2000 GMC Sierra 1500 won't shift into 3rd

[richard wysong]

if it's 2wd that estimate seems a little high but about right for 4wd. it can be done without a lift using a rented trans jack and big jack stands. hows the fluid look/ smell ?

[Brenden Burnham]

1 minute ago, richard wysong said:

if it's 2wd that estimate seems a little high but about right for 4wd. it can be done without a lift using a rented trans jack and big jack stands. hows the fluid look/ smell ?

Fluid at correct level and looks fine, not dark at all. No leak's at all looking underneath.  is 4wd.

[richard wysong]

try a parts store and see if they have a free scan that will do trans codes /data. if its the selector or the solenoids it should show a code. when you get there don't shut the truck off as some codes may not stay memorized. if the scanner does data shift thru the gears while watching the shift position on the scanner, that checks the position part of the switch that communicates that back to the ecm. you can change the solenoids out yourself for a couple hundred $, watch the utube video. if I wasn't 2500 miles away I would give you a hand. good luck! a regular obd scanner that does data can check the  position switch

[Brenden Burnham]

1 hour ago, richard wysong said:

try a parts store and see if they have a free scan that will do trans codes /data. if its the selector or the solenoids it should show a code. when you get there don't shut the truck off as some codes may not stay memorized. if the scanner does data shift thru the gears while watching the shift position on the scanner, that checks the position part of the switch that communicates that back to the ecm. you can change the solenoids out yourself for a couple hundred $, watch the utube video. if I wasn't 2500 miles away I would give you a hand. good luck! a regular obd scanner that does data can check the  position switch

You have been a great help thanks so much.

[Sharpz]

gyour tranny probably is bad.  You can get a bottle of that anti tranny slip stuff and see if it helps you a bit. If it does there is a good chance your tranny is shot.  If it were a wire problem outside the tranny I doubt it would shift in any gears.  Lucas transmission fix is supposed to be a good product. 

[richard wysong]

you are welcome, keep us posted. it says for sale and parts are ok to post here if you decide to go that way too

[Brenden Burnham]

Just got back doing diagnostic.  The 3-4 clutch pack is done.  So will need a complete rebuild($3200).  Ugh 

[Brenden Burnham]

On 1/22/2022 at 4:25 PM, Sharpz said:

gyour tranny probably is bad.  You can get a bottle of that anti tranny slip stuff and see if it helps you a bit. If it does there is a good chance your tranny is shot.  If it were a wire problem outside the tranny I doubt it would shift in any gears.  Lucas transmission fix is supposed to be a good product. 

Yes true and they also confirmed if it was electrical it would of thrown a code.  Said tranny fluid dark most likely the piston hardened up leaking oil destroying the 3-4 clutch pack which they said is all too common issue on these Tranny's.  

[shakenfake]

Rebuilding the trans ain't so bad. Youtube engineer it and you can probably do it. 

I blew my 3-4 up as well so I am in the same boat right now.

[Brenden Burnham]

1 minute ago, shakenfake said:

Rebuilding the trans ain't so bad. Youtube engineer it and you can probably do it. 

I blew my 3-4 up as well so I am in the same boat right now.

Oh dang really sorry to hear that.  I have seen some videos.  Really more than what I can do tool/space and patience wise lol.  If I had a lift I most likely would.  The one benefit of having a shop do it is warranty.  These guys do good work I had a dodge ram where they did a tranny rebuild in.  Was good to go(till it got wrecked not my fault).

 

Is yours the clutch pack as well that went out?  Seems that is a common problem in these.  Seems in my case the piston became hard and leaked oil and burned up the 3-4 clutch pack.  Can tell with the piston oil in the fluid.  You will notice a darker fluid and it will smell as well.

 

 

[dna9656]

On 1/22/2022 at 12:33 PM, richard wysong said:

Good point, I don't think water alone would cause a problem unless the 

connection was already compromised by corrosion etc. the selector switch is the most likely culprit to be affected by water alone. being in Nevada the truck probably hasn't seen lots of road salt or freezing temps so corrosion may not be an issue

Point taken however.... basic corrosion: it takes in the presences of an electrolyte, you said it started after a visit to the car wash, well there's you possible introduction of an electrolyte (water AND soap) soap is caustic which could speed the corrosion process right along and you live in a place where the extreme heat could accelerate the drying out and cracking of your wire harness plugs. Water and soap getting into the plugs. I had some serious corrosion under the drivers seat of an S-10 Blazer I drove in Alaska, melted snow (water) migrated up the carpet under the seat to the large white plug that joins the lighting circuits for brake, tail and turn signals. I pulled the plug apart and it was all green junk where the brass and water made beautiful corrosion together.

[Brenden Burnham]

18 minutes ago, shakenfake said:

Rebuilding the trans ain't so bad. Youtube engineer it and you can probably do it. 

I blew my 3-4 up as well so I am in the same boat right now.

And did yours throw a code?

[shakenfake]

I messed mine up in a way different way than you most likely. We have not torn it down yet but we are thinking it is a clutch pack.

No codes, I never looked anyways. I just put the truck in my shop and walked away from it.

[Brenden Burnham]

So an update.  I am getting the Transmission rebuilt.  Right now the shop has a core and will be building one for me starting Monday.  So basically all new parts and the ones that have been addressed as weak points upgraded to the better parts.  For example a better Sunshel, better Pistons, better clutch pack, etc.  This shop is good to go all they do is work on Transmissions.  And I will get an unlimited 3 year warranty.  

 

It was suspected that the 3-4 Piston had locked up causing damage.  This is a common problem on these Transmissions.  They could tell by the color and smell of the fluid.  This and the other common problems they address on these transmissions. Am happy about that as to not just get a replacement that may sooner than later have same issue/s.  So regardless there is internal damage effecting for now gear's 3-4.  1-2 and reverse all work fine.

 

So the truck goes in next Wednesday or thursday when the remanufactured Transmission is completed and they will swap mine.  So my truck only needs to be in the shop for a day or two.  Just put a deposit down so am all in.  

 

The positive out of all of this is a learning experience for me.  During this time I have done a ton of research and therefore have learned more about transmissions and their problems than I have ever known.  This has helped me to ask questions to ensure that I am getting the best service and parts from the shop.  

[Sharpz]

I am glad that you are in line to get your truck up and moving again.  I am just curious why this shop didnt have a rebuilt tranny already if thats all they do.  The 3 year unlimited is pretty standard here for a rebuilt tranny.  You can get a rebuilt w/ new torque converter w/ a 1 year unlimited and your core deposit for about 800 bucks, but the upgraded tranny w/ the 3 year is the way to go.