Transmission or other Drive line issues???

**sgodder** · 10-01-2008, 03:46 PM

2002 suburban 4x2 105000 mi...just had 90K mile factory recommended service/PM,(all fluids done).
Engaging transmission into D or R from Park is a hard or rough engagement. once driving, shifts up thru the gears nice and smooth. When first speeding up or when slowing back down, under 25 mph, clicking noise is heard and felt from the rear end. Also, at 65mph and above there is a substantial vibration. I have had the Michelin tires rotated and balanced, dont know if all of this is realated.
Any ideas before I take it in and someone wants to sell me a new transmission? Is this tranny, rear diff, any other driveline issue?

**MrShorty** · 10-01-2008, 06:08 PM

Next thing I would look at would be the u-joints in the driveshaft. I don't know if you have drum brakes or disck brakes in the rear, but, if you have drum brakes, I might also pull the drums off and make sure something hasn't come loose. Where you just had the fluids changed, you might make sure they filled the rear diff up full and that the fluid looks clean. I would probably also check the transmission fluid level that they got it correct.

**57 shaker** · 10-10-2008, 11:09 PM

SGODDER a clunk when going from rev. to dr.,105k miles,trans shifts ok,and a clicking noise at hiway speeds is a classic u-joint prob.so MRSHORTY in my opinion is correct ding!ding!ding! good luck

**CoolAirVw** · 11-12-2008, 11:22 PM

Some trouble codes can cause a "high line pressure failsafe" in the transmission. Computer notices something, triggers a code then makes the trans shift hard trying to protect it.

Scan computer system for codes, after you check your u-joints.

Also the pressure control solenoid can stick causing "high line" as well.

**sgodder** · 12-04-2008, 02:41 PM

I thought I owed you guys what the problem actually was and that is a bad driveshaft and u joints. I had the it all replaced and it is running like a charm. Thanks for all the help!