. The brake fluid makes the seals swell some. As said earlier see where it is leaking from. You can replace the rear seal, pan gasket and dipstick O-ring fairly easy.

Oh, yeah, don't forget to "HAVE FUN" !!!!

[tabbat2069]

I'm having the same problam with the trany and i thought it was leaking from the pan or the drain ( it looked like it was ) but it's the frount seal. I got reverse but like you i had to rev it up alot till it catches and i got to do it all over again if i stop ( Low fluid ) I'm just going to replace it since its not the original trany, and it wimes @ slow speeds. (Been sitten for 6 years) I'ed advise against the leak stop, like belt dressing its only temporary. but it sounds like the trany is close to death, might wana replace or rebuild it.
good luck