Technical Cadillac 390 power loss when in gear

Why don't you replace the ignition switch, and see if the problem persists. Just shaking the keys and being able to kill the motor, could be what's causing your burbling loss of power. Revs up OK when sitting still in neutral, and causes grief when put in gear and moving.
I suspect the ignition is the culprit. I THINK the ignition switch has a push on connector on the back of it. Check all the connectors.
Good luck, cool car.

 

Thanks
I Ordered the switch yesterday, just waiting for it to arrive.

I went under her to start draining the pan to pull it and noticed the pan is covered in tranny fluid. I removed the torus cover and there is no sign of any leaks in the front bell housing section, tranny is draining now. While I was down there I adjusted the manual linkage which seemed pretty off...it is now dead on.

I bypassed the ignition switch to test and the issue persist so...off comes the pan...to be continued...

 

Fluid drained and pan dropped

Initial findings:
Fluid is nice and red very little shavings in pan, not really much to speak of

The fluid pickup screen was laying on he bottom of the pan not connected to the pickup tube

Pickup tube was very loose

Just draining the pan near filled a 10qt oil drain pan

It’s 1:45 I’ll pull the valve assemblies in the morning. Pans back on for the night.

 

Before I did too much expensive transmission work, I'd test for a plugged or semi plugged exhaust. Here's how I do it:
Plug your vacuum gauge into manifold vacuum after the engine is at operating temperature. Fire the engine up in neutral and note vacuum reading...you said yours was 20" vacuum at idle. Now, slowly raise RPMs to about 2000 rpm and observe vacuum reading. If the reading drops to 15 or below, you've got an obstruction in the exhaust. If there's a bad obstruction, the reading will drop as the RPMs go up...all the way to zero sometimes.
It's a cheap and easy to eliminate a possible problem.

 

AHA! You type faster than I do...hope tranny fix solves your problem.

 

Last paragraph of first post

Tried it, only dropped to 19” and maintained...but good to know I was on the right track by testing it. Thanks!

 

Me too...I do have a bead on a working tranny about a 4 hr drive away

 

Additional observations: rear band is pretty loose
Rear unit drum assembly may have signs of rust...but nothing else appears to...

 

Well pulled the valve assembly and only got into the manual valve before I had to head off to work.

There was a ball of black gunk at the end of the throttle valve which I cleaned out, but everything moved freely. I’ll get to the shift valve and more importantly the coupling valve after work.

 

Well found more random black mud in the coupling valve body...it’s in the ultrasonic cleaner now. Everything seemed to move freely though...so :shrug:

 

I’m guessing the black stuff is just normal clutch pack material wear

 

Instead of another Jetaway how about a 700R4 and a adapter. I had a good friend that owned AAAndrews transmission Shop in Dallas that made lots of money off them. A 700R4 would make it a lot easier to get parts and fixed. If you were out on the road if you had any problems. I personally would not drive 4 hours to get a used Jetaway that might have the same problem yours has. It worked when parked. Then you would be ahead to reseal it before you put it in. If that black stuff is in there what's in the converter? I bet the converter is full of it because that's where the trash always winds up. That's why transmission shops will not guarantee their work with a used converter. I seen hundreds cut open and they all had trash like that in them.Frank

 

I’m guessing you mean the front torus/coupler? Haven’t even drained it yet, but will later today.

 

Yes that's what I am talking about, but you probably can't get all the junk out by draining it but to worth a try.

 

The ones from the 50's could be taken apart. I don't know about the '62.

 

Yup, it is a 2-piece job

 

Well I have gone through all three valve bodies and the servo, I’ll mount it all back tonight, but I have to wait for the pan gasket to arrive before filling.

Going to drain the front torus tonight as well and see what comes out

 

If you find it's not the transmission I have seen wiped cam lobes produce the same symptoms.

 

I was about to change the leaky valve cover gaskets anyway, might as well check.

Wouldn’t it manifest itself on the vacuum gauge test and/or the compression check?

 

Drained the front torus, nothing but clear red fluid.

Pan gasket arrives later today, so I’ll refill and test.

Timing was supposed to arrive today but delivery was delayed until tomorrow.

After draining the torus, the 10qt oil catch overflowed, which has me thinking it was overfilled. Fsm says it should take 8.5-9qts.

 

Well, thinking it is clogged exhaust now.
Can get to 5k rpm in park and neutral. 2500 in gear... vacuum is low when timed to FSM specs

Waiting for timing spring to arrive today, will retime and check again.

Then dropping exhaust

 

Glad to see that this is turning into a more logical troubleshooting exercise. When you install the advance springs double check that the vacuum advance is also working properly. And then very thoroughly check all the wiring in the distributor. Make sure that all terminals are clean, tight and properly crimped. Inspect all the insulation closely for signs of flex or stress cracking. Check the coil lead to the points for any chafing where it passes through the distributor housing.

Dropping the exhaust should tell you quickly if there's an exhaust restriction. I think some of the Cads and Lincolns and Chryslers may have used double walled exhaust pipes and the inner pipe could fail and collapse without any visible signs from the outside. Does your 390 have a heat riser valve in one of the exhaust manifolds? Make sure it's not stuck in the closed position.

 

Replaced both advance springs, and retimed using timing light and vacuum gauge, it still likes to be a bit more advanced in general. (Set without using the vacuum advance)

Tested vacuum advance with vac pump...ok

All connections to ignition are good

Disconnect the exhaust at the manifold flanges (I no longer have the heat riser)
Backed the timing off just a hair to avoid pinging.

Still cannot smoke a tire.

Idle has gotten a little “searchy” after dropping the exhaust, I’ll adjust it out.

Letting off the gas at ~45 mph w/o exhaust almost got me pulled over

Might switch the mechanical springs to a stiffer set

Guess I’m checking for cam lobes tomorrow...

I really wanted to resolve this before I go on vacation...fingers crossed

 

Checked the driver side for wiped cam lobes...looks fine to me, all rockers seem to move the same amount. Went ahead and checked all the push rods and rockers in the driver’s side while I was in there. Pardon the shitty camera work. Was trying to get the video quickly before pissing off the neighborhood.

 

Given all of this maybe I'll come out tomorrow evening after work if you're going to be working on this thing tomorrow. .would be glad to pitch in .....

 

Watch out, I’ll take you up on that...

 

Why would you want to do that, if I might ask?

 

Good question! When I replaced the single un mated spring with a matching pair from the set I purchased they seemed to not be as stiff as the one I removed, so the advance is coming in a little earlier. Does that make sense? The set came with 3 different pairs of various degrees of stifness

 

Just thought of something. ..maybe that 390 is havin' a little trouble pushin' three tons around!

 

Lol, oh I know it is hence why I’m here

It shouldn’t have THIS much trouble though...