every now and then when shifting into fourth gear(automatic) i feel a vibration,at first i thought i was going over those markers in the highway because that's exactly what it sounds like.

thanks JOE

 

Search "shudder" in the transmission area. Don't let it continue or you'll need a torque converter. When was your last ATF change? To begin with, if it shudders, you should change at 30K. If it still shudders, change at 20K.

 

i changed my atf at 50,000 miles,now i have 68,486,also changed diff oil same time.how do i check my torqe converter.

thank's

 

You're Welcome ! It was a common problem for transmissions in your age range. There isn't much you can check or do for it. It gets progressively worse as the clutch wears. The lower mileage fluid changes help in some cases and in others does nothing. You can try the fluid changes and if you have no success, you can drive with the shudder or buy a new torque converter. The installation price includes a transmission removal. I know the prognosis sounds bleak, but that's the straight shot.

 

I know some people have replaced two different valves in their transmission's valve body with Sonnax replacements. One of them, the bypass clutch control valve, is supposed to prevent and eliminate torque converter clutch slip. See the following link:

http://www.baumannengineering.com/aodecat.htm

I don't know how you feel about doing the work yourself but this would require you to remove the valve body. Or you could pay someone to replace it. I would be interested to see if it fixes your problem. If it worked, it would help out a bunch on people on this site. I don't have the problem as of yet, but I have considered changing the valves now as preventative maintenance.

You might also add another transmission cooler to help keep the temps of the fluid down.

 

Sonnax makes some wonderful products that solve many known problems. I put both of those Sonnax valves from BE in my 2000 4R70W. I was installing their shift kit, so already having it torn apart, including them was a no brainer. I didn't have shudder and the exchange was preventative IMO. You can try the valves, but depending on the problem, they won't fix a damaged clutch in the converter.