starting last week, my trans started shifting softer. now, it's important to note that nothing is slipping. i'm not throwing any codes or anything like that. my trans used to have decent bite on the 1-2 shift. now, it just feels softer. it's just as fast as usual, but there's no kick. it just shifts and you don't feel it much. the 2-3 shift has the same or more kick than the 1-2 shift...when i'm going in a straight line. however, if i'm turning the corner and it shifts during the turn, it has the same amount of bite as usual. it's really funny, considering my 1-2 shift always had pretty decent bite to it and was really nice and firm under heavier throttle. now there isn't really any bite at all in the 1-2 shift, even shifting at 4k

now, it's important to know that last week, i swapped out my stock steel driveshaft for an aluminum race driveshaft. the driveshaft feels about 20 lbs lighter than the stocker. also, the yoke needed to be greased up because it was a tighter fit than the stock yoke, obviously since it didn't have 35,000 miles worth of wear on it. now, would taking 20 lbs off the driveshaft account for the softer shift? should i have anything to worry about? again, everything is shifting fine, no slipping or driveability problems. the shift is just a lot weaker and a lot less satisfying. it feels like a damn 4 cylinder shifting. no ***** at all. this problem didn't start until i replaced my driveshaft with the lighter one. does this make any sense?

 

Well just a theory but the lighter weight drive shaft would have less inertial resistance and that could reduce shift shock to a certain level remember it does take more energy to increase the rate of rotation of a heavier object and thats would make for more shock to the drive train

 

that's what i was thinking, but wouldn't that meant that the people with stock aluminum driveshafts (3.23 geared A4's) would have weaker feeling shifts than the people with stock steel driveshafts (2.73 geared A4's like me)? people say the 4L60E is a hard shifting trans by comparison to most stock trans's out there. i want my tougher shifts back

 

FWIW, my 3.23 auto shifts felt the same as my 2.73 auto shifts when both were stock, firmness wise. Both were actually quite firm for a stock auto, as you mentioned.

Howeever, I beleive the stock steel driveshaft is only 11-12lbs heavier than the stock aluminum shaft. So if your new shaft is actually 20lbs lighter, that's a much bigger differeance than what it would be from the stock steel to the stock aluminum.

 

Swap it back and see if it firms up. If it does then go back to an aluminum and put a shift kit in. I did my transgo and drove it for about 2 months before the converter swap and you had to be ready for that 2nd shift. I did two washers but it was way different then the stock shifts that is for sure.

 

That sounds like a plan , and 20 lbs with a rotating mass would be a big difference in the inertial factor

 

i have no idea how heavy the shafts are. i just picked up one, put it down and picked up the other. it sure felt like a pretty big difference in weight. at LEAST 10 lbs. this is a race aluminum driveshaft, so i'd figure it would be heavier than the stock one. who knows, but it was a pretty significant difference in weight. the fact that your 3.23 auto shifted the same scares me. i have no idea why my shifts softened up so much.
i don't have the old steel driveshaft. i tossed it. it was pointless to keep it IMO. i had no use for it, and i didn't wanna keep it in storage. also, it wasn't worth selling it on ebay. no one would want that big heavy weight. even if someone bought it, the costs wouldn't cover the annoyance of selling it. i also am leery of ever installing a shift kit. having someone mess with my valve body scares me, and i have no well known tranny shops in my area that i feel are trustworthy, not to mention the big installation costs of the shift kit install. besides, i hear to fully appreciate the shift kit, you gotta remove torque management, and i don't want to because of the extra wear my tranny will suffer.
20 lbs estimated. the fact that RPMWS6 has driven both the stock aluminum driveshaft cars and the stock steel driveshaft cars felt the same makes me nervous. it makes me feel like it's just a coincidence that it softened up at that time. i haven't gone WOT in 2 or 3 weeks. i can't see how anything could have happened to it. i haven't raced it in months, too it used to shift even firmer when it was cold. even cold, it shifts softer than it used to when it was warmed up fully.

 

vince PM'd me and stated that it's possible if airflow was obstructed, or if i have a K&N filter and oil got onto the MAF, it's possible the PCM could lower line pressure to the trans. i looked at my air filter and what i got was a big surprise. my air filter had about exactly 10,000 miles on it, and i check it every 1,000 miles or sooner and blow it off often. however, when i pulled it out, the metal mesh on top was dented to hell! it was all crumpled and looked like someone banged it with a hammer! i check this filter every month and have never seen this. it's always perfectly straight on top.

i went to napa today and put a new napa gold paper filter in. trans is still shifting soft. however, when i'm making a wide LEFT turn and the trans shifts 1-2 during the turn, i still get that nice kick in the pants i always had before. this leads me to believe that it is the new light driveshaft that is causing the weak shifts. maybe the yoke is still very tight. we had a tough time getting it to bolt up since it was so new, and we had to grease it up to get it in there. it just feels like the trans isn't hitting the rear as hard. maybe this is a good thing? time will tell. i'm just confused as to why the 2-3 shift feels the same or better than the 1-2 shift.

anymore ideas, anyone? has anyone else replaced their steel driveshaft with a lighter driveshaft and had their shifts soften?

 

Choco,

Have you checked your trans. fluid level...?

