Powerglide damage from 'clicking' engine off in lights
 

Gents, how are all of you who shut the engine down at the traps keeping the powerglide alive?? Roller bearings? Run high fluid level?? Other tricks?? Pretty sure some of the recent glide issues I have been having are from this... Anybody run an oil pressure accumulator so that you dont have to kill the engine in the lights to keep oil pressure whilst braking hard??

Any and all input welcome.

Kevin

Re: Powerglide damage from 'clicking' engine off in lights
 

what about shifting to neutral and let the engine idle

Re: Powerglide damage from 'clicking' engine off in lights
 

Problem is I still loose engine oil pressure when I do that... Even with the trap door in the steff's pan and 5 quarts of oil. 6 quarts is Ok though...

Perhaps I need to restrict more oil from going 'upstairs'....

Or maybe running 6 quarts isnt really any power loss than running 5... Never did a back to back, but enough guys on here are running only 4 quarts, I figured there is something there....

Re: Powerglide damage from 'clicking' engine off in lights
 

Shifting a powerglide into neutral in the lights can be very dangerous. It's very easy for it to slip into reverse if shift linkage isn't adjusted just right, and that will make car control very difficult. I was racing a guy in Gainsville several years (1985 bracket finals) ago and he lost control. Crashed in front of me then came across the track behind me and hit the other guardrail. They took him to Shands Hospital in a hellicopter as he really messed his ankle up bad..

Re: Powerglide damage from 'clicking' engine off in lights
 

pushing the shifter into neutral in the lights with any trans other than one having a clean neutral is very dangerous and countless racers have lost their car and ended up in the hospital because of it.

Re: Powerglide damage from 'clicking' engine off in lights
 

Clean neutral is the only way to go unless you want to run a lot of oil. Besides the oil pressure issue, I don't want me engine gearing down from 8500 or more RPM. I push mine in neutral and click it off in the lights. Clean neutral is the next position forward of high gear, no problem with putting it in Park. Park & normal Neutral is at the back.

Re: Powerglide damage from 'clicking' engine off in lights
 

Unless you have aluminum rods leave it in hi gear.as far as the accumulator, it takes longer to lose oil pressure and longer to get it back too! I took mine off after one season. :)

Re: Powerglide damage from 'clicking' engine off in lights
 

Guys, its a forward pattern powerglide, so there is no "clean neutral' valve body, nor a need for one... Yes I understand the implications of accidentally hitting reverse at trap speed. I have a very good reverse lockout shifter, which requires a second lever be pushed to engage reverse, I use nylon locknuts on my cable linkage, and I dont 'slam' it into nuetral, I lightly slide it forward.... All that is OK.

What I am wondering and asking about is how the guys who click it off in the traps are keeping the glide from damaging itself, when the engine stops and thus the front pump stops, so there is no forced trans fluid/oil flow through the assemblies at 8200 + RPM...

Bill, I had heard the same thing about the accumulator, but I thought it through, and you could arrange a check valve and orifice setup, such that when the engine starts the full line flow back to the accumulator is blocked by a check valve, but passes through a small orificed bypass line, so it charges very slowly and it wont cause a delay in building engine oil pressure. Now when you shut the engine down and the accumulator flow reverses back to the engine, it does so quickly through the full line size through the now open check valve....

Re: Powerglide damage from 'clicking' engine off in lights
 

then you don't need to push it into neutral at the stripe.

Lots of monkey see monkey do for no good reason!

Re: Powerglide damage from 'clicking' engine off in lights
 

Many people who run an accumulator run it through a ball valve in the hose. Close the ball valve before you shut the engine off. Open it when you crank the engine, and you have a pre oiler every time you start it. Mount a cable such as you'd use for a mechanical choke and connect it to the ball valve, and you can do it from the driver's seat.

Re: Powerglide damage from 'clicking' engine off in lights
 

accusump makes a real nice set up,instead of a ball valve it has an electric solenoid that has a hobbs switch on it (25 psi or 50 psi) if oil pressure drops below those pressures it will open and feed back to the oil pump ,, it also acts as a prelube for engine before cranking,,,, I ran this on my car it works gmonde

Re: Powerglide damage from 'clicking' engine off in lights
 

Kevin, what issues are you having?

