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? about D or OD

George_Pimpdaddy

George_Pimpdaddy

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I was wondering if it would be okay to drive in Over drive in my dd 89 blazer in the city so like should i be drivign it in Drive only then shift to OD for the faster 80km/h or is it acceptble to leave it in OD for the softer shifts and less rev's? thanks for any anwsers
 
leave in drive, od is for highway speeds, (not quite sure 80kmh is but i use od at 55mph or faster.
 
I don't think it would hurt it any to leave it in OD . I have done it in my 83 when I had 31's , then D only when I had 33's and 3.08's , then back to using OD when I got 3.73's . And then when I had 35's and 3.73's went back to using D only . Now I am full circle and back to using OD with 4.56 and 35's .

Doubt it would hurt anything , if you DO NOT tow in OD .
 
thats what i was hopin its a freshly rebuilt and built up 700r4 with hd sprag shift kit and corvette servo and what not and i got 31" on my stock 10 bolts for now with a posi in the rear. I do alot of city driving now with the blazer and was hoping to be esier on it by using od more often. The big hills around here i do switch to Drive.
 
On a big hill , you give it some gas , and it shifts on its own . Or yes you do shift down yourself . Best bet is to read the owners manual ( sold on Ebay ) .

I am ( knocks on wood ) still hanging around on the 700r4 that was in my 83 when I bought it . And by CK5 standards , should of killed it 80,000 miles ago :wink1:
 
i run my 700r4 and 4l60e in OD all the time, unless i'm offroad, towing (very rare) or hauling something really heavy.
 
pauly383 said:
On a big hill , you give it some gas , and it shifts on its own . Or yes you do shift down yourself . Best bet is to read the owners manual ( sold on Ebay ) .

I am ( knocks on wood ) still hanging around on the 700r4 that was in my 83 when I bought it . And by CK5 standards , should of killed it 80,000 miles ago :wink1:
Click to expand...

I know a lot of 4L60's and E's that have given up before 100K and they're supposed to be better than the 700's? I got 240K out of my 700 before the convertor went, and took the rest with it. And I only got 110K out of the 60E in my 95 Burb..I did a lot of towing with the 700 (only in D) and the Burb never had any towing til I bought it at 102K. Catastrophic internal failure while in the Black Hills on Vacation at 110K.

Anyway back to the thread....I would use OD if you regularly drive over 80km/h. Otherwise I think you will see a lot of up/down shifts.
 
Hijack on

Which is OD and D? Is OD the D inside the square or is OD the D ?
I know its a noob ? But thats because im still a noob:D

Hijack off
 
od is the d in the square.


as you can leave your truck in OD for anything but towing a good size load, part of the electronic part in your trans, is knowing when od is needed and when it isn't if you're in the city you're probably not using it.
 
I'll jump on the bandwagon with my 2 cent addmission. You could just use the OD, and if you feel it hunting back and forth bewtween 3rd and OD excessively, then shift into D.
 
Exactly. Problem with the TH700 is gear hunting. My '83 with 3.08's and 31" tires would go about 50MPH on flat ground without hunting in OD. Anything less MPH than that, the slightest throttle would downshift.

Doesn't matter if you race from a light or not in OD, you aren't getting to OD, and it's not hunting gears.

Other problem is the torque converter clutch, unlocked it generates heat, a good tranny cooler helps, but again, hunting gears keeps it locking and unlocking, generating more heat.
 
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FWIW, I cruise around town in D only, and save the OD for the highway. I find that my tranny likes to drop into OD any time after 60 km/h, and in everyday city driving the tranny will be constantly switching back and forth between D and OD. It doesn't harm the tranny to drive around in D, anyways.

Regardless of what you choose to do, make sure you install a good quality stacked plate auxilliary tranny cooler on your truck. 700r4s hate heat.
 
To clarify, the way the trans shifts (firmness, at what speed/rpm, etc..) does NOT change when you have it in D or OD. The only difference is that if you put the shifter in OD it will allow the trans to shift into 4th gear (OD).

