Unexplainable Transmission Stutter... help?

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DentalDart

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Ozark Missouri
Timeline of events- (long post sorry)
3 weeks ago transmission worked perfectly before I tore down the engine to replace the camshaft, lifters and springs. Everything put back together and finished last week. First time driving car the transmission had an awful stutter when putting it in drive or even when trying to start in first. Adjusted the lokar kickdown cable to the installation instructions and to the instructions of the hot rod magazine instructions. This was done even though the adjustment on it was never changed from before the engine was disassembled.
Transmission fluid has been checked multiple times in neutral and it's not low, I've added and taken fluid out as well- fluid level has even been confirmed by Tony.

Timing is set with the Mallory Limiting Kit at 16 initial and 34 all in. Car idles beautifully and revs with no problems in neutral

Only things new are spark plugs, wires, fuel line and fuel filter.

Video of what car does when trying to go forward. It feels as if the transmission is slipping really bad and not catching- essentially a horrible stutter then once it starts rolling it will not shift into 2nd gear. The car has no problems with reverse. This has also been confirmed by Tony.

The car does this with vacuum disconnected and plugged at the carb and distributor. The car also does the same thing with vacuum hooked up to the carb and the distributor.

Picture #1 is how linkage looked before I took the car apart.

Picture #2 is how linkage currently is. I've tried loosening the cable all the way and then tightening it little by little and it goes from taking tons of throttle to move then once it tightens up a little starts the slipping/stutter.

Picture #3 is how the linkage looks on the kickdown lever on the transmission. It is adjusted to the position where it just starts getting internal resistance (as per instructions)

Any ideas? Anything we can be missing?





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I know you said it idles beautiful. By what I’m able to see and hear, it sounds like a misfire to me. There’s a difference in a free wheeling engine and one that’s loaded. I’d go thru and verify firing order and wiring to spark plugs. Also make sure plug wires are pushed on cap and plug all the way. Then personally I’d take my timing light and check each wire to ensure the timing light flashes consistently on each wire. I’ve messed up plug wires and crossed them to where it’ll seem to idle good with no back fire but will miss under load. You didn’t mess with trans other than linkage so go back to what you did and recheck. There are a lot of variables that have been added. New plugs and wires being a couple. New doesn’t mean good.
 
I know you said it idles beautiful. By what I’m able to see and hear, it sounds like a misfire to me. There’s a difference in a free wheeling engine and one that’s loaded. I’d go thru and verify firing order and wiring to spark plugs. Also make sure plug wires are pushed on cap and plug all the way. Then personally I’d take my timing light and check each wire to ensure the timing light flashes consistently on each wire. I’ve messed up plug wires and crossed them to where it’ll seem to idle good with no back fire but will miss under load. You didn’t mess with trans other than linkage so go back to what you did and recheck. There are a lot of variables that have been added. New plugs and wires being a couple. New doesn’t mean good.

Thanks. I'll hook up to every wire with the light tomorrow. It idles at about 800, we turned it down just a smidge. Timing is at 16 initial and 34 total, set with mechanical advance limiter today and it is right on the money at 34 under load.

Edit- I'll try and get a better video of the stutter in the morning as well. It's hard to drive and video at the same time.


 
Was just reading thru your other thread dartin for divorce. It seems you’ve got someone knowledgeable helping so what I put may be frivolous. Just what my initial reaction was to video. Another thing maybe to verify would be the air gap between the reluctor and pick up in the distributor. The being “normal” in reverse throws a wrench in things. But it can’t “hurt” to do some basics I guess. Wasn’t trying to lead you down a path.
 
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Was just reading thru your other thread dartin for divorce. It seems you’ve got someone knowledgeable helping so what I put may be frivolous. Just what my initial reaction was to video. The being “normal” in reverse throws a wrench in things. But it can’t “hurt” to do some basics I guess. Wasn’t trying to lead you down a path.

Most definitely agree with the basics all the help I get is appreciated and it's never a bad thing to double/triple check things. I do have a friend helping me and he is super smart.(he may not claim me as a friend anymore after this car and the little problems it gives us lol). It's just something that has us both stumped currently. I'm sure he could figure it out but hes not always here and I need to do my homework to at least be of some help when he is here :) that's only fair I think.

I always ask here still thinking maybe someone has run into or had the same type of problem/delima before. It would be awesome if I could get something fixed and then when he gets here just let him enjoy riding in the car he has been helping with, instead of us having to chase little problems:(. This is all good for me though, I'm learning so much from everyone on this site.

As always, I appreciate everyone and their help.
 
That third video is the most informative. Not electrical; too inconsistent. Sounds like a lean condition. Pull plug wires from the cap with it running to find the weak cylinder. Pull two or three side by side to narrow it down. Pull four alternating; then the other four; to isolate the side of the carb that's off.
 
