Help !! Loud bang noise when making turns

[LScott]

I have a 2004 H2 with 25,000 miles, I've been experiencing a huge bang noise when I'm making sharp right or left turns going forward and the same when i'm backing up, it doesn't happen everytime, just occasionly. The noise and shake of the whole car will bring you out of your seat !! as if you had hit something hard !! The noise sounds like it is coming from a rear axle traveling all the way to the front end. It nevers does it on freeway or at high speeds.
Recently, I had to have the motor in the transfer case replaced because it would not shift out of 4wd Hi Lock to 4hi even though the dash light showed it had. Could these 2 problems be related ??? It's going back to the dealership for the 4th time - they are not fixing the problem !!!
I would appreciate everyones input.

[MDimitri]

If this bang occurs and the whole truck shudders it's a good chance the T-case drive chain may be loose or one of the spider gears are damaged within the case. Either way get it into a service provider as soon as possible, I've seen several bad T-case failures all of which can cause alot of risidual problems if not taken care of soon. When you say you had the motor changed in the T-case I think you are talking about the Encoder, it is not in the T-case, it is located on the outside of the T-Case. The encoder motor manages the current flow channels which allow the transfer case shift control module to determine what position the transfer case is in. Check under the hood to see if the TREC fuse is blown, this will cause the encoder to not function. Have them check the planetary differential pinion gears, they may have not been timed properly after the encoder was installed, this will directly influence the output shaft bearing and drive shaft and could easily be the shuddering you are feeling when going forward or backwards. One good point to remember is that when you engage the T-case in 4low, in order to properly dissengage the T-case back to normal 4High, you need to put the rig in reverse for about 15-20 feet and then put in 4high and continue driving as normal. Hope this helps.

Cheers.

[HUMTECH]

Sounds to me you may have A damaged range shift fork and it is not fully engaging into 4hi causing an intermittant bang from the t-case when loaded on A turn. The encoder motor rotates the shift shaft which moves the shift forks and if A fork is damaged or broken will not fully engage the range selected. No need to worry about pinion gear timing as the t-case was never apart if just the encoder was changed and if they were not timed correctly there would be constant binding in the t-case. Try all t-case ranges for proper engagement, if A fork is damaged you may or may not get all ranges depends on the extent of the damage.

[LScott]

Originally Posted by LScott

I have a 2004 H2 with 25,000 miles, I've been experiencing a huge bang noise when I'm making sharp right or left turns going forward and the same when i'm backing up, it doesn't happen everytime, just occasionly. The noise and shake of the whole car will bring you out of your seat !! as if you had hit something hard !! The noise sounds like it is coming from a rear axle traveling all the way to the front end. It nevers does it on freeway or at high speeds.
Recently, I had to have the motor in the transfer case replaced because it would not shift out of 4wd Hi Lock to 4hi even though the dash light showed it had. Could these 2 problems be related ??? It's going back to the dealership for the 4th time - they are not fixing the problem !!!
I would appreciate everyones input.

By replacing the encoder motor the dealership felt that this would fix the problem, It didn't and they seem to be baffled - apparently when they are test driving the car, it hasn't made the BANG !!! with them. Even though the 3rd time I dropped the car off at the dealership, I gave a test ride with the service guy and it did make the noise, not once but 3 times. Need your expertise and advice !

[MDimitri]

Sorry I could not find a better image for you, but If you look at the diagram you'll see that #9 & #15 are your range forks, #11 is the SHIFT MODE SYNCHRONIZER ASSEMBLY. Your problem lies therin for some reason you have a binding issue and I agree with Htech that it is probably your range forks which may be damaged, if it's under warranty have them open it up and have a look. Worst case scenario is that they replace your T-Case.