Transmission

[Malibu02]

Hey guys,
I'm a little concerned. My 2021 custom trailboss which i have babied since i have owned it. All service is current. No real modifications wheels tires. Today my son drove it to GYM. then he calls me and tells me the truck will not move and the engine just revs up when he puts it into drive. He said reverse is no issues just in drive. He was able to limp the truck home by diving it in "L" mode and manually shifting gears. He also mentioned yesterday at the light the truck from the stop light when the light turned green the truck just rev'd up. then it drove. Truck has 58000 miles. what do you think. i plan on taking it to the dealer tomorrow. I'm worried some how the trans is gone. Forgot to mention.. I drove it when i got home from work no issues everything runs smooth. No check engine lights to hard shift or anything telling. Any thoughts?

 

[clstark7]

Hey guys,
I'm a little concerned. My 2021 custom trailboss which i have babied since i have owned it. All service is current. No real modifications wheels tires. Today my son drove it to GYM. then he calls me and tells me the truck will not move and the engine just revs up when he puts it into drive. He said reverse is no issues just in drive. He was able to limp the truck home by diving it in "L" mode and manually shifting gears. He also mentioned yesterday at the light the truck from the stop light when the light turned green the truck just rev'd up. then it drove. Truck has 58000 miles. what do you think. i plan on taking it to the dealer tomorrow. I'm worried some how the trans is gone. Forgot to mention.. I drove it when i got home from work no issues everything runs smooth. No check engine lights to hard shift or anything telling. Any thoughts?

Hopefully it's just some sort of electrical issues. Hopefully it's nothing major. Keep us posted!

 

[Malibu02]

I left it with the dealer. And of course they cant find any issues. They said they will keep it a couple of days. He did say my truck has he 6 speed and they usually don't have issues. I will keep you posted.

 

[mrcolieman]

If your problem stays intermittent check out this video. Its an older truck (and a 2500) but has the six speed. The plastic check balls in the valve body can wear and get stuck in the separator plate causing no forward gears. If you have the dealer drop the pan to do a service it might be worth it to have them pull the valve body and check for that while things are apart. Good luck!

 

[Malibu02]

I appreciate the comments. I’ll reach out to the dealer and see if i can get them to drop the pan and check it out. Even if i have to pay a few bucks for an in depth diagnostics. Thank you

 

[Malibu02]

Well I got it back yesterday and no solution. Today its getting towed back to the dealer. I have no forward movement at all. my guess is it will run once its at the dealer. Let me see what they say on Monday.

 

[DAW]

Well I got it back yesterday and no solution. Today its getting towed back to the dealer. I have no forward movement at all. my guess is it will run once its at the dealer. Let me see what they say on Monday.

I had a 2022 Custom Trail Boss. Same issue you described. It turned out the valve body failed and needed replaced. I filed a Lemon Law case and won. Now I have a 2025 LT Trail Boss...no issues with it yet.

 

[Malibu02]

When the TB arrived to the dealer the service guy sat in and tested it. So if anything changes next week that would be interesting. I wounder if its to late for a Lemon law. This is the first and only problem i have had with it. Another note.. When you take your trucks in for service like oil changes make sure the dealer puts the correct miles. The service guy said that since my last oil change in Aug 21 2025 I have put 8000 miles. That would be driving cross country.