Troubleshooting the 4R70W Trans or Converter?

[TJCOX]

The transmission in my 2003 Marauder seems to be shuddering at around 75 mph. Has anyone experienced this issue, (174k)?

Thanks!

[88LTDCV351]

When was the last time you changed your spark plugs? Last time I had a shudder on the highway, it was dirty spark plugs.

[Agent2006]

My 2000 MGM had a shudder in my case a tube of Dr Trannys friction modifier made it stop. The fluid had begun to breakdown. When's the last fluid change been done? Get it at Napa...costs 6 bucks...don't spill any it really stinks. Thin red goo comes out of the tube fast. If that doesn't do anything there may be other issues...TC going bad, U joint going out.....

[88LTDCV351]

https://www.mercurymarauder.net/foru...=102572&page=2

[Gerry24]

I would change the plugs and coils. Mine did the same when I first bought her.

[crouse]

This is what makes site great. The knowledge of the members here is invaluable.

He thinks he has a problem with either the transmission or torque converter and it's probably just a simple inexpensive job of replacing spark plugs.

Something similar happened to me. I thought my power steering rack or power steering pump was failing because at times it was hard to turn the steering wheel. I posted my issue and someone said the u-joint on the steering shaft might need lubricating. Sure enough, that was the problem.

Just wanted to share my appreciation and the value of this site.

Thanks,
Curt

[Gerry24]

This is what makes site great. The knowledge of the members here is invaluable.

He thinks he has a problem with either the transmission or torque converter and it's probably just a simple inexpensive job of replacing spark plugs.

Something similar happened to me. I thought my power steering rack or power steering pump was failing because at times it was hard to turn the steering wheel. I posted my issue and someone said the u-joint on the steering shaft might need lubricating. Sure enough, that was the problem.

Just wanted to share my appreciation and the value of this site.

Thanks,
Curt

^^^^^^^^^^

[TJCOX]

Thanks fellow Marauders for all of your inputs. I just so happen to have the Motorcraft friction modifier and added the four ounces. I've changed the sparks plugs a few years back and I also drained the transmission fluid and added four quarts. I'll have to review my records. Not too long ago I would drain my trans fluid by removing the pan and the torque converter by removing the plugs. I believe the plug(s) have since been eliminated.
I'll use my Xalibrator II and see what it might reveal. I've not noticed any plug misfires when hard accelerating. It seemed that the shuddering would occur when I was de-accelerating as opposed to accelerating. Thanks again!

[TJCOX]

After adding the friction modifier Saturday morning I drove down to the grandson's double header baseball games and the Marauder ran well with no shuddering down there and back, a total of 150 miles round trip. I know the wife was worried the whole trip down there and back. Thanks again everyone!

Has anyone flushed their transmission or had it flushed and what the cost might be?
Thanks!

Thanks fellow Marauders for all of your inputs. I just so happen to have the Motorcraft friction modifier and added the four ounces. I've changed the sparks plugs a few years back and I also drained the transmission fluid and added four quarts. I'll have to review my records. Not too long ago I would drain my trans fluid by removing the pan and the torque converter by removing the plugs. I believe the plug(s) have since been eliminated.
I'll use my Xalibrator II and see what it might reveal. I've not noticed any plug misfires when hard accelerating. It seemed that the shuddering would occur when I was de-accelerating as opposed to accelerating. Thanks again!

[decipha]

I have done them myself in the past its about $100 in fluid and you waste quite a bit of it. Best bet is to just drain the pan and replace the filter and just top off what you lost.

Flushing is overrated IMO and WILL cause trans failure if its been neglected and gets changed. If you have over 100k miles of old fluid just leave it be.