my 92 automatic has stock 2.59 gears.... which are WEAK. I'd really like to change them out to 3.45 or 3.54 but the HUGE initial expense and the resulting disadvanages (such as gas milage) are sort of putting me off. So i'm looking for a cheaper alternative

Today while cruising a bit I decided to what it was like if I put my car into 3rd instead of 4th... WOW. I noticed a big difference. Torque was greatly improved. I tried 2nd and it was even better.... but I didn't do any driving about 30 in 2nd. I did however cruise for a few miles at 60 mph in 3rd gear. Everything seemed to be going ok... My question is this: Are there disadvantages to this? Am i going to ruin my transmission if I do this over time? What about downshifting while driving.... like when I slow to 30mph shifting out of 4th into 3rd???

If this is OK for my tranny I think I can live w/ the gears I have.

I'm also considering a shift kit. I know transgo is highly recommended. Will this increase my low end performence? I know kits cost around $150 but how much to have one installed?

I know gears are the way to go..... but after the gears, the install, the speedo correction and the upgrade to a new rear end .... i'm looking at major $$$$ So i'm looking for another solution.

thanks

 

There is no problem driving your vette in 3rd instead of OD. Just don't drive over 100 in 3rd all the time :D. That would keep your engine reving pretty high. I drive in 3rd all the time... only use OD for highway driving for gas mileage.

A shift kit would be good, but don't do it on a high mileage tranny.

Gears aren't going to cut your gas mileage in half, so I wouldn't worry too much about that. You either want speed, or you want fuel economy. My thought, screw fuel economy.

If you want to have some really good power around town.. drive in 2nd :D. I wouldn't do this a lot though.. puts strain on your tranny and engine during deceleration.

 

Ive been told that downshifting when you are off the throttle and at speed is really bad. "Normal" downshifts done by the tranny with the hammer down don't hurt anything.

The reason given is that the load on the clutches is high and the fluid pressure is low. That lets the clutches slip and burn.

I believe the 4-3 downshift has a few more things going for it that may lessen the effect.

I would suggest that you keep checking 'till you get a good answer from a real tranny guy. Those things aren't cheap.

 

Here is something to consider. The aspect we always look at when considering a rear gear change, is the torque multiplication. Another thing to remimber is that the lower the gear ratio is, the less load is on your transmission, and engine. I have a 2.59 gear, and my tranny just went out AGAIN :mad and I will replace my rear the same time i rebuild the tranny. A 3.59 gear, would reduce the load on your drivetrain significantly. That will shift the wear on the tranny to the bearing surfaces as opposed to the clutches, becasue the tranny will turn more RPMs. Just something else to consider.

 

Downshift with off throttle also requires the transmission to push the engine rpm up because of the downshift. Manual transmission guys should rev the motor before engaging the clutch if down shift is will require the engine to be running over 2500 - 3000 rpm.

I think the 92 auto is computer controlled. If it is, you should get your computer shift points adjusted to make the transmission more performance oriented. The trans is designed to give max gas mileage instead of reponding to the drivers needs. I have had several 700R4 cars and I really hated the way the transmission worked. The gear spacing sucks too. GM needs to dump the trans and go to 5 speed auto like a lot of other companies have done. I drove a BMW 5 series V8 with one. That trans was great.

 

If I get new gears do I NEED to replace my rear end? I'd only have about $1,000 to spend on all of this, that's why I'm considering a shift kit instead. Besides the fact that you can set your car up to act sort of like a manual.... which I'd like (I wish it wasn't SO hard to find a manual transmission vette!!! I found an auto I fell in LOVE w/ so I had to buy it ) My transmission was totally rebuilt 15,000 miles ago so I should be ok.

I'm pretty sure that my tranny is NOT computer controlled.... can anyone tell me for sure? If it IS computer controlled can't I just reprogram it to shift at different points?

I know that I shouldn't downshift while I'm driving 50, but if I slow to 30 or 20 would it be ok? Or should I just stop?

Just to clarify... driving 60mph in 3rd is ok... and even driving around town in 2nd sometimes is alright correct?

And finally... I don't really understand. I'm not very mechanically inclined, but why is it that putting the shifter in 2nd or 3rd gives you so much more pull then putting it in 4th? A quick overview would be appreciated.

Thanks a TON you guys are a terrific help!

 

You don't have to replace the entire rear end to do a gear change. If you want to go to really low gears like 4.10 or something, you'll need to buy a new diff. carrier (Dana 44) which is more sturdy. A shift kit and gears are completely different things. The shift kit will only make shifts more firm.

The 4L60E tranny (computer controlled) was put in most Chevy cars in '92 I believe.

No, do not down shift n order to make your car slow down. Auto trannies are completely different.. it puts wear on it... manual trannies don't have near the wear put on them when down shifting. Just hit the brake.

Yes, driving 60 in 3rd is ok. I don't know if driving in 2nd around town is a great idea, because it does put wear on the engine and tranny everytime you you let off the gas and the tranny starts to slow the car. Brakes are made for a reason.. to slow the vehicle, not the tranny.

From my experience... putting it is 2nd or 3rd DOESN'T give more pull, it just keeps your tranny from upshifting, which puts your car in lower rpm's where there isn't as much power. After spending some time with the 4L60E diagrams in my service manuals, the only justification that I could see that 3rd would pull more than OD at all, would be that possilby the OD band or clutches aren't engauged at all. But I might be completely wrong on that.. those diagrams are pretty confusing.

 

1st pulls harder than 2nd, because a lower gear ratio, which provides more torque multiplication. same is tru with 2nd and 3rd, as wella s3rd and 4th

 

I drive around in D all off the time but I upshift to OD at 55mph. If the freeway slows down at around 40mph how can I downshift safely?