Re: Powerglide damage from 'clicking' engine off in lights
 

Jody, burnt up band and high clutches, even though they are not slipping at all during the pass....

Re: Powerglide damage from 'clicking' engine off in lights
 

I don't think shutting motor off would do this. I shut mine off and have only burned up high gear clutches when my line pressure was too low. Do you know what your pressure is?

Does it still shift hard before you take it apart?

Aluminum drum?

Re: Powerglide damage from 'clicking' engine off in lights
 

Jody, thank you very much for the reply and info. Yes,I tend to agree with you, but Im grasping at this point... Line pressure is 150 Psi. 5 cutches in high pack, 3 in reverse pack. Std Red lining Band, and yes aluminum drum. Fluid started getting a bit burnt smelling, and then I noticed a bit of flare on the shift on the last pass. So then I pulled it out and found the burnt frictions and steels... I went all through it this weekend and took the two valve body halves apart and cleaned it all out. Found a fair amount of friction material and debris in some passages... Havent had the valve body apart in ages, so this debris may have been part of it....

I also took a very close look at the low band servo piston rings, and did an air test on it, since leakage past these will bleed into the high clutch apply, and cause drag/heat/losses. There was some leakage, but not terrible. I drilled an .070" hole through the high apply piston (similar to what you do to the reverse piston when installing the t-brake), to 'bleed' off any slight leakage past the servo rings while in low. Right now, I am learning towards that as being the problem all along. The car is down almost a full tenth in 60 ft, and at least .2 in 1/4 but its not slipping (RPMs jive with speed and known converter slip)... I think the high clutch pack might have been dragging a bit all along in low gear... Also thinking about switching to an o-ring style servo piston instead of twin cast iron rings....

Re: Powerglide damage from 'clicking' engine off in lights
 

Have you ever tried one of the solid teflon "O" rings. I would bump the line pressure to 170. I have always had difficulties with lower pressures.I fixed up a fixture to put my leakdown tester on the servo and tried a bunch of different servo's and ring combinations.You do get rid of the cushion spring?? Which way do you space the servo when you get rid of the cushion spring? The double "O" ring will seal, but won't release as clean as a single ring. If you are going to use the twin ring try putting two of the stock Alum rings with the coated face on that servo. Seals and moves well.

Re: Powerglide damage from 'clicking' engine off in lights
 

How fast is your car and what does it weigh? I found with mine 10.80s 3400 lbs that 150 wasn't enough. It would burn up high gear clutches in 50 runs or so.

Re: Powerglide damage from 'clicking' engine off in lights
 

Jody, 10.40's at 3280 lbs (has been 10.20's before the woes) Probably very similar stresses on the glide as yours. How high did you have to go above 150? my engine is pretty weak compared to most 350 255/294's so id hate to rob any more power than i have to. Ill try to get a 175 psi spring and try that as Adger recommended. Also going to look into the Teflon ring.

Many thanks for the help guys!!

Re: Powerglide damage from 'clicking' engine off in lights
 

Kevin,

In our Corvettes, we had to bump the line pressure up to around 200 PSI and run 6 clutches to get them to live. Admittedly, this is in a 3300 lb Big Block car, so it's making a little more power than your combo. We have always put the trans in neutral and shut them off. No trans issues from doing that.

Also, and I'm sure I'll hear a lot of arguments about this, don't shift in the burnout. Do the burnout in high gear only. The shift in the burnout is one of the hardest things on the trans. When we started doing that years ago, the trans life increased exponentially. Just make sure the tires are wet and stab the gas. I have done this with all the cars I have driven (fast / slow / big tire / small tire doesn't matter) for years with no issues.

Hope this helps.

Re: Powerglide damage from 'clicking' engine off in lights
 

Well, I suppose that may be the case. Strange thing is that I don 'see' any slip... But there could be 1-200 RPM of slip, and I might not notice.. Could be slipping during the shift as well, which I wouldnt really be able to tell, since its a glide, and thus it gets back down on the converter anyway, and it would be hard to tell.

