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700R4 low pressures?

27K views 136 replies 9 participants last post by  '49 Ford Coupe 
#1 · (Edited)
Hi folks, I am getting ready to go into my 700R4 to do some more mods and correct some errors I made in last winter's build. I did before work pressure tests this morning and got some troubling results. Minimum TV, in P, N, D, 3 @ 1,000rpm, pressure is 90psi which is fine. But then in reverse, pressure @ 1,000 is only 110. In manual 1st and 2nd, pressure @ 1,000 is still just 90 psi. Full TV, pressure in P is 105. N is 110. D is 95. Man 3rd is 100. Man 1st and 2nd is 100. When I raise rpm to 2,000, pressures @ full TV are P & N- 220, R-210, D 190, 3-200, 1&2-210. Gauge is steady(no wiggly needle). In R, D and 3, when I rev the motor with the TV locked full open, pressure jumps to 240 before falling back off to the readings listed above. I wonder if that might be the pressure relief valve opening. I would like that to hold til 300psi if possible.

The unit has a .296 rev boost valve and the .500 TV boost valve with a high rate regulator valve spring. I have dual springs on the line bias valve and a new 10 vane pump. I expected much better readings. My ignorance is that I put the unit together and drove it most of the summer without pressure testing. Won't make that mistake again. To make things worse, the TCC never worked since the build and I know I got it hot. I know that there are probably several things that could cause this kind of behavior. Does anyone have any thoughts? What jumps to the front of your mind? Sealing ring(s)? Damaged pump? Gasket blown? I plan to go into the unit first thing in the morning and have the weekend to get it back together. I have a full gasket set, new sealing rings, and some other goodies to put in it. If I need other parts, I will need to run to Portland tomorrow to get them. Up side is that it is coming winter and I don't drive the car in anything but sunshine. Worst case is I find something wasted that I can't get tomorrow, I put it back together best I can, limp it home and go back in later better prepared. Moral of this story is pressure test before you drive it. Damn!

I am very thankful for any help. Go ahead and chew my butt. I've earned it.
 
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#3 ·
Tried to reply to you and it went somewhere ? So here it goes again. I would agree that I think its your pump, since your pressures are low across all the gears. Since you've got the kit, look at the clutches and see how much wear. A good indicator will be the amount of stuff is lying in the bottom of the pan. Buy the gauge set. I test mine twice a year. First when I get it out of the garage in the spring and then in the middle of the year when its handy. When if first built my 200 4r, my pressures were ok, but not like they were suppose to be. Found that when I rebuilt my pump and did all that work to it, I forgot to put the bigger valves in it. So don't feel bad, it happens to all of us. Doing you pump over may not be ok unless its done right. It maybe worn, and only a new pump will be your answer.
 
#4 ·
That does suck for me. I put this pump in last winter about 2,500 miles ago. I had it open to install the high rev slide spring. Maybe I screwed it up. I thought I was super careful with it, but. I can get a new one at PTW in Portland but I will have to leave the shop early and run there today since they're closed tomorrow. I'll tear the pump down in the morning and see what may have happened to it. If it looks okay, I'll look for sealing rings or anything else that may be dumping pressure. It is awful strange though that pressure at idle, min TV is so good. Wouldn't a bad pump cause low pressure period? Maybe not.
 
#5 ·
i'm no expert on the 700 or 200 pumps. When I rebuilt my 200 4r pump, I upped it to a 10 vane from a 7 vane, and used the larger steel rings. I was told that the harder steel rings are a fraction larger which helps keep the pressure up when it gets warmed up. I didn't use the high rev springs on mine for mine was going to be used in a lot of high rpm's. I did open up the return passage a little to prevent seal blow out.
 
#7 ·
Brisco left HR long time ago.

Your problem with low reading of PSI @ 1000 rpm is all pump. It is set up too loose. Clearances too loose on slide, on rotor , the side clearance is too loose on those pieces.

