700r4 Overdrive

[Subourbon]

I should know how to do this but recent artie readings indicate I might not.
6.2 diesel 4x4 1982 burban
I was told i could drive my truck OD constantly.
Gears are
P R N (D) D 2 1
(D) being overdrive.
So basically guy said yeah shift it in (D) and leave it there all day, doesn't hurt coz OD won't kick in until it's needed on the highway and that's that.

But now I read that it's not good, wears out trans faster and messes with shift points.
Is this true?
In that case, I'd shift into (D) at say a stop light before getting on the highway?
Can i shift between D and (D) while vehicle is moving? With gas pedal pressed? I just want the dos and don'ts here. Coz I typically don't touch the gear lever until I'm stopped and foot on brake, going between drive neutral reverse park etc etc...

Thanks for the driving lessons, lol.
Genuinely I thought it didn't make a difference because overdrive would just kinda hang out having a smoke until it was needed on the highway, not that I'd have to shift into it while on highway.

Thanks folks

 

[Ricko1966]

Any 700r4 I've had I put it in OD, drive it and forget about it. If I'm towing something of any substance. I put it in D to keep it out of OD.

 

[PrairieDrifter]

You can shift any gear up at any time. Down any time as long as the speed is in range for down shifts(not too fast for the next gear lower) it will over rev. Will skid the rear tires or break something if you do it really bad.

People say leave it out of overdrive in town because it will shift way more often instead of being in 3rd gear and just revving higher.

I've noticed there's basically no decel in 4th gear on my 700, pretty sure that's normal. 3rd gear has a nice light decel and I dont don't need 4th or overdrive in my small city, if I do I just shift into OD. Decel is necessary, unless you're in the flatlands, to not ride the brakes all the time.

 

[HotWheelsBurban]

Any 700r4 I've had I put it in OD drive it and forget about it. If I'm towing something of any substance. I put it in D to keep it out of OD.

Same here, also do that with the 4L60E in my current Burb. The one ton has a 4L80E so no worries there; truck only knows we're towing something when we slow down and stop. I'm using U Haul rental trailers with single axle, no brakes on those.

 

[Blue Ox]

Any 700r4 I've had I put it in OD drive it and forget about it. If I'm towing something of any substance. I put it in D to keep it out of OD.

Interesting. When I was towing with mine, if I had to drop it out of OD the temps would skyrocket when the converter unlocked.

For the OP, just leave it in OD unless you're local driving and your speed and gear combo leave it hunting in and out of OD constantly.

 

[Subourbon]

Ok, woah, woke up to a lot of answera appreciate them all.

Asking coz, well 2, 3 years back was driving round and would try tonautonshift into 3rd. And nope. Would just rev it's gut out and then it was like i was in neutral. Burnt clutch pack. And i dont tow with this truck. Ive had a trailer on it once in a blue moon but anyways. Tranny rebuild which sucked. Took forever tonget get parts and cost me an arm and leg.

Now, fast forwardntona couple months ago, onnthe highway, entering construction zone, let off throttlr to coast down naturally, out of the zone, back on the skinny pedal and nothing. Just rev
Oh no not again come on..... shifted into D and injad those gears luckily.
Few days latee had to help a friend move, needed my truck, highway again, in (D) and I tried it. It worked!

I don't know how to interpret these events. Am I heating up too much? Has me driving in (D) all this time messed something up?

I forget what forum it was, but someone said when driving in (D) when you're not on the gas pedal the torque converter locks up and it shifts into OD, and it does that multiple times and hour which ?isn't good? Or that driving in normal D heats up the torque converter way more and thatll ruin your trans as opposed to driving in OD.... i dont know if all of this matter between when you're driving a diesel, a gas 350. Ive got diesel flavour.

I mean now ill likely just stick to D and shift up to OD when I'm at the light before the hgihway.


I've also got a derale cooler fornthe trans, and placement has been bugging me. I was gonna put it behind my grille for max air flow. But then winter will come. Its gonna take a while for that ATF to warm up eh.

YouTube videos show guys mounting them under the car, which... I dunno to be honest.

 

[Ricko1966]

Ok, woah, woke up to a lot of answera appreciate them all.

Asking coz, well 2, 3 years back was driving round and would try tonautonshift into 3rd. And nope. Would just rev it's gut out and then it was like i was in neutral. Burnt clutch pack. And i dont tow with this truck. Ive had a trailer on it once in a blue moon but anyways. Tranny rebuild which sucked. Took forever tonget get parts and cost me an arm and leg.

Now, fast forwardntona couple months ago, onnthe highway, entering construction zone, let off throttlr to coast down naturally, out of the zone, back on the skinny pedal and nothing. Just rev
Oh no not again come on..... shifted into D and injad those gears luckily.
Few days latee had to help a friend move, needed my truck, highway again, in (D) and I tried it. It worked!

I don't know how to interpret these events. Am I heating up too much? Has me driving in (D) all this time messed something up?

I forget what forum it was, but someone said when driving in (D) when you're not on the gas pedal the torque converter locks up and it shifts into OD, and it does that multiple times and hour which ?isn't good? Or that driving in normal D heats up the torque converter way more and thatll ruin your trans as opposed to driving in OD.... i dont know if all of this matter between when you're driving a diesel, a gas 350. Ive got diesel flavour.

I mean now ill likely just stick to D and shift up to OD when I'm at the light before the hgihway.


I've also got a derale cooler fornthe trans, and placement has been bugging me. I was gonna put it behind my grille for max air flow. But then winter will come. Its gonna take a while for that ATF to warm up eh.

