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Discussion Starter · #1 ·
Hey guys,

I’ve been trying to chase this issue with my TCC for a little while now and I am stuck. I don’t want to throw money at a simple problem so I am asking for help.

I have a 86 700r swapped into my 71.
I am using the TCI lock up kit
Stock TCC solenoid that came with the trans
A 9.5” 3800 stall Perfect shift (Winners Circle) converter with lock up.
10 vane pump upgrade, 4l60e lockup upgrade (dual pass check ball in input shaft)
Beast sunshell
Trans-go shift kit, and improver.
Entire kit came from Pro-Built automatics.
Assembled myself.

When I got it all together and installed in the car, the converter would lock up in 4th only like its supposed to. But due to my engine only making 12” of vacuum it would constantly lock and unlock while driving down the road. So I decided to wire the green wire to a toggle switch so I could override the lock up, and lock it up in 2nd, 3rd or 4th, instead of adjusting the vacuum module.
Since I wired the solenoid to a toggle switch I have lost all lock up. I have redone all the connections. Cleaned everything off. Tried different switches, different ground locations.

Couple things I can think of.
-The 12v power is spliced into another wire that feeds the 12v to my electric choke. Does the solenoid need full 12v, or is this okay?
-Possibly the vacuum module is bad? (the lockup is wired as directions state for without the toggle switch, with the addition of running the green wire to a switch, and then grounding the switch) is this correct?
-The TCC solenoid is bad. Maybe it got shorted out when the toggle switch was wired? Maybe it was coincidental that when the switch was wired the solenoid stopped working from locking and unlocking.
-I am using a lighted switch, when in 2nd, 3rd or 4th and I flip the switch to lock the converter the light lights, then it dims, and then it starts to slowly blink on and off, and will occasionally go out. This is two different switches it does this to. Which made me think it might be a wiring issue outside of the trans, but maybe not?
-Maybe the connections inside the trans from the solenoid to the 4 plug connector are loose?

I am kind of leaning towards pulling the pan and replacing the solenoid and redoing the wiring on the valve body.

On an unrelated note, possibly related note, instead of making two threads ill post it in here.

Also while the engine is running in park or gear, at 1700-2200 rpms I have a very nice vibration, that is almost inconsistent. It only does it at that rpm. While driving and while in park.
When I unbolt the converter from the flexplate (TCI SFI plate), and push it out of the way and start the car up, there is no vibration, but there also is no weight/load on the engine.
Nothing inside the trans is spinning while it is in park correct?

Any thoughts?

If I grab my driveshaft at the yoke and push up and pull down on it, I am able to move it up and down enough to notice. Cannot say how much, possibly .050-.100” but it is enough to notice, which may be part of my vibration while cruising, but not while parked.


Any help or direction is helpful!

Thanks

Aaron
 

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I feel your pain Aaron, I went through this same issue with my 700r4 last August. I will almost guar·an·tee that the vibration is the trans banging the floor board.....ask me how I know. Do what I tried, jack the trans up and take mount out, install a small block of wood, maybe 1/2-1" high in place of it. Lower trans onto block of wood, vibration should have gone away. So, now you need to either find a shorter trans isolator (which I already had) or what I had to do is cut off the cross member tab, flip it and weld it back on. Now the isolator sits about 1" lower, thus lowering trans from tunnel. I don't know what to tell you about the lock up issue? I don't have the TCC one in mine. I have stock set up wired to a toggle with a double pole single throw relay wired into my brake switch. It only locks up in 4th when toggle is armed and shuts off if I hit the brakes.
 

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Discussion Starter · #3 ·
if it were something rubbing against the floor it would do it at more than just 1700-2200. mainly at 2000 rpms, in park or gear.
the vibration is almost eccentric, conistant but like a wuh wuh wuh pause, wuh wuh wuh kind of sound.

maybe the converter isnt centered in the crank hub? im not sure.

i forgot to mention i talked with the converter guy a few weeks back when this issue started, he said its probably not the converter but i can take it out and send it back to him (about 30 min drive actually) and hell check it out. its a multi disk clutch IIRC.

aaron
 

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Mine vibrated just like that, at a certain rpm whether I was in gear cruising or in park and revved it. I did the same as you and unbolted it from the motor and the vibration went away. I even tried a new converter a buddy of mine hooked me up with. In the end......the trans is 3" longer then a TH350 and it was just enough to bang into the tunnel somewhere. Try the lowering of trans method first and lmk if it cured the vibration before you go and pull the converter (like I did).
 

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Discussion Starter · #5 ·
When I get under the car this weekend and change the oil I will try that!
It's worth a shot at this point!

Thanks!

Aaron
 

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There should be a sticky on this. Anyone who installs a 700 r4 in an A body has to set pinion angle. The 3" longer Trans has the tail shaft pointing DOWN... And causing all the grief. "Ask me how I know" ?
Raise the Trans with spacers till tailshaft is zero or 1 degree up if you can. Now mark floorboard where front yoke is going to hit the floor. Remove drive shaft. Now this is your call. Pean up with large hammer or cut the floor, add metal and reweld. You also have to check rear pinion angle. I dont race so I set mine 1* down.
This will elimininate all vibration issues, period !!
Oh, I also had to install dbl adjustable upper and lower control arms from Summit. $199
Good Luck to all.
 

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Discussion Starter · #10 ·
Rich,

pinion angle has been set. every change to the car it gets reset. i cant remember what it is off hand.

my issue is at idle, and its the same vibration at idle as it is while driving at the same exact rpms from 1700-2200.

there is enough space around the trans and my floor for it not to rub, got my hands up there and felt around, and can see visible light all around.

i am going after it being converter/trans related. having issue with lock up not working when this started to happen.

we will see, as of now im still driving it until it grenades or i have time to fix it LOL, or buy another daily driver.

aaron
 

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Hey Aaron, sorry..... this post seems to have a few questions/problems being discussed.
Concerning your original post, I actually have had a cracked flex plate once that vibrated at certain rpm. Didn't find that out right off the bat either. You gotta keep searchin. It sucks till you actually find it. I wish you all the luck in the world......
 
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