Rough Shifting Buick GL6 Needs Transfer Case Fix

Had similar symptoms with my 2015 Buick Envision. The rough shifting and slipping between gears turned out to be significant gear wear in the transfer case. During my last garage visit, the inspection revealed metal shavings in the transfer fluid, indicating severe internal damage. The repair required a complete transfer case overhaul. Main issues found were: Worn gear teeth causing grinding, Damaged bearings from insufficient lubrication, Contaminated transfer fluid needed complete flush The repair process took several days as they needed to: 1. Remove and disassemble the transfer case 2. Replace worn gears and bearings 3. Install new seals 4. Perform a full transfer fluid change 5. Recalibrate the system This was definitely a serious repair job requiring specialized tools and expertise. The symptoms you describe match what I experienced, particularly the rough gear changes and slipping. Would strongly suggest getting it checked soon, as continuing to drive with these symptoms can lead to complete transfer case failure. The gear wear typically progresses faster once it starts showing these symptoms. Regular transfer fluid changes might have prevented this, but at 134k miles some wear is expected.

Thanks for sharing your experience. My symptoms were exactly the same. The repair shop did find metal particles in the transfer case oil when they checked, which matched what you described. Since getting it fixed, the gear changes are smooth again and no more slipping issues. Just curious, do you remember roughly what you paid for the full repair? Also, have you noticed any other transfer case related problems since the work was done?

Since getting my transfer case repaired, the transmission has worked flawlessly, no more mechanical wear or gear grinding issues at all. The total bill came to 330 for the repair, which included replacing the defective gears and doing a complete transfer case oil change. The price was fair considering the amount of work involved. The oil wear fault was definitely the root cause of my problems, and fixing it resolved all the symptoms completely. I have not had any transfer case related problems in the months since the repair. The gear changes are back to being buttery smooth, just like when the car was new. Would definitely recommend getting it fixed as soon as those symptoms appear to prevent more extensive damage. My suggestion would be to stay on top of regular transfer fluid changes going forward, its much cheaper than having to replace worn gears again. Been about 8 months since my repair and everything is still working perfectly.

After dealing with those rough shifting problems, I finally took my car to the mechanic last week. They confirmed what I suspected, metal particles in the transfer case oil and worn gears causing the issues. The inspection showed significant wear in the transfer case, just like you mentioned. The repair took 3 days total. They had to pull the transfer case, replace several worn components, and do a complete transfer fluid flush. Bill came to about 2800 including parts and labor. Seemed steep at first, but seeing how much work was involved and the specialized equipment needed, I understand the cost now. Been driving it for a few days since the repair and what a difference. The gear changes are perfectly smooth again with no slipping. The mechanic recommended regular transfer case oil changes every 30k miles to prevent similar issues in the future. Definitely learned my lesson about staying on top of maintenance. Thanks again for sharing your experience, it helped me know what to expect going in. The symptoms and repair process matched exactly what you described.