YouTube videos show guys mounting them under the car, which... I dunno to be honest.

You route the cooler so warm fluid from the transmission goes to the external cooler,from the external cooler,you plumb to the radiator cooler. This keeps your ATF at a regulated temperature. Coolant temperature is your regulator,just one of the reasons the factory uses a cooler inside the radiator.

 

[Subourbon]

@Ricko1966
Yeah see that's the dilemna, in summer I wanna bypass it, coz, it does get hot here, andnive already got an external aux oil cooler, while small, (16row evil energy AN fitting cooler) it is still a blockage to the main rad, over on driver side behind the grille.

So in winter, what you're saying makes total sense, itll coom and so that it doesn't dip below its operating temp, the stock rad will regulate.
Excellent, I understand that fully. But, wouldn't the opposite happen in summer, where the aux cooler rooms it more efficiently, ok and back we go to the stock rad which, might warm it up again and then I'm right back to square one?

Feel like i need a thermostat and bypass on the aux cooler. I literally got off the phone with derale, great customer service, and he said you can make a cover over the cooler see how much h heat you can retain. And i mean worst case scenario, the fans just don't turn on all winter and the cooler just acts as a cooler.

 

[Ricko1966]

@Ricko1966
Yeah see that's the dilemna, in summer I wanna bypass it, coz, it does get hot here, andnive already got an external aux oil cooler, while small, (16row evil energy AN fitting cooler) it is still a blockage to the main rad, over on driver side behind the grille.

So in winter, what you're saying makes total sense, itll coom and so that it doesn't dip below its operating temp, the stock rad will regulate.
Excellent, I understand that fully. But, wouldn't the opposite happen in summer, where the aux cooler rooms it more efficiently, ok and back we go to the stock rad which, might warm it up again and then I'm right back to square one?

Feel like i need a thermostat and bypass on the aux cooler. I literally got off the phone with derale, great customer service, and he said you can make a cover over the cooler see how much h heat you can retain. And i mean worst case scenario, the fans just don't turn on all winter and the cooler just acts as a cooler.

They make thermostats to control transmission coolers,GM now has transmission cooler thermostats. But the cheap way and the inexpensive way was do it the factory did for decades. Radiator temperature controls transmission fluid temperature. Your radiator should never be hot enough to overheat your transmission fluid,and a liquid cooler is more efficient and works better than air cooler. Don't believe me when you burn your finger what works better,wave it around in the air or put it in your mouth.

 

[Subourbon]

I definitely understand that! My rad pierced and leaked and I had tonreplace it, it was the first time it had taken apart the cooler lines, anyways made sense.

However, it's known that 700r4s overheat, mine did, and indont tow much if at all with the truck. I bought one of those decked drawer systems for cheap and that in the back to hold tools and fluids n other stuff, so let's say 100 - 150lbs (and thats being generous) of stuff in the back at all times. So all that to say, it's not exactly 'working hard".

Yeah liquid cooling always wins for sure.

Id rather eliminate the old 700r4 lines completely and bypass the radiator. But yeah, winter will be rough on the fluids.

I'm just trying to find the simplest way to do it...
I've got the engine oil cooler i put in back in April? Haven't done a winter with thst yet. It'd literally out of engine into cooler back to engine.

This is food for thought.

 

[gmbellew]

I keep mine in D unless I am on a hwy and consistently above 55mph. I dont think i am losing much in the way of MPG efficiency doing that and I am sure it saves some wear on the transmission. almost any towing should be in D unless it is a very light pull, and keep the speed appropriate.

 

[Subourbon]

@gmbellew
And do you shift up in OD while driving? Or stopped, foot on brake.
And same question for shifting back down to D.
touching the gear lever unless car is stopped and foot on brake has been beaten out of me lol.

 

[gmbellew]

@gmbellew
And do you shift up in OD while driving? Or stopped, foot on brake.
And same question for shifting back down to D.
touching the gear lever unless car is stopped and foot on brake has been beaten out of me lol.

you can shift while driving. when I get on the hwy and am accelerating up to speeed (70-75mph), I shift sometime between 55 and 60 usually. sometimes it stays in 3rd and sometimes it upshifts right away, depending on my acceleration. I usually downshift when coasting as I get off the hwy sometime around 40-45mph. although you can technically shift up or down whenever you want....I just try to take care of the ole transmission as much as I can...

 

[Ricko1966]

I definitely understand that! My rad pierced and leaked and I had tonreplace it, it was the first time it had taken apart the cooler lines, anyways made sense.

However, it's known that 700r4s overheat, mine did, and indont tow much if at all with the truck. I bought one of those decked drawer systems for cheap and that in the back to hold tools and fluids n other stuff, so let's say 100 - 150lbs (and thats being generous) of stuff in the back at all times. So all that to say, it's not exactly 'working hard".

Yeah liquid cooling always wins for sure.

Id rather eliminate the old 700r4 lines completely and bypass the radiator. But yeah, winter will be rough on the fluids.

I'm just trying to find the simplest way to do it...
I've got the engine oil cooler i put in back in April? Haven't done a winter with thst yet. It'd literally out of engine into cooler back to engine.

This is food for thought.

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[Subourbon]

Thats really helpful, as well as other comments, cheers everyone.

There's still seems to be a split between driving daily in OD vs taking care to city drive in D and highway in OD.

Well, I've been doing it in OD, no matter where, for years. I'll try it the other way, see if there's a difference.