That third video is the most informative. Not electrical; too inconsistent. Sounds like a lean condition. Pull plug wires from the cap with it running to find the weak cylinder. Pull two or three side by side to narrow it down. Pull four alternating; then the other four; to isolate the side of the carb that's off.

Good catch! That was right after we broke in the cam, since then the air fuel was adjusted using the timing light.

I mainly posted it to help rule out a misfire. But I will pull the plugs and see how they look.
 
Is that an AVS2 carb? How much vacuum is it pulling? Depending on how much overlap that cam has it may be dropping vacuum too early and the "power" mode of the carb is kicking in way too early. If that's the case you would need to put heavier springs in to keep the plungers down. Pull a plug and see if its sooty.
 
Is that an AVS2 carb? How much vacuum is it pulling? Depending on how much overlap that cam has it may be dropping vacuum too early and the "power" mode of the carb is kicking in way too early. If that's the case you would need to put heavier springs in to keep the plungers down. Pull a plug and see if its sooty.

Yes it's an AVS2, I dont know how much vacuum its pulling. It was doing it with the vacuum plugged on the carb. I'll try and check it out tomorrow as well.
 
Takes too long to pull plugs. Just pull the wire; that will tell you all you need to know. Just make sure you pull the cap end, not the plug end. And don't stand facing the car with your pelvis area touching the fender....me; I didn't like it very much..
 
I think my timing light is on my work bench somewhere..maybe. I don't use it anymore. Every motor is different in what it likes. Turn the distributor with it running, to the highest idle; then go as far retard as possible while still maintaining the highest idle; there's a large window of high idle operation; usually. Also, try manifold vacuum to the advance then ported vacuum. Reset the timing each time; it will respond differently. Sometimes night and day; depends on what your motor likes.
 
Heres a video I just took. The car is loud but you hear the transmission making that clanking sound, that's the transmission slipping and making a little shaking sound. I did another one inside the car. It's not quite as good as this one.

 
Timeline of events- (long post sorry)
3 weeks ago transmission worked perfectly before I tore down the engine to replace the camshaft, lifters and springs. Everything put back together and finished last week. First time driving car the transmission had an awful stutter when putting it in drive or even when trying to start in first. Adjusted the lokar kickdown cable to the installation instructions and to the instructions of the hot rod magazine instructions. This was done even though the adjustment on it was never changed from before the engine was disassembled.
Transmission fluid has been checked multiple times in neutral and it's not low, I've added and taken fluid out as well- fluid level has even been confirmed by Tony.

Timing is set with the Mallory Limiting Kit at 16 initial and 34 all in. Car idles beautifully and revs with no problems in neutral

Only things new are spark plugs, wires, fuel line and fuel filter.

Video of what car does when trying to go forward. It feels as if the transmission is slipping really bad and not catching- essentially a horrible stutter then once it starts rolling it will not shift into 2nd gear. The car has no problems with reverse. This has also been confirmed by Tony.

The car does this with vacuum disconnected and plugged at the carb and distributor. The car also does the same thing with vacuum hooked up to the carb and the distributor.

Picture #1 is how linkage looked before I took the car apart.

Picture #2 is how linkage currently is. I've tried loosening the cable all the way and then tightening it little by little and it goes from taking tons of throttle to move then once it tightens up a little starts the slipping/stutter.

Picture #3 is how the linkage looks on the kickdown lever on the transmission. It is adjusted to the position where it just starts getting internal resistance (as per instructions)

Any ideas? Anything we can be missing?





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That's an engine miss, and something loose under the car rattling because of the engine shaking from the miss.

Verify (probably again) your firing order (wires in the right order)
Make sure no plug wires are burned on headers.
No plugs are cracked from the work done. (this is kinda easy to do)
Get under it and bang on things with your fist.
(mufflers can come loose inside)
 
Just pull one plug and see if its black and sooty.
I have seen this before after a cam swap and AVS2 carb. Sounds like an ignition misfire around 2k rpm but will idle just fine. Its because when you open the throttle blades the vac drops and the carb switches to the power circuit(or whatever it may be referred to as). Bigger cam means this happens earlier and you need to tune the carb to get them needles opening when you need them too, not at low rpm. So heavier springs make them open later. These are the two plates you swing open on the top of the carb. Very easy to change out but you will need to buy the calibration kit to get the springs.
Im not saying this is your problem but its worth looking into.
 
That's an engine miss, and something loose under the car rattling because of the engine shaking from the miss.

