I do still believe that I am in 2hi because today I was going up my snowy driveway and tires were just spinning an d I felt zero grabbing from the front wheels at all otherwise I would have made it up the hill. when I went really slow up the hill it went better but I think that was just because I wasn't spinning the tires
2003 envoy I6 lost all power to the wheels while driving
- Thread starter juiceboxxx26
- Start date
Sorry, got wicked busy this weekend. Since you were in 2WD safely, I put you on my medium burner instead of the front. Hope you don't mind. Try to get something together tonight.
now when I come to a stop in drive I get a random jolting feeling coming from the drivetrain. it also happens when I am in reverse too.
It feels like a bump forward but very quickly. not like a misfire or anything like that but when I put the car in neutral it goes away! hmm hmm hmm hmm hmm
It feels like a bump forward but very quickly. not like a misfire or anything like that but when I put the car in neutral it goes away! hmm hmm hmm hmm hmm
IllogicTC
Member
- Dec 30, 2013
- 3,452
juiceboxxx26 said:now when I come to a stop in drive I get a random jolting feeling coming from the drivetrain. it also happens when I am in reverse too.
Would you happen to have your defrost or A/C on at the time it happens? And do you feel any difference in the brake pedal, like it sinks a little bit or suddenly feels like there's a little more resistance to your pushing it?
http://gmtnation.com/f79/feels-like-i-get-rear-ended-when-sitting-red-light-2430/
Read every post - follow every link.
Read every post - follow every link.
IllogicTC
Member
- Dec 30, 2013
- 3,452
The_Roadie said:
I forgot about this one. It was a great discussion too!
I was thinking more along the lines of differences in vacuum pressure perhaps causing some "jumpiness." Doesn't seem to happen on our platform too much but the basic concept is known at least among other platforms. Don't ask, I'm really really tired.
I'm not really worries about the jumpiness. I am more concerned about the 4x4 problem that I have. I do have a service 4x4 light on and when I switch my selector I get no action. The light is stuck on A4WD and when I switch I get nothing.
Kelly@PCMofNC
Member
- Mar 16, 2013
- 184
Sorry to hear about this. If you covered this I apologize, but have you had a look at the fluid in the transfer case yet? Curious if its condition.
Kelly@PCMofNC said:
Just replaced the transfer case with brand new fluid too two quarts of autotrack 2
Need to figure out this jumpiness that I'm having. Sitting at a red light or stop with the truck in drive it feels like a hesitation and slight engagement of something. Sorta feels like it's coming from the front passenger side but I may be wrong. The only thing that i have not checked or replaced in this 4wd system is the disconnect. But I have a service 4x4 light on. Is there a sensor that would throw a light on the disconnect??
Also it feels like hesitation when start driving once I pick up speed it goes away.
Switch says I'm in A4WD
Makes me think the disconnect is the problem
Also it feels like hesitation when start driving once I pick up speed it goes away.
Switch says I'm in A4WD
Makes me think the disconnect is the problem
IllogicTC
Member
- Dec 30, 2013
- 3,452
juiceboxxx26 said:
The jumpiness is probably still the rear axle as mentioned above. Check the link given above, "feels like I'm being rear-ended while stopped." I'm feeling like when you drop the cover on your rear differential you're not going to be exactly impressed with how the internals look. It is technically part of your 4-wheel system, too, and at a stop your transfer case should only be sending about 5% torque forward so it really shouldn't be coming from up front.
Things that would upset the system and cause Service 4x4:
-Front axle disconnect. This would be a failure of the actuator to retract or extend as commanded. If the actuator's able to do so but something internal to the disconnect is broken, it likely will not "see" it, which is a shame since more often than not it's something internal to the disconnect that is broken.
-Transfer case encoder motor. If the expected position does not meet the desired position, or there is an issue with the encoder motor brake, it will throw this.
-TCCM. The control module itself could be biting the dust. Actually not that rare, now that I think about it.
-There may be something I'm missing, but the only sensors I know it checks are on the disconnect and the encoder motor.
If absolutely nothing else, and you've tossed in parts and it won't go away, it may be time to just take it in to get it read on a Tech 2 scanner. It'll read all the fancy C and U codes in addition to the standard P codes that any old scanner will do. Get the code numbers and what they mean, the devil is in the details and I'm betting there's a C-code or codes stored in there that'll point you to the holy grail fix.
Yes. The disconnect actuator (2 bolts) will throw a light if it fails to move fully one way or the other when commanded. You can remove it from the disconnect assembly, and operate it in mid air to see what it does. You can run the 4WD mode switch with the ignition in RUN but the engine off, to hear it better. The actuator should ONLY change state (from in to out and vice versa) in two mode transitions: 2HI->A4WD and A4WD->2HI.juiceboxxx26 said:
I already replaced front disconnect actuator with a brand new one. Why would the rear start doing this weird thumping thing after I replaced the transfer case? Before transfer case replacement there was no thumping ever. Leading me to the front disconnect. That is the only part that I have not changed or even looked into.