The other thing that I find a bit strange, is that I can get the trans plenty hot, just in warming up the engine in park and not moving the car at all. That makes me think there is something rubbing in the trans even sitting there in park... In the time it takes to get the enging up to 160F, the trans is 150F, just sitting there... Do you folks see the same thing, or is this out of line ???

Kevin

Re: Powerglide damage from 'clicking' engine off in lights
 

175 would be good. Is your pressure gauge accurate? That's what bit me.

There's another way to bump pressure without changing spring if you have access to some other pressure regulator valves. Even a shim if it doesn't already have one.

Building heat while not up against the converter can't be good.

Where's your sender located?

Re: Powerglide damage from 'clicking' engine off in lights
 

If you have been running steel sealing rings the snout on your pump is probably worn and contributing to the low pressure issue. The first thing to go will be the band will burn up in less than 10 runs. If you notice the car trying to back up when you get on the brake then the band is starting to burn up. This is what was wrong with my car several years back. Coan turned me on to a new pump and valve body and I started using the Teflon seal rings. Coan set my line pressure to 170. I would replace the pump and have a good trans builder like Coan rebuild your valve body. The Teflon seal rings work real good and eliminate the wear in the grooves on the pump snout.

Re: Powerglide damage from 'clicking' engine off in lights
 

Sounds like to diffrant problems which needs to be fixed . Low oil psi in the shut down and you will kill the motor . When you say you loose oil psi , it goes from what to what . What problem are you having with the trans. You could be over heating the trans by shutting off its oiling system and lose its cooling effects. Do you run and trans cooler ?

Re: Powerglide damage from 'clicking' engine off in lights
 

Well, guys, I got to the bottom of this. You wont believe what I found... Amazing...

The shutting down in the traps was not the issue. Bearings, bushings etc were all fine. The issue I was having was burnt up high gear clutches and fairly excessive band wear and occasional burning of same.

I was convinced I was doing everything perfectly regarding setup, clearances, etc...

Both ATI, and TSR racing kept suggesting it was shifter adjustment, and/or a shifter problem. I had previously checked this several times, but checked again in the most thorough fashion. It was perfect.

So then I decided to tear into the valve body (ATI #203300) and take a close look at everything there, suspecting an internal problem. Everything looked ok in there with one exception.. The manual spool valve seemed to not line up properly with all the lands in the body as I moved it into each gear position. I had bought a new manual valve from ATI a week earlier figuring I would change it out as well, if perhaps mine was worn in diameter and causing leakage....

Well what I found is that my manual spool valve had two of the spools in a roughly 1/8" different position than the new spool valve, as well as one spool which was narrower. See the attached pic below of the comparison. When I put the new spool valve in the body, each spool lined up perfectly with each land in the body.

Further analysis of each position, and each port showed that in Low gear, only 1/16" of the low apply port was being connected to line pressure. Likewise in high gear the same problem was present. depending on ever so slight slop, it could have even been worse, as well as causing leakage from each port into another, or to exhaust...

I never would have thought of this. I assumed all powerglide manual spool valves were identical. Most folks I talked to did as well. I don't know where that spool valve came from, and what the heck could be the history of it, but I know realize I have had all these problems since installing that valve body, and this was the cause.

So moral to the story, if you build glides, have several manual valves on hand, compare them and make sure they are all the same, and that they line up well with each land in the valve body.

The car picked up .2 and 3 MPH, shifted like a raped ape, and ran four passes within .01 of each other. And the fluid is as perfect as when I poured it out of the bottle.

Sorry for the long post, but I don't want ANYONE to have to go through what I have gone through the past month, and its certainly a 'weird' one, so keep this in mind.

See pics below. 1st pic: both spools. 2nd pic, the old spool in 1st gear position. 3rd pic the new, correct spool in 1st gear position.

Than you everyone for the replies and the help.

Kevin

Re: Powerglide damage from 'clicking' engine off in lights
 

Turbo Action shifter for the glide as far as I am concerned. We have run the SCS shifter for years. This is the only shifter to run, Herb Sr. put dad onto this years ago. New drivers should practice going to neutral while rolling through the pits. I would not run any other automatic shifter.

