3rd gear on 95 sentra, is it ok to drive at high speed?

Neil · Feb 14th, 2003, 02:01 PM

Just wondering since the car seems a hell of a lot faster with the overdrive off in 3rd gear, even if it makes a lot of noise. Will it damage anything to be driving at 80+ in 3rd gear or wear anything out faster?

nissanracer805 · Feb 14th, 2003, 02:18 PM

on an automatic, third gear can take u to the fuel cut off

Equivocal · Feb 14th, 2003, 02:19 PM

hmm.. not sure what you mean here. Driving to get up to 80 in 3rd gear? I guess that wouldnt be too bad if your tryin to haul ass. But staying in 3rd while at 80 doesnt seem like a great idea. If im going 80 im in fifth.

Neil · Feb 14th, 2003, 02:46 PM

I thought i only had 4 gears on the 95 sentra auto, perhaps im wrong though. What happens is with overdrive off it revs like crazy then I put it on overdrive "essentially another gear" and it quiets down a lot and gets smooth but while its smooth accerlation blows big time.

Its just that overdrive had been sluggish it seems after my accident and accelerating hard when im around 70 is difficult with overdrive on. I really have to pound the floor to get it to accelerate like I want it to. Had the car checked out so nothing is physically wrong.

I guess I just wanna make sure that using no overdrive when going fast isnt going to screw something up. I dont have a rev guage on my car so I can't tell how high that is.

Equivocal · Feb 14th, 2003, 04:02 PM

yea Im no expert, but I guess overdrive is like 4th and/or fifth gear to you basically. I guess when you get up to 70-80 you could put overdrive on just to play it safe? I dunno maybe someone who knows a bit more then me can help. It seems essentially that when you take off overdrive, you are downshiting. that why its easy for you to accelerate, your revs are up.

BIGBULS · Feb 14th, 2003, 04:10 PM

You want to remain in "OD" for normal cruising, but feel free to manually downshift to "D" to get a little more punch (or do you just hit the "OD off" button, I can't remember?) for pulling up long grades or passing etc. The other option is to just use you right foot more to trip the downshift automatically.........

"D" (with the OD off) is for in town driving, and hilly regions.....the idea is to stop it from up and downshifting constantly to keep internal heat down......heat is the big killer of autos.

Neil · Feb 14th, 2003, 07:24 PM

Yeah most of the time I use OD because it just feels smoother, and many times I can just gun it to the floor to make it accelerate but sometimes just too slow. Yeah you just hit the OD button to turn it off and then it starts whining

I think when i drove through the pennsylvania mountains that was the worst. Its like 5+ miles of all mountain steep uphills and I had probably a few hundred extra lbs in the car with all the college stuff. I used the OD off on those but I was afraid my car would blow up

tsi200sx · Feb 14th, 2003, 11:53 PM

You're right your transmission is a 4-speed, if you turn off the OD it only uses the first three gear ratios, and depending on the tranny it may adjust the shift points on those 3 gears accordingly so it stays in each gear longer.

verno-dub · Feb 15th, 2003, 07:35 PM

If you are going to drive with OD off for extended periods, then I would suggest a trans cooler, just to be safe.

-verno

azkicker0027 · Feb 15th, 2003, 09:01 PM

od is actually torque converter lock-up, wherein the flexplate is running at the same speed as the input shaft and pump, why, doesn't the kick-down downshift the car properly???

himilefrontier · Feb 16th, 2003, 03:11 AM

It's actually a seperate gear.Torque convertor lockup is triggered by the computer or a hydraulic "switch" that locks it up under certain conditions.I had a GM TH200C 3 speed auto trans in my Olds with a lockup convertor,but no overdrive.I now have a TH2004R 4 speed auto trans which has both a lockup convertor and a .67 overdrive 4th gear.Variants of the same trans,but one has OD.So,they're NOT the same thing.I agree with those who said to turn it off when the trans is "hunting" for gear but use it when steady state driving.Otherwise you will wear out the clutch packs(when Hunting) or wear out the engine quicker.BTW, Sentra E's with GA16DE's had 4 spd manual trannies w/o od.Also(my this post is rambling!)some manufacturers also engage the TCC(torque convertor clutch) in 3rd gear.

Neil · Feb 16th, 2003, 01:20 PM

I'm gettin rid of the car after this year anyways, just sorta always wondered about it.

Why did nissan have overdrive in the car instead of just having a full 4 gear configuration then or was it just so that you have the option of shuttin the gear off when you need acceleration?

Feb 17th, 2003, 11:32 AM

Overdrive is 4th gear.

For instance, here's a GM 4T65-E's gear ratios

1st:2.921
2nd:1.568
3rd:1.000
4th: 0.705

Since 4th is overdriven (less than a 1:1 ratio), its called overdrive.

Most trannies will also lock up the torque converter in 4th gear, making a direct connection between the engine and trans (most of the time in an auto there is no direct connection, the fluid transfers the power). Some will do it in 3rd as well.

Anyway, it is not a good idea to drive in a lower gear like 3rd for high speeds for extended periods of time with an automatic. You will heat up the tranny fluid and kill your trans.

now in a manual, you can throw it in whatever gear you like, direct connection between engine and trans, and no need to worry about any of that junk!

azkicker0027 · Feb 17th, 2003, 04:25 PM

so that's why "real men drive stick......", although never ovelook the capacity of the clutch,flywheel, and pressureplate..........

Neil · Feb 18th, 2003, 01:39 PM

but the next car i get isnt going to have 100hp either so i wont have to worry about getting over a hill like i do now

i'll guess i'll be easy on the 3rd gear and use it as my little turbo button till i ditch the car. Thanks for the info!