Technical Another 700R4 issue to be solved.

At 62, I already know too much about too many things automotive ( to get myself in trouble ) and why I choose to have the transmission built and not go down that learning road. It's nice to say I don't know for once, but I also didn't plan on this going sideways also. It never fails that I can do 95% of the work on a build and it's the other 5% that bites me in the ass. Brings back memories of why I quit depending on others years ago. Okay, I'll quit whining now and maybe have a cold beverage or two. Thanks for the help fella's.

 

It sounds like he did it all right, it will just require a closer look. I know that sucks. I would look at what controls the shifts for 3rd and 4th. Hope it is easy !

 

Okay the latest update with pressures included. First ran a "normal test with the TV cable adjusted correctly foot on brake and 1000rpm's on the tach. Readings were in pounds: P- 75, N-75, R-120, O.D.-75, 3rd-75, 2nd-180, 1st-180. Next we did a "full" test with TV cable disconnected and pulled all the way out ( with string and tied in position) foot on brake and 1000 rpm's. Reading were: P-180, N-175, R-180, O.D.-150, 3rd-150, 2nd-150, 1st 140. By the chart we used "normals" were all within range, "full" P & N were okay, R, O.D., 3rd, 2nd, & 1st all read low. Also a stock valve body was installed before this to no avail. I conveyed what was told to me on here numerous times and now, finally, the guy will be back later to check the pressure regulator valve and TV boost valves in the pump when things cool down. If I never have to drain the fluid on this transmission, it'll be too soon, think this is the 5th or 6th time, kinda lost track by now. Again thanks for the help and I'll update as I know more. Guessing the other valve body with the re-programming kit is probably just fine also. Happy Thursday everyone !

 

As far as year of the transmission I believe it to be a 1993 ? number on the pad reads 3 BBM 1. First two letters are faint and only half stamped so could be another letter. Transmission has no pressure ports on the passenger side and the stamped 3 & 1 are clear to read, so can I assume this is a 1993 model ? Also that would be the last year of production for these. Anyone have letter codes for that year and a line pressure chart ? Want to be sure of what the pressures should be for that year. Finding the correct chart on the net seems to be top secret.

 

Your not alone, i would rather learn from mistakes building myself than be angry at someone else for doing a bad job and i paid 2500 to have a 700 like yours built it lasted all of 60 miles and my only recourse was few thousand for a lawyer because the transmission shop told me to bad sue us,would have been cheaper to buy one from summit or something, i am the same age as you and know most things about sbc , tranny's i don't know an don't care to learn except for laying on my back trying to lift it up an getting that first bolt started , I Feel for you !

 

Chart we used... not easy to find and lists BBM...http://i695.photobucket.com/albums/vv318/moldymac/700r4.png I know it says 4L60 but they didn't start those until 1993-94

 

Took the pressure regulator valve / TV boost valve out and checked the assembly as to anything being in backwards. All checked out correct, BUT, the spring that came with the reprogramming kit is suppose to be green, there's a pink one in the assembly, maybe the stock one ? Builder has no idea where the green one is... Also on the PR valve where you are suppose to grind the third land flush with the diameter the second land was compromised about 50 % when the third land was ground. Now has a chamfer in various area's. I have no idea if these two things would drop the line pressure down to where it is, any help on that one is appreciated. If that answer is no, Then the trans is coming out and time for a plan "B". Not the summer fun I had envisioned...

 

@saltflats, I need a voice of reason !!!

 

If the PR valve is damaged on the second land it sure can cause problems.
Also need to make sure the line bias spring matches the TV boost valve.

 

Thanks, new parts are on the way.

 

Currently waiting on new front pump. will be here later today. At this point all I can do is hope for the best ! We literally disassembled the entire trans, inspected and are re-assembling. Could not get the line pressures high enough with the old pump. Should be back together by tomorrow and hopefully back in the car by Friday / Saturday.

 

Man hope it starts to work out for you.....

 

Hi, I had one built for my wagon for $1k. It lasted around 30k til the planetary gear wasted itself on a roadtrip back from Texas. Put it back on the bench, I built it this time. New high pressure pump, 5 pinion planets, Corvette servo, local rebuild on Hughes tow converter, new valve body plate and red kolene clutches. I bought the GM service manual for 1992 Buick Roadmaster and followed to the tee. So far so good since January. I did have to pull the tv cable a few "clicks" tighter than the wide open throttle method.
Here is the pressure chart from 1992 for the 700r4. Hope this helps.
Good luck Nick

 

Also the 700r4 is aka 4l60. They added the "E" when it went electronic.

 

Was the pump worn ? does the guy have the tools to size the seals on the pump ?

