Chevy Trailblazer SS Forum banner

2007 TBSS AWD front diff exploded

17K views 32 replies 9 participants last post by  chad740 
#1 ·
Something gave loose driving down the interstate on the front end. I'm assuming the Diff came apart? There was something that looked to be about 3in in dia that was glowing cherry red and Large chunks on alum. that caught the cross member and took a big gouge out of it. I didn't get to look underneath it to good as I was sitting along the istate. Whats common to come apart? We just paid it off last month and this thing has been a nightmare of problems this being the biggest.
I don't mean to sound to stupid but never had and experience with all wheel drive vehicles.
That being said will only TBSS front diff work? Or will other AWD TB that are AWD work?
Where do I find the gear ratio also?
Also why would putting it in park not work with something in the front come apart? I cant even start the motor with out something clattering.
 
#2 · (Edited)
You've got alot going on here. First off generally the differential doesnt go on these but the passenger side carrier does. They don't get lubrication which causes the splines to wear and eventually you hear a bang and the truck wont drive. If you put it in park and it still rolls I would bet on this being the issue. It stems from the design of our transfer case. You need the AWD diff from a tbss. The components are slightly different than the 4wd version. All TBSS have 4.10 gears. Now you mention clattering when you start the engine, did the front axle problem blow up your oil pan and cause you to lose oil pressure? Can you post pics ?
 
#4 ·
The pc that was cherry red was on the driver side looking down in the engine compartment. there was also a large pc of alum housing ribbed blown out. also on pass side. It sits so low and I was so close to moving traffic I gave up looking to close plus it was only 15 out and getting dark. lol

The first thing I did was check the oil I thought the motor came apart when it exploded and there was a lot of smoke. I shut it off so fast I didn't have time to look at oil pressure. That's why I looked at oil. It just caught me off guard when I went to put it in park and I had nothing. Im assuming oil from what ever came apart and got on manifold from all the smoke or maybe the pc the was glowing red. I was very luck it didn't catch fire.
When I was sitting waiting for tow truck I tried to start it for heat and just as it fired up I heard something making a heck of a noise so I shut it off. of was I new something went thur the pans on these and I thought shit its busted.

Im going to try to get pics this weekend of the carnage. I don't have a garage to work on it in and its way to cold on the street. just was trying to pick ppls brains on what I might expect to find. That way maybe I could start looking for parts.

I think I also seen there is a oil pickup tube upgrade that I could do since im going to be in it this far?
 
#3 ·
Sounds like a poorly lubricated carrier that exploded to me.

Because the transfer case in the Tbss is a torsion style unit there is nearly unlimited slip potential between the front and rear outputs. Meaning if one output or the other provides no resistance they can both spin (over simplified of course). So no park in the event of a diff carrier failure is completely normal.

And as stated above if you did have a complete melt down (unlikely and not common) you could have wiped out the oil pan as well. Since the diff and carrier both bolt to it. But that would have been fairly obvious by a gallon or more of oil on the ground.
 
#5 ·
There was a good amount of oil on the ground. Im going to try to get pics that way ppl will know better what they are looking at then I will. Maybe give me and idea where to go from there on fixing it. Im pretty good at fixing just about anything this will be another to add to the list.
 
#6 ·
Best guess, here is a list of possible parts needed.

-Intermediate axle shaft
-Awd carrier (us powertrain makes a nice unit)
-Oil pan, with extra carrier mount pedestal.
-Differential (bully racing sells complete units) with a limited slip diff if your interested.
-Front drive shaft.
-pcmofnc oil pickup tube if the pan if broken and coming off.

That’s all best guess not knowing for sure what happened.
 
#9 ·
urban SS17 I read you just did the pcm of nc pickup tube,i was curious if you would entertain for a fee in helping myself install my pickup tube, motor city speed wants 1000.00 to do it, but they have not called me back in over 2 months and I'm not one to be a pest I figured there just to busy,im located in Livonia and have a fully heated and functional garage if your interested in making some extra money,thanx 4 reading
 
#13 ·
Not hijacking but help do one yesterday in an I6 TB.
.
.
.
.



Sent from my iPhone using Tapatalk
 
  • Like
Reactions: chad740
#16 ·
I picked up a unit at a local yard. Opened it up and cleaned / inspected replaced seals which NAPA had the outboard one but not the inner one. Filled with oil and sent it on its way.


Sent from my iPhone using Tapatalk
 
  • Like
Reactions: chad740
#18 ·
My SS was an AWD so I didnt think twice about dropping passenger side steering rack and pulling oil pan to get it out. Did it on a lift and was in and out in 5 hrs.


Sent from my iPhone using Tapatalk
 
  • Like
Reactions: chad740
#21 ·
It took me about 8 hours since I tried to rebuild the actuator and did a ton of cleaning and replacing parts. One I thing I didn't get about it was how everyone seems to jack up the motor and it comes out. Comes out where??? I ended up cutting some of the frame, I'll take pics when it goes back up on the lift on Wednesday. Now It slides right in and out from the back. I read how one guy took his out from the engine bay by removing the Alt/PwrStr bracket, that made tons of sense after I had reinstalled it :lol:
 
#27 · (Edited)
Holy poop! Looks like you can add a transmission bell housing to the parts list. If you were to have, let’s say run over something in the road? that might have caused the damage, in a hypothetical situation it may be covered by your Insurance. It sure looks to me like you might have hit something causing that damage, if you catch my drift.

The above was stated for your consideration. I am in no way telling you to commit insurance fraud. In less of course that is what happened.

Kinda looks that diff was run without any oil for quite sometime causing the pinion to overheat until cherry red and sheer off under the engine load. I’ve seen this a couple times in my career never on an ss though.
 
#29 ·
Did anyone work on it recently? I have seen extremely high pinion preload cause the same failure. Basically when someone changes a pinion seal and just impact guns the pinion nut back on as tight as they can without checking preload. You can create a lot of friction that way.
 
#31 ·
Ok the farther i get into this the more i find. Does anybody have a good source for motor mount pc that bolts to the block? And thoughts on getting out busted manifold bolts. Looks like when it gave loose the rear bolt is busted and the metal motor mount is destroyed and motor fell on frame. Not sure if mf is good or not.

Sent from my SM-G935V using Tapatalk
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top