Pump cover may not be flat. Was it checked? Was it surfaced to flatten it?

If you had proper testing setup, flow gauge and psi reading on cooler lines.... That wil drop to nothing, indicates weak pump.
 
#8 · (Edited)
I was just going the say that. To much clearance between the the halfs.I flat sanded mine on glass using spray on adhesive an 400 gr. wet/dry & WD 40. I did both sides & the stupid thing was I didn't measure. Use a flat edge an a feeler gauge. I didn't know this at the time but a very good flat edge is a drafting square an I have one, just didn't know about this at the time. Just have to be careful with the plexy glass edge. I forgot what the clearance should be if I remember right its pretty tight.
 
#10 ·
Set up the rotor first is what I do, .0015 to .002 side clearnce. Set rotor into pump pocket, measure with depth gauge

The check the slide. Since the slide has a rubber O-ring under the sealing ring, you can run .003 clearance on the slide
 
#11 ·
Thanks guys for your help. I tore the unit down this morning and found the pump casing chewed pretty good. I also found where I missed filing down a couple of plugs in the separator plate. I'm sure these plugs created a nice cross leak. Now the bummer is that I missed my chance to pick up a new pump yesterday in Portland(too much work to leave early). Now I may be stuck until Monday.

Good news is, besides a fried, and I mean wasted 3-4 clutch pack, everything looks good. I guess one down side to the huge 3-4 clutch capacity of this Smart tech housing is that when the clutches fry, they really leave a gap. Clearance right now is a spacious 1/4 inch I bet. A little expanded from the .040 that I set it at last winter. The friction material is completely gone from every friction plate. Amazing they would still apply at all.

I will not run this unit again without verifying pressures first. Just because it seemed to shift great obviously doesn't mean it's all good. I must have screwed something up in the pump. I think maybe I didn't use a good enough assembly lube. This time, I'll just use my Fed Mog engine assembly lube. It's a much better lubricant than the trans gel. I was afraid this would happen. There is alot of non ferrous metal in the fluid too(metal that isn't attracted to the magnet). I wonder if the converter took a dump on me. I'm thinking the Edge unit that's replacing it will do better. Especially since I'll have the lock up working before it sees the road. It makes sense that everything was fine until I ran the car on the freeway in slow traffic on a very hot day. I'm sure that was when I fried the converter and probably started the destruction.

This will have been a great and expensive learning experience when it's finally done. I have learned to be much more patient and thorough. At this point, for what I have invested in this transmission over the time I've owned the car, I could have a custom built T56. :rolleyes:
 
#13 ·
New issue. I cleaned up the input housing, removing about a pound of friction material, and found that the input shaft is worn down at the front support bushing point. When I put the pump together, I followed a method I found on line to align the pump halves by installing the bolts loose, bolting the pump in place in the case, then tightening the pump bolts. It seemed like this would work out okay. But now I find that the input shaft is worn at the converter end. Is it possible that misalignment of the pump halves caused this? It doesn't seem like the halves could have been off by that much. Or is it just the converter being a pile. The input shaft in my old housing is in good shape. Has anyone ever tried removing an input shaft from the housing with the reinforcement ring installed?
 
#14 ·
WOW I used a very long wide band that I had that looked like a giant radiator clamp, to put my pump back together. Being a novice transmission guy, is why I use the pressure gauge several times a year. Sounds like you've got a major rebuild ahead of you. Don't get down. Think of it as fun and experience. I've had my pan off my tranny so many times I think I will wear out the pan bolts. Rebuild it again You've learned a lot and know put it to use.
 
#15 ·
Got it! I warmed the housing up gently with a propane torch to loosen the sleeve retaining compound. The shaft came out clean and nice. The other one went right in.

I checked out the pump to case clearance to see how tightly the pump is held in alignment by the case. It is within a few thousands. The pump is very snug in the case. The band clamp couldn't be much tighter. I am thinking that this pump or the converter was out of whack. I remember no issues with the stator support going over the shaft on assembly. Still, it is a possible issue. I might see if a local trans shop can do the pump assembly for me.