Re: Powerglide damage from 'clicking' engine off in lights
 

A long time ago I sold Trans King a big box of P/G parts I had collected.
There were about 11 V/B's in with all the other stuff. I did not get credit for two of the V/B's because he said they were older PG that had a rear pump. I questioned him and he said he couldn't use them because they were different. I just accepted it and went on. I can't remember if they were out of some old iron case PG's I had or the alum cased that had rear pumps. NOW!! I am wondering if the porting in the V/B was different. Could your Spool Valve be out of one of the older P/G's that could have had different porting??? Just wondering.
I'm not a PG expert on old parts by any streach!!

BTY: Where did you get those nice fluid diagrams in the pictures?? Nice!

Re: Powerglide damage from 'clicking' engine off in lights
 

I found it on the http://www.brianswayneonline.info/index.html
Swayne has the pictures of the non rear pump and the rear pump VB's and they are different.Check out the size, spacing difference of the passages around the spool valve area!!
I would bet the spool valve that goes with each is different. It is not shown... :~(
I will try to upload the picture. You can use that link and look around for the pictures is you like. well, another case of Al's internet paying off with info!! :~) Kevin, I'm just like you... didn't know that one!!

Re: Powerglide damage from 'clicking' engine off in lights
 

That's some great mechanical detective work. I've had similar problems with camshafts of all things. Same issue as your spool valve; camshaft journal (which is ground from a "spool") that is off center in the cam tunnel and protrudes into the lifter bore ever so slightly. Of course the first time you don't notice until the cam is installed, degree'd, etc. Take it out and put it in the lathe. I've had this happen 2 or 3 times. And I guess everybody with a trans valve body will be taking them apart this weekend!

Re: Powerglide damage from 'clicking' engine off in lights
 

I have a bunch of Glide stuff up on a shelf and need to assemble a trans out of all of it. Now, you got me to thinking not to ever disassemble a bunch of valve bodies and toss all the parts into one container. Very possible that the manual valves are spaced differently. Those pictures are worth 10,000 words in this scenario. I've had glides that lasted for years and years and still would work, and the clutch and band issues just weren't there. I hurt a high gear clutch pack in my Chevelle some seasons ago, it seemed that fluid level was the cause. This scenario you just described and located would drive a sane man nuts before he found it! Thanks for the message to all of us.

Re: Powerglide damage from 'clicking' engine off in lights
 

In park, the first journal on the manual valve, will be flush with the VB, if it is the correct manual valve for the VB in play.

Re: Powerglide damage from 'clicking' engine off in lights
 

Kevin, I've been neutraling my Glide and clicking off the engine for 30 plus years with no issues or special parts .
Over the years I have rollerized the transmission , but had no issues before with babbet sleeve bearings.
For me it's never been an issue about oil pressure ,It's about turning unnecessary revolutions in the engine and valvetrain and not using it for a "Jake Brake".
There are a few short shutdown tracks I leave it in gear a little bit ,but it pains my ears hearing the engine being used as an anchor !
If there is any downside to this it is there is a spike in trans temp but it drops as soon as you fire up and drive to the timeslip booth.
A side note on the valve alignment issue , I have seen misalignment issues with both Transmission specialties and early ATI cases due to boor bolt hole /shifter shaft hole alignment.
I had a customer co thru 3 sets of high gear clutches in 50 runs before I saw the same issue you had .

Re: Powerglide damage from 'clicking' engine off in lights
 

My ProTrans (T350) has the “Clean Neutral” option for that.

Re: Powerglide damage from 'clicking' engine off in lights
 

Thank you very much for the schematics of the valve body. Sometimes when using some one else's race trans, it's sometimes hard to find out just what the fine points of each builder's transes are. The schematic really helped. Now its time to compare some spool valves without mixing anything up and see what the differences are. Thanks again,Greg
P.S. Are the cases the same from a rear pump earlier aluminum trans to the later ones without the rear case?

