DigitalMonarch0

As you can tell from the subject line, my car shifts a lot harder when it's cold. About a month ago I dropped my tranny down and installed a b&m shift improver kit and it is running great... but I find that it doesn't shift nearly as hard once it's past about 190*. Can someone explain to me why engine temp would have an effect on how hard the transmission gets into gear.

Also, my projects when I take the car out next spring are going to include swapping out my rear end gears and getting new ones. I can't decide whether I should go with 3.73's or smaller. Does anyone have an opinion? I know this is the cooling board, but it fits with my temp question so I figured that i'd kill two birds with one stone.

DigitalMonarch0

come on now, no one has any imput on this one?

DigitalMonarch0

input*

MechCD

I have the saem problem, but stock shifter and it only happens when downshifting to 4th or starting in 1st.

Zap Racing

As your engine temp rises, so does the tranny oil temp. Unless U have a weird system, the atf goes through the radiator to be cooled. It's normal for the atf temp to rise as does the water temp, so if it shifts better when cooler, add an external tranny cooler in addition to the normal system.

MechCD

Its the other way around, it shifts easeier warm, and harder cold. I probably need tranny work, but shifting doesn't grind or anything, its just a bit easier and smoother once its warmed up.

I have a 5-speed BTW, not sure about the original poster

Zap Racing

Maybe I misunderstood the original post-- when U sais it shifts harder--did U mean it has a more positive, solid, no slip shift, or did U mean it is harder to move gear shift lever from ger to gear?

DigitalMonarch0

When I said that I meant that it was a more positive, solid shift. It's enough to chirp the tires into second gear. After it warms up a little bit it tones down and feels less powerful. It's actually kinda nice that way because if I am in the car for extended periods, I don't always want it kicking me back into my seat. I was just curuous as to the cause of the change.

Zap Racing

Well that's pretty much normal as far as I know Both 89 IROC's I have owned do that. One was stock tranny 700 r4 and the other was a modified 700 r4. Although the second one shifts so hard it's hard to notice it shift softer, but I think it does!

Basically, what is hapening is that as the tranny oil gets hotter, U lose some internal pressure on the clutch packs. Same way that yoou have higher motor oil pressure when cold as opposed to when it is warmed up.

If U want the shifts to stay harder, put on an external cooler--if not, leave it like it is.

MechCD

Maybe I'm not describing my problem right.........

When everything is cold, it is "difficult" to get into reverse and sometimes 2nd and 3rd. AFter everything is warmed up, the shifter seems to almost pop in place by itself.

Now for the reverse thing. When its warm, theres no sounds, it just goes right into reverse. When cold, it clunks a few times. (usually once)

Then theres 4th. I haven't figured this out. Its smooth from 3rd to 4th, but going from 5th to 4th causes grinding noises, but it does go into gear without forcing it. If i go from 5th to 3rd to 4th, everything is fine also. My dad says a few times he went from 5th to nuetral for like 5 seconds and then 4th and it worked ok too.

Zap Racing

Are we talking about a 5 speed manual?

I feel stupid now--I thought we were talking about an automatic! DUH!!!

NEVER MIND!!!

DigitalMonarch0

We were talking about an automatic, you were very helpful. This guy is having a different problem.. somehow he ended up looking for help in my thread.. don't get his tranny confused with mine because they're two completely different situations.

MechCD

Sorry guys, I thought I was having the saem problem as the original poster. I'll probably start a new thread sometime

freestylzz

Digital, I have a B&M shift kit in my '91 GTA. I have also noticed that the auto shifts more agressively when the tranny is cooler. Take Zap's advice and add an aftermarket tranny cooler to your automatic transmission if you don't already have one. You can mount it directly in front of the engine rad. They are fairly small and inexpensive and will obviously allow your tranny to run cooler and provide you with better performance. It will also help prolong the life of your transmission.

Air_Adam

For the 5 speed guy...

Its hard to shift because the gear oil in the tranny is still cold, which thickens it up.