anyone experienced this?

[Oldskool153]

i noticed the other night that when im upshifting from 2cd to 3cd in direct with the Overdrive off, right when i reach about 24-28 mph and im about to upshift it feels like the trans slips for a second because it jumps from about 2600rpm to 3500rpm.. but its not doing it in any of the other gears and it drives perfectly in 2cd until i start getting up in speed. have u ever heard of anything like that or is the jump in rpm normal? i never noticed it b4 but is not slipping when i shift into 2cd the jump in rpm comes right as im winding out 2cd and about to go into 3rd.. maybe im paranoid?

 

[MBDiagMan]

I drive an 88 4+3 and I don't experience anything like this. I would not panic, however.

When was the last time you changed the oil and filter?

For the sake of discussion, let's just assumed that the OD unit is slipping, although I don't think that is happening since you say it is solid in other gears.

If it IS slipping the only thing it could be would be the clutches in the OD unit. If the time were to come when it is FOR SURE slipping it should be easily fixed. The clutches and planetary in the OD unit are just standard parts from some particular GM automatic transmission or another. I would be surprised if you couldn't find a competent automatic transmission shop that could fix it without too much trouble.

If it were come to that, you would just have to be careful to find someone who is a straight dealing shop. A crooked shop will either try to make you believe that it is something more complicated than it really is OR they will just take it apart and twist the steels so it won't slip long enough for you to pay them and drive out of sight.

You want to make sure that the shop uses new clutch plates and steels. No big deal at all. With the Vette it will probably be as much trouble to get the trans out and back in as it will be to replace the clutch pack.

Also, the valve body in the OD unit is super simple, but there could be something going on that is preventing adequate clutch pressure under specific conditions.

 

[Oldskool153]

thanks, lol actually i just read ur reply to my other thread before I read this, you know alot about the 4+3 and i would like to keep incontact with you if thats ok? Its not comming out of OD though..I put 152 miles on her the other night doing 75-80mph on the highway and she stayed in OD perfectly. maybe its in my head? like my dad says "just drive it, than if it breaks fix it" Im affraid to change the OD fluid and filter, I bought the car in Dec. and i dont know when the last time it was changed was, I dont wanna open pandoras box, so i just keep checking the fluid level every so often.

 

[muddywaters]

I think I mentioned in a past thread. Service the OD unit. If you find the magnet in the pan covered in particulate, service it, drive it, then service it again, that's what I did and my OD works perfectly.....For the relative inexpensive cost of two quarts of ATF and the silicone sealant you can't go wrong with that approach.

 

[vetteoz]

I Service the OD unit. .For the relative inexpensive cost of two quarts of ATF and the silicone sealant you can't go wrong with that approach.

And a filter from a Ford FMX auto ;
not the expensive one from Ecklers

 

[MBDiagMan]

As the others correctly recommend, CHANGE THE FLUID AND FILTER. It is not a big deal, just don't overfill and then check it several times frequently after you've changed it to make sure that the level is correct.

Doing a fluid/filter change is no pandora's box. Ignoring it and dealing with failure will be a Pandora's box.