Transmission swap

Jboht · September 21, 2016

So I did a transmission swap in my 99 gmc Sierra 1500 got it done and truck won't move the service 4wheel light is on and it wasn't before the swap the indicator light blinks when key is turned on but stays off when truck is started would this keep the truck from moving and what are some things I should look at

Jboht · September 21, 2016

I believe there all hooked up right. If I put it in gear it doesn't move at all I've got the service 4 wheel light on after it was put back together and it wasn't on before hand

Jboht · September 23, 2016

I used the torque converter from the original trans I mean

Duelin · September 23, 2016

I think you are going to have to go back to square one. Did you check and see if the transmission that you installed was compatible with your application? And if so did you check and see if the 2 torque converters are compatible with your application? There are a lot of different variables that has to be considered. Most good salvage yards will have a data base with the information to cross reference the different applications. So that would be a good place to start. And then if everything is compatible you can go from there and start your troubleshooting.

hexumaz · September 22, 2016

Make sure your fluid level is good. If its low you wont get enough internal pressure to get things moving. Is it the 'service 4wd' message or the ABS/brake light?

Jay P · September 23, 2016

Is your 99 a 4.8/5.3 or a 5.7 (350). I'm guessing the blazer was an S-10 with a 4.3l engine. If you have the newer engine and the blazer has the 4.3, they are not compatible. The 4.8/5.3 have a different ecm/pcm. The other problem is the Blazer would have a lighter duty transmission since it's a lighter vehicle and has a lower towing capacity. Lastly you should never put a torque converter from a failed transmission on a working transmission. Any stuff from the failed transmission was in that converter and now is in the the working transmission.

Jay

Jboht · September 22, 2016

Yes it's the service 4wd light that's on

hexumaz · September 22, 2016

Service 4wd won't keep you from moving. Get the codes read to narrow down whats causing the CEL. I would guess that a plug/wire is either broken or in the wrong spot.

Jboht · September 22, 2016

Well I used a trans from a blazer but I swapped the bell housing and used the right toque converter would that work

hexumaz · September 21, 2016

I had an issue when I swapped the tranny in my 99 silverado. Mine is 4wd and I had incorrectly connected the three speed sensors on the transfer case tail housing. Had brake warning lights on and wouldnt shift out of first. Check those sensor connections.