My tranny has a strange pause in it when I go to take off from sitting at a light,stop sign or drive thru. It's like I have no pressure for only a second or two and then it will kick in. It has done this since I bought it (50,000k) and I was hoping the rebuild would take care of it. (@130,000k now @ 152,000) It doesn't do it all the time but it does it under all circumstances, i.e. hot or cold summer or winter. Just wondering if anybody else has had this problem? I've had my tranny guy look at it and he went through everything and all is good inside. No problems with shifting or anything the tranny is tight, just this little qwerk!


It is a tale as old as time, It won't act up when the mechanic has it

 

1. If you don't feel it shift down to first just before coming to a stop then the pause you are describing might be the shift to first gear triggered by the attempted acceleration.
2. My ATS had a bigger pause after the first startup in the morning. After backing out of my garage and shifting to D it was like no gear, neutral, for a few seconds. Took it back to ATS (I live nearby) and they adjusted the tranny fluid level (up or down, I don't remember) and it never happened again.

 

Does it free rev, or does the engine just bog and then pick up? When it catches, is there a "bump" like a downshift, or more like a manual trans. clutch engaging?

 

Had the same thing with mine. Since the trans has been rebuilt it hasn't occurred again. It happened very infrequently and started when the truck had only a few thousand miles on it till bebuild around 120k. As you described it happened while trying to start from a dead stop ,without any warning and you sit there for a second or two then it goes, no clunk or abnormal sounds just a hesitation.
Never caused me to breakdown tho , if that helps.

 

Yea Eskimo, it free rev's for a sec then bumps (or slides) into gear, It has 2 or 3 grab pulses then pressure builds up and off I go. I guess it feels kinda like your T/C was slippin' but I don't think it's that. When I first had the Tranny done it didn't do it, but I had shifting issues, wouldn't drop into first unless I came to a complete stop, so I took it back to them and they fixed the shift times. Discovered that it was the speed sensor to the tranny...I think it drops in @ 5mph, with oversized tires the speedo is off so it doesn't register 5mph to the tranny until like 1mph so...something I'll just have to live with.

Now the slipping is becoming a little more frequent, like I said it did it with the original tranny as well. I don't feel like it's hurting anything but I've never encountered it before and I've had a lot of Auto's

 

slippage is never a good thing, period.

I'm far from an auto trans guru, but I'd suspect valve body isn't sending enough pressure where it should be going - does it do it if you pull the lever into 1st manually? (My guess is that it won't)

Point is, the rebuild wasn't done correctly. Any codes? (AutoZone/Advance auto will pull 'em for free)