Changing to synthetic trans fluid

Ron Gusack · 08-16-2011, 11:34 PM

After my 4th run Saturday, the trans temp was at 220. I got it to 200 just before the 5th run. I've heard synthetic ATF will lower the temps, currently I'm running type F.
Which synthetic lowers the temps the most?
Do I have to get the type F flushed out to get all of it out?
TH 400

Tom Goldman · 08-17-2011, 08:36 AM

Synthetic fluid wont lower the temps, it just survives them better.
200 deg is not that hot, discharge temps coming out of the converter can run over 300 deg. depending on the converter design.

If your concerned about the temp,by all means use the synthetic fluid ,it cant hurt anything but your wallet.
But I would consider a bigger trans cooler[ if you have one ] and get it in the air flow.
Spray the cooler and the trans pan with water between rounds if you have time.

Ron Gusack · 08-17-2011, 11:21 AM

I thought anything over 200 was harmful to the trans and hurt ET. I got concerned when it hit 220.
I have a small cooler mounted about 2" off the firewall and inline with the right front tire.
Is one synthetic better than another?
I usually have time to spray it, but I'd rather not have to.

ss3011 · 08-17-2011, 11:39 AM

Try using some Allison Trans-Synd , which is a synthetic. Allison specs it for their automatics. It is formulated by Castrol, and is a high quality fluid.

Myron Piatek · 08-17-2011, 11:48 AM

I've been using Amsoil Supershift synthetic, which has enhanced frictional properties specifically for racing applications. I've gotten years out of my transmissions footbraking, pulling them as a precaution rather than because of band/clutch issues. My trans builder says to keep using whatever I'm using in them.

As mentioned, synthetics will work better and longer than conventional fluids because of their higher resistance to heat. Good insurance policy, especially if you get into a "hot-lapping" situation.

Robbie Draughon · 08-17-2011, 11:50 AM

John Deere Hy-Guard. We ran it in a powerglide pro mod behind a 2000hp hemi. A lot of T/S guys run it in bruno lencos. Stuff really works

Jim Kaekel · 08-17-2011, 12:32 PM

Don't forget that trans temperatures will differ depending on where you have your temperature sender located. Temps will read lower when the sender is located in the pan vs. on the pressure side of the cooling line.

tim worner · 08-17-2011, 12:33 PM

The new ATI trans fluid really works well and does keep temp down.

njk53 · 08-17-2011, 02:00 PM

200 degrees F is nothing to be worried about. The hottest point in the transmission for the fluid is at the stator. Put a temp gauge on the outlet line as close as you can get it to the transmission case and monitor that. 300 degree F outlet temps for short durations like drag racing isn't going to hurt the trans. We would test production vehicles pulling trailers with stator temps higher than 300 F with no issue.

Ron Gusack · 08-17-2011, 04:53 PM

It's surprising how many racers differ on where the temp should be taken from. Mine is as low as I could get it in the pan.

If I change to synthetic, do I have to get a shop to do a flush or can I drain the pan and refill? Doing that would leave me with a mix of standard and synthetic.

08-16-2011, 11:34 PM	#1
Ron Gusack Member Join Date: Feb 2009 Posts: 244 Likes: 1 Liked 7 Times in 6 Posts	Changing to synthetic trans fluid After my 4th run Saturday, the trans temp was at 220. I got it to 200 just before the 5th run. I've heard synthetic ATF will lower the temps, currently I'm running type F. Which synthetic lowers the temps the most? Do I have to get the type F flushed out to get all of it out? TH 400

08-17-2011, 08:36 AM	#2
Tom Goldman VIP Member Join Date: Jan 2003 Location: Allentown,PA Posts: 2,473 Likes: 881 Liked 858 Times in 234 Posts	Re: Changing to synthetic trans fluid Synthetic fluid wont lower the temps, it just survives them better. 200 deg is not that hot, discharge temps coming out of the converter can run over 300 deg. depending on the converter design. If your concerned about the temp,by all means use the synthetic fluid ,it cant hurt anything but your wallet. But I would consider a bigger trans cooler[ if you have one ] and get it in the air flow. Spray the cooler and the trans pan with water between rounds if you have time. __________________ Tom Goldman 1500 SG , 1506 STK