 

Pump was from an unknown origin and was showing signs of wear. Rebuilt HD 87-93 pump is here now and the rest of the re-assembly will be done tonight.

 

Thanks, mine turns out to be a BBM which is 1991 and I have the chart for that. Why the first digit is 3 and then BBM I have no idea on the case stamping. I too have 5 pin planetary front and rear, beast sunshell, Z-pac clutches, Wide band on the drum etc... Tried not to go cheap and make this live. First it has to come to life though....

 

Sounds like I will be dropping my next one off with @saltflats ......

 

So little things that make you go huh? Turns out my Transmission is indeed a 1993 with a 1993 only valve body. Unknown to the builder or myself, is a 93 only valve body has an extra checkball in it unlike all the rest. Checkball #11 for reverse input. Just one more piece of a long drawn out puzzle. The modified valve body never had this installed and we are currently trying to figure out the purpose of that checkball and guessing it should have been in there since day one. On the plus side, I've gotten a ton of stuff done on a 79 year old friends 40 Ford while this has been going on. At least his is alive and back running nicely. Carry on.....

 

Mystery solved on the checkball. Seems it was a Corvette and 1993 VB only application and acts as a cushion for reverse due to higher line pressures in this unit. Trans will be completely final assembled tonight, then I can install it for the 4th and hopefully last time tomorrow. Kind of ironic the checkball was for higher line pressures and that's what I'm still searching for.

 

Good luck and hopefully the tranny saga has a happy ending! Then you can get on to using and abusing it!

 

Transmission is back in one piece. If I could find a transmission Dyno close that would check it, I'd gladly pay rather then install / remove / repeat. Problem is all that have one around here, will only do it to ones they build, which I can understand. I'd gladly sign a waiver to get them out of any bad situation, and pay accordingly. Guess I know what's up for tomorrow morning, sad that I'm now paranoid of the end result. Time for happy, positive thoughts or something like that.

 

oooooohhhhhhhmmmmmmm

For you

 

Ha Ha, I'll try to center myself and find my Zen...

 

hope it all works out for you .at least you have expertise local.i purchased a 700r4 from GEARSTAR.uprated to handle 400 plus hp.you never know what you will need.4wd case and all the goodies.it took me a while to get it working correct.first couldnt get a correcter kit for a demon carb so we modified a holley kit.knew how important the cable adjustment was ,was nervous as hell.no local knowledge.my friend with a knightrider trans am had his tranny wear out ,sent to the uk for a build and it wasnt cheap.refitted the trans and couldnt get it operating correctly.sold it off eventually.anyone i asked had one play up and was afraid of the trany.got good after sales service from gearstar including calling me internationally to make sure things were going to be ok.full marks to them.when making adjustments i used two nipples on the cable loosening one at a time and sliding along the cable allowed me to gauge the adjustments and keep track of them.working well now a little too responsive maybe.just last week i replaced the rear tyres from 255/60 x 15 to 235/60 x 15.geared it down just a tad and made it a more pleasant drive
slan

 

I'm in a holding pattern right now. The builder couldn't guarantee it would have pressures and in fact stated, "you know if it still has low pressure it will burn up the trans and we'll have to pull it again. That was the last straw with him for me. "We" never pulled the transmission, "I" did four times now. I excused him and currently waiting on a 4L79 input drum to arrive from IN, about as strong as you can get for the 3/4 shifts. The reasoning behind that decision is I want the trans dyno'ed before it goes back in so I know things are right. With the place that I'm taking it to, they only dyno stuff they build, so I figure if they are going to tear it down to inspect the work and parts already installed, why not fix the weak link in the process also. For what I'll have in this thing in the end, you'd think it would be gold plated. Just hoping to get some miles on it now before winter and move on to the next project.

 

You said, when you manually change gears it works and drives . Once it has managed to arrive in OD , will it kick down and then change back up while you are driving? If you stop and drive away, does it work normally or require you to manually select first and then change through the gears again ?

 

Manually it shifts all 4 gears, won't downshift and you have to manually downshift it all the way back into 1st in order for it to work. This was roughly a month ago the last time it was on the road. since then all things have been done on jack stands. The latest on jack stands 1st and 2nd worked normal and would downshift, had no 3rd or 4th and line pressures were low in every gear.

 

Have you tried disconnecting the shifter from the transmission, and then operating the shift lever on the trans itself.
CAR EFULLY start it in drive to test drive the trans, you may have to bypass the inhibiter if it is on the trans, instead of the shifter) . I have observed problems like you describe when a shifter is only slightly out of sync , and holding the trans lever slightly out of some of the internal detents .

 

https://gearstar.com/gm-700-r4-and-200-4r-transmission-installation-instructions/ .might come in handy