Glad it is working out for you, well done
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.
700r4 fun
- Thread starter wheels87k5
- Start date
bigcitybrianwright
Registered Member
I think "Daddy's Truck" is having this problem. It's definitely noticeable when it's cold. That will be my project this week before it gets worse.
#itsalwayssomething
http://youtu.be/TX_g-SMCvMo
#itsalwayssomething
http://youtu.be/TX_g-SMCvMo
Question for Greg or whomever: What factors can influence/cause the 2-3 shift to be firmer than the 1-2 or 3-4 shifts? My truck follows the same pattern, and I've always felt that the 2-3 shift is too firm. Almost jerky.
At least you don't have to remove the tranny to check the pressure switch. If this is what you check, as Greg said, shoot air into the threaded end and see if air seeps through. That's what it did on mine plus the center section would turn out of its position.
Hope that's all it is. Good luck and keep us posted.
Also, loved the music and video.
Not sure if the new pressure switch made the difference on all my shifts or replacing the gasket that was torn near the second gear accumulator passage. But it does shift like I think it should. NO complaints yet and no leaks.
Greg will probably chime in soon and give us some help.
Usually a stock 700R4 will have a firmer 1-2 shift than 2-3 shift. Does your trans shift firm from 2-3 at all throttle openings or only under light throttle /lower speeds? If the converter clutch is applied during a shift it will make it pretty firm so that may be one reason. 2-3 shift oil is accumulated in the servo as the band is released so there could possibly be a broken spring in there, but that would be incredibly rare. Has anyone installed a shift kit in your trans? I would try disconnecting voltage to the trans first to see if the firmness subsides, that will rule out the converter clutch, then go from there. If it doesn't bother you there is nothing wrong with a firm 2-3 shift and in fact it is desirable over a soft one for this gear change.
The 2-3 shift is the hard one to set up in the 700. The band is disengaged while the 3-4 clutch is engaged, so the timing is important. If the band release is too slow, you're almost "going through" 4th gear to get into 3rd, which is like a binding. If the clutch apply is too slow, the rpms can "flare up" as the tranny is starting to go back to 1st gear for an instant before it's in 3rd. Changing the servo surface area (like swapping to Corvette or aftermarket servo) slows down the band release. Shimming the accumulators (i.e. a shift kit) speeds things up a bit, so these kinds of changes affect the 2-3 feel.
If you just had high line pressure, all the shifts would be firmer, but especially the 1-2.
If you just had high line pressure, all the shifts would be firmer, but especially the 1-2.
Mine shifts firmly at all throttle positions. I do not know what aftermarket parts have been installed in my tranny, but I do know that it was professionally rebuilt when I first got the truck in 2010 (the need for such is why the P.O. wanted to get rid of it).
It doesn't bother me that much. Overall, the tranny is as nice as any older automatic I've driven (I really like having a TC that locks up nicely).
Also, when downshifting under load, the TC unlocks, then the gear changes, and then TC locks up again. When I manually downshift with the column shifter, it jumps right into gear without unlocking the TC. Is this normal? If so, why?
Most factory TCC control systems have the ability to cancel lockup on throttle lift and under high throttle demand. Your TCC will automatically unlock as you depress the throttle far enough to induce a forced downshift to a lower gear, however, if you manually select a lower gear without the same throttle input the TCC will stay locked if your system has lockup capability in both gears.
Gotcha.
That is exactly what it does.
Are there any downsides to shifting while locked? It seems like it would save some wear & tear to manually downshift it instead of going through the lockup dance...
Having the TCC engaged during a shift is harder on the transmission since the fluid coupling is not able to act as a cushion between the engine and trans components. With the TCC engaged only the clutch damper in the converter is left as a cushion which isn't much. That is why there is virtually no automatic that leaves the TCC engaged during a shift.
