Excursion Issue- Tranny related I think???

[CSIPSD]

Driving Chelseas Excursion this weekend (she was driving but I noticed it as well) and she went to pass someone. The truck seemed to shudder, felt to me a lot like a slipping trans... Let off and it goes away. She lowered the setting on the chip and we could not repeat it off hand.

She just texted me and said it did it again, twice when she was trying to pass someone.

Fuel pressure is fine and remains constant, HPOP is fine and very respectable with the AC code injectors...

Could this be a line pressure issue? Or does it sound more like a tranny on its last legs?

This is a HD 4R100 from Ford installed about 5 years ago. It has about 80-85k on it... Just had it serviced about 8-10k ago at a local shop. I should have checked the fluid level this weekend but forgot. I will have chelsea check it today.

Any ideas???

 

[firehunter]

Did the RPM's stay the same the whole time? Won't the RPM's climb when the transmission slips?

Wife's auto truck had a shudder a while back when harder on the throttle, like when passing, and it turned out to be the u-joint right in front of the rear differential. Light acceleration wouldn't make it happen.

 

[CSIPSD]

I didnt notice if the RPM's climbed or not... Good question!

 

[Mark Kovalsky]

If it really is slipping it's easy to detect. All you need to do is look at the fluid. Put a drop from the dipstick on something white. See if the fluid is turning brown or black and if there is any fine particles visible. If so, there is a clutch slipping and the trans needs to be rebuilt. Once a clutch slips it must be replaced.

 

[CSIPSD]

I was hoping you would chime in...

I will check the fluid when I get home friday, see if I can see anything. I dont mind pulling the plug and dumping some out of the bottom of the pan if you think that is worth it. As I said it was just "serviced" at a local place. Chelsea took it to the place and they changed the filter and fluid... I noticed it still has the Magnifine filter we installed when the tranny went in 80k ago...

Trying to think of anything and everything it could be or could help to diognose over the internet...

She does not rod on the truck at all, other then being a slightly agressive driver from time to time its a DD grosery getter.

She did Dyno it a few times, last time was 340hp...