LilJayV10

iTrader: (5)

The transmission in my friends 93Z that I built w/ the help of my buddy who owns a transmission shop here in town, I checked the line pressure on it because of a shifting problem that it has, it bang shifts the 2-3 shift. I put the pressure guage on it tonight and it has 250-275 psi all the time. In park, in gear, idle, 2500 RPMs, w/ and w/o the TV cable pulled.

I called dana tonight and he said it sounded like the TV system was jammed up and thats why, I checked that, everything was free, called him back and said to call transgo. I did that, the guy I talked to said it's in either the TV system or the boost valve assembly. He said to take out the TV system, take out the roll pin, pull out the plunger, bushing, washer shim, red spring and leave the back roll bin in holding the self cleaning valve. He said to put it back together, start it and check the pressure, if the pressure is the same, then its not the TV system, because it's been eliminated, and the next place to look is the boost valve.

I did all that, put it back together and its still 250-275psi as soon as I start the car.

I am going to call transgo back tomorrow, but was wondering if anyone has ran into this problem before.

Thanks.

I will keep you guys updated on anything I find.

Jason

LilJayV10

iTrader: (5)

just to keep everyone updated, I talked to transgo today and dana both.

I checked the TV system, thats not the problem, I checked the boost valve system, and the PR valve, everthing looked good. Everyone said it's going to be the slide in the front pump.

Dana said the slide is stuck in the WOT posistion and thats why the pressure is so high. I took the trans out today and the front pump, I'm going to take it to the trans shop in the morning and have the rotor and slide assembley checked.

The trans is super clean, and I guess it's better to have 250psi instead of 50psi.

I'll keep you updated.

SMasterson

Well?

Gotta know!

LilJayV10

iTrader: (5)

Well, as usual things didn't go the way I wanted them. Took the front pump apart, everything looked ok, I checked the slide, it is free. Put it back together, still 250-275 psi.



I talked to Dana again, he has no idea. I'm obviously clueless. I can't call trangso till monday morning. Dana said they might answer their phone in the morning.

I need a beer.

LilJayV10

iTrader: (5)

Well, I can say I now have stumped my local tranny guy, dana at probuilt and transgo.

I have spent the last 4 hours talking to transgo trying to figure out why I have excess line pressure.

First off, I want to say that everyone that has helped my with this trans has been nothing short of great, tony here in town, dana at probuilt and larry at transgo. I have talked to larry atleast 15 times tonight, and he gave me his cell phone so I can call him when he's not at work, just like dana at probuilt, now thats customer service.

These are the things I have done, took out the TV system, checked the pressure, the same.

Drained all the fluid out of the tranny, still high pressure, took off the gauge on the trans line, emptied more fluid out. The wheels were turning with no fluid in the pan, I dropped the pan again to check the fluid, less than 1/2 a quart, still had 30psi of pressure and still had all the gears.

Larry and Dana both said thats not possible but it's doing it. Like Larry asked me, how can do you drive your car with no gas in tank, you can't. and how can you have 30-50psi of line pressure with no fluid? Obviously the answer to the latter has not been found yet.

I took out the boost valve, turned it around so it would block off the feed whole to eliminate the boost system, still 150psi+.

The trans is coming back out in the morning and the pump is coming back out.

I'm off to have a beer now. this is ridiculous.

oh, and all these tests, running the tranny with no fluid were done under the direction of larry at transgo while i was on the phone with him.

I didn't think a tranny would turn the wheels with no fluid in the pan, but nobody else did either.

this **** only happens to me.

chris718

it is impossible to have line pressure without oil,after all the fluid is what is pressurized.if the tv was stuck youd have late shifts in all ranges and a brutal apply into reverse and drive.the wheels moving on the lift is due to the input housing and turbine shaft being driven by the torque convertor and the forward clutch dragging on the input sprag driving the wheelsbecause there is no load applied to the rear of the trans.this is common .if you grab the wheels theyll stop,but they wont with a working trans and the car in gear.the gauge may be reading air pressure not oil pressure but still higfhly unlikely in the mind of this well respected 20 year veteran.

SMasterson

Sounds like you've got it weaned.

Tony sees trannys like that all the time! Well, they *think* they will run without fluid anyway.

Sorry, can't help with fixing it.

LilJayV10

iTrader: (5)

regardless, of whats making the guage move, it's moving fluid or air, I don't know. but the wheels are still turning, you can apply the brakes, it over powers them.

