Rebuilt 727 Giving Me a Headache

[Mason]

Hi everyone, I have recently installed a 727 into my car that has a lock-up style converter onto my 360. When I have my car put into park or neutral, it revs perfect and goes up to 7000 rpm with ease. All gears work fine except when I have it put into first gear, when I punch down on the gas it feels like I'm towing a trailer of bricks or I'm in second gear. I double checked the linkages on my trans as well as the kick down cable and am so confused. Does anyone have any insight on what might be the issue? Any help would be greatly appreciated.

 

[451Mopar]

Is the trans designed for the lockup converter? I haven't messed with the later lockup 3-speed automatics, so hopefully someone will have a better idea.

 

[Mason]

Is the trans designed for the lockup converter? I haven't messed with the later lockup 3-speed automatics, so hopefully someone will have a better idea.

Hey 451Mopar, I picked up the transmission from a reputable Hot Rod shop in Houston who said that the 727 is from a mid-80's Dodge Truck, the converter was brand new in the box that they gave us also if that clears it up, not sure if it's made for it or not.

 

[493 Mike]

Sounds like the converter may be locking up early or the stall speed is very low.
Mike

 

[mopar 3 B]

Did you release the emergency brake? Like put it in neutral and see if you can push it. Yes these things happen. Lining come loss and wedge inside the rear brake drum can cause things like this. Check it out before blaming the trans. Also the input shaft for a lockup convertor is different than a non lockup. No step on the shaft and no lockup. Not sure the converter would even drop into the pump if using a lockup on a standard shaft.

 

[dvw]

So 1st gear feels fine in D, but drags in manual selection of 1st?
Doug

 

[Mason]

Did you release the emergency brake? Like put it in neutral and see if you can push it. Yes these things happen. Lining come loss and wedge inside the rear brake drum can cause things like this. Check it out before blaming the trans. Also the input shaft for a lockup convertor is different than a non lockup. No step on the shaft and no lockup. Not sure the converter would even drop into the pump if using a lockup on a standard shaft.

Hey, I actually have no emergency brake, the line snapped off before I was the owner of it so that's not the case.

 

[Mason]

So 1st gear feels fine in D, but drags in manual selection of 1st?
Doug

Hey Doug, first gear actually is sluggish either in Drive or 1st gear selection, I'm sure the linkage is right because I felt the change from 1st to 2nd when I did it manually. It's very weird, so yes in both selections it feels like I'm hauling a trailer.

 

[Dipstick]

When I have my car put into park or neutral, it revs perfect and goes up to 7000 rpm with ease. All gears work fine except when I have it put into first gear, when I punch down on the gas it feels like I'm towing a trailer of bricks or I'm in second gear.

If you takeoff normally, wait for it to shift into 2nd and then slowly punch it in 2nd, does it accelerate OK? I'm thinking it might not be transmission related.

 

[Mason]

If you takeoff normally, wait for it to shift into 2nd and then slowly punch it in 2nd, does it accelerate OK? I'm thinking it might not be transmission related.

Everything feels sluggish, even second since I barely get up to speed doing so. I could post videos on this forum for people to better understand. The engine is well built, idles perfectly, and has everything you can imagine done to it. Heads ported, weiand single plane intake, brand new Quick Fuel 750 cfm carb, long tube headers, lunati cam 525 lift with the matching springs, and bored 30 over. When in neutral and in park it sounds like its a monster, but when it's in gear it takes off like a dog. Something is definitely not transferring power correctly.

 

[Aeronet]

Band adjustments too tight? Bands won't affect 3rd.

 

[mopar 3 B]

If the bands are to tight he should know it long before stepping into it. In like it would lock 1st and reverse or second and drive against themselves long before a down shift. This sounds like a valve body problem to me.

 

[Aeronet]

He said everything feels sluggish. Bands that are too tight could cause that. Anyway, I would start with the simple stuff first. I would adjust the front band and see if it made a difference and go from there.

 

[Bad B-rad]

I am not a 727 expert, but if in D it shifts ok, and when in 1 its sluggish, I think that when in low, or 1, the trans applies the low/reverse band and wont do that in D.

That may be where to start looking.

I am sorry I miss read, I thought you said it was fine in D, sluggish in 1.

 

[Mason]

If the bands are to tight he should know it long before stepping into it. In like it would lock 1st and reverse or second and drive against themselves long before a down shift. This sounds like a valve body problem to me.

I've heard on some forums about the valve body i just didn't know because my situation was slightly different than theirs, what do you think could be causing that in the valve body? I was already planning on putting a manual one in the trans to call it a day.

 

[Mason]

He said everything feels sluggish. Bands that are too tight could cause that. Anyway, I would start with the simple stuff first. I would adjust the front band and see if it made a difference and go from there.

I've never had to tighten bands on a trans before, is it something I can do in my garage or should it be taken to a shop? Haven't seen any forums with my exact situation so I'm just confused on what to do. Thanks for the advice im going to look more into it.

 

[dvw]

If the low reverse band was to tight it wouldn't affect 1st gear. If the front band was was to tight it wouldn't affect 2nd gear. Jack up the rear wheels. Can you turn them forward without to much effort? Turning them backward will be more difficult. A
s a guess it sounds like the converter is to tight. How is it once its rolling and you hit it? There aren't a lot of off the shelf lock up converters available with higher stall.
Doug

 

[Mason]

If the low reverse band was to tight it wouldn't affect 1st gear. If the front band was was to tight it wouldn't affect 2nd gear. Jack up the rear wheels. Can you turn them forward without to much effort? Turning them backward will be more difficult. A
s a guess it sounds like the converter is to tight. How is it once its rolling and you hit it? There aren't a lot of off the shelf lock up converters available with higher stall.
Doug

The tires are pretty easy to move, I say that because i had them jacked up yesterday to make sure my shifter was in the right gears. But it all feels sluggish, I say second gear too but thats just because I can barely get my car up to speed. When its rolling and I punch it I get the same effect, i literally couldn't even break the tires loose on a rainy day.

 

[dvw]

Where is the ignition timing? Was TDC verified?
Doug

 

[Mason]

Where is the ignition timing? Was TDC verified?
Doug

The timing is dead on, it starts up in less than a second without even having to pump the gas. I don't know the specifics though.