I did have one other disappointment today. I wanted to set my TCC up to have lock up in 4th always and selectable lock up in 3rd using my old fog light switch. I found out that my valve body doesn't have the 3rd clutch pressure switch passage drilled. Even if I did drill it, it appears to feed off the 3rd accumulator circuit which is now deleted in the Transgo shift kit. Oh well. I'll go with what I've seen on Tony's pages and have lock up in 4th and selectable lockup in all but 1st gear. I guess that the 700R4 be design won't activate the TCC in 1st so with 12v applied to the TCC solenoid, you get lock up in all but 1st. I'll try it and see if it works out.
 
#16 ·
Second thought. I will definitely have the pump assembled by a professional. No more screwing around with it. It makes perfect sense that the pump was off. Even just a little. It may have just been a little tight at first. Not enough to really notice on assembly but then once the shaft started wearing with the uneven support, the wear was accelerated. I'll just take my high rev slide spring in with the pump and have someone put it together for me. Right now, I'm assembling the gear train and clutches up to the front pump. Then I'll put my TCC wiring together and work on cooler lines.
 
#17 ·
Got things assembled up to the pump. I feel good about everything at this point. Took extra care to be sure that the plugs in the separator plate were ground flat. Installed, removed and reinstalled the pistons in the input housing a few times to be sure no lip seals were rolled over. I did find one rolled on the OR clutch piston on tear down. OR clutches are fine though. I also am pretty sure that I got the 4th servo in backwards. That would cause fluid to bypass the lip seal and create soft 4th shifts. I don't know if it's even possible to put in backward but when I looked at the servo stack up last night, I swear it was in the housing backward. Maybe I just did that yesterday after teardown and don't remember. I installed a pre assembled Sonnax dual piston Superhold 4th servo this time so won't be an issue.

3-4 clutch clearance is a little more than before and more than Probuilt recommends. I did'nt have the right combination of steels to make .040 -.050, .060 is as close as I could get. It's at the minimum of what ATSG recommends for stock rebuild. I know that tighter is supposed to give faster shifts but after burning the last set of clutches, I think I like the idea of more oil clearance when the pack is disengaged for better cooling. With the pressures I should be running now with the line bias blocked, I think I'll still have pretty good shifts. Does anyone have any thoughts on this? If I need to pull the housing back out to change things I will. I can get a thicker steel when I pick up the new pump tomorrow.

I was thinking about this thing yesterday after I broke for the night. The way the input shaft is worn uneven, it almost has to be bent. I know that I put quite a bit of pressure on it seating it in the housing when I assembled it last year. My press is a sad HF cheapy with a sprung frame from people overloading it. I wasn't sure about using it for this job last year but I went ahead when I couldn't find anyone close who had a good press. I wonder if I could have bent the shaft. That would take alot of force wouldn't it. You would also think if it was bent I would have gotten a vibration at speed. I was much more careful with the new shaft yesterday. If I have issues with this new shaft, I will get the assembly into a lathe and spin it with a dial indicator against it to check for runout before I do anything more.

I figured out my TCC controls as well. I can't use a 3rd clutch pressure switch but I can use a 2nd clutch switch. Using a NC dual pole switch in the ground circuit to the solenoid will disable TCC in 2nd so that using my dash mounted switch(old fog light switch), I can have lock up in 3rd and 4th or just in 4th by selecting switch position. I'm getting it wired up right now and also getting my new 3/8" cooler lines bent and installed. Sure wish I had that new pump, but patience is a virtue right? Got a 27hr engine job coming in tomorrow so between that and getting this project done, it could be a long day.