Re: Powerglide damage from 'clicking' engine off in lights
 

The oil passages at the rear of the cases are different from rear pump models and the non rear pump models (both alum cases).
If you block off the rear passages with a plate and drill the rear pump case for a transbrake it works the same as a non rear pump case.
The plate blocks the oil bleed to the stock rear support where the governor is removed also.
Hope this answers your question.
Just my experience.
Rick Cates
Canyon, TX

Re: Powerglide damage from 'clicking' engine off in lights
 

I always have subscribed to two philosophies in life, personal mottoes if you will, one being that if you didn't learn something new each day, you've wasted the day. The other personal motto is the saying"Success is the best revenge".
I decided to assemble some transmissions that I have around the place, and needed to check for a stuck pressure reg valve in one that lost trans oil pressure, so I disassembled the valve body. The previously posted exploded view of the PG OEM valve bodies came in handy. The fact that there were two different manual valves concerned me. I slipped the manual valve out of the valve body I was working on and looked it over, everything was OK, no binding in the valve body, etc. but any Glide guy knows that the valve body has two parts, both cast iron, with a date code in the casting right below the OEM part number. I got curious, went into my store room where there is a couple of plastic milk bottle crates full of PG small parts, and I dug out a couple of valve bodies and brought them out front for evaluation.Here's what I found:


The upper castings were all part number 3847715.The four that I looked at were cast on
C 10 3, E 27 8, F 15 4, and A 23 7.

The lower casting, the main part of the valve body that bolts to the trans case, had GM part number 3819476. The date codes on these 4 were:
6 9 3, F 13 8, F 18 4,and C 27 7.

This indicates two early transes with a rear pump, and two late ones without a rear pump.

The next comparison was when I took the spool valve(manual valve), out one at a time, for comparison. The two later (post 66) glides had the spool valves with the slender spool about 2/3rds of the way back, the other two had the spool valves with the wide spools all the way back.

The rear pump disappeared in mid 66 or so, I never really took one of those apart to verify it. If I come up with a core with the valve bodies cast in 1966, I'll check and see which manual valve it has.
It would probably be wisest to stay with whichever spool valve you currently have rather than switch them and discover you now have a problem where you didn't have one before.

Some time ago, one of our local racer friends came up with a 69 Camaro convertible with a 250 inch 6 cylinder, and a cheap version of the Glide called a Torque Drive. It was a manual shift trans with no governor, passing gear accommodations, and no automatic upshift at all. I would have liked to dissect it and inspect what made that one different, but I never got the chance. Those transes were rare when they were new, so there's no use looking for one 50+years after they were made.

Hope all this helps. I'm no authority on transmissions, there are many excellent ones, but it was interesting learning a few things!!

Re: Powerglide damage from 'clicking' engine off in lights
 

Always wondered why GM made that Torque Drive trans. Back then a Powerglide transmission probably only cost them $50.to make, and they had to come up with a cheaper one? Saw a 69 or 70 Nova in a wrecking yard a few years ago that had a 4 cylinder and a T Drive trans in it. Bet they didn't make a whole lot cars with that combination.

Re: Powerglide damage from 'clicking' engine off in lights
 

I wanted to open one up and see what they did to make it full manual. I was interested in seeing if the valve body might be useful in a stocker, at least a low horsepower slower car. It seems like it was an afterthought. I wonder how many people just stuck it in High rather than knowing that it was designed to be manually upshifted while they drove around slowing everybody else down that was stuck behind them?

Re: Powerglide damage from 'clicking' engine off in lights
 

Greg,
Did you compare the diameter of the boost valves in the two different valve bodies?
It would be interesting if one was a higher pressure than the other.

Re: Powerglide damage from 'clicking' engine off in lights
 

No, I have not. Which valve on that exploded picture is the boost valve? I would assume the bore diameter of all those valves is probably the same, there doesn't at first glance appear to be a difference in valve bore size, but I haven't totally disassembled anything in search of something like that. I remember in the days of working on cars in dealerships, running changes used to come along when engineers came upon a better way to do things. Sometimes a technical service bulletin would come out describing changes, sometimes not. I suspect the valve with the thin spool about 2/3rds of the way into it, and the varied spacing between two of the valves near the center of the valve could be because of a running change. It would be imperative to be sure your linkage is perfectly adjusted and that the little pin that engages the manual valve isn't bent or the plate that it comes off of isn't damaged, either.