This shift timing timing is pretty good, it has a bad 2-3 clunk shift, and does other strange things.

I don't know much about trannys, this is the farthest I have been into one. I'm just the messanger.

chris718

then there is a misbuild or mechanical damage causing this.

SSC

I had a truck do that but it was a crap in the TV system causing it. Dig up an old Transfix Leo thread and shoot him an email.

Fast355

iTrader: (2)

You checked the TV valve but did you check the TV boost valve? It that hangs up you will also get full line pressure.

LilJayV10

iTrader: (5)

Yeah, thats the last thing I checked. I turned the small valve upside down in the boost valve to cover up the oil feed hole at the bottom. The pressure was still 150 psi in gear, and would jump to 250 in park and neutrel.

I talked to larry tonight from transgo, he said he'd call me back but never heard from him. The front pump is back out and apart on the work bench. Right now I don't think he know's were to go next. Apparently this type of thing doesn't ever happen.

Fast355

iTrader: (2)

I guess it is possible that one of the seperator plate gaskets is ripped allowing fluid to bypass from one passage to another.

chris718

good point /if line pressure is leeaking into the modulated tv oil circuit ,this could happen although there would be other problems.does your pr valve have a hole in it ?if you use an early pump cover with a late pump body .or a pr valve with no hole in it with a late body or cover itll do the same thing.if the pressure is max all the time what happens at full tv with the engine at 3000 rpms?you should hear the oil bypass in the pump opening and closing also.

LilJayV10

iTrader: (5)

Sorry it took so long to respond. I started my new job this week. I am a emergency vehicle technician. Fancy way of saying I work on ambulances. I had to get all sorts of certifications and such. I took my driving test today. The head guy of safety and risk managment went with me. The mechanic I work with told me to mess with him when I got into the truck and told me what to do.

We got in the ambulance, put my seat belt on, turn the lights and sirens on, threw it into gear and put it to the floor, came around the corner spinning tires hitting the yelp button. It was great. You should have seen the look on his face and everyone was laughing when I got back from the test drive, it was great.

Back to my tranny issues.

Yes the PR valve has a hole in the top of it. The tranny is back out, and the front pump is apart again. Larry at transgo swears its in the front pump, and that the spring isn't collapsing letting it run at lower pressure. My local tranny guy thinks it's in the valvebody and dana said he is out of ideas.

Larry wants me to put a different front pump in it, but I can't see how that pump is bad. The slide is moving I checked it.

I do not want to put this damn thing back in without finding something. It's been so cold here this week I haven't messed with it.

Chris, do you have anymore ideas. The more posts of yours I read on this forum the more I realize you build a good product too. I appreciate your input as well as everyone elses.

This **** only happens to me.

I am lost, pissed off, and tired of taking the tranny out.

LilJayV10

iTrader: (5)

Chris, I wasn't able to get your number from your last post. If you could post it again, or PM me I would appreciate it. I haven't done anything with the car, it's still on jack stands in my car with the tranny apart. I appreciate your help. Like I said, I don't want to put the tranny back in the car untill either I find something, or change something.

Jason

chris718

phone number is 718 784 4256 at the shop

Driveshaft

LilJayV10
any updates to your problem ?

LilJayV10

iTrader: (5)

no, I haven't worked on the thing for a while, i called chris this week but he was busy and haven't had a chance to call him back. I haven't talked to dana or larry at transgo, i need to get back on it and try to figure something out.

Precision Trans

LilJayV10:

Hope you don't mind if I take a stab at this. You mentioned earlier that the trans was doing, "other strange things". Could you be a bit more specific, please? Did I read correctly that line pressure is higher in Park/Neutral than in any forward ranges? If you fiddle with the Throttle Valve cable, do the shift points change? If you can vary shift points either with throttle opening, or cable adjustment, this all but rules out any problem with the Throttle Valve train.

In the 700-R4/4L60 and 4L60-E transmisions, the pressure regulating system is actually more of a pump volume regulating set-up. When pressure reaches its require level based on spring tension, TV boost, and/or Reverse boost, and 2nd boost, the pressure regulator valve directs oil to the "decrease" side of the pump slide. If the pump slide were to stick in the high volume position, then yes pressures could be quite high, but would tend to get even higher as engine/pump speed were increased. Vane type pumps are capable of developing pressures in excess of 500-600 psi.

