No shift indicator lights after tranny swap

[UTMorpheus]

Hello all! Let me apologize for asking a question for my first post, but I have an issue that I cannot seem to find an answer for.

I bought a 94 Skylark with 3.1l v6 in 2006 with 137k on it. Around 175k the 4T60-E would not shift out of 1st. I got a used junkyard 4T60-E with 58k out of an unknown donor in 2009 and had it installed. Ever since then I do not have 4th gear, or ANY shift light. I took apart the instrument cluster and verified that the light functions, but it will not illuminate in any gear. The transmission shifts 1-3 perfectly, no slipping, no other issues, however with the rising cost of gas prices I would greatly enjoy the O/D gear. The shift light is less of an issue, but I feel it's related.

Now that the car has 215k on it, and still running like a tank, I'm about to drain the trans fluid and replace the filter as preventative maintenance. I figured this would be a good time to do any repairs while I have the pan dropped. Do any of you have a direction in which you can point me for looking into what needs to be replaced? Or even better, a part that you are pretty sure will fix it. Or best yet, an actual part number/link to a replacement?

I have done quite extensive searches of this forum, the Buick and GM forums, and other websites, but have not found much information that is relevant to my problem. Most places point to loss of 1st and 4th, or slipping/clutch problems none of which are occurring with my transmission. As I stated previous, the 1-2 and 2-3 shifts are smooth and precise both up and down shifting, it just seems like the transmission doesn't acknowledge that it even has a 4th gear. Well, smooth unless I'm at WOT, then the shifts are sharp and precise...exactly how they should be. (Yes, the car can still hit the limiter and ask for more, even with 215k. Gods I love this engine.)

[robertisaar]

the fact that it came from an unknown donor is what points me to think that your issue may lie there.

are there any identification tags still on it?

[pocket-rocket]

I've never seen a factory auto get a shift light stock. Car-part.com doesn't even give an option for a manual (where a shift light would have been used stock) for a 94 Skylark.

[UTMorpheus]

the fact that it came from an unknown donor is what points me to think that your issue may lie there.

are there any identification tags still on it?

All I know about the donor is it had a blown head gasket(although with the plastic intake mani gaskets it could have been that), that's why I got the transmission out of it. Where would I find identification tags on this model transmission.

I've never seen a factory auto get a shift light stock. Car-part.com doesn't even give an option for a manual (where a shift light would have been used stock) for a 94 Skylark.

It's not a "shift now" light, it's a shift select light. As in PRND32 selection indicator. I have a column shift, and it's supposed to have an little orange light showing what 'gear' you're in. This light does not illuminate in any 'gear', BUT works when direct power (I used a 3v battery pack) is applied. Which is what's making me think it's a switch or sensor or something of the sort. Possibly incorrect wiring harness, however I don't want to go throwing money at it until I know I'm not just throwing money at it.

[robertisaar]

you know..... i think the 94-95 N-cars used the 4 switch PRNDL decoder to run that.... i wonder if it's either unplugged or the incorrect one for your car.

[UTMorpheus]

you know..... i think the 94-95 N-cars used the 4 switch PRNDL decoder to run that.... i wonder if it's either unplugged or the incorrect one for your car.

I checked the connections, and they're all tight and not corroded. Would it be possible to go junkyard diving and just replace the part on the transmission(I assume this would be the shift lever part on top)? Or would it require major rework/not be feasible?

[pocket-rocket]

Ah, I see.

Getting that part off of the trans (yes it is the part under the shift arm on top of the trans) should be pretty cake. Do you still have your old tranny?

Sent from my HTC One X using Tapatalk 2

[robertisaar]

yeah, it's the little black box looking item that is connected to the shift lever/cable on the transmission.

here's the troubleshooting flowchart for the PRNDL display.... i get the feeling if that's fixed, then the PCM will read the correct shifter position as well.

http://i.imgur.com/Lwu5i.png

http://i.imgur.com/RkhTu.png

and assuming it's a 4T60E and not a 3T40 that was put in place of it(which would explain a few things), then this will get your ID info.

http://i.imgur.com/ut2WS.png

if it is a 3T40 that was swapped in, you'll find the ID info here:

http://i.imgur.com/cpyoR.png

[UTMorpheus]

Ah, I see.

Getting that part off of the trans (yes it is the part under the shift arm on top of the trans) should be pretty cake. Do you still have your old tranny?

Sent from my HTC One X using Tapatalk 2

Unfortunately that was scrapped long ago, which is why I need to go junkyard diving.

yeah, it's the little black box looking item that is connected to the shift lever/cable on the transmission.

here's the troubleshooting flowchart for the PRNDL display.... i get the feeling if that's fixed, then the PCM will read the correct shifter position as well.

http://i.imgur.com/Lwu5i.png

http://i.imgur.com/RkhTu.png

and assuming it's a 4T60E and not a 3T40 that was put in place of it(which would explain a few things), then this will get your ID info.

http://i.imgur.com/ut2WS.png

if it is a 3T40 that was swapped in, you'll find the ID info here:

http://i.imgur.com/cpyoR.png

4T60-E for sure, I though it was a 3T40 until I read the bottom of the pan and it's definitely stamped 4T60-E. Where is this diagnostic connector, I will play with it when I get a chance this weekend. Those flow charts are the exact type of troubleshooting I was looking for, you are a savior.

It will probably take me a couple weeks to source the correct parts and fiddle with it, however it if works I will report back. (I hate people who post questions on forums and never follow up)

[UTMorpheus]

Well here's the update: today wasn't raining so I went to the self-service graveyard to pick some bones. Came across a 94 maroon Skylark with a 3100 in it, same as I have. So I took a chance and pulled the PRND32 switch out of it along with a couple interior trim pieces(kid only had 90k on her before she died, what a sad story). Walked out to my car in the parking lot, two bolts, a nut and $9 later I have a working shift indicator light and 4th gear! Although pumping fluid through 4th gear for the first time in probably 5+ years really didn't make the tranny happy the first couple miles. Really need to change the filter now. Once my new EGR valve arrives on Wednesday I think I can get this 215k beast to at least 300k before the winters take their toll.

I just wanted to stop by and say thank you to robertissar and pocket-rocket for the help and direction in getting this fixed. I'm glad to see there is a forum network besides Miata.net that actually help newbies.

[pocket-rocket]

Awesome news Glad it was a simple fix, too.

Sent from my HTC One X using Tapatalk 2