So for "racing stop light to stop light", it would make absolutely no difference. First of all the trans will never shift into OD under full throttle (unless the kickdown function was modified), and even under heavy but not full throttle I doubt you would ever get going fast enough between stop lights to shift into OD.

The transmissions were designed and tested to be left in OD all of the time, so just leaving it in OD really won't hurt anything but could slightly decrease the overall lifespan of the trans...keep in mind this if for a stock setup (ie. mainly small factory tires). The problem is when you start putting even slightly larger tires on but don't change the axle gearing you get in a situation where the engine is in too low of an rpm range to have enough power to pull the tires at low speed, and therefore you get it constantly shifting in an out of OD. In this case you should leave it in D around town, or anyplace that you can't maintain 55 mph + for long periods of time. But with that said, it also does not hurt anything to put the trans in D around town with any setup because you won't be turning that high of engine rpm at 15-30 mph.
 
I know a lot of 4L60's and E's that have given up before 100K and they're supposed to be better than the 700's?
Click to expand...

my '82 700 has about 267K on it. still going. but a friend's '86 tanked at 95K.my 4l60e needed a rebuild at 120K because the PO was a moron and tired to put "performance" parts in it. well, he used cheap junk and didn't upgrade everything he should have. my friend's 1996 4l60e lasted about 220K with drag racing and daily driving in dfw (hundreds of miles of stop-and-go driving every week). and the 4l60e lasts very well in the lighter vehicles, like f-bodies, vettes and s-10s, but that's a little different situation.

i think tranny life is more about how you treat it than what it is.
 
Chrisblazzer89 said:
Hijack on

Which is OD and D? Is OD the D inside the square or is OD the D ?
I know its a noob ? But thats because im still a noob:D

Hijack off
Click to expand...
Correct answer depends on year , the indicators are different . My 83 says "Automatic Overdrive" above the indicator . The shift pattern is P-R-N-D-3-2-1 .

Newer truck/ k5'S ,( MAYBE AROUND 87 ???)have P-R-N-OD-D-2-1-
 
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pauly383 said:
Correct answer depends on year , the indicators are different . My 83 says "Automatic Overdrive" above the indicator . The shift pattern is P-R-N-D-3-2-1 .

Newer truck/ k5'S ,( MAYBE AROUND 87 ???)have P-R-N-OD-D-2-1-
Click to expand...
yep yep...what he said.

Remington
 
6.2Blazer said:
To clarify, the way the trans shifts (firmness, at what speed/rpm, etc..) does NOT change when you have it in D or OD. The only difference is that if you put the shifter in OD it will allow the trans to shift into 4th gear (OD).

So for "racing stop light to stop light", it would make absolutely no difference. First of all the trans will never shift into OD under full throttle (unless the kickdown function was modified), and even under heavy but not full throttle I doubt you would ever get going fast enough between stop lights to shift into OD.

The transmissions were designed and tested to be left in OD all of the time, so just leaving it in OD really won't hurt anything but could slightly decrease the overall lifespan of the trans...keep in mind this if for a stock setup (ie. mainly small factory tires). The problem is when you start putting even slightly larger tires on but don't change the axle gearing you get in a situation where the engine is in too low of an rpm range to have enough power to pull the tires at low speed, and therefore you get it constantly shifting in an out of OD. In this case you should leave it in D around town, or anyplace that you can't maintain 55 mph + for long periods of time. But with that said, it also does not hurt anything to put the trans in D around town with any setup because you won't be turning that high of engine rpm at 15-30 mph.
Click to expand...

I gotta disagree with you here.
My 85 700r4 definitely shifted a lot harsher in Drive than Overdrive. After talking with a local trans shop (cert. niase) he said the fluid path was different when in drive, causing the harshness. And the TV cable was properly adjusted.
And if the OD was considered for permanent use, why does everyone (trans shops) say to never tow or haul even 2000lbs in OD?
Just my personal experiences with these trannys.
Your results may vary, check local listings.:D
 
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