Did you clean your MAF sensor...?

Joe

 

trans fluid is fine. red as kool aid. just checked it today. i just changed it maybe 4,000 miles ago.

did i clean the MAF sensor? no, but i did when i put my FTRA in a few months ago.

 

i went from a stock steel driveshaft to a stock al driveshaft and noticed no difference. i think you have a problem with the trans or a mount or something...be sure to double check all of your work with the driveshaft r&r. did you remove the torque arm for any reason?

 

nope. took out the old one, greased up the new yoke (which was a very tight fit) and bolted it back up, all done on a lift in about 5 minutes. piece of cake. i was getting my whole exhaust system retorqued and lifted up a bit because it was banging at my buddy's brother's shop and he offered me this new driveshaft with less than 500 miles on it for $200, so i said fine and he put it in for me in no time.

 

Just seems odd that this issue would happen immeaditly after swapping driveshafts. Seems like that must be somehow connected. Since you don't have the stock one to swap back for a test, I guess you'll just have to wait and see what happens.....

 

i know. it's kind of like watching a forest fire near your house. there's nothing you can do about it. all you can do is hope it goes in another direction. i feel like it's gotta be SOMEHOW related to the driveshaft, or else it would be one hell of a coincidence. vince PM'd me and said if it's a transmission problem, sometimes the 1-2 accumulator pistons crack since they're plastic and that will cause a softer shift. if it goes unattended, you'll eventually smoke your clutches. he said a set of aluminum ones can be had for some $10, and it's no more than an hour's labor to change them. i'd love to get it done, but i just spent $700 on the damn car and i don't know of any competent tranny shops in my neck of the woods. plus, if i get someone to do it, then i'm gonna have to pay for more fluid, a new filter...it's gonna be another $200 bill and it may all be for nothing plus, i have no time for the car to sit at a shop again. argh!

 

How is the level? Asking because I had my transmission flushed over the summer and the tranny was shifting weird after the flush (would shift at 5900 instead of 5800 at WOT). 2 days after the flush, checked the level and it was a lil low, added more fluid, and the tranny is back to the way it was before the flush ever since.

 

well, the filter and fluid has been changed a few months ago. i checked the fluid today, but not so much the level, as i checked it while it was turned off. i know you have to check the tranny fluid in park while the engine was running. i will do that wednesday.

it's important to tell you the tranny was not flushed. it was a simple fluid/filter change. i'd be wary about flushing a trans.

i CAN tell you that when i originally changed the tranny fluid, the fluid level was a bit high. it was overfilled a tad, maybe an inch over the line. it shifted easier after the fluid swap as i didn't fill it as high. still though, it was a pretty decent shift.

but like i said, i'll check wednesady. i'd check tomorrow, but i will be in philly until 11pm and it'll be dark out by the time i'm free

 

Well all of the advice you are getting sounds competant. The orignal pistons can crack and the unit will go downhill soon thereafter if it is hammered on. The fluid level is crucial. The aluminum driveshaft will be much lighter and at the same time stronger than it's steel counterpart. That can change the feel of the shifts in the seat of your pants. But I too question that deduction.

One thing you mentioned is that you had your exhaust retorqued. If it was hitting the floorpan the PCM can and will see this as a misfire. This will affect the EPC output.

Was your battery disconnected at any point recently? If so your PCM is probably in a relearning cycle. But really though, there is no one in your area that can understand and diagnose this condition? Really?

Oh one more thing... don't make the mistake of taking it through a violent WOT until you understand the problem better. There is always a cause and effect when any vehicle becomes symptomatic... do yourself a favor and don't contribute to the severity of the effect.

g

 

i don't hammer much on the car at all, and since the "problem" happened right after the driveshaft install, it leads me to believe that it's not a problem with the trans. also, since it shifts as firm as it used to when i'm making a turn, that means to me the trans is shifting fine, and it's the way the power is hitting the rear that is affecting the SOTP feel of the shift

the exhaust was just rattling in reverse and i had a vibration at 50mph. it wasn't like it was banging against the floor during cruise or over bumps or anything.

i don't think it was disconnected at all recently.

too late. for the first time in a few weeks, i went WOT today. i threw it to the floor at 30 mph so i could make sure the trans wasn't slipping on the 1-2 shift. it shifted right at redline, perfectly. i think that the shift softening at the same time the new, tight, light driveshaft was installed is too much of a coincidence. the only part that troubles me is that the 2-3 shift still feels the same. i'm going to check the fluid soon to make sure it's at the proper level.

 

Check the fluid level. It's too low. DON'T go WOT with it being too low. You WILL smoke the transmission. It's OK to run it a little overfilled, not OK to run it underfilled.
Rob

 

the trans felt a little better today for some reason. driving it, when it was cold (meaning when i just pulled it out of the driveway), shifting from 1-2 at only 1600 rpm's still pushed the car forward, just like it always did. it felt more solid going in a straight line, also. again, the yoke was VERY TIGHT fitting into the transaxle, so perhaps it was absorbing the shift shock i normally felt? perhaps when the yoke wears, the trans will feel like it's getting back to normal. i'll keep an eye on it over the new few hundred miles.

i will also check the fluid level tomorrow with the trans warmed up in park.