In reverse, this trans is supposed to have pressures in excess of 300psi with engine speed at 1000rpm, and TV cable pulled out all the way. If you do not get this but still get varying shift points in forward ranges by manipulating the TV cable, you most likely has a misassembly of the parts in the pressure regulator valve train. This can be serviced without pulling the trans from the car. Any more info as to the diagnostics you have performed will be most helpful. If you wish, you may contact me by phone at the number on our website, (902) 892-4819 from 8:00am to 5:00pm Atlantic time.

All the luck
Don.
Precision Transmission
http://precisiontransmission.pe.ca

F-Bobby

im not a trans guy, but typical pressure is suppoed to be somewhere from 70 to 100 psi correct? Now if the trans has as much pressure as you say it does wouldnt it blow the lines from the trans to the cooler in the radiator? i mean they are just rubber hoses with some compression fittings on them right? That pressure would have to be equal throughout the transmission because the fluid cannot be compressed. are you sure that gauge is reading right? the 2nd to 3rd shift being hard i would think that would have something to do with the 2nd to 3rd shift accumlulator, and spring. almost like the spring tension is too much.
Also you did put a shift kit in? Are you sure that all the check ***** are in their correct places and are releasing when they should be, and make sure the valve body gasket is the correct one and isnt blocking fluid flow to a chamber that should be receving it. Also if that Kit required you to drill holes in the valve body, did you make sure that you cleaned them out?

Sorry if im asking a lot of rookie questions, I dunno those are just my guesses.

LilJayV10

iTrader: (5)

I spoke with chris tonight and he was very helpful. I appreciate him taking time out of his day to try and help me. He thought at first that I had a mismatched pump cover and body but he checked the numbers and they are correct. He thinks that there's a leak or a crack in the front pump thats letting the fluid backfeed into the PR system or something was done wrong with assembly of the pump. Basically he said to put a different front pump in it and that should take care of the problem. Hopefully this fixes it, but the fact that I don't know for sure what the problem is I don't like.

Jason

LilJayV10

iTrader: (5)

Chris, I posted as well as I could from memory of what you told me. If there was more or if you would give a better explanation of what was said, i'd appreciate it.

I aslo talked with don today and he was very helpful. He stated that there shouldn't be any reason that this suddenly became a problem after a rebuild unless something was installed incorrectly. Most everyone right now is saying to install a different front pump, which I am getting one, but not installing it as of yet.

Again. I thank everyone for the patience and help they have offered. Apperntly this doesn't happen to often, if ever.

Jason

LilJayV10

iTrader: (5)

pump

LilJayV10

iTrader: (5)

boost assembly

LilJayV10

iTrader: (5)

PR valve

LilJayV10

iTrader: (5)

spring

LilJayV10

iTrader: (5)

don, here are the pics that you wanted.

Jason

Precision Trans

Jason:

Thank you for posting the pictures. Your problem is now readily apparent!! You have incorrectly modified your pressure regulator valve. The land you have ground down is dumping all the oil that is directed to the reduce side of the pump slide. The valve land you should have ground down is the second land from the small end. Will post a picture later.

Don.

Precision Trans

Jason:

The pictures I promised you may be delayed as I am having difficulties posting them to this board.

However, I have a few additional comments. You may or may not want to replace your pump assy, but there is probably a better way. A company named Sonnax supplies oversize replacement PR valves. Since PR valve bore wear in the cover/stator support body is a problem in these unit, I would suggest you go this route. Any good transmission shop should be able to supply this part, and be able to machine the the bore to accept the oversize valve. The valve comes with the correct land already modified. If you are unable to find anyone to do this, I would be happy to do it for you. The Sonnax part number for this valve is 77917-06. Tool kit # required to ream the bore oversize is 77917-TL.

If, upon inspection of the pump slide pivot pin, you find ANY signs of wear, Sonnax has a replacement for that also. Part # 65797 should be available from any good transmission shop.

If you have any additional questions please do not hesitate to contact me.

Don

P.S. I'll send the pictures directly to your mailbox. You obviously know how to post them, so I will ask you do do so for anyone else who wishes to see them. Thank you.

LilJayV10

iTrader: (5)

Don, that is the valve that came with the transgo kit, and they said not to modify it. to the best of my knowledge it hasn't been.

