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Discussion Starter #1
I was running watkins glen and after about 25 minutes I saw tranny warnings progress from high to HOT! I took it easy when I saw the hot readings, but am wondering what the long term effects are of going into the HOT zone. I know there are tranny coolers out there but for the once a month track time I'll probably see, I dont really want to spend a couple grand. I guess I'm asking if its ok for the tranny to occassionally get that hot.

On a side note, oil temps hit 290.
 

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High temps shouldn't cause any tranny problems if you change the lube immediately afterwards.
 

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How high did the tranny temp. reading get when it changed from High temp. warning to...

HOT ???

I've seen high transmission temp. readings ~ 278.... occasionally.

I run synthethic Fluids and I change both transmission and rear diff. annually !!! I added a Rippie Larger radiator/oil cooler combo, high oil temp. is ~ 265 now. Was seeing 302 before change-over.
 

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I have heard from a good source that wraping the exhaust where it passes by the tranny cuts the temps quite a bit. It seams that lots of high rpm 2nd gear brings on this condition. Also heard tacking on some heat shielding works as well.

I have never seen it on the longer tracks where 2nd is not used or second is followed by a long straight. I use redline in mine and feel pretty comfortable that it will take the abuse.

The thing that really pisses me off is that running a cooler will in many cases void the warranty on the eng/trans/diff. The general cleaned up these issues with coolers on the c6 z51 pkg and even a dry sump on the new Z, but offers no aftermarket solution for the C5 that won't void the warranty:(.
 

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Z06Machine said:
I have never seen it on the longer tracks where 2nd is not used or second is followed by a long straight. I use redline in mine and feel pretty comfortable that it will take the abuse.
I have only gotten the warning, while running the long course at Ponoco in August, at the end of the day (last 30 minutes session). Within a lap, all five z06's pulled over with the warning.
 

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Discussion Starter #7
Trumper, I am not sure how high the temps went. My guess is 290-300 when it went to HOT. Watkins is primarily a 3rd gear track for me, with 4th seen after the front straight until the bus stop. I'd hit 5th for a few seconds on the straights. Its definitely a fast track. I guess I'll just change fluids after each event and when I see HOT, pull in for a cool down.

An interesting side note is that when it was at and nearing HOT, I noticed it was harder to get from 3rd to 4th - I really had to push it in the perfect direction for it to go in. It wanted to go to 2nd when I was trying a upshift to 4th.
 

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On a side note, My car hasn't had any heat related problems since I started putting Mobile-1 synthetic fluid in the tranny and Red Line in the diff.
 

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Backlash,

I have never run any East coast tracks except Mid Ohio. So I am not familiar with Pocono. All I hear is that it has a very high speed straight. Were the sessions back to back or with less time between them than normal?. The track is a common denominator for sure.
 

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Z06Machine said:
Backlash,

I have never run any East coast tracks except Mid Ohio. So I am not familiar with Pocono. All I hear is that it has a very high speed straight. Were the sessions back to back or with less time between them than normal?. The track is a common denominator for sure.

The long course has two straights connected by a NASCAR style turn. You hit over 150, then down to 100-110 and then back up again before braking into the in-field (70-80), roughly 2.5 miles per lap. Sessions were about 90 minutes apart.

Did Walkins Glen in the spring, 80 degree days and had zero problem with long sessions (45 minutes), with no problems both days. Going back on the 18 and 19th, so we'll see what it is like in the summer. Changing the tranny and rear end fluid is on the list for this week. :thumb:
 

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Subw00er said:
An interesting side note is that when it was at and nearing HOT, I noticed it was harder to get from 3rd to 4th - I really had to push it in the perfect direction for it to go in. It wanted to go to 2nd when I was trying a upshift to 4th.
I had this happen to me at Summit Point WV. HIgh trans temp warning and then the 2-3 shifts became hard to make, it would kinda get stuck inthe middle somewhere and I had to pull it back to 2nd and then back to 3rd.... Thought it may be a shifter problem (Hurst).... Like noted in other posts, this track had lots of 2-3 shifts.... I run POCONO as well, and NEVER had this warning....
 

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Running high trans temp will damage the Tranny and also the Diff. The Diff probably gets hotter than the Tranny. It is a common occurance after 20-25 minutes of track time, especially in hot weather.

Quote from Chuck Mallett "An occasionally tracked car should have the Tranny and Diff either Blueprinted or a Cooler installed, preferrably BOTH. A car that sees track use at least once a month NEEDS BOTH."

You should also install a good (racing) Synthetic ATF in the Tranny and Synthetic Gear Lube in the Diff PRIOR to any track use. Such as AMSOIL, Mobil 1, RedLine etc.. Even these Synthetic fluids need to be changed more often in a tracked car. I recommend AT LEAST 3 times per year on seriously tracked cars: Pre Season, Mid Season and End of Season.

If you get the "TRANS HIGH TEMP" Warning you shouild immediately pit and let it cool off (30-40 minutes). You can run subsequent laps until the light comes ON again. You need to change BOTH the Tranny & Diff fluids after the event.
 

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As always DJ you are a wealth of info..... Do you think these temps would casue the tight shift from 2nd to 3rd tho?
 

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DJWorm said:
Running high trans temp will damage the Tranny and also the Diff.
DJ is correct. I should have gone into more detail.
High temps shouldn't have hurt anything IF you pulled off the track and let it cool down immediately after seeing the warning on the DIC. Any time it gets hot enough to cause a warning, you will need to change the fluid. A good fully synthetic fluid will help to keep the warning messages from reappearing.
 

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I used to get "HIGH TRANS TEMP" a few years ago at the track quite often. I then starting changing my driving style. I carried more speed thru the turns and was able to keep the car in higher gears.

If you get the warning on the DIC, hit the reset button and that will give you the tranny temp on the DIC. As long as you don't change out of the "gage" menu on the DIC you will always have the tranny temp along with oil/water temp, ect. If you go to "fuel" or "trip" on the DIC the tranny temp will be gone till it goes into overheat again.

I highly recommend doing a cool down lap, then parking it till the next session when you get the "HIGH TRANS TEMP". You are pushing your luck when you wait for the "HOT" before pulling off.

I use the Amsoil "severe gear" in the diff:

http://www.amsoil.com/storefront/svg.aspx

Also use amsoil ATF in the tranny.

Like said above if you get the "HIGH TRANS TEMP" warning you need to change the fluids (diff/tranny) soon after the event.
 

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OK got synthetic ATF & DIFF fluids in. Heading to Pocono Friday for the short course...Dont know how hard I will push it tho....my one front Hoosier got corded at Summit last month... :cry: so I put the Victoracers on... but as the first Porsche THINKS he is gonna pass me... I am sure I will test the Kuhmos as well! :yeadog:
 

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You might give Bounderaunt Performance Diving school in Arizona a call to see how the heat is effecting their trannys, those guys and the students just punish those Z06's all year round and on a hot day in AZ it's nothing to see temps of 115 degrees.

It's seem that if the trannys were failing we would have heard about them from some one on the forum.
 
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