jlyke

i have just reacently rebuilt my transmission, this is the second time i have done this one the first time it worked great but this time not so much. i noticed the accumulator bleed plug no longer moves like it use to, is this an issue? and when i test it with the back wheels off the ground i shift to reverse and it doesn't seem to engauge infact the wheels start turning slowly forward. i am waiting on a new boost valve and the a&b selenoids. is there anything else i am missing? i assume the forward movement would be a leak on the statorshaft seals but i'm not sure. can anyone maybe point me in the right direction?

mrvedit

Welcome to the forum, and sorry for the grief I gave you for hijacking other threads.

I'm still confused about what part you are referring to. Do you mean the "3rd accumulator check valve" which is in the case in the servo area? It is critical that this check valve be loose but also seal correctly; otherwise your 3-4 clutch will fail. If worn/damaged it needs to be pulled out and replaced. It is not related to Reverse.

Assuming your boost valve is properly installed, "No reverse" is often due to a sealing problem between the stator shaft and reverse drum. If the teflon seals on the stator shaft wore out, they often ruin the inside of the reverse drum.

Just before final assembly, it is a good idea to air test the entire input drum, reverse drum and pump assembly. You can then apply air to the holes in the pump and test all the clutches. Some air leakage is normal (air leaks faster than the fluid will), but all the clutches should clearly apply.

With the rear wheels up, they will move forward even in Neutral due to residual friction in the forward clutch. If the reverse clutch didn't apply, the wheels would also move forward.

jlyke

oh dont worry about it, i deffinately had it comming.

and i'm refering to the valve/plug/what ever it is that is right behind the low/reverse feed holes, and next to the rear case lube hole

i found today that i had forgotten to put the low overrun valve in and well looking at the hydraullic ciruites that could deffinatel cause issues.
but i am trying to figure it out if its a valve problem or a cross leak before i pull the trans.
i air checked everything before assembley and all was well.
i also had put new teflons on the stator and turbine shafts, the stator rings were the L cut and the turbine rings were solid. would the L cut rings leak that bad??

mrvedit

Not sure how you could leave out the low-overrun valve - did you completely disassemble the valve body?
Yes, looking at the hydraulic circuits it appears the low/reverse clutch would never get pressure without that valve. (I experiment a lot, but don't leave entire valves out.)

I think the "valve/plug/whatever" you are referring to is checkball "#10" in the diagrams and called "accumulator bleed" in the ATSG manual. I have read that some builders just leave it out; it slows down the engagement of the low/reverse clutch to synchronize it with the reverse drum engagement. This thread explains it a a bit:

http://www.impalassforum.com/vBullet....php?p=2704831

Obviously you can fix the valve body and take care of checkball #10 without removing the trans. Do that first and see if you then have reverse.

I'm sure the L-cut stator shaft rings will be fine, but did you check the inside of the reverse drum where those rings run to be sure it is a prestine surface.

jlyke

yea i checked it.
lol i wouldn't think leaving valves out does much good.
thank you for your help

jlyke

great now i have reverse but its in limp home mode. the SES light isnt on.
i checked connections and i have power to the transmiission.
i unhooked the batterie to reset the pcm. any suggestions?

mrvedit

Glad to got Reverse working again.
Good news is that limp mode is rarely caused by an internal problem, usually electrical, bad solenoid, etc.
You might need to hook up a scanner as some codes don't (at least not immediately) turn on the MIL light. Most auto stores will run a scan in the parking lot, or give you a free rental on the scanner, although you have to leave a $350 deposit.

Ted.

jlyke

i had it scanned and there wasnt any codes except for one about the cattilitic converter but thats just because its no longer there.
i checked for power to the selenoids and i had power.
the selenoids were good
i'm going to try a different pcm and see if thats the issue

mrvedit

Very strange to have limp mode without any codes.

Does anyone else have ideas? Am I missing something obvious?

jlyke

i put a new pcm in it and new wiring harness test drive tomorrow hope it was just the pcm that was the problem because if this doesnt work i have no idea because its new selenoids all around and new wiring harness

mrvedit

Finger and toes crossed.

jlyke

sounds about right to me

jlyke

okay well now the pcm says everything is bad.
seems like a grounding issue to me...
what do you think?

mrvedit

We would need a lot more detail to help you. What does "everything is bad" mean? Just transmission codes or many codes? Does the engine start? If just trans codes, perhaps the PCM was tuned for a manual trans.

jlyke

yea it just says all the selenoids are bad and i cleaned up all the ground wire connections
and still the same
the pcm was tuned for this transmission the old one and the new one

NOS LS1

iTrader: (3)

Get rid of the 4l60e. Go with a 4l80e conversion. much stronger & more reliable transmission. i found mine on craigslist for 300.00. i installed the trans go 2 shift kit & really like the way it shifts. i shift it manually with a b&m pro stick shifter. great set up.

jlyke

oh great blowin fuses now everytime i turn the key
checked wires to transmission all looks good o2 looks good vss looks good
you suppose it could be just the connecter to the transmission??

jlyke

yea have to return the new harness because the shorts in there unpluged the transmission and didnt blow the fuse shame when new parts dont work

jlyke

now i got a new harness not blowin fuses or anything but still in limp mode
i dont get it

mrvedit

I would confirm that the PCM is correctly wired to the trans.
I detail the pin numbers in post #4 of this thread:
https://ls1tech.com/forums/automatic...lems-help.html

Note this is for 99 and later PCM. What year PCM do you have?