[TRADERMIKE 2012]

Originally Posted by Dragncar

Maybe we could all go "third person" and make this really all weird?
Myself, I would recommend not rebuilding anything.
That way no one can over think it all and make simple things super complicated.
T400s are very tough, plenty full and cheap. Hard to screw one up.
Just get a Sessions book and be done with it.

If you have read this Thread from the beginning, you would know that this is a rebuilt Trans., from start to finish, using, Sonnex parts with the forums help, without whom I could not have successfully built this Trans. The Trans. works great, I am just finishing by taking the Final pressure Tests for my records. I feel that after two years of study and looking at videos and taking notes, tooling up and purchasing the parts. I owe it to myself to record the Transmissions internal pressures, especially when it comes to the upgrades Incorporated into this particular build. We had absolutely no Idea after replacing the Torque Converter and rebuilding this Trans. to better than spec., that we would find additional issues with the Flexplate and Harmonic Balancer. This ordeal began with an accident that occurred some 2-3 years ago by now.

We went over a tree root under an Asphalt driveway that was unseen, it raised the drivetrain of this Vehicle at the Trans. oil pan and broke a dime size chunk out of the Torque Converter, that I replaced with a Hughes new unit.

The force destroyed the Pump, by breaking the two metal "o"- rings that clasp together and seal between the rear of the Pump and forward of the Front Drum and one completely broke and landed in the forward Drum hollow area and the other just unclasped and stayed in its groove. I believe it was "Cliff" that diagnosed the problem spot on. The oil could not get past that point to lube the rest of the clutches and steels, etc...

We then replaced the Valve body and rebuilt the inside with a B+M Trans. complete rebuild kit. We added some extra parts and you can read about the entire build if you wish between this and one other thread connected to this Thread.

Lastly, we found that the damage went further than we ever thought. The Flexplate and Harmonic Balancer, being on the same driveline going forward were cracked and bolt holes were "out of round" on the Flexplate. Both needed to be replaced. A very expensive accident that I paid dearly in costs and labor. The investigation of noises and vibrations led us to remove the Heads and send them out for remanufacturing. We installed a deeper Truck type oil pan and a remote Trans. oil Filter. We have a Trans. Temp. Gauge in the center console and two Trans. oil coolers, one in the radiator and an air-cooled unit out in front of the condenser.

[TRADERMIKE 2012]

Originally Posted by Dragncar

None of that matters. Trans. Go shift kit after a basic rebuild with basic modifications and run that B!&h !
Is this transmission even doing anything wrong? Rebuilt several, never a issue except for drinking a few beers while installing front pump and broke a ring. Caused some damage due to me, not the wonderfully designed Turbo Hydromatic 400 !
If you have a good pump, seals/bushings are OK and the clutch/steel clearances are right these things work and can take a beating. It's the people who screw them up. Or just overthink their own problems that do not exist in reality and chase their tails.

Mikes reply:

I reused the drilled plate from the B+M shift kit that came in this Trans. and replaced the paper thin two gaskets with new ones that came in the rebuild kit, from B+M, we used the same number of balls and all the holes were present on the gaskets.

[TRADERMIKE 2012]

Originally Posted by Half-Inch Stud

Looks to me from the Before/After PSI readings; the Center-Support Babbit Bushing was clapped-out, and replaced.

Mikes reply:

I bought a Bushing driver kit and got my monies worth out of it on this one job, I replaced each and every one of the Bushings, no problem when you use the correct tool for a particular job.

[TRADERMIKE 2012]

Originally Posted by Half-Inch Stud

So, how does the TH400 do while driving? HIS wants to know.

Mikes reply:

The Trans., works well, after we replaced a defective Modulator that was not very old, unless the accident ruined it too, I think it was a defective part from the manufacture but I can't prove it.

[TRADERMIKE 2012]

Originally Posted by Schurkey

Schurkey wonders why the pressures are lower when the vacuum modulator is not supplied with vacuum. The pressure is higher with vacuum???

Mikes reply:

It would appear that way with reverse only, I am not sure where my roommate found that particular info.

Some of the info. came from different sources and Factory manuals, we all know that Draftsmen make mistakes, just look at the Pistons from the "1967 Pontiac Service Manual" about the Piston slap conversation.

