2nd Gear Poster
Join Date: Jan 2005
Location: Fargo, North Dakota
'96 4R70W mild mods; late 1-2; wants to be in 1st when in D at low speeds
I have a weird (or maybe not so weird) problem. For background, I have a 4R70W rebuilt a while ago (maybe 35k, I forget) and the fluid dates back to then. 129000 miles on the car. The fluid looks/smells OK, level might be a mite high (just above the plastic thing) because it WAS low and I added some but I couldn't read the darn dipstick. When the trans was rebuilt it was switched to Mercon V and it has some upgrades (the shop where we took it does some Highway Patrol cars and they gave me the same improvements they do for them.) The rebuild was for forward/reverse crosstalk where with a hot trans it had to be revved to engage R.
Anyway, what it's been doing is that until today, it would very rarely make the 1-2 shift a little late at partial throttle. It might rev to say 3500 when it would normally have shifted at 2000, and the 1-2 would be a little harder than usual. It occurred randomly; I could have it do it twice in a work week but then make a 600 mile trip with no unusual behavior from it at all. In April or so the week it started doing this I checked the fluid and added a bit because after cycling it P-1 and back the level barely registered on the aforementioned stupid white plastic thing.
Now (as of this evening), it'll push the engine to/past redline before going 1-2 in D. If I let off, it will eventually shift, but I have to be gentle with the gas or it'll drop into 1 if I'm in D. When it gets beyond the appropriate shift point I hear a kind of clattering noise (ala Paul Bunyan's 10-speed-bicycle's hub coasting.) When slowing for a turn when it would ordinarily have dropped down no lower than 2nd, it goes to 1st. If the shift occurs it's fairly violent, i can hear the belt screech. No codes on the computer, (I checked with my scanner deal -- just 2 P1443's from some darn emissions thing) and no flashing O/D light.
I can start in 2nd gear and it seems to hold the gear fine, but if I want to be in 3rd I have to let off when I move the lever to D or it will drop to 1st. Kickdown from 3rd seems a little odd but I haven't played with that much for fear of over-revving the engine and having to do the whole driveline at once. 3rd-OD seems just fine and the OD-off mode doesn't seem to make any difference to it. Forward/reverse shifting/engagement is also OK (I verified that rocking the car out of a stuck on wet grass and slight incline!)
The dipstick end feels quite hot, as does the fluid -- it's in that range where 1-2 seconds of touching it is okay but not 10. I did take the car on a highway trip today so it was still all warmed up when I made the short trip when this problem really appeared (and on that longer trip it did do one 1-2 where I was yelling "WTF" but I made the remaining 60% of the trip without any more incidents and not babying it.)
Any ideas on what to do with it? I was figuring fluid for starters but I've gotta limp the thing 150 miles home tomorrow somehow. I knew I should have driven the Dodge today...
1996 Ford Thunderbird 4.6L/auto, 195k miles, semi-retired
2005 Dodge Dakota Club Cab 4x4 4.7L/auto
2015 Dodge Challenger R/T 5.7 Hemi/auto
Gone but not forgotten: 1973 Mercury Cougar XR-7 351C-2V/FMX - 2010 Dodge Challenger R/T 5.7L/manual
Last edited by ptschett; 06-11-2005 at 10:54 PM.