Verify (probably again) your firing order (wires in the right order)
Make sure no plug wires are burned on headers.
No plugs are cracked from the work done. (this is kinda easy to do)
Get under it and bang on things with your fist.
(mufflers can come loose inside)

Why would an engine miss cause the car to not shift from first to second, or even go forward really but be totally fine driving in reverse? Also I can adjust the linkage all the way out, rev the engine and have no problem?

Then if misfire why can I rev the snot out of the car in neutral and it doesn't misfire and timing stays perfect to where it was set to?

Distributor- correct firing order
Wires- all good and none burned
Spark plugs- pictures posted. A little dark, these are the NgK plugs so they run hotter than the champions. I may get some champions just to change them out anyways.

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See, this is why cars have computer controlled fuel injection. A carbureted system is EXTREMELY complicated with lots of variables. Plugs won't tell the story on this one because it's lean part of the time and rich others. I think you should get an air/fuel gauge, but if you have a vacuum leak, like I suspect, an O2 sensor will just go nutz.
 
See, this is why cars have computer controlled fuel injection. A carbureted system is EXTREMELY complicated with lots of variables. Plugs won't tell the story on this one because it's lean part of the time and rich others. I think you should get an air/fuel gauge, but if you have a vacuum leak, like I suspect, an O2 sensor will just go nutz.

We were actually going to set up and do more tuning with an air/fuel guage, we just havent yet because now we have to figure out why it's not moving.

Can I have a vac leak if my vac on the distributor and carb are plugged?
 
We were actually going to set up and do more tuning with an air/fuel guage, we just havent yet because now we have to figure out why it's not moving.

Can I have a vac leak if my vac on the distributor and carb are plugged?

A vacuum leak would/could cause the plugs to look the way they do AND cause what sounds like the miss.
It is obviously richer'n hell, but some plugs show pretty lean.
This can happen when air is getting in somewhere it shouldn't. (vac leak)
You sure you plugged everything back in (even on the back of the carb?)
Vacuum leaks can be anywhere, not just the vac can hose.

Did anything go on in the trans recently?
Filter change or anything?

Also, are you holding those plugs in the order they go in the motor?
 
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You need to get a vacuum gauge and tune with it. Those plugs are pig rich except for maybe one of them. The suggestion to tune the enrichment circuit on the carb is a good one. You need stiffer step up springs. And it looks like you may have a vacuum leak. Yes you can have a vacuum leak at many, many different locations. Makes no difference if the ported vacuum line to the carb is plugged or hooked up to the distributor.
 
Dont put champions in. They arent as good as they used to be.
The one cleaner plug would concern me.
Engine stayed attatched to trans so convertor was not disturbed.
Tv cable must be the culprit.
Hope you find the problem.
 
A vacuum leak would/could cause the plugs to look the way they do AND cause what sounds like the miss.
It is obviously richer'n hell, but some plugs show pretty lean.
This can happen when air is getting in somewhere it shouldn't. (vac leak)
You sure you plugged everything back in (even on the back of the carb?)
Vacuum leaks can be anywhere, not just the vac can hose.

Did anything go on in the trans recently?
Filter change or anything?

Also, are you holding those plugs in the order they go in the motor?

Looked a little rich, but the car also hasn't been driven and those plugs are 1step hotter than the champion plugs even with them being the cross reference plug. I got some autolite 65s just now and it runs the same lol.

Yes the plugs were held in order that they came out. Its habit to take them keeping them in order and putting them back in the same hole they came out of.

See pics/ videos below.

Carb plugged in the rear (always was). Distributor to carb vac line reinstalled. Vac line at expansion valve (? I think that's what it's called for the ac/heater), vac line for on the intake is hooked up.
 
You need to get a vacuum gauge and tune with it. Those plugs are pig rich except for maybe one of them. The suggestion to tune the enrichment circuit on the carb is a good one. You need stiffer step up springs. And it looks like you may have a vacuum leak. Yes you can have a vacuum leak at many, many different locations. Makes no difference if the ported vacuum line to the carb is plugged or hooked up to the distributor.

I have a vac guage. I'll read up on tuning it with that as well, since I dont know how lol.
 
Dont put champions in. They arent as good as they used to be.
The one cleaner plug would concern me.
Engine stayed attatched to trans so convertor was not disturbed.
Tv cable must be the culprit.
Hope you find the problem.

Engine and trans stayed hooked up, just jacked up the engine and installed new motor mounts. Plus it makes it easier to jack it up to undo and reinstall the headers (hookers are the worst to install)
 
Here is the car idling and revving. I definitely do not hear a misfire and the timing stays right in point to where we set it.

Carb/vac lines that I know about all shown and hooked up.





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Engine and trans stayed hooked up, just jacked up the engine and installed new motor mounts. Plus it makes it easier to jack it up to undo and reinstall the headers (hookers are the worst to install)
Bend shifter linkage? Im thinking not, you would have noticed a change.
 
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