Thanks to Crosley and dwwl for all your help on this so far. It's nice to atleast share my greif, frustration and victory(if in fact it ends up being that) with other fellow wrench turners. I hope someone can chime in on the 3-4 clutch pack clearance for me. Thanks
 
#18 · (Edited)
Use a low roller clutch assembly snap ring. Its thicker than the 3-4 clutch snap ring, you need to cut an inch off one of the ends to make it fit. Do a Google search for 700r4 pump slide clearance, then scroll down some an look for 4l60 an 4l60e rebuild something or the other, its from uscars you really need to look at this. I had this in an above post but might of put the address in wrong. Its a PDF docm. I wish I would of know about this when I rebuild mine. Let me know if you found it.
 
#19 ·
Thanks dogwater. I will try again to find that pdf. I couldn't find it before. My input housing doesn't take a 3-4 snap ring. It's a trick(read as pricey) Sonnax peice with a bolt on backing plate. With the shorter 3-4 apply ring(stamped "7") it has 1.2"+ of 3-4 clutch capacity. Tha's why I paid so much for it. Now I'm really hoping I didn't ruin it by pressing the shaft into it with my crappy crooked press. I'll see how this other shaft wears. If the housing is ruined, I'll just buy another one. I like it that much. Maybe Sonnax will help me out some if I do need a new one.

Got my TCC wiring done. Very cool. The OE fog light switch, in the on position, now provides a steady ground on pin D of the TCC connector, which will provide an alternative ground path to the TCC solenoid, except when the 2nd clutch switch is open, which will break the circuit. With the switch off, the TCC will be grounded by the 4th clutch switch. So, with the switch on, I'll have TCC lockup in 3rd and 4th. With the switch off, I'll have lock up in 4th only. With a double throw switch, I could also have no TCC lockup at all, but I can't think of when I would ever want that. The car will do 170 in 3rd. Don't ask me how I know that.

Also got my new 3/8 cooler lines run and my new cooler assembly put together. I am using two Hayden 1405 coolers. One in front of the other, attached to the front of the radiator core. The hot fluid enters at the top of the rear cooler and cool fluid exits at the bottom of the front cooler. It should really drop heat. The lines aren't as pretty as I would have liked. The routing was tough. At the end of bending each line, I had to make bends with the lines mostly routed in place as they wouldn't go in once the bends were all made. But no kinks and pretty decent looking anyway. The larger tubes will flow better providing improved cooling and more lube flow. Also will slow down flow through the cooler system which means even more heat drop.

Now that it's Monday, I've got to get the motor pulled on a customer's car to start the reseal and get the trans in it ready to go out for overhaul(not going to mess with anyone's trans but my own). Then, I have to get to Portland before PTW closes to get my new pump. I'm going to see if they will install the high rev spring for me. Hopefully they have one on hand so it can be done and ready for pick up.

Thanks again to everyone for all of your help.
 
#21 ·
Like your idea of running two coolers. I'm running two single pass tube coolers on mine because I believe its more effective and not running it threw the radiator. I' lowering mine a little because might have a problem with them bleeding back into the pan. When that happens, it over flows out the fill tube seal. Would like to give a little more advise on your project, but have never worked on the 700's.
 
#22 · (Edited)
Hi dwwl, I decided to follow your lead and I'll pick up an alignment tool for the pump along with the pump this afternoon. That way I can do the alignment myself and do it right. My buddy who does these units alot and runs them in 9 second cars says he just uses the case to align the pump but I'm still nervous about it.

Oh, and I just figured something out too. The reason why my input shaft got worn uneven and so quick. When the 3-4 clutches burned up, most of the friction material was peeled right off. This left about .200 clearance in the pack. Enough so that the locating tabs of the pressure plate were able to lift off of the apply ring and the pressure plate side stepped in the housing. This would have applied side force against the housing which was communicated to the shaft and bushings in the stator support. I remember at one point the trans seemed to get stuck between 2nd and 3rd, as if both clutches were applied at once. It was just that the 3-4 pressure plate was wedged against the pack. The pressure plate seems to be fine, aside from a slight witness mark on one side that indicates it ran against the input ring gear for a moment. The ring looks fine also. Lucky. Of course I'm not discounting that the converter may have gone south and contributed to this side loading also.
 
