Transmission shudder?

[1996XLT-68]

Hey guys,

I've got a strange problem that's recently cropped up. Every once in a while, the truck will shudder alarmingly when I put it into reverse to back out of a parking spot/driveway. It never used to do that until after last summer when I towed a 20' boat up to North Carolina (about 3 hours).

I've also noticed that on smooth roads at highway speeds, if I lightly goose the throttle I can feel a mild 'clunk' in the drivetrain when the truck is in overdrive.

Anyone else have these symptoms or any solutions?

The truck is 96 2wd 4.0 with the Posi 3.73, tow package, 111k miles. I change the trans fluid regularly, about every 15k (full torque flush).

Thanks in advance,
Scott

 

[MrShorty]

As a start, how do the tranny/motor mounts look?

 

[1996XLT-68]

They look just fine.

 

[MrShorty]

u-joints? axle wrap?

 

[1996XLT-68]

How about instead of single word questions, you actually give me symptoms of those problems you are naming? What you're doing isn't really helpful, no offense. Thanks man.

 

[iceplorer]

Hi!
I have noticed this same problem on my Explorer, but not every time I drive it. It seems to me that it happens only when the engine is under 1800rpm in O/D or D and when I take off in D or R. My guess is a vacum leak, MAF or other engine related fault. I am checking my car step by step and will let you know if I find the cure.

 

[MrShorty]

Sorry about the one word answers.
I wonder if your highway clunk could be the torque converter clutch disengaging. At steady cruise conditions, the computer engages the TCC for economy reasons. When you apply enough throttle, the computer disengages the TCC, which can feel like a shift or maybe a clunk. If there were problems with the TCC disengaging and the computer decided to downshift 4-3, it could make that shift feel harsh. It could also create a low speed shudder/"lug".

 

[taylormanson]

I might be having the same reverse problem he is. It's almost as if there's extended hesitation before the tranny slips it into reverse. For instance, when I back out of my drive, I'll fully stop and put it in drive but if I hit the gas immediately you definately something catch and you take off - almost as if the transmission hasn't fully shifted from reverse to drive eventhough I'm at a complete stop and idling.

 

[iceplorer]

HEY there.
In my case the engine hesitates or misses out and has poor power until it seems to get going again when I take off. On the highway it sems to hic-up while under some load or when I push the pedal to keep up the speed.

The engine and the automatic transmission are connected to each other by a computer and if the engine does not work properly can´t it affect the transmission performance?

I cleaned my MAF sensor yesterday and it is not the problem in my case so I´m gonna check the fuel-filter and the O2 sensor.