AWD problems presist!

[Mike1973]

Hi Guys,
Still dealing with AWD problems on my 2004 Rainier V8. More help would be much appreciated! Its been blowing through transfer case motors for three or four years, honestly its been so long I cant remember, think I have gone through 4, three dorman (junk, I know thanks to you guys) last one was a used acdelco. I was experiencing crow-hop, each time I replaced the motor everything would work fine.
When the Acdelco went I heard a clunk, then no AWD. Put it up on stands, and the front tires were not engaging, front driveshaft trying to turn but barley moving.
Just finished replacing transfer case and transfer case motor with a parts truck I picked up, AWD is now sort of working in that the front drive shaft is turning, here's the kicker, the truck slowly comes to a halt when turning, not crow hopping but not working right either.
Put it back up on the stands, let er go in drive, three of four tire turn, same in reverse, the front passenger tire will not turn! Occasionally it will try to but no dice, when I try to turn the wheel by hand it does not move freely but still will not turn on its own.
Anyone know where to go from here? dont know much about AWD, but I'm slowly learning! could it be the disconnect? and if it is, is there a step by step to replacing it, my SUV is an early model 2004 and the tranny lines run in front of the disconnect, if you all think that's my next plan of attack is there any easy way to moving those lines without causing damage to them, mine look kind of corroded.
Sorry for the long post, just wanted to give as much detail as I could think of, thanks.

 

[Mooseman]

Long posts are fine as long as it's relevant info.

Your disconnect is basically a 'fake' as it never disconnects. It's a solid connection but does have a shaft and bearings that could fail. I don't think this is your issue.

Try removing the encoder motor and see if it rectifies the issues. If it does, then you just have another bad motor. Since it's used, you have no idea of the history.

 

[j-bone]

The front passenger wheel not turning sounds like something is binding are the brakes dragging ? ( remove caliper and see if it frees up)
Is the cv shaft bound up ?
It also could be a failure in the front diff but there would be some serious noise if it was .
removing the shift motor will cause a dash light but no drivability issues. start there.

 

[Mike1973]

Ok, so I removed the TC motor, drove to town no problem obviously rear wheel only, on the way home it started acting like it was locking up again! dont know why because the motor isn't even attached.
J-bone, I will check calipers in the AM, I'm embarrassed to say, I'm not sure what a CV shaft is, will have to do some searching and will check that too.
Thanks

 

[j-bone]

the cv shaft goes from the wheel to the front diff ( has two rubber boots ).
if you look up a cv shaft for your Rainier on the internet you can get an idea what it looks like .

 

[Mike1973]

Ok,
So there is no abnormal noise from the front differential, and the cv shaft, although feels like its engaged, doesn't seem to be binding up. Bench tested the TC motor and it seems to turn as it should.
New development, when up on the jack stands testing it out again, all tires except for the passenger front tire turns, the front passenger tire turns for 10 seconds then stops but now the truck just threw an ABS light!
Both sensors are less than 2 years old as the wheel bearings were replaced within that time, tested both sensors with volt meter, they are both reading a constant 1.08 ohms resistance.
Any other sensors I should be looking for and how would I test them? are there any on the rear wheels? I cant see any, but that doesn't mean anything.
Forgot to mention, calipers were ok, re-greased anyway.

 

[j-bone]

see if you can pull the abs code .
there are abs sensors in the rear they are behind the backing plate and go directly into the axle tubes they have a torx head bolt.
Does the passenger wheel spin free when key is off but not when key is on?
do you hear the abs pump running ?

 

[hockeyman]

The ABS light probably came on due to the fact that it recognized that one wheel wasn't turning (or stopped after a few seconds) when you had it up in the air, engine running and in drive. The code should go away once you're back on the ground and rolling again on all 4.
*Side note; You can also get an ABS light if you ever install a different tire (donut) or mismatch tire sizes/heights. The computer recognizes that one or more wheels aren't turning as fast as the others and throws a code. A mismatch in one tire height, shorter or taller, spins at a different revolution than the other tires -when on the road, and the engine lights up the ABS for 'ya.

I got an ABS code on a different car that I own and found that the sensor was covered with grease/dirt. Removed the sensors, cleaned them, re-installed, and the code was gone. I know it's not always the case, but it's something to consider.

You asked about how to replace the disconnect, so here's a video:

I got a noise from the front differential also, and it turned out to be a bad disconnect. One way to test it is to grab the inner part of the CV (passenger side), and try to shake it. If you do not know what a CV is, just get under the truck and follow the driveshaft from the front passenger tire, going into the oil pan. Here's another video explaining it and showing what one symptom (the most common symptom) of a bad disconnect looks like:

 

[j-bone]

The AWD system does not have a front axle disconnect, it is a live axle all the time .

 

[Mike1973]

Thanks for all the help, I'll try to answer everything.
1. ABS light is off, disconnected the battery, reconnected and test drove it and it has not returned. Hopefully it was as "hockeyman" said and was triggered due to the tire not spinning. A friend thinks that with all four tires off the ground that the passenger front tire wont spin because it needs pressure due to the fact that the front drive shaft is on the drivers side! Anyone got a comment on this theory?

2. I can't for the life of me find the rear ABS sensors, nor could 2 others, even with j-bone's description even tried google and still cant find anything relevant. Oh well, hopefully won't have to worry about them anyway. Next time anyone is changing one I'd sure appreciate a picture.

3. Found out what the CV shaft is, boy do I feel pretty stupid! oh well, now I know!

Thanks again everyone, haven't resolved all my problems yet, but have learned a lot more, have to call it quiets for today, turkey dinner time! Happy thanksgiving to all you fellow Canadian's!
Cheers

 

[Mooseman]

The AWD system does not have a front axle disconnect, it is a live axle all the time .

Yes and no. Yes, it is "on" all the time but there is a "fake" disconnect on the passenger side oil pan that does not have an actuator. It does have bearings and moving parts that can wear out.

1. ABS light is off, disconnected the battery, reconnected and test drove it and it has not returned. Hopefully it was as "hockeyman" said and was triggered due to the tire not spinning. A friend thinks that with all four tires off the ground that the passenger front tire wont spin because it needs pressure due to the fact that the front drive shaft is on the drivers side! Anyone got a comment on this theory?

The front diff is "open". In other words, one wheel may spin while the other remains stationary. If you were to grab the wheel that's spinning, the other would start spinning.

2. I can't for the life of me find the rear ABS sensors, nor could 2 others, even with j-bone's description even tried google and still cant find anything relevant. Oh well, hopefully won't have to worry about them anyway. Next time anyone is changing one I'd sure appreciate a picture.

It's on the Transfer Case. Only later years have sensors at each end of the axle tubes. (2006+)

 

[j-bone]

the ABS light very well could of been from not having all wheels spinning .

The front diff is an open diff so one wheel can spin and one wheel can be stationary but, with it up in the air either they both spin the same direction or then spin opposite directions unless something is binding like you are describing.
hope this makes sense , with both front wheels off the ground spin one side by hand and the opposite side should turn in the opposite direction. Tell us what happens.

 

[Mike1973]

the ABS light very well could of been from not having all wheels spinning .

The front diff is an open diff so one wheel can spin and one wheel can be stationary but, with it up in the air either they both spin the same direction or then spin opposite directions unless something is binding like you are describing.
hope this makes sense , with both front wheels off the ground spin one side by hand and the opposite side should turn in the opposite direction. Tell us what happens.

OK,
With the front tires off the ground I can turn either wheel and the other wheel turns in the opposite direction. This is normal? i guess.

 

[Mooseman]

Yes it is.