LilJayV10

iTrader: (5)

PR valve

RBob

iTrader: (1)

LilJayV10, I was just taking a pic to post. The new PR valve just didn't look right. Your pic of the original PR valve is correct. That is the land to remove. I wonder if the new PR valve that was sent with the kit is the wrong one. Maybe a side-by-side comparison would reveal something.

Here is the pic I took that shows a stock 700R4 PR valve along with the land to remove.

RBob.

LilJayV10

iTrader: (5)

The PR valve sent with the kit looks completely different. Why I don't know. I looked at the instructions. I got the kit from dana at probuilt, he sent a new PR valve, and on the instructions it says not to grind on the ne PR valve, the flats that are on the valve were already there.

RBob

iTrader: (1)

Can you install the original PR valve and try the trans? This would show whether the PR valve is the problem or not.

RBob.

LilJayV10

iTrader: (5)

I guess I should call dana, there has to be a reason he sent that valve.

LilJayV10

iTrader: (5)

Dana said thats an aftermarket valve that was designed by gene mason that use to work for transgo. There are two flats on the side of the valve, which looks like where it's been ground down. He said to check and make sure the whole in the PR valve isn't clogged or something. Thats what i'm off to do now.

Jason

Nope, the valve is fine.

Precision Trans

Jason:

Just got in this morning and read your posts. I assure you, that the valve you got from Pro-Bilt is WRONG!!! Unless it is intended to go with other obscure, not explained, mods to the pump, but I have no idea what they could possibly be. Perhaps Dana can post here explaining to the rest of us about this valve. A hydraulic system schematic showing the function of this valve would be most helpful. It's certainly nothing I have seen or heard of before, and judging from Jason's frustration seen in this thread, I hope I never do! And, Dana, if you are taking this valve on faith because it alledgedly come from " Gene Mason who used to work for Trans-Go" maybe you now know why he "USED TO" work for Transgo. Maybe Larry, from Trans-Go, can clarify that for all concerned.

From your previous posts, Jason, and talking with you on the phone, I knew that it had to be something that you had built into the transmission, and I firmly believe this valve is the problem. Having used many Trans-Go kits over the years, I can assure you that, as of the last time we took delivery of a 700-2-3 kit, it does NOT come with a PR valve. You are instructed to modify your stock valve as shown in the picture I e-mailed to you. By the way, thank you for posting it for me; and thank you RBob for your picture, and for backing me up on this. Perhaps you may want to contact Larry at Trans-Go and show him the pictures in this thread. I'm sure he will concur with both RBob and myself.

I realize that you purchased the kit in good faith from Dana at Probilt. Trans-Go make very good comprehensive kits that do what they claim, and should be installed as instructed. All their research, development, and testing is done so that you don't have to spend your time trying to make things work, and can instead enjoy your vehicle. If builders out there wish to incorporate their own little tricks and magic spells, they should stick to selling complete drop-in fully dyno tested units, not dropping additional parts into someone elses kit and causing unending frustration. I can just imagine the beating Trans-Go's reputation has taken as a result of these events. Think for a minute, how much time was spent by both yourself, Jason, and Larry at Trans-Go over a problem not of Trans-Go's doing. Larry deserves a medal for his commitment to his product and for all the after hours help he was willing to give you.

Dana, in the future if you still insist on sending this valve with Trans-Go's 700 kit, perhaps you could do your customers a favour and include a disclaimer stating that the valve is not part of the kit, and is not recommended by Trans-Go.

Thank you for listening

Don

LilJayV10

iTrader: (5)

I PM'd dana about this thread, hopefully he will respond. I have been talking to him for a long time and he's giving me a lot of info on how trannys work. I also know there a lot of people on this board who love his transmissions. I don't know why he would put an inferior part with his kit, it's just bad for business. I guess in a way I am defending him because he has been so helpful to me, but at the same time I don't want anyone to think that Don's, Chris's or anyone elses opinion doesn't mean anything to me but that's just not the case. I have had a lot of people try and help me on this matter and I very much appreciate it. The last thing I want to do is make someone mad, especially someone who is taking time out of their day.

Jason

dimented24x7

iTrader: (2)

Have you tried swapping a standard PR valve back in to see what happens? That would end alot of the speculation right there.

chris718

i have never seen anyone grind that land either.if the decrease circuit is constantly charged in theory it should only reduce pump volume and not adversely affect pressure.what it appears to do in this case at first glance is to be applying a positive force on the valve greater than that on the upshift side of the pr valve thereby increasing pressure.i would need to study the circuit to be sure however i would bet if you installed a stock type pr valve with hole itll work fine.we dont use transgo kits and dont modify the valve at all.our pressures are 90 at idle with 0 tv which is exactly what the line bias feeds the tv valve and 240 at wot with stock unmodified pr valve.

