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So I need some help. I got to the servo assembly, and again, I am confussed when it comes to the spring. The "servo return" spring I got from transmissionpartsusa is not the spring I thought I was missing. The spring I was missing goes between the pin and the case, here is a picture of the assembly showing the spring I am missing:
I have the other smaller spring that matches the diameter of the servo return spring according to transmissionpartsusa.com, so what is this bigger spring called and do I need it??
The 2nd Servo Return Spring is what it is called, The smaller spring is the Servo Pin Return Spring.
I would stroll a junkyard & get one out of a 700R4/4L60E, Probably one laying in a core pile somewhere, If your close to Ft.Worth, TX I will give you one. (I didn't check your location). A Local trans shop probably have one laying around also.
I wanted to get the trans in the car tonight so I assembled the servo without the 2nd servo return spring(I've seen it referred to as a cushion spring also). I found a thread that performabuilt commented on and said you can leave the cushion spring out. I imagine that would just force the band to apply more rapidly, is the necessarily a bad thing? I ordered a cushion spring online, but I can see that taking out the servo with the trans in the car can be a pain. Any other thoughts clinebarger or mrvedit?
I likely have a spare one for your next visit to Ann Arbor.
Sorry, I don't have experience with leaving out springs in the servo.
If the servo were easy to removed, e.g. in a truck/SUV, I would say, sure give it a try.
However since the servo is not easily removed from most cars (need to angle the trans down quite a bit),
I suggest waiting until you have the correct spring.
But I will defer to clinebarger's experience and suggestion.
I always run a 2nd servo return spring, In 1st gear or a downshift from any other gear to 1st, The spring is the only thing knocking the servo completely "Off", 3rd accumulator oil knocks the 2nd servo "Off" hydraulically in 3rd & 4th gear.
The servo return spring showed up today. I took the trans out of the car and re-installed the servo. The trans is now mated back to the engine for hopefully the final time. First drive should hopefully be this weekend.
Took the car for a short test ride today without any real issues. The only issue was fluid coming out of the vent tube because I overfilled the trans. I'll try to put miles on the car this weekend....feels good to know I'm driving around on a built trans now. Can't thank everyone that has helped me on this thread enough!
Took the car for a short test ride today without any real issues. The only issue was fluid coming out of the vent tube because I overfilled the trans. I'll try to put miles on the car this weekend....feels good to know I'm driving around on a built trans now. Can't thank everyone that has helped me on this thread enough!
Congrats, I have been following this thread and will be diving head first into my first rebuild myself this winter on my 4l60e out of my t/a
Congrats, I have been following this thread and will be diving head first into my first rebuild myself this winter on my 4l60e out of my t/a
The transmission bench videos are really the only thing I referenced for the rebuild. I didn't watch the videos before hand but would suggest doing so. Overall, I'd say I had between 60-80 hours into the rebuild but I was really taking my time and had to retrace my steps a few times. If I did it again, i could easily cut the time in half.
The transmission bench videos are really the only thing I referenced for the rebuild. I didn't watch the videos before hand but would suggest doing so. Overall, I'd say I had between 60-80 hours into the rebuild but I was really taking my time and had to retrace my steps a few times. If I did it again, i could easily cut the time in half.
Sounds good, ya I have been watching videos over and over and over lol drilling it into my head. I plan on taking a week off work this winter and doing the rebuild and only the rebuild taking my time and hopefully it works out as yours have.
So today I took the car to the store and on the way there noticed what seemed like 2nd gear could be slipping. Ever since the trans was rebuilt I always thought it shifted into 2nd gear odd, it always felt like it was slipping because the car felt like it had lost acceleration. I never was really sure if it was just the characteristics of having a very loose stall converter or not. I had to limp the car home because it seemed like I only had 1st gear. I checked for DTC's, and there are none. I also used vcm controls to see if I could hear the solenoids clicking, and I do. While driving I can only hear the rpms drop when commanding 4th with the tcc locked. I looked at a data log, and with the ratio between engine rpm and output speed seem to give me something close to 2nd gear(when commanding 4th with tcc locked). It seems that I only have 1st and 2nd again. Reverse works fine. The trans only has maybe 500 miles on it and maybe 6 passes. Attached is a data log if it helps anyone.
First, I suggest putting a pressure gauge on it. ("atd 5550" on Amazon for $35)
Second, what is the servo end play? While holding a ruler nearby, press on the servo cover with a crowbar. Amount 1/16" is perfect, 1/8" is OK, 1/4" will slip in even modest throttle.
I was able to get under the car to check servo play tonight and it was definitely close to 1/4". I put 1 gold shim in and the trans still slips. I'll have to order some when I order the pressure gauge.
Did you check the servo end play when you first assembled the trans?
I check it before installing the pump to verify the servo and band are engaging properly.
If you don't want to pull the trans, you might be able to lengthen the servo pin in one of three ways:
1. Weld a blob on the existing one.
2. Install the Sonnax 2nd gear Servo which comes with a too-long servo pin which needs to be ground down.
3. I think GM also has a longer servo pin, but I don't know the part #.
NJNETSFAN, I highly recommend checking pressures with a gauge, Then pulling the Unit back out & going back through it. While adjusting band clearance may get you by for a little while.....You have, At the very least "Glazed" the Band, And the holding power of the band will never be right.
You make it sound as if the 3-4's aren't holding either???
Only gears that have power on their own are 1st and reverse. If I use hptuners to command 4th with the tcc locked, the rpms drop like it's going into gear but the ratio between engine rpm/trans output speed is not 4th gear. I will check pump pressure before pulling the trans.
Originally Posted by clinebarger
NJNETSFAN, I highly recommend checking pressures with a gauge, Then pulling the Unit back out & going back through it. While adjusting band clearance may get you by for a little while.....You have, At the very least "Glazed" the Band, And the holding power of the band will never be right.
You make it sound as if the 3-4's aren't holding either???
Yes, be sure to check the line pressure before pulling the trans as that will help you know what to look for.
Obviously clinebarger's comments are correct; lengthening the servo pin is just a bandaid to at best give you some daily-driving life before the trans absolutely needs to pulled.
As always, I'm happy to help and you could even bring to trans to my (heated) garage and we can open it together.
Did you buy a billet 2/4 servo when you did the rebuild, or did you reuse the old servo? Pin length has a lot to do with several functions of this trans, and I'm worried that you used the old pin that may have been worn down.
Lots of good info has already been posted, and I'm wishing for an easy fix (worn pin).
09-29-2015, 04:26 PM
