New 4L60 build, notchy 2-3 shift.
My latest 4L60 build, this one is for ME.
'89 2WD truck core
13 vane pump
TransGo hardened rings and big slide spring
Ground PR valve land
.471 boost valve
New reverse drum
Wide carbon band HD anchor
Resized reverse piston orfice
Alto reds with kolene steels
Z-pak 3-4 clutch
5-pinion GM planets- the build price goes up quickly here.
Closed input drum orifice
29 element fwd sprag
New bushings, thrusts.
Wide low/rev roller
TransGo 700 2&3 recal kit (auto)
Governor recal kit
Fairbanks billet 2&4 servo
TransGo seperator plate
Orifice'd low/rev piston .030
That should just about be IT. This thing is quite aggressive, but will play nice when I'm just putting around. Had a 'no 4th' deal at first, but went heavier on weight and spring in the governor, then played with the TV adj. and all is well. Except one last thing:
I have a notchy 2-3 shift in D3. This appears to subside when in D4, (over run off..?) I say notchy meaning that I think the 2-4 band isn't releasing quick enough when the 3-4 clutch comes on. It kind of noses over quickly then immediately pops into 3rd. Imagine your head nodding forward-back real quick but not violently. Most noticeable at light throttle.
Definitely need to get this smoothed out before I get happier with the throttle.
The servos I have, furnished a rather heavy red return spring.
Do I need to get more 3rd oil into the servo bore to force off the big servos quicker? Any other things to check?
Am I barking up the right tree? Any thoughts or prayers?
Last edited by C-10; 06-19-2008 at 03:02 AM.
couple of items;
describe the "closed orifice" in the input drum.
The billet 2-4 servo....... If it is the large billet style servo , replacing the OEM release spring with a t-400 coasting band spring will increase the release speed of the 2-4 band.
It may be a stiffer spring than the provided one.. perhaps not.
What is the clearance set to for the 2-4 servo? I set at 1/8 inch movement of the servo cover
Yesterday is history.
Input drum, (pic-arrow) JB weld from the inside.
2-4 servo, using the Superior K012 & K034... return spring is pretty darn heavy. Could try the TH400 spring.
2-4 servo is .120"- I used a dial indicator, depressing cover minus o-ring with clip in place.
Thanks for the reply.
A thread bump...
I still would like to 'clean up' the 2-3 shift in this trans. I've done some tinkering and it stays consistently -well, notchy. Different 2-4 servos, release springs have been tried, 2-4 band preload is good.
It's just a toy for me and not a daily driver, but I really would like to get the upper hand on this thing.
I found a product from Sonnax. The links should give you the info for all the trans enthusiasts out there. I *think* this part will do the trick based on my seat 'o' the pants feel of the 2-4 band release and 3-4 clutch application NOT being synchronized in my trans...
Give these links a look. Has anybody used this part?
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