#23 ·
I had though about using a parts tranny to set my pump in to to do the pump, But I had this funny looking big wide one inch band that I gotten years ago off of an old sign and kept it. Know I have it with my tranny tools so I don't ruin it or use it and ruin it. When I rebuilt mine, old tranny guy told me to act like your stupid. and check everything twice, and then question yourself as to why you did it. Seriously, I put mine together and then found a part. I had to take it back down and set it all back up in the correct order again and then reassemble. Seals have to be correct. Air test your tranny as you assemble. I enjoyed it so much that I rebuilt another one and I modified it also. I was lucky on both of my pumps I rebuilt. They were in real good shape and tight. I rebuilt them with 10 vane kits with the steel rings and relieved them. The two best trannys I had were low mile units. One was out of an old monte carlo an old lady wrecked with 60 k miles. The other was sitting for the last 20 years in a garage on the shelf. The other two were for better words, junk, but came in handy for parts. When you get it done. Drop use a line back on this cite and let us know.
 
#24 · (Edited)
Try this, type it just like this ATRF - 4L60 Rebuild (GM700R4).pdf- US Cars
It has clear color pictures & shows how to measure the clearences for the pump. There seems to be more info. than what the ATGS manual had in it. Its 184 pages. I haven't been thru all of it yet.
Now I'm worried about my pump because Other than running both sides of the pump over some 400 gr. I just used all new parts in it then put it back together.
 
#25 ·
Baby steps. I had a mostly successful afternoon running to Portland. Picked up a great looking rebuilt pump. It's done by Oregon Converter who are the go to guys for converters in our area. It's a beautiful piece with heat treated rotor and slide and already had the high rev slide spring installed so I didn't have to wrestle with it. It also has the triple lip front seal and PTFE bushing. I installed the Transgo steel rings from the PK700 kit. The stator support is heat treated with teflon coated rear bushing and PTFE front bushing. Gorgeous part for the price. I also picked up the alignment tool so no more guessing.

Now the bad news. It is also a bare bones pump, meaning that it comes with no valves installed. The counter guy tried to warn me that it's best to keep the core until you're all done but in a moment of cheapness I just couldn't let that $30 core deposit go. I did manage to grab the regulator valve stem and I kept my big boost valves and high rate reg spring. I realized way too late that the pump is not complete. Now I have to beg a local trans shop to let me rifle through an old pump for the parts I'm missing. Good thing I have some good parts to barter with. Also, it doesn't look like the TCC valvetrain or pressure relief valves changed through the years so early or late pump will do.

This all means that here it is Tuesday and my car is still on the rack. Fortunately work is slow so it shouldn't be in the way today. I hope to have it out tomorrow morning after one more late night and early morning. I already work 5 am to 5 pm Monday through Friday so atleast I'm somewhat used to the long hours. I really do love doing these projects on my Beasty, but this isn't how this job was meant to go. Then again, what project ever does go as planned. I do feel good though that this job is really coming together well. This should be a solid unit this go round. I will take my time and pressure test before it goes anywhere.

More good news, I did get the thicker steel I needed to correct 3-4 clutch clearance. It's set now at .045 which is right at middle of the range suggested by Pro Built Automatics. I also got the NC dual pole pressure switch I needed to complete my TCC wiring. Baby steps but still progress.

I will post my pressure test results for a before and after comparo and let you know how it all went.
 
#26 ·
Your getting there. It took me months to finalize my project. I'm driving it and still working on it. Not to be a liar, I know that i'll have that pan off a couple more times before i'm done. Make sure you have that drain plug installed in the pan, it will safe you a big headache down the road. It also gives you the option to change fluid down the road without the big hassle.
 
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