[TRADERMIKE 2012]

While I wait for the "on the road Trans. Test" results to happen this weekend, "I would like to know if anyone has done this kind of work to their vehicles, especially when it comes to moving the drive line up into the vehicle, as this company is doing"? The reason for my interest is because, had I known/done what Detroit speed is doing, to my car, I might have avoided this accident altogether. I could have saved myself a lot of money and time "not" repairing this second-hand project...FWIW

I have noticed that some companies that build these old classics, build the drive train up into the body area. SEE:


https://www.flickr.com/photos/detroitspeedinc/albums/

[Schurkey]

Originally Posted by TRADERMIKE 2012

Lou found these numbers in a book, most likely the 1967 Pontiac Manual.


Vacuum disconnected/ Vacuum connected
by the book/ by the book
Drive 70/ 150

Neutral 70/ 150

Park 70/ 150

Second 150/ 150

First 150/ 150

Reverse 265/ 244

Originally Posted by TRADERMIKE 2012

Mikes reply:

It would appear that way with reverse only

Schurkey's reply:
???

Reverse is the only one where applying vacuum to the modulator reduces pressure, as I'd expect. All the others are either the same, or "apparently" backwards, where no vacuum results in lower pressure--the opposite of what I'd expect.

[TRADERMIKE 2012]

We had to re-adjust the shift linkage to the B+M shifter tonight. We took it for a 5-mile road test, but when we got to the gas station, we heard a noise after driving under a load. We were stopped and the noise was between 1500 -3000 rpm.

I was able to grab some Trans. readings, "Not by the book":

Park/130 psi.

First/150 psi @ idle-250 psi with my foot on the Break until it broke loose.

Second/same test as above/150-250 psi.

Drive/same Test as above/120-180.

Neutral/170 @ idle-190psi revved-up.

We will be listening to the motor tomorrow to locate where the noise is emanating from with the Stethoscope.

"Without ruling out the Piston slap theory", we still have to consider what the Head Mechanic did to these Heads when he Knurled the Valve guides, perhaps one needed a new Valve guide instead?

He was told to do just what needed to be done, the way they did things in 1967, so maybe I am to blame here.

However, if this is a Valve slapping in the knurled guide area, I could always remove the left Bank Head to get to the (# 7) area, that is our suspect/superficial guess for tonight. Tonight, we listened to the top only. Tomorrow, we can jack up the Vehicle and listen to the bottom more carefully. It would be advantageous for me, if we only needed one Valve guide, keeping to the plan, that is fixing only what is broken for now.

The temp. readings at the I/P gauge on the dash is 200-30 =170 degrees F. We are running the side kick and the condenser fans with the new radiator cap, so water temps. are good. Note: my water Temp. gauge reads: plus 30 degrees F., higher on the rally gauge on the I/P vs measuring using the Lazor temp. gauge from harbor freight @ the thermostat. The recalibrated temp. adjustment is to remember to subtract 30 degrees from the water I/P gauge to get the actual reading. I should not have to mess with this, because I was careful to take into consideration that the sending unit must match the rally gauge in a 1979 Pontiac TA. What went wrong with the order? I would imagine that as long as the thermostat opens at 180 degrees F. and the HD temp. actuated clutch fans viscous fluid works as stated, the Vehicle's fluids/water should flow when needed.

[TRADERMIKE 2012]

Originally Posted by Schurkey

Schurkey's reply:
???

Reverse is the only one where applying vacuum to the modulator reduces pressure, as I'd expect. All the others are either the same, or "apparently" backwards, where no vacuum results in lower pressure--the opposite of what I'd expect.

Miks reply:

Now that I think about it, we were using the broken modulator in our tests in those days, therefore the test results are skewed. We did not learn of the defective Modulator until we were completely done with the Trans. rebuild. As we were testing the rebuilt Trans., we could not get it to upshift, so I tried another Mod. that I had in storage, that one works and is the one we use now. Sorry about the misunderstanding. Please look at the new Trans. data because some of the old trans. data that uses the Vacuum Modulator connected is useless.

[TRADERMIKE 2012]

Originally Posted by TRADERMIKE 2012

Mikes reply:

Now that I think about it, we were using the broken modulator in our tests in those days, therefore the test results are skewed. We did not learn of the defective Modulator until we were completely done with the Trans. rebuild. As we were testing the rebuilt Trans., we could not get it to upshift, so I tried another Mod. that I had in storage, that one works and is the one we use now. Sorry about the misunderstanding. Please look at the new Trans. data because some of the old trans. data that uses the Vacuum Modulator connected is useless.

Mikes reply:

Just making sure that you know that the Test data with the Vacuum Modulator connected is flawed, because I later discovered that the modulator was defective.