08-17-2011, 11:21 AM	#3
Ron Gusack Member Join Date: Feb 2009 Posts: 244 Likes: 1 Liked 7 Times in 6 Posts	Re: Changing to synthetic trans fluid I thought anything over 200 was harmful to the trans and hurt ET. I got concerned when it hit 220. I have a small cooler mounted about 2" off the firewall and inline with the right front tire. Is one synthetic better than another? I usually have time to spray it, but I'd rather not have to.

08-17-2011, 11:39 AM	#4
ss3011 Senior Member Join Date: Feb 2002 Location: Southeast Michigan Posts: 908 Likes: 70 Liked 238 Times in 113 Posts	Re: Changing to synthetic trans fluid Try using some Allison Trans-Synd , which is a synthetic. Allison specs it for their automatics. It is formulated by Castrol, and is a high quality fluid.

08-17-2011, 11:48 AM	#5
Myron Piatek VIP Member Join Date: Nov 2001 Location: Florida Posts: 1,542 Likes: 34 Liked 138 Times in 51 Posts	Re: Changing to synthetic trans fluid I've been using Amsoil Supershift synthetic, which has enhanced frictional properties specifically for racing applications. I've gotten years out of my transmissions footbraking, pulling them as a precaution rather than because of band/clutch issues. My trans builder says to keep using whatever I'm using in them. As mentioned, synthetics will work better and longer than conventional fluids because of their higher resistance to heat. Good insurance policy, especially if you get into a "hot-lapping" situation.

08-17-2011, 11:50 AM	#6
Robbie Draughon Junior Member Join Date: Jul 2007 Location: Fayetteville, NC Posts: 76 Likes: 14 Liked 28 Times in 4 Posts	Re: Changing to synthetic trans fluid John Deere Hy-Guard. We ran it in a powerglide pro mod behind a 2000hp hemi. A lot of T/S guys run it in bruno lencos. Stuff really works __________________ SS/AM 2917

08-17-2011, 12:32 PM	#7
Jim Kaekel VIP Member Join Date: Jul 2002 Location: Michigan Posts: 1,226 Likes: 133 Liked 529 Times in 107 Posts	Re: Changing to synthetic trans fluid Don't forget that trans temperatures will differ depending on where you have your temperature sender located. Temps will read lower when the sender is located in the pan vs. on the pressure side of the cooling line. __________________ Jim Kaekel 3836 STK

08-17-2011, 12:33 PM	#8
tim worner Senior Member Join Date: Jan 2002 Location: duncannon Posts: 837 Likes: 14 Liked 126 Times in 20 Posts	Re: Changing to synthetic trans fluid The new ATI trans fluid really works well and does keep temp down. __________________ Tim Worner SS 1747

08-17-2011, 02:00 PM	#9
njk53 Senior Member Join Date: Jul 2007 Location: East China, MI Posts: 504 Likes: 0 Liked 0 Times in 0 Posts	Re: Changing to synthetic trans fluid 200 degrees F is nothing to be worried about. The hottest point in the transmission for the fluid is at the stator. Put a temp gauge on the outlet line as close as you can get it to the transmission case and monitor that. 300 degree F outlet temps for short durations like drag racing isn't going to hurt the trans. We would test production vehicles pulling trailers with stator temps higher than 300 F with no issue. __________________ Nelson Kowal Stock 345 Last edited by njk53; 08-17-2011 at 02:08 PM.

08-17-2011, 04:53 PM	#10
Ron Gusack Member Join Date: Feb 2009 Posts: 244 Likes: 1 Liked 7 Times in 6 Posts	Re: Changing to synthetic trans fluid It's surprising how many racers differ on where the temp should be taken from. Mine is as low as I could get it in the pan. If I change to synthetic, do I have to get a shop to do a flush or can I drain the pan and refill? Doing that would leave me with a mix of standard and synthetic.