700R4 3rd as strong as the 3rd in a 400 - The 1947 - Present Chevrolet & GMC Truck Message Board Network

beeroh · 09-24-2003, 01:18 AM

Just Curious?
My truck has a hard time staying in OD, 4th gear @ .70.
Since my third is a 1.0, but it not being my top gear, does it make it weaker than say the top gear in a 400 or 350?

Does it hurt the tranny if I never use the OD?

Blazer1970 · 09-24-2003, 08:10 AM

Third gear in a TH700R4 is exactly the same as third in a TH350. It is direct drive in both cases, so there are no gears involved, just the third gear clutch pack. I would assume that a TH400 has larger/more clutch disks, so it will hold more torque in third.

If your 700R4 will not stay in O/D with 33 inch tires and 4.56 gears, something else is wrong. It should have no problem running in O/D with that overall ratio.

It will not hurt the tranny at all to run in D instead of O/D, in fact it is better for the tranny.

kevenak · 09-24-2003, 10:43 AM

I'm in the process of swapping out my 350 turbo for a 700R4. I'm getting my parts from (BowtieOverDrives.com) and they have a Trottle Valve Cable that is supposed to properly maintain shifting on the 700R4. I have not installed it yet, but It might be worth looking into (tvmadeez.com).

lukecp · 09-24-2003, 01:15 PM

Are you saying that the motor dosen't have the power to pull the truck in OD, or the tranny won't go into OD?

It won't hurt the tranny to stay in 3rd all the time as stated above.....but if it won't go into 4th or slips in 4th....you have some tranny issues.

beeroh · 09-24-2003, 01:54 PM

the tranny goes into 4th after I take my foot completely off the gas pedal then it looses 10mph and I can't accelerate without it dropping down to third,

It sometimes feels like there is a 3.5 gear in there, like it would almost lock up but not quite make it to full lockup but inbetween 3rd and 4th.

Is this normal?

Destructo · 09-24-2003, 04:48 PM

Sounds like you have a problem. Your clutches might be gone. I noticed that if I leave my 700r4 in D when I come to a stop it clunks downshifting from 2-1, but if I put it in OD it does not. My friends camaro does this too.

cableguy0 · 09-24-2003, 06:08 PM

the 700r4 have very tiny od clutches and they burn up easily so any stress on the tranny in overdrive is a bad idea

nate68 · 09-25-2003, 07:47 PM

Quote:

Originally posted by Destructo
Sounds like you have a problem. Your clutches might be gone. I noticed that if I leave my 700r4 in D when I come to a stop it clunks downshifting from 2-1, but if I put it in OD it does not. My friends camaro does this too.

these transmissions do this. i asked my tranny guy when i got mine built and he said that nothing is wrong it's just how they are. mine doesnt clunk but sometimes i can feel the downshift when coming to a stop

Blazer1970 · 09-30-2003, 08:09 AM

Quote:

Originally posted by nate68

these transmissions do this. i asked my tranny guy when i got mine built and he said that nothing is wrong it's just how they are. mine doesnt clunk but sometimes i can feel the downshift when coming to a stop

Yup, all 700R4s do that. You get more engine braking in D than in OD. Someone said that they run a higher line pressure in D than in OD. I think they are designed to coast in OD in order to get the best possible fuel economy.

Old Chevy Lover · 09-30-2003, 10:51 AM

So what is changed in these tranny's when they are built for performance? Anyone know?

09-24-2003, 01:18 AM	#1
beeroh Registered User Join Date: Sep 2003 Location: Atascadero, CA. Posts: 149	700R4 3rd as strong as the 3rd in a 400 Just Curious? My truck has a hard time staying in OD, 4th gear @ .70. Since my third is a 1.0, but it not being my top gear, does it make it weaker than say the top gear in a 400 or 350? Does it hurt the tranny if I never use the OD? __________________ 84 Silverado,

09-24-2003, 08:10 AM	#2
Blazer1970 Registered User Join Date: Dec 1999 Location: Old Mission, MI, USA Posts: 2,510	Third gear in a TH700R4 is exactly the same as third in a TH350. It is direct drive in both cases, so there are no gears involved, just the third gear clutch pack. I would assume that a TH400 has larger/more clutch disks, so it will hold more torque in third. If your 700R4 will not stay in O/D with 33 inch tires and 4.56 gears, something else is wrong. It should have no problem running in O/D with that overall ratio. It will not hurt the tranny at all to run in D instead of O/D, in fact it is better for the tranny. __________________ Tim

09-24-2003, 10:43 AM	#3
kevenak Registered User Join Date: Sep 2003 Location: Tampa, FL Posts: 4	I'm in the process of swapping out my 350 turbo for a 700R4. I'm getting my parts from (BowtieOverDrives.com) and they have a Trottle Valve Cable that is supposed to properly maintain shifting on the 700R4. I have not installed it yet, but It might be worth looking into (tvmadeez.com). __________________ 71 GMC Super Custom, shortbed, stepside, 350 cu in, Auto, Air, and Power. Hugger Orange.

09-24-2003, 01:15 PM	#4
lukecp Formerly yellow72custom Join Date: May 2001 Location: Austin, TX Posts: 7,531	Are you saying that the motor dosen't have the power to pull the truck in OD, or the tranny won't go into OD? It won't hurt the tranny to stay in 3rd all the time as stated above.....but if it won't go into 4th or slips in 4th....you have some tranny issues. __________________ '72 Chevy C10 Mild 350/TH350/3.07. Ochre/White. Old high school ride. '70 GMC C2500 '62 327 4bbl/SM465/4.56-geared Dana 60. White/White. Project or parts truck. '97 Saturn SL DD. 1.9/5-speed. 40+ highway mpg

09-24-2003, 01:54 PM	#5
beeroh Registered User Join Date: Sep 2003 Location: Atascadero, CA. Posts: 149	the tranny goes into 4th after I take my foot completely off the gas pedal then it looses 10mph and I can't accelerate without it dropping down to third, It sometimes feels like there is a 3.5 gear in there, like it would almost lock up but not quite make it to full lockup but inbetween 3rd and 4th. Is this normal? __________________ 84 Silverado,

09-24-2003, 04:48 PM	#6
Destructo Registered User Join Date: Sep 2003 Location: Lewisville, NC Posts: 1,836	Sounds like you have a problem. Your clutches might be gone. I noticed that if I leave my 700r4 in D when I come to a stop it clunks downshifting from 2-1, but if I put it in OD it does not. My friends camaro does this too.

09-24-2003, 06:08 PM	#7
cableguy0 Senior Member Join Date: Apr 2000 Location: Delta,Pa Posts: 14,950	the 700r4 have very tiny od clutches and they burn up easily so any stress on the tranny in overdrive is a bad idea __________________ Owner of North Point Car Care in Dundalk Md. We specialize in custom exhaust on both modern and classic vehicles. We are a full service auto shop from classics to modern vehicles. Feel free to contact me with questions. I will give a 10% discount to any board member.

09-30-2003, 10:51 AM	#10
Old Chevy Lover Registered User Join Date: Dec 2002 Location: Chillicothe OHIO Posts: 718	So what is changed in these tranny's when they are built for performance? Anyone know? __________________ Keith 70 Chevelle Malibu SS Clone 468/Auto 72 C10 SWB 350/Auto 13 Camaro SS/RS 6.2/Auto

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