Precision Trans

Chris:

Posting a picture of the circuits. As you can see, by modifying the PR valve similar to the one Jason had in his trans, you can see that "reduce" oil is dumped, and no control is possible. Here is the link.
http://photos.groups.yahoo.com/group...iew=t&.hires=t

Don

TRANSAM38387

i'm not a tranny guru but my atsg manual also said to modify the valve like RBob and don have stated

LilJayV10

iTrader: (5)

I left a message for dana but haven't heard back from him or seen him post. I haven't looked at the tranny either. I've been working a lot trying to get two ambulances done, i think I've worked about 56 hours so far this week. I haven't had time to do anything else.

I gotta get this car done. With all this overtime, my 406 will be going back together next month.

LilJayV10

iTrader: (5)

I talked to dana this evening, he said he will reply in this thread later tonight.

Pro Built Automatics

Is it possible that this valve could be causing this? Yes, it could be possible. Maybe the "Dean Mason" valve that I supplied could do this. I have used well over 500 of these valves without a problem, on my units, and have sold more than that in the valve body kits. So if it is the valve, and the only way we will know is, if it is changed out to the "original" valve. So make the change, and see what happens. Dean Mason has been making his own valve body kits & fixes for transmissions for years with much success. And yes, he worked for Trans-Go at the time that he started making these valves in the mid 1980's. This valve will eliminate pressure regulator valve noise, raise main line pressure by about 5-10 pounds, eliminate drain back, and supply the lube circuit with more lube than the stock valve does. The grinding of the land on the PR valve, as per Trans-Go instructions, has similar effects, but it increases the "drain back. I hope this helps.

LilJayV10

iTrader: (5)

So I'm stuck again with no definative answers. It's not anyone's fault, it's just a bad situation. I have several different options to go about, I can either replace the front pump or the PR valve. I'm really aggrevated, but not at anyone but at the problem itself and that I don't know enough about trannys to fix it, but at the same time there is probably more than 75+ years of tranny experience from the people in this thread and no concrete answer has been nailed down yet. The thing that really upsets me is this isn't even my car. It's my friends car who I built the engine/tranny for but still doesn't work correctly, and again it's no one's fault. I appreciate everyones help in this. I know a lot of time has been spent in trying to figure out this problem that never seems to happen.

Thanks.

Jason

Pro Built Automatics

Try talking to Terry Hedrick about this & tell him I sent you, at (901)466-0267. Let me know what he might suggest (if anything)?

Precision Trans

Dana:

First off, I apologize to the rest of you for hijacking this thread.

I'd really like to learn more about this valve you include in your VB kits. It is unlike any I have seen up to this time and I hope you will understand my curiousity. Would it be possible for you to show me how the hydraulic circuits are altered by using this valve along with any other mods necessary for it to perform correctly. Even though I have been working on transmissions for over 25 years, hardly a week goes by that some new or different doesn't come along, and this valve appears to be one of those things.

Thank you
Don

Kingtal0n

About a year ago, I purchased a Rebuild kit from Dana at PRO-BUILT. I had no transmission experience prior to the rebuild, have never pulled apart a transmission before in my life. this was for the 700R4.

Dana and I were on the phone almost every day for a month straight. I even compiled a list of everything he told me, found here: (http://geocities.com/kingtaling/tranny.html).

Using his help and a Haynes manual on trannies, I finnaly finished my 700R4. But I did a something wrong...

In the instructions from trans-go, you need to drill a hole from the "bathtub" into the shifter linkage channel. Well, I looked at the arrow pointing to the "bathtub" and consequently drilled right through it.

Your problem is similar, although not identical, to mine. Do you recall where you drilled your holes in the valve body? when you installed the block-off pieces into the valve body, did you flat-sane them smooth? My 2nd mistake was one of them wasnt smooth, causing the valvebody to **** sideways giving me weird shifting characteristics. My 3rd mistake... well lets not go there.

If anything, I just want to point out that through all of this, Dana spent his money and time through my issues without so much as a word of complaint. I recommend you check out my list of "things to do" above, incase you missed anything he said. there are some pictures as well.