[TRADERMIKE 2012]

Originally Posted by Half-Inch Stud

So, how does the TH400 do while driving? HIS wants to know.

Mikes reply:

The Trans. road test will be tonight after we stethoscope the Engine for the noise between 1500- 3000 rpm?

[Half-Inch Stud]

I am curious about the Line PSI at idle, and drive while cruising.

[TRADERMIKE 2012]

Originally Posted by Half-Inch Stud

I am curious about the Line PSI at idle, and drive while cruising.

Last night I took it out for a 10-mile run and the noise is back under load between 1500-3000 rpm.

Tonight, Lou will use the stethoscope that I bought from Harbor freight, that costs $8.00 to analyze the lower side of the motor and he will pull the Left Bank Valve cover to inspect the Valve train at #7 area and the entire Head while it is apart. It is possible that while he originally adjusted the Valve lash, this recent time, that he could have over tightened one or one is loose. We must look at our own work first when these noises, in this case, act up. We will pull each spark plug to see if when pulled from the Distributor cap with a plier with tape on the handle, so as not to get a shock.

The Head work that was recently done is also suspect, we surmise that at the knurled Valve guides, one could need a new Valve guide/sleeve installed, best to do them all, we will see.

We have not yet done the "on the road test," because the noise has returned under a load and we have other testing to perform tonight.

I took these readings last night while driving around the neighborhood for you to look at tonight, perhaps tomorrow night I will get to the "Road test from the Book".


Park/Idle-130psi

First/Idle-150-250- psi- with foot on break, until it broke free.

Second/same as above-150-250- psi.

Drive/same as above-120-180- psi.

Neutral/Idle-170-190 psi- revved-up.

I forgot to get the Reverse reading?


We have "not" forgotten that there is a possible Piston slap in this motor, even though it was never heard, by us, prior to the Trans. accident. That is why it is last in my diagnostics, but I am aware and I have read all the internet information that was posted in the "041" Cam Thread. I do understand everything told to me by the many PY forum members and I am following my own intuitions, especially when it comes down to "What I did last", must take precedent first with my evaluation while diagnosing problems. My tenacity worked in the past and it continues to work for me now. Never say always and never say never.

[TRADERMIKE 2012]

This is a control test by the book @ 1200 rpm with the Vacuum Modulator Hooked up and @ rest. 12/13/23 Actual Test Results:

Park/130-psi

Reverse/210-230

Neutral/170-psi

Drive/120

Second/150

First/150-psi



This is older test results from 2/15/20 @ 1200 rpm at rest, @ operating temp. and Vacuum Hooked up. Trans. was in used operational condition.

Park/ 140-psi

Reverse/220-psi

Neutral/140-psi

Drive/120-psi

Second/120-psi

First/120-psi



As you can see since this new rebuild of this TH 400 Trans., there is an increase of Pressure across the board due to the sonnex improved Pressure regulator Boost kit that we installed. OfCourse a total replacement of clutches, steels, all O-rings and Bushings helps. Not to mention the new Valve body and Accumulator kits. We serviced the hard parts by buffing the Hubs and added roller bearings throughout the Trans. We kept tight tolerances and shimmed the reaction carrier area for tighter tolerances as well. We also installed a new pump and Torque Converter.

[Half-Inch Stud]

Idle and drive oght be around 60 PSI. Seems the Pump is working too hard doing nuthin. I would not have used that sonnex boost ting.

My TH400 build go for maximal dynamics in Regulator function: sensitive to Vac Modulator is a good ting. 3-2 kickdown too.

[Schurkey]

Originally Posted by TRADERMIKE 2012

We will pull each spark plug to see if when pulled from the Distributor cap with a plier with tape on the handle, so as not to get a shock.

NO!

"Pulling a plug wire" with the engine running will cause an open-circuit in the secondary ignition system. This drives the voltage sky-high which causes unneeded stress on the insulation of "everything" including the internal windings of the ignition coil.

Get eight small finishing nails. Blunt the sharp points on a grinder or whetstone. Wipe a little Silicone dielectric grease on the blunted "points" of the nails, and slip them BETWEEN the distributor boots and the plug wires. DO NOT PUNCTURE THE INSULATION.

When you slide the nails under the boots, you'll feel when the nails contact the metal terminals of the plug wires.

Then, connect a jumper wire or a 12-volt incandescent (NOT LED) test light to ground. Touch each nail in turn to short out the spark instead of creating an open circuit. Voltage to that spark plug drops to zero, causing no stress to the insulation. Don't forget to remove the nails when you're done.

