Torque convertor or OD band failure?

[derik]

Trying to figure out if I have torque convertor "shudder" or OD band failure. MM has 140,000 miles, transmission was rebuilt and TC replaced in May 2003 after 13,300 miles. The last transmission service (BG flush?) was in June 2008 at 123,000 miles. In Feb 2009 the battery was serviced. Since then I'm getting like a jerking at about 40 mph with slight throttle pressure when in overdrive. Taking OD off will stop the jerking a majority of the time. It occurs mainly in the 35-45 range but also at 60 if a lot of throttle is given. The jerking is almost like an engine miss, but not rhythmic like going over rumble strips. The event is transient and some days does not occur at all.

Could there be a connection between battery service (cable disconnect) and TC where the TC has to "relearn" shift points? It's been over 1000 miles since battery service.

[Blk Mamba]

...there are times when mine shifts in and out of OD at different speeds, doesn't seem as bad as you state, but at 31 mph it'll continue to do it.

[CBT]

At the risk of sounding stupid, have you checked the fluid?

[Haggis]

To test the OD band; while driving up a hill OD off engage the cruise control once cruise is fully engaged and pulling vehicle on its own turn OD on. If OD light blinks or does not turn off and/or OD does not engage OD band is bad.

[derik]

At the risk of sounding stupid, have you checked the fluid?

Fluid is where it belongs, looks good, and does not smell (except like transmission fluid).

I'll attempt the cruise control - OD engage procedure if I can find a hill with no traffic. Hopefully on the way home tonight.

[Local Boy]

Certainly, not a Batt. issue...

Sounds like it's down shifting into 3rd and locking and un-locking ALL at the same time...or very close together...

That will cause it to "clash"...and buck...

Wouldn't TC shudder be noticeable at all rpm's..?

Good Luck...

ALOHA

[derik]

The OD band appears to be OK based on the test procedure from Haggis. I'll have it checked Saturday. If a new TC is needed, the 2004 will fit the 2003? Any PCM changes needed? I'm stock; never got around to getting a tune.

[Zack]

So you went 110,000 miles between transmission services?
Is that right?

[derik]

No, about every 30-35K. Last one was about 17,000 ago (at 123,000). Never had a transmission related problem since May 2003 as stated.

[Bradley G]

A misfire can cause this symptom, change the spark plugs and check for an intemittant Coil on plug.

[derik]

I don't have a scanner. Will a code be thrown for TC or transmission problems? What about intermittent plug misfire? No CEL with my current problem.

[mrjones]

I had this same problem with an F150. Felt like running over rumble strips as it shifted into OD or locked up the TC. I fluid change fixed it. I've read from several sources that recommended using the friction modifier for the rear end in the AT fluid to eliminate the shudder.

Another flush would probably help, and make sure that they use the correct fluid.

[derik]

A misfire can cause this symptom, change the spark plugs and check for an intemittant Coil on plug.

So right you are. Diagnosed as misfire on COP #1. Changing all plugs on Monday.

[Bradley G]

I try! I had it happen on the wifes' Grand Monkey
I told my guy, it was a trans problem :D
So right you are. Diagnosed as misfire on COP #1. Changing all plugs on Monday.

[JimmyXR7]

So right you are. Diagnosed as misfire on COP #1. Changing all plugs on Monday.

Your MM has 140,000 miles on its spark plugs before a problem!!! Or were they replace before?

Amazing, the plug technology and valve seal improvements really keep the plugs good for that long. I am still replacing the spark plugs in my old 'classic' vehicles every 6,000 miles. My MM has 60,000 miles on the original spark plugs.

Jim

[derik]

Plugs were changed at 96,000. No problems, just wanted them changed before extended warranty was up in case there was a problem removing them.