tranny recommendations please - harsh shift

[briandors]

Hello.

1995 CS Convertible, 3100 engine.

I bought the car at 118k, it was on its second transmission. Mileage now is 143k. I have topped the tranny off slightly once, but there aren't any leaks.

 

My only complaint is that the 1-2 shift is harsh under normal driving throttle. If I accelerate VERY gently, the shift feels good. If I accelerate WOT, shift feels good. In between, the shift is jerky, and the whole car kind of lunges.

 

I have replaced the vacuum modulator with a brand new one, from GM. I don't think it did much of anything.

 

I do not know what mileage the rebuilt tranny was put in. If I had to guess, based on what the previous owner told me, it would have been around 80-90k. Fluid color is good.

 

Do you guys recommend me changing my fluid and filter? I was thinking of using non-synth DEX III. I was just gonna drop the pan and refill, not a flush.

 

I read someone's post saying this symptom could be valve/spring related. More info on that would be appreciated.

 

Basically, this is car #3 in the household. I simply don't want to put serious money into it. If I can improve things through a fluid change, great. If not I'll drive it like it is (especially if a fluid change could make it worse).

 

Thanks

Brian

[Justin]

I'd recommend an actual flush in place of just dropping the pan, then you know you can rule out fluid. If possible, let the trans flush additive circulate in the trans for a while, like a week, then get the fluid exchanged. It gets a lot more garbage out that way.

[THe_DeTAiL3R]

My tranny shifts really hard 1-2 under moderate-hard acceleration as well. However, my tranny fluid was burnt, and when I dropped the pan there was metal shavings and grey goop from the clutch. I'm gonna have it looked at on Saturday...

[DaveFromColorado]

I'd recomend droppin' the pan, changing the filter, adding new CHEAP Dex-3 and then getting a trans flush, that way, you know you've got all your areas covered.

 

as for letting the trans flush stuff run for a week, that can actually be bad for the seals, because it's got a seal conditioner, which when used for a SHORT period of time, allows the seals to swell a LITTLE bit, added for too long can cause the seals to swell too much and create more problems.

 

--Dave.

[Canada]

Fluid and filter change will not solve your problem. It sounds like you have something sticking slightly inside the valve body.

[briandors]

Ok, thanks guys. Maybe I'll take it to a tranny shop and get an estimate. If it's a sticking valve maybe it won't be too expensive to fix.

[DaveFromColorado]

all the detergents in transmission fluid can USUALLY loosen up those sticking valves, which is why I recomended both a pan-drop change, and a full flush afterwards - USUALLY that can fix those harsh shifting problems - but every now and then, it can make the problems worse.

 

--Dave.

[briandors]

Hmmm, "fluid and flush won't help"... "fluid and flush usually will help"... I guess it makes sense that fresh fluid with detergent cold loosen up a slightly sticky valve. Seems like a flip of a coin, but since it's a good, cheap place to start, I'll try a fluid change, followed by a flush, followed by a visit to a tranny shop.

[ShockTherapy]

backflush it, make sure you have CLEAN fluid, then grab a few tires, and back up next to a house, and leave the car in reverse for 20-25 minutes, it'll essentially backflush the valve body. it's the evivalent to driving in reverse for 30 miles. this usually helps on most cars. then have the old fluid flushed out with the good stuff.

[THe_DeTAiL3R]

backflush it, make sure you have CLEAN fluid, then grab a few tires, and back up next to a house, and leave the car in reverse for 20-25 minutes, it'll essentially backflush the valve body. it's the evivalent to driving in reverse for 30 miles. this usually helps on most cars. then have the old fluid flushed out with the good stuff.

 

I'm almost tempted to try that!!

 

 

 

IMO, if you think your tranny has issues it's best to take it to the pros. Sure, you can spend $10 on new fluid, $15 on a filter kit, but if that didn't solve your problem then you really just wasted some time and money. I'm going to Mister Transmission (i dunno if they exist in the State or not) but they do FREE diagnosis and have fancy scanning tools that smaller tranny shops don't have. Tomorrow I'll know what's wrong with my tranny (or at least how much it will cost to get fixed).