Hello everyone at gmt400! I have a 93 C1500 2x4 5.7 4L60E that does not have any power in drive or overdrive from a stop.

[Gratefuldiver]

Hello! My 93 C1500 has no power in drive or Overdrive from a stop. I can shift it down first second and reverse are normal and once I start going, I can shift it up to drive and overdrive and it seems to be fine. From a stop though, it seems like your power breaking it slightly or possibly the transmission is slipping. I was thinking the clutches were bad and transmission was shot until I read some of the other threads and realized it could very well be an electrical issue.? Any thoughts, experience, or expertise would be greatly appreciated!

 

[Drunkcanuk]

Paging @NickTransmissions LOL

 

[NickTransmissions]

Hello! My 93 C1500 has no power in drive or Overdrive from a stop. I can shift it down first second and reverse are normal and once I start going, I can shift it up to drive and overdrive and it seems to be fine. From a stop though, it seems like your power breaking it slightly or possibly the transmission is slipping. I was thinking the clutches were bad and transmission was shot until I read some of the other threads and realized it could very well be an electrical issue.? Any thoughts, experience, or expertise would be greatly appreciated!

What specific threads? Link them in your reply.

Any codes? If you have an electrical issue assiciated with the transmission, you'd have a DTC set and stored in the pcm. Scan it and let us know what, if any, codes are present.

My guesses: Either your forward sprag is rolling over or your forward clutch pack is shot. Trans has to come out for overhaul.

Torque converter stator may also be failing.

Drop the pan and have a look - take a pic and post it here.

Will you be rebuilding it yourself or having a shop do it?

 

[Gratefuldiver]

What specific threads? Link them in your reply.

Any codes? If you have an electrical issue assiciated with the transmission, you'd have a DTC set and stored in the pcm. Scan it and let us know what, if any, codes are present.

My guesses: Either your forward sprag is rolling over or your forward clutch pack is shot. Trans has to come out for overhaul.

Torque converter stator may also be failing.

Drop the pan and have a look - take a pic and post it here.

Will you be rebuilding it yourself or having a shop do it?

Hi Nick thanks for replying. 28,35,66,67,81, 82 are the codes.

 

[NickTransmissions]

Hi Nick thanks for replying. 28,35,66,67,81, 82 are the codes.

You're welcome - please respond to my other question.

Also, any of those transmission related codes? I dont have the OBD1 trans codes memorized and figure you will have looked them up to see what they are.

 

[scott2093]

You're welcome - please respond to my other question.

Also, any of those transmission related codes? I dont have the OBD1 trans codes memorized and figure you will have looked them up to see what they are.

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[Gratefuldiver]

You're welcome - please respond to my other question.

Also, any of those transmission related codes? I dont have the OBD1 trans codes memorized and figure you will have looked them up to see what they are.

I was trying to maybe be able to do it myself but I'm not exactly a transmission guy.

 

[NickTransmissions]

I was trying to maybe be able to do it myself but I'm not exactly a transmission guy.

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Thanks, both.

This strikes me as an electrical problem in the internal trans wiring harness or external harness (or even PCM itself) as it's very unlikely all of your solenoids would fail at once.

My first step would be to disconnect the harness (or yank the trans fuse) fire it up and put it in drive - see if it moves. You will be in third gear (or 2nd if you drop it into manual low or 2). If it moves forward, step 2 is to ohm out the internal harness pins to see if you get anomalous readings. Then drop the pan and see what's at the bottom.

If you see a ton of metal, burnt clutch material, etc then yank it for overhaul.

Otherwise, use a multimeter to continuity test the solenoids.

 

[Gratefuldiver]

That's what I was thinking is it was highly unlikely. Thank you very much for the input as I'm going to go try that. I did just change the fluid and filter and there was not a bunch of metal in the bottom of the pan. Even though the fluid didn't smell burnt, it seemed to be quite dark. Thanks again.

 

[Gratefuldiver]

That's what I was thinking is it was highly unlikely. Thank you very much for the input as I'm going to go try that. I did just change the fluid and filter and there was not a bunch of metal in the bottom of the pan. Even though the fluid didn't smell burnt, it seemed to be quite dark. Thanks again.

Ok, so the truck's fixed. I thank you very much for all of the input and help that you have provided. So I took the fuse out and it didn't look burnt but I put a new fuse in it... thank the Lord that was actually the problem. I feel kind of dumb for pulling the fuse and putting it back in there previously , without changing it just to be sure. I'm f----n thrilled w a huge weight lifted for this to be the issue.
Again thanks.