Drive or Overdrive in a 700r4

[Coach]

OK guys, this is probably a stupid question but I'm going to ask it anyway. Just picked up my truck last night, had the tranny rebuilt since it never had Overdrive (had been driving it like a 3 speed). Should I leave it in D (Drive) all the time around town and only shift into OD (Overdrive) when on the freeway, or should I drive around all the time in OD. I'm thinking D all the time then shift to OD on the freeway, but wanted some advice from guys who have had 700r4 in the past. Thanks for any advice.

[c20pickup]

Originally Posted by Coach

OK guys, this is probably a stupid question but I'm going to ask it anyway. Just picked up my truck last night, had the tranny rebuilt since it never had Overdrive (had been driving it like a 3 speed). Should I leave it in D (Drive) all the time around town and only shift into OD (Overdrive) when on the freeway, or should I drive around all the time in OD. I'm thinking D all the time then shift to OD on the freeway, but wanted some advice from guys who have had 700r4 in the past. Thanks for any advice.

keep it in od, it will shift automatically, unless its lugging really bad in od then pull it back down to drive or adjust the tv cable to shift later. what rear gears in the truck?

[hugger6933]

Leave it in OD but if it starts to wander between gears at like 53 to 58 mph pull it down a notch and make double barrel sure the TV cable is set right or you may have trans problems in the near future. If it does wander in search of a gear don't feel alone a lot of the trucks that came new with the 700 did that, if it does try tapping on the brake pedal if you have the TCC hooked up and if it stops it is the clutch on the converter and pulling it down a gear will solve that. Jim

[Andy4639]

I used mine for 15 years in OD all the time only used drive if I towed my trailer which I did only a few times with it. The trans cable has to be right are your going to burn it up again pretty quick from what I have been told. I was lucky. I got the motor & trans as a unit so it had all the correct brackets for the cable. No adjusting for me.

[Coach]

My rear gears are 3.73 No issue with wandering between gears. Tranny was rebuilt by a very experienced/reputable shop with a long history of rebuilding 700r4's. Also had them install the Lokar shifter and Bowtie Overdrive TV cable kit, so no issues with the TV cable. Sounds like majority of people just leave it in OD on a normal basis and let the tranny do its thing. Not sure if if matters, but the engine is a mild crate 350/290hp with a Melling MTC-1 camshaft.

[truckster]

OD is good for most situations. If you're towing, especially going up long grades, you might want to downshift, but most of the time you can just leave it in OD.

[HeavyD]

Im the opposite, i use d (or lock it out depends on vehicle) unless I plan a freeway blast. Od seems to kick in at times i dont want it and the vehicle feels sugggish.

[Andy4639]

I also had a B&M wiring harness on mine so I could keep the torque converter from locking up if I wanted. Flip the toggle switch and it would never go into OD even in Drive.

[mechanicalman]

Originally Posted by Coach

My rear gears are 3.73 No issue with wandering between gears. Tranny was rebuilt by a very experienced/reputable shop with a long history of rebuilding 700r4's. Also had them install the Lokar shifter and Bowtie Overdrive TV cable kit, so no issues with the TV cable. Sounds like majority of people just leave it in OD on a normal basis and let the tranny do its thing. Not sure if if matters, but the engine is a mild crate 350/290hp with a Melling MTC-1 camshaft.

Sounds like you are good to go in OD or whatever suits you. Good choice on cam.

May I ask: Did you buy the 350 290HP then just remove the "too big" cam and slide in the Melling?

[snipescastle2]

I believe if you hold it in drive-vs. O.D. you would be putting undue wear on the band in your transmission, you might want to search about this condition before taking anyone's advice, just giving you a heads up, it's burnt a few bands up doing this. I know there is a forum member here that specializes in GM transmissions,I'm sure he'll chime in and set the record straight.
HTH,
Ben

[Keith Seymore]

The GM recommendation is OD all the time, except trailering/hauling (then you put it in "D").

K

[67ChevyRedneck]

I have a lokar floor shift in mine and I "bump shift" it.

I also have a Bowtie Overdrives TVmadeEZ kit and brake switch lock out kit.

I've long lost the link I had, but I set my trans up using a pressure gauge and adjusting the BTO cam.

The "problem" I have is that under light throttle (like in slow moving/rolling) traffic it will shift into OD around 40-43mph. The motor doesn't like this and will "lug." I did try to "adjust this out" with the pressure gauge years ago, and I didn't like how hard the shifts were getting, so I adjusted it back down to the middle area.

Now, 1/3 throttle or more, and she won't do this, but I can't drive like that around here, I'll smack into the back of someone.

So, I put it in D, and when she gets over 45 mph I can bump it into OD. Anything over 45 mph and she's good... doesn't like hills, but can still handle it. Anything over 50 and she's fine.

My trans has been in the truck for 9 years and about 40K miles. Still shifts like it did when I installed it - it was a new rebuild.

[jjzepplin]

I leave mine in OD but downshift if necessary. I have 4.10's and a disable switch. I only flip the switch above 60 or so mph on a long run. I never tow in OD or lockup.

[Coach]

Thanks for all the advice guys, I appreciate it. Mechanical man, that's exactly what I did. The stock can was too big for the 350/290, so I swapped it out for the Melling with new lifters as well, it made a huge difference!!

[70blackfish]

i say around town, just keep in D not od

[mechanicalman]

Originally Posted by 70blackfish

i say around town, just keep in D not od

IMO, less shift busy-ness that way. When in D though you get engine braking and the trans will have a firmer downshift feel that you hardly notice when in OD.

A lot has to do with driving habits as well.

[davischevy]

Originally Posted by Coach

My rear gears are 3.73 No issue with wandering between gears. Tranny was rebuilt by a very experienced/reputable shop with a long history of rebuilding 700r4's. Also had them install the Lokar shifter and Bowtie Overdrive TV cable kit, so no issues with the TV cable. Sounds like majority of people just leave it in OD on a normal basis and let the tranny do its thing. Not sure if if matters, but the engine is a mild crate 350/290hp with a Melling MTC-1 camshaft.

Same for me, except mines a bigblock, in a Longhorn.

I use overdrive even when towing. When I go into a "pull" I just tap the throttle and shift down. Haven't had a problem so far. TV cable adjustment is very important.

My two cents,
Larry

[macdodd]

I've a 3 speed auto in a '69 chevy 350/395 heads,,,,at around 3k,,,I'm running 71mph,,,is that hard on the engine,,,,,of course ,,,its eating gas too,,,,LOL.

[WIDESIDE72]

I have a 700r4 275/60r15 tires (28" tall?) and 3.73's in my 72 swb step. I leave it in overdrive. It doesn't hunt with that low of a gear.