stomperxj

I have a freshly rebuilt 4L60E that will not manually shift into 1st gear. Cable and shifter are working fine and have plenty of travel. When it is shifted down into 1st, it starts in 2nd. When in drive it shifts 1-4 as expected with nice solid shifts.

Any Ideas?

Thanks
Jess

SiskMan

Could be a shift solenoid acting up. But you said 4th gear works fine and it shares the solenoid with 1st.

When the wiring harness is unplugged the trans is in limp mode and only commands 2nd and 3rd I believe. Make sure that is connected and the vehicle speed sensor is connected.

and finally it could be in the tune too. In HP tuners there are numerous tables that control everything about manual shifter position and D shifter position

98CayenneT/A

Possible low/reverse clutch issue...... In both D and manually selecting 1st the low roller clutch is holding but the low/reverse clutch pack is only applied in manual 1, reverse and park.

Any issues with reverse?
And like said, if you have 4th is doubtful is a solenoid issue.

bbond105

Double check that your shift linkage is pulling the trans shift lever all of the way back. The only way to know for sure is to put the shifter in 1st gear, get under the car and unhook the linkage and see if you can pull it back another click.

wht/73

I did this when I installed my 80E.
I also converted my Quicksilver shifter from a 3 speed to a 4 speed.
I checked it in every position, twice.

performabuilt

iTrader: (25)

If it starts in first in drive I would say not a solenoid issue nor a low/ reverse clutch issue since the only additional thing that happens in manual low is the low/ reverse clutch set applies for engine braking in fact other than that you would notice nothing different between manual 1 and d4 1.
My guess is a linkage or position switch issue telling the PCM your in manual second when you are in manual 1

stomperxj

Trans harness and VSS are connected and reporting data to the PCM and the Speedo. Trans part of the tune has not been touched from the factory settings. I will go into HPT and verify this though just to make sure. Thanks for the reply.

No issues with reverse at all. This trans is brand new front to back including all solenoids

I can feel 3 distinct "clicks" in the shifter when moving it down to 1st. I checked the linkage/cable once but I'm going to go double check it and make sure it is pulling down all the way to first.

Thanks for the help troubleshooting.

Thanks again everyone. I'm going to go double check everything again and maybe swap out the position switch with another known good working unit to see if that does anything. I'm just stumped because this thing is literally brand new front to back including solenoids and even the internal harness.

stomperxj

Alright just came back in...

Cable is pulling the shift lever to first with a little extra to spare. I pulled the connector off of the PRNDL switch and tried again. Still won't go to first.

I need to go get a new PRNDL switch and try it but I don't think that is it after testing it disconnected.

performabuilt

iTrader: (25)

I think the PCM uses the Manifold pressure switch on the valve body to make that determination and you can I think actually observe what it is reading in the data stream.

mrvedit

Right, the PRNDL is an optional part that does not affect the transmission.
For '94 thru '08 the Manifold Pressure Switch on the valve body tells the PCM what position your shifter is in. They go bad and are easy to replace after dropping on the pan.

stomperxj

Thanks for the reply. Now that I think about it, the MPS is the only original part left in this thing. I'll have to see about replacing this. I have to pull the trans again (4th time) to replace a bad torque converter so I'll replace the MPS when I do that.

SiskMan

I just rebuilt my 4l60e and the manifold pressure switch was cracked and stuck to the valve body. I had to kinda pry and scrape it off. I had another trans laying around and looked that that MPS too. Same thing, and caked with trans 'dirt'. I would replace the MPS for any quality rebuild

stomperxj

Thanks for the reply. I just ordered a new MPS and torque converter that will be here for the weekend so I can swap them out.

Thanks for the replies everyone. Sincerely appreciated.

stomperxj

OK so I put a brand new AC Delco MPS in this weekend. Made no difference. Still won't shift into first. I guess the only thing left to do is double check wiring between the trans and the PCM.

I don't know what else it could be....

stomperxj

Tested it today with HP Tuners. I can command first gear with VCM Scanner and it will stay in first gear but will not select first when the shifter is in 1st position.

SiskMan

Here is a good hydraulic diagram I found. I thought maybe it would be worth checking out since you said you had to pull the trans again.

stomperxj

Just bumping this up for some new eyes to see if anyone else has an opinion on this.

Trans has 6k miles on it now. Had some problems with a couple Transtar converters. I put a Cascade in and seems to be good although the stall is too low. Still doesn't manually shift into 1st, literally brand new from front to back including MPS and all solenoids. Linkage has been triple checked for travel.

Anyone care to take a guess?

01ssreda4

iTrader: (96)

Are any trouble codes being thrown?

stomperxj

No codes. Everything functions as normal except the manual first issue.

Fuhnortoner

I could be wrong, but i didnt see you say you checked the gear selector switch.