Feels like dragging an anchor

[jcskokos]

I have been leaning on replacing the muffler anyway even before these symptoms showed up...
I have just replaced the fuel pump while I had the front cover off. Another thing that kinda pushes me away from fuel issue is after it "kicks back on" I can get on it and it will accelerate fine for the rest of the drive, though as I noted ive been keeping them very local due to the condition of my tires(new ones coming in tomorrow).
I rechecked the kickdown adjustment last night and realized it was a BIT tight so I turned it in about 10 turns to give it that 1/16" freeplay ay WOT. I have the wheels off to take to the tire shop right now but I'll update if that had any affect on it late tomorrow.

 

[RemCharger]

I have a car that does the same thing (340-727) and initially you would think the drum brakes just applied themselves.. but its not, no pull or anything. I have the trans out to get it checked, thinking a band is grabbing or something similar . The one thing i do know, is at one time the driveshaft was too long and punched out the end of the yoke. Cant be good for it..

 

[jcskokos]

I do have a follow up question as I cant find a very good picture online: is the original kickdown supposed to have some kind of spring retention to the throttle linkage? Mine sits about 1/2 way in the adjuster linkage at idle. Always been this way as far as I can remember. I can physically pull the linkage forward with no effort and pushing it back I feel immediate spring pressure..

Picture attached for clarification. Ignore the water spilled on the intake.

 

[WP29440SE]

I do have a follow up question as I cant find a very good picture online: is the original kickdown supposed to have some kind of spring retention to the throttle linkage? Mine sits about 1/2 way in the adjuster linkage at idle. Always been this way as far as I can remember. I can physically pull the linkage forward with no effort and pushing it back I feel immediate spring pressure..

Picture attached for clarification. Ignore the water spilled on the intake.

yes there should be a spring connected from the kd arm to the throttle arm keeping it pulled forward. not a heavy spring , just enough to keep it snug

 

[Johnpat]

Attach a vaccum gauge up to manifold &
Check to see if it drops off at the same time this
starts to happen.
If it starts dropping right before lose of power
Exhaust is being plugged up.

 

[Wietse]

See my linkage, this is on my '69 440, yours will be similar though.
The red spring keeps the throttle pressure linkage pulled forward.
If you have a service manual check the procedure to set it up properly.
Once set, check that the carb throttle can reach WOT position and it is not restricted in stroke by the throttle pressure linkage.
If that is ok, also check that when the carb is at WOT position, the throttle pressure linkage is almost fully bottomed out.
If you can still push the throttle pressure linkage further before it hits the end of stroke with say 1/4" or more, you need to re-adjust the linkage to make sure that it provides maximum pressure at WOT.
My transmission was lazy as **** because i still had another 5/16" to go on the linkage when the carb was at WOT.
This delays the shift points over all stroke and causes the tranny to shift like a grandma.

 

[jcskokos]

I'll check around at work to see if I have a spring tucked away in my toolbox somewhere that will fit it, or maybe check napa tomorrow in their misc hardware section. It's always shifted like a granny since I've had the car about 10 years now but then again I dont drive it hard. Shifts at 20 and 30 most of the time, although a ton smoother since I adjusted the bands. I'll stick a light spring on it and recheck my adjustment tomorrow afternoon. Thank you for the picture as well.

 

[myk r sanchez]

I've seen screwed up fuel systems and carbs that would kill power. not to mention wacky timing.
a little history here would help. when did this start happening.
if you had the throttle wide open and the TP arm on the trans adjusted all the way back you are very close to having it right.

I tried that adjustment and afterwards the car wouldn't downshift on WOT.

As for the OP I'd get that exhaust sorted out too...

 

[coloradodave]

2 suggestions:
1) Crawl under the car and bang the bottom of the muffler with a plastic or dead blow hammer. Listen for any type of rattle which could indicate a loose baffle.
2) Next time this happens, pull off the road without using the brakes and feel the front wheels. See if they are excessively hot, indicating a drag situation not easily diagnosed when cold or on jackstands.
I offer these, but feel the problem is probably with the A/T linkage...

 

[cosgig]

Electronic or points distributor?

 

[jcskokos]

Electronic or points distributor?

Electronic. Confirmed proper air gap and distributor play when I had everything apart.
I dont get my oil pressure light coming on when it happens and that has been one thing that was always the first thing to pop on when I've had an running issue down to flickering with a previous misfire from pikachu chewing my spark plug wires.

 

[Thrashingcows]

I rebuilt it myself. Carter 2bbl (the square one, not the round one). The only change I made to that was running the dist off manifold vacuum instead of ported at the recommendations of a few engine builders. All linkage and float adjustments were done to the installation instructions that came with the rebuild kit. I had to move my accelerator pump pin to compensate for cutting out from a stop.
Before all the work done I do remember having really bad pinging when going up even the smallest hills. Seems to be better currently but I'm waiting till I get my new tires on before extended driving.
I didnt change any jetting on it and I have never had a problem with maintaining constant throttle, say merging onto a freeway.

You do not want to be running the distributor vacuum advance off the manifold, you are engaging all your timing at idle, I did this by accident years ago and my motor was a dog and would over heat. Your distributor has a mechanical advance built into it with springs and weights...should start to engage around 1000rpm and should be full in by about 2000-2500rpm. If you want to run the vacuum advance then it needs to be hooked to the proper ported vacuum so that it is engaged only when your motor needs it, mostly when cruising on the Hwy.

 

[cosgig]

I think I found your problem!!.....

 

[WP29440SE]

I tried that adjustment and afterwards the car wouldn't downshift on WOT

I wonder why? been doing it for years and they always work like they should. of course it does take a little fine tuning because they are not all exactly the same.

 

[jcskokos]

Update: so today I put on new tires, readjusted kickdown, installed a kickdown return spring and went for a spin. No issues out today. With the return spring gives a new meaning to shifting like a granny. Driving through a parking lot I was in 2nd at 12mph and 3rd at 20 just feathering the throttle. Actually holds in gear when stepping on it too. Hopefully it's all fixed but I'll post if it does it again.

 

[Thrashingcows]

You need a little more throttle pressure to crisp up those shift points.

 

[Wietse]

You did not mention you rear axle ratio, that 727 was put together to attach to a certain rear axle ratio.
I think they all have a different governor weight; depending on axle ratio.
Could be the wrong ones are in there, mine also shifts early in a too low speed because i now have a 4.10 ratio while the car came original with a 3.23.
So the axle speed is relative high already at low speeds, providing more governor pressure which throws the upshift in.
Replacing the governor for a lighter one is also on my to-do list already.

Did you check that the kd linkage is almost at full stroke at carb WOT position?

 

[myk r sanchez]

I wonder why? been doing it for years and they always work like they should. of course it does take a little fine tuning because they are not all exactly the same.

Maybe my linkage is bent, damaged, incorrect...

 

[Slap Stick]

Wasn't there a transmission repair shop ad with cars dragging anchors and pianos?
The thread title made me think of it.
I agree with a bit more throttle pressure. If it holds the gear too long put it back where it was and do the governor swap.

 

[Wietse]

I agree with a bit more throttle pressure. If it holds the gear too long put it back where it was and do the governor swap.

How do you increase throttle pressure then? You mean with the throttle pressure linkage?