3rd Gen / L98 Engine Tech 1982 - 1992 Engine Related

What could be causing my soft shifts.

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Old Mar 25, 2003 | 06:44 PM
  #1  
Momar's Avatar
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From: Decatur
What could be causing my soft shifts.

Ok, here's the deal. I have a 85 trans am that I had the transmission completely rebuilt in and it had a B&M shiftkit installed at the time(I know, I know, but I hadnt heard anything bad about them at the time). Anyway, this was back in the 305 days. just got the car going again, but in the time the car was down(about 16 months) I put a corvette servo, larger boost valves, a B&M cooler, and Mobil 1 Synthetic. The car was only driven probably 3 or 4 months after the shiftkit until the motor went. It now has the 350 in the sig, along with a 3.45 posi rear and Potenza RE730 tires. Is it possible that the servo or boost valves being istalled wrong could cause this? I think that they are right, but just want to know what could cause this.

Now for the problem. I took it out for the first time and when I drove it it seemed to pull pretty good and it doesnt seem to rev up between shifts or anything(that I can tell so far because I have only driven it a few minutes), but it doesnt chirp the tires on the shifts anymore. It still seems to shift fine from what I can tell from driving it around the neighborhood other than not being as firm as I want at full throttle. I put a 3000 stall in it so I know that the shifts wont be as firm as they were at part throtle but that is fine. I reset the tv cable today and took it out for another quick drive but it seems to be the same.

I dont think it is a lack of power because I had a worn out LG4 before that wouldnt even lite the tires up from a stop and now I can lite them up pretty good from a 10+mph(speedo isnt wired up completely yet) roll.

Also, I know you are supposed to check the tranny fluid when it is warmed up, but I have only driven it twice so far. I think my fluid is right about at full when cold, but I dont havent got a chance to check it hot. Would it be higher or lower? I would think higher, because I thought stuff expanded when hot but am not sure.

Does anyone know what my problem is?

Thanks

Ben
Old Mar 26, 2003 | 07:33 AM
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From: Decatur
ttt
Old Mar 26, 2003 | 10:25 AM
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i was thinking about putting a B&m shift kit im my camaro my self, and i think i heard you say you put it in before you heard all the bad things about it, what bad things did you hear about them?? cause i don't want to put it in if it is going to mess up my car? any suggestions about it would be greatly appreciated thanks!!!
Old Mar 26, 2003 | 01:14 PM
  #4  
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Well, over on thirdgen.org, they sware by transgo. They say that B&M is just hard on the tranny and doesnt fix any of the problems it already has. I think that for the most part that there are a couple of people that know what they are talking about over there and everyone just repeats what they hear. I have also heard a couple people that really disliked transgo. I can say I liked mine, and it did fine until I stoped driving the car and I did some things to it and now it didnt seem to work like it did. I dont think that the problem I am having is because of the shiftkit. I also have seen some people with cars in the 12's and even some in the 11's that havent had problems with B&M. Whatever you do I would make sure that whoever installs it knows what they are doing, and if you install it to do everything exactly like the directions say. I also still plan on checking the fluid level when hot to see. I have only driven the car 1 mile or less so far so it is kind of hard to tell. I guess it could have worked some of the fluid around and actually may still be low on fluid.

If anyone has any suggestions I would really like to hear them.

Ben
Old Mar 26, 2003 | 01:31 PM
  #5  
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A guy on thirdgen told me that his transmission shifted increadibly soft when he first had it rebuilt and started shifting harder after he put some miles on it and the fluid soaked into the friction material. I hope that is what is going on with mine.

Ben
Old Mar 27, 2003 | 08:45 AM
  #6  
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Your 3000 stall converter is why it isn't chirping the tires. Your no longer multiplying torque at low RPMs, you're now doing it at 3000 which is not going to bark tires, it's just going to throw you in your seat every time you upshift.
Old Mar 27, 2003 | 01:29 PM
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Well, that was the thing is it wasnt even throwing me back. Not to worry though. I just took it for a drive and it was a bit better. I then came back and checked the tranny fluid while hot and in idle and it was pretty low. I filled it up and took it for a drive again and it kicks me back in my seat pretty good on the shifts now.

Thanks

Ben
Old Mar 27, 2003 | 02:25 PM
  #8  
insomniac 92z28's Avatar
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700r4 trannys are weird.
One will shift good and another setup the same will not. I have a friend who runs one behind a 425hp 475ft. lb 400 sb in a 4wd truck and it is nasty. Shifts like mad and never slips. So I took it to the same (very reputable) shop and had mine rebuilt to the same specifications but it is not nearly as stout. I think old lady luck plays a big role here.
JMO
Old Mar 27, 2003 | 04:09 PM
  #9  
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Well, mine had been real nice. It is again now. It just was low on fluid. Makes a big difference. She really kicks you back in the seat now. The powerband on this cam is supposed to peak around 5800 I think and I have only had it up to 5000 so it could be interesting. Sure beats the heck out of the old LG4.

Ben
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