Had occasion to drive a '90 (3800 "C"/4T60) with rather high milage (closer to 200k than 100k) and the transmission seemed to be slipping as if it had a high stall converter. On our cars if I put it in gear on the flat, idle is good for 3-5 mph. This one needed to rev to about 1500 rom before it would move at all. Had not seen this before, anyone know what would cause (besides low trans fluid) ?

When was the last fluid flush?


-justin

No idea, possibly never. Was a car I went to look at & supposadly well maintained but no knowlege other than high milage. Lofs of little things wrong indicating limitied maintenance. Just had never seen a 440T4/4T60 do that.

Mine does it, and its a PITA. A big pain.. It scared the crap out of my g/f the first time she road with me, because if the conditions are just right, I can get it to rev to 2500rpm and not move. This is on a slight incline though.

First step, grab some seafoam transtune, i've got some in mine, and I was only able to start the car and run it through the gears.. but they were instantly smoother. I have yet to drive the car like this though [brakes are still being fixed]. Put some magnets on the pan. I am using a combo of strip magnets, and those circle ones... both seem to be the same for me, but my whole pan is pretty much covered in magnets, just in case. Drive the car at least 25 miles. Seafoam suggests 5 miles, but more can't hurt, and Bill suggested 100 miles, so pick your distance. Then flush the tranny, grabbing some cheapo ATF [non-synthetic, dex II], and flushing the tranny through the cooling lines.. you don't have the "resident gearhead" for no reason, you can figure it out from there .


-justin

Can do a lot of things but two I leave to professionals: automatic transmissions (other than R&R) and a/c.

Wow, that big of a difference. Incase you didn't know about this test...Hold the brake down as hard as you can and press the gas, as long as you don't overpower the brakes the rpm'* will stop climbing where your TC is stalling at. Don't do this for more than 5secs though. The other way is flash stall, slam the gas from a stop and see where the rpm'* jump to. First way is easier though

My tranny slips A LOT, mine goes up to about 3500 rpm. If your brakes can't hold the engine back.. you either have really crappy brakes or you have waaaay too much toque, and I hate you! loL.

I like the second better, that jumps right to 2400rpm.. then she starts pulling, and VINTAGE 3800 performance kicks in


-justin

I figured i'd add my little opinion, after going for a spin around the block. I manually shifted today, and I was able to chirp the tires with 3/4 throttle at a stopsign. I tried the brake torquing in OD [at a standstill, in first gear, supposidly], and it went up to 3200 with the engine warm. I put it in first gear, and it revved to 2300rpm. I thought.. hmm, that'* strange. I did the take off trick, and got 3400 in OD, and 2500rpm in 1st. So, now that has me wondering if this will help you in anyway. I will be looking at my FSM this evening, and see what it says. That trans-tune stuff is AWESOME! My shifts are MUCH smoother, and it took almost 4 seconds for 1st gear to engage, and its not instantanious. Use this stuff, you won't be disappointed!


-justin

Just tested with the 88 since could give exact numbers. 700 rpm idle, 5 mph in drive or reverse on flat. With hard brake rpm flashed to 2675 rpm. All stock and about 50K miles.

Car I was looking at (and decided to pass on had 160K+ and did not move at all when brake was released at idle, had to give gas to 1200-1500 rpm before it would begin to move.