Whoadi96

As the title mentioned, i rebuilt the transmission last weekend (Master Kit, all new plates, bushing, etc). After the rebuild it appeared that initially i had 3rd and 4th. After Maybe 5-10 miles MAYBE, it's no longer shifting into 3rd. Because i replaced all the bushing, plates, etc i decided that i would replace the Shift solenoids before ripping the entire transmission back out. I left the truck parked all week as to not cause any further damage. I found a valve body with new solenoids and a 1 year warranty, so i installed it. NO CHANGE, still not shifting into 3rd or 4th. I'm gonna pull the wiring harness today and force it in to 3rd to see what happens. At this point i'm assuming the 3-4 pack is smoked and i'm thinking the culprit is the teflon rings on the input shaft got broken, nicked, something.

The local transmission shop here looked at the internal parts and determined everything was actually in pretty good condition ( I did replace the sunshell, rear planet sun gear and the input sprag).

My question is, after JUST replacing most of the parts in the transmission would it be neccessary to remove and check the lower components in the transmission or simply remove the input drum, replace the 3-4 pack and reinstall?

I have all other gears. When it attempts to shift into 3rd, transmission goes into neytral and then eventually back into 2nd or 1st if i pull over.

Whoadi96

I forgot to mention that I did Air check the input drum prior to installation but i DID NOT check on the pump. The rebuild instructions i had at the time didn't mention this method.
This is my 1st 4l60e rebuild but i Build/Repair motorcycle so i figured i'd save myself some money and learn something new about the truck.
The radiator leaked coolant into the transmission was the reason for the initial rebuild.

bbond105

It would depend on how dirty the fluid is. When a clutch pack goes bad that brunt clutch material goes through the whole trans. I would take it all of the way down and clean all of that out. Be sure to blow out the trans cooler and lines. Try to get as much of the old fluid out of the torque converter as you can. After trans has been reinstalled and verified that it is working you may want to change the filter and fluid again because you can never get all of the fluid out of the torque converter, or you could send the torque converter out to be cleaned.

You can reuse all of the parts that are still good. Be sure to check that the input shaft where it presses into the input drum is not leaking and there are no leaks around the boost valve in the pump. I have attached some instruction on the last few pages it tell you how to air test for leaks.

Whoadi96

I removed the wiring harness from the transmission and i was able to take off in 3rd. I was under the impression if the 3-4 clutch is smoked the truck shouldn't move at all. Is this correct? If so what does that indicate as to the issue with the transmission?
I've read that it shouldn't be the sprag if you're able to engage 1st, 2nd & Rev.
I removed the transmission from the truck last night, but I haven't had a chance to get it open.
I did check the check ball in the servo with mineral spirits and tranny fluid.
Should the truck take off in 1st gear and then shift to 2nd if I put the tranny in M2? Just throw out some ideas that might help someone point me in the right direction.

performabuilt

iTrader: (25)

With the harness unplugged you should eb able to take off in manual second or 3rd, If the 3-4 clutch is smoked totally 3rd will feel like first and second like a higher gear, .
The Trans will do NO auto shift with harness unplugged you will only have manual 2nd and 3rd gears