Photo attached, shows the nails on a Chevy TBI distributor, but the concept is the same regardless of make or model.

[MatthewKlein]

Originally Posted by Schurkey

NO!

"Pulling a plug wire" with the engine running will cause an open-circuit in the secondary ignition system. This drives the voltage sky-high which causes unneeded stress on the insulation of "everything" including the internal windings of the ignition coil.

Get eight small finishing nails. Blunt the sharp points on a grinder or whetstone. Wipe a little Silicone dielectric grease on the blunted "points" of the nails, and slip them BETWEEN the distributor boots and the plug wires. DO NOT PUNCTURE THE INSULATION.

When you slide the nails under the boots, you'll feel when the nails contact the metal terminals of the plug wires.

Then, connect a jumper wire or a 12-volt incandescent (NOT LED) test light to ground. Touch each nail in turn to short out the spark instead of creating an open circuit. Voltage to that spark plug drops to zero, causing no stress to the insulation. Don't forget to remove the nails when you're done.

Photo attached, shows the nails on a Chevy TBI distributor, but the concept is the same regardless of make or model.

Dad showed me something similar years ago. He used short lengths of vacuum hose and grounded them with a wire. Not sure how it worked but it did.

Edit: Missed your picture. He put the vacuum hose between the wire and cap

[TRADERMIKE 2012]

Mikes reply: I last said:

We have "not" forgotten that there is a possible Piston slap in this motor, even though it was never heard, by us, prior to the Trans. accident. That is why it is last in my diagnostics, but I am aware and I have read all the internet information that was posted in the "041" Cam Thread. I do understand everything told to me by the many PY forum members and I am following my own intuitions, especially when it comes down to "What I did last", must take precedent first with my evaluation while diagnosing problems. My tenacity worked in the past and it continues to work for me now. Never say always and never say never.

I want to add:

"I had not heard this new noise prior to the rebuilding of the Heads, this leads me to be Leary of just what the Head Mechanic did to these Heads"?

SUSPECT:

(1) New Head Gasket with the added Fire-Ring acting as an Acoustic Coupler?

This allows us to hear what is going on in the motor, that we could not hear before we installed this particular Head Gasket. Similarly, we extended the exhaust system with the dryer hose and extended the drier hose outside, so we did not have to smell the fumes and eliminated the exhaust noise in the garage area at the same time, where-by we heard our first noise anomaly that was most likely the cracked Harmonic Balancer.

Now that this current noise did not disappear when we replaced the Flexplate, we can deduce that the Flexplate was never a noise contributor after all, replacing it is best because of the out of roundness of the Bolt hole circles.

(2) How good is the Remanufactured Heads with Knurled Valve Guides VS New ones? What if at least one Valve Guide needs a replacement Guide? What if there was Valve Slop instead of Piston Slap? We would have to pull the Heads to find that out for sure, one can get close using the Stethoscope, but it has its limitations.

(3) Piston Slap, ironically manifesting itself at this particular time? Why all of a sudden, I still have not completely bought into that one yet. I drove this Motor 7-thousand miles without a single bit of noise until I had the Heads remanufactured?

(4) I can't forget, that when I recently flushed my Motor out with Transmission fluid, for one half an hour running time and used a new filter while doing so, did it have any effect on the Motor that is contributing to this noise? I have always had success with that trick and used it plenty of times over the years, thicker oil on top of that procedure might be just what the Doctor ordered? This is like on my Gear Vendors unit when I used Synthetic oil in the case and it was too thick, so I went back to ATF and it was fine.

We pulled the Valve covers tonight and re-lashed the Valves to Lifters and did not notice any issues, in other words this was not needed, but we tested for improvements and found none. We tightened the Splash shields and they were already tight. The Push Rod Guides were also tight. We are installing the Valve covers as I speak.

Tomorrow, we will buy Heavier oil and ZDDP additive with a new oil filter. We will add Lucas Engine Oil additive in this Motor as well, were thinking about straight 40 weight? I am going to research Synthetic oil tonight.

[Dragncar]

What ? You make a post actually referring to that acoustic coupler nonsense and then you tell us you are planning on running straight 40 WT WITH Lucas !
And what is a "Head Mechanic" ?
Stop the madness.

[Half-Inch Stud]

Noise; A Roller rocker just might be hitting the valvecover. Bearing in Front Pump or Alternator, or a bum lifter guts.