97 850R tranny rough shifts, new fluid? Lucas slip additive?

sacricide · Post by **sacricide** » 15 Mar 2015, 21:55

i have a 850r that has a rough shift tranny, it has 146k and the fluid looks like it's been changed since it's not dark or brown. it works fine without hesitations but it has hard shift under heavy throttle in a few gears. I'd describe it as kicking . Also it kicks shifting to reverse. I'll drive it as is until it completely goes out since it might last a while as it is. So I know I'll need to replacement rebuild it to truely remedy the issue. Fluid is clean and pink in color. I heard that replacing the fluid with new fluid is a bad idea on a OLD tranny and can make it even worse, is that true? And I'm considering using Lucas addictive in hopes it could make it behave a bit better. Is it worth a shot knowing I'll need a new tranny later anyway?

Any thoughts and explanations would be appreciated I've searched online for ages with literally no insight, some advise against lucas slip additive, and some claiming it helps with high mileage transmissions

Post by **jreed** » 16 Mar 2015, 05:04

I would also check the motor mounts and subframe bushings to make sure that the engine is not shifting around too much.

Post by **Ozark Lee** » 16 Mar 2015, 07:09

Replacing the fluid through a series of drain and fills never hurts but there are cases where a full flush, particularly one that uses a flushing machine, can cause seal leaks. I'm personally pretty neutral on transmission additives like the Lucas stuff. They rarely do much if anything good but at the same time I haven't heard of them doing anything bad.

The only "Miracle in a Can" product that has ever worked for me is Valvoline Automatic Transmission Stop Leak used on a power steering rack. Some of the canned products are really bad like radiator stop leak and the canned head gasket repair products but I haven't heard of bad things after any of the transmission related products other than some wallet pain.

jreed's idea on the motor mounts is a good one.

...Lee

sacricide · Post by **sacricide** » 17 Mar 2015, 11:55

I'm checking everything this weekend. But if the mounts look good, I suspect they are, I guess there's not much left to do? I checked the fluid on a white paper towel last night again and its suprisingly fresh looking. Not even sure adding new fluid is Going to do much now.

Post by **erikv11** » 17 Mar 2015, 12:59

Maybe they put in the wrong transmission fluid? Long shot but worth a try, you could change it out with some cheap Dex III ATF for not much money. Super Tech from Wal-mart would be fine, it is what I use all the time.

sacricide · Post by **sacricide** » 17 Mar 2015, 16:56

thanks for the TIP, i assume this is the one your talking about

http://www.walmart.com/ip/Super-Tech-Au ... d/16213433

the price is really cheap, i might as well do this first considering its no wallet breaker. thanks

Post by **erikv11** » 17 Mar 2015, 17:01

That's the stuff. Also Sam's club is sometimes even cheaper, their product is packaged differently but may be the same thing.

sacricide · Post by **sacricide** » 20 Mar 2015, 18:41

quick update, on my second drain and refill. i poured in 4 quarts for both. The first time i drained it, it was nearly 4 quarts. unsure what the true SPEC for its capacity there. if it ends up measuring a little too high ill prob even it out on the last Drain and fill.

unfortunately i haven't felt any difference in performance, however the fluid while red at the dipstick is murky brown after its settled down in the pan after it drained both times. Odd but not as clean as it appeared. I'm assuming this is what happens when your tranny has no filter.