tranny fluid info - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**bigmac73** · 10-24-2013, 06:37 PM

when rebuilding my tranny what fluid do i use since Dex III is not made anymore, should i use the Dex IV????

Wrenchbender Ret · 10-24-2013, 10:44 PM

Dexron III should still be available. Dexron IV is synthetic & is OK to use but is expensive & not nessesary in the older trans.

**truckdude239** · 10-25-2013, 10:20 AM

Advance auto still sells there brand of dex/mecron

motorcritter · 10-26-2013, 11:39 AM

High grade fluid is cheap insurance- an auxiliary cooler is a good investment also. High temperatures kill automatic transmissions, the fluid degrades and it all goes downhill from there. LubeGard additives are the only ones that are approved by the OEMs, and they work great- lower temps, more stable fluid viscosity. Just my experience with running a transmission rebuild shop, I saw a whole lotta abused units in there, and some preventive measures could have saved many of them.

txgp17 · 10-26-2013, 11:50 AM

I'm considering putting Allison TranSynd in my GM transmissions next time I change the fluid. That stuff is engineered to the nth degree.

I have a 99' 4L80E, and I put Valvoline Dexron-IV in it and it's working fine.

Last time I changed the fluid in my 72' TH350 (original, never been rebuild) I used Mobil 1 Synthetic ATF, and it's shifting fine too.

Also, be aware, that since GM no longer does any Dexron-III licensing, you are relying on the good faith of the fluid manufacturer that it does indeed meet the old Dexron-III requirements. Read the label. Some will say "Recommend for application requiring Dexron-III". Meaning, the fluid manufacture recommends it, not necessarily that it meets the Dexron-III requirements.

Honestly, the your safest bet is to buy a fluid that carries the Dexron-IV label.

**bigmac73** · 10-26-2013, 08:05 PM

well when i installed my crate engine and new stall converter i used the Dexron VI and when i changed the pan gasket and filter i also used Dex VI and have had no issues since.
just wondering for a break in period?? and what is the required break in period for a new rebuild??

hugger6933 · 10-26-2013, 08:18 PM

Break in time for a rebuild? I'd say 100,k. Just kidding I have never given any thought to a break in time or procedure for a rebuilt tranny but it kinda makes sense to have one, but I think that the interval would be closer to a normal trans oil change time. Jim

Green Hornet · 10-26-2013, 08:28 PM

Just picked my tranny up from the shop after a rebuild (700). I specifically asked him what fluid and what they recommended was the Chrysler 4 fluid.

10-24-2013, 06:37 PM	#1
bigmac73 Senior Member Join Date: Mar 2012 Location: Chesapeake, Va Posts: 1,275	tranny fluid info when rebuilding my tranny what fluid do i use since Dex III is not made anymore, should i use the Dex IV???? __________________ Mike 72 C-10 Cheyenne off frame resto and Upgraded to 4 wheel disk, Tilt, Dakota Digital Dash / Rear slider. 421 SBC / TH350 3000RPM Stall Progression Ignition /Holley 750 DP/3:73 gear Eaton Limited Slip unit / 2 1/2 exhaust glasspacks

10-24-2013, 10:44 PM	#2
Wrenchbender Ret Registered User Join Date: Oct 2005 Location: Overland Park, Ks. Posts: 5,229	Re: tranny fluid info Dexron III should still be available. Dexron IV is synthetic & is OK to use but is expensive & not nessesary in the older trans.

10-25-2013, 10:20 AM	#3
truckdude239 Senior Member Join Date: Sep 2005 Location: Lewisville, Nc Posts: 10,237	Re: tranny fluid info Advance auto still sells there brand of dex/mecron __________________ David fuller Ase Certified Mechanic Click here to help support our board!! 1971 Chevy c-10 under going a 4.8l LSx swap Build Thread http://67-72chevytrucks.com/vboard/s...d.php?t=421305 2007 Honda Accord my daily 145kmiles 2002 Honda Accord 4 door With 330k(sisters car) 2005 toyota Avalon 228k( brothers car) 2002 Sububran 5.3 245k 2000 Tahoe 5.3l 378 General manager for Marco's Carwash & lube

10-26-2013, 11:39 AM	#4
motorcritter Registered User Join Date: Mar 2012 Location: Boulder, CO Posts: 350	Re: tranny fluid info High grade fluid is cheap insurance- an auxiliary cooler is a good investment also. High temperatures kill automatic transmissions, the fluid degrades and it all goes downhill from there. LubeGard additives are the only ones that are approved by the OEMs, and they work great- lower temps, more stable fluid viscosity. Just my experience with running a transmission rebuild shop, I saw a whole lotta abused units in there, and some preventive measures could have saved many of them. __________________ If 'that which does not kill me, makes me stronger', then I should be Superman by now!

10-26-2013, 11:50 AM	#5
txgp17 Registered User Join Date: Mar 2013 Location: Kernersville, NC Posts: 8	Re: tranny fluid info I'm considering putting Allison TranSynd in my GM transmissions next time I change the fluid. That stuff is engineered to the nth degree. I have a 99' 4L80E, and I put Valvoline Dexron-IV in it and it's working fine. Last time I changed the fluid in my 72' TH350 (original, never been rebuild) I used Mobil 1 Synthetic ATF, and it's shifting fine too. Also, be aware, that since GM no longer does any Dexron-III licensing, you are relying on the good faith of the fluid manufacturer that it does indeed meet the old Dexron-III requirements. Read the label. Some will say "Recommend for application requiring Dexron-III". Meaning, the fluid manufacture recommends it, not necessarily that it meets the Dexron-III requirements. Honestly, the your safest bet is to buy a fluid that carries the Dexron-IV label.

10-26-2013, 08:05 PM	#6
bigmac73 Senior Member Join Date: Mar 2012 Location: Chesapeake, Va Posts: 1,275	Re: tranny fluid info well when i installed my crate engine and new stall converter i used the Dexron VI and when i changed the pan gasket and filter i also used Dex VI and have had no issues since. just wondering for a break in period?? and what is the required break in period for a new rebuild?? __________________ Mike 72 C-10 Cheyenne off frame resto and Upgraded to 4 wheel disk, Tilt, Dakota Digital Dash / Rear slider. 421 SBC / TH350 3000RPM Stall Progression Ignition /Holley 750 DP/3:73 gear Eaton Limited Slip unit / 2 1/2 exhaust glasspacks

10-26-2013, 08:18 PM	#7
hugger6933 Registered User Join Date: Oct 2008 Location: Marianna Arkansas Posts: 7,280	Re: tranny fluid info Break in time for a rebuild? I'd say 100,k. Just kidding I have never given any thought to a break in time or procedure for a rebuilt tranny but it kinda makes sense to have one, but I think that the interval would be closer to a normal trans oil change time. Jim

10-26-2013, 08:28 PM	#8
Green Hornet Registered User Join Date: Oct 2013 Location: Schaghticoke NY Posts: 77	Re: tranny fluid info Just picked my tranny up from the shop after a rebuild (700). I specifically asked him what fluid and what they recommended was the Chrysler 4 fluid. __________________ 69 Chevy C10 Fleetside Long box



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