Z 51 option and "Additional Cooling"

[skips1]

Hey Guy:
I have a 2007 Z51 coupe with about 8400 miles on it. We took it on a 2000 mile trip last October with our friends who have a 2003 Z06. After returning from the trip, my friend's 2003 Z06 encountered transmission issues which lead to a rebuild.

The oil in his transmission was black and pretty much all the seals were shot. I do not believe that his vehicle has a tranmission /transaxle fluid cooler. The mechanic said that he has seen these things happen before on Corvettes but gave no specifics as to why. To my friend's credit; he never abuses his car and treats it pretty much like another child.

My questions are: Does the Z51 option on the 2007 coupe also include a transmission / transaxel fluid coolerl? Is a transmission rebuild something I should watch out for? ( I do know that oil cooling and power steering cooling is something that has been mentioned on the Z51 package)

I do not "beat" my Vette as I had to save 45 years to get it!
Anyone have a clue?
Thanks in advance!
SKIP:confused

 

[c4c5specialist]

Hey Guy:
I have a 2007 Z51 coupe with about 8400 miles on it. We took it on a 2000 mile trip last October with our friends who have a 2003 Z06. After returning from the trip, my friend's 2003 Z06 encountered transmission issues which lead to a rebuild.

The oil in his transmission was black and pretty much all the seals were shot. I do not believe that his vehicle has a tranmission /transaxle fluid cooler. The mechanic said that he has seen these things happen before on Corvettes but gave no specifics as to why. To my friend's credit; he never abuses his car and treats it pretty much like another child.

My questions are: Does the Z51 option on the 2007 coupe also include a transmission / transaxel fluid coolerl? Is a transmission rebuild something I should watch out for? ( I do know that oil cooling and power steering cooling is something that has been mentioned on the Z51 package)

I do not "beat" my Vette as I had to save 45 years to get it!
Anyone have a clue?
Thanks in advance!
SKIP:confused

HI there,
Actually, I would be VERY VERY interested as to WHAT actually failed.
If it was just seals, then its NOT necessary to overhaul the entire unit.
2, if the car was stored and then driven, there may be leakage from the rear output shaft seal when they take a set.
Clarification is needed here to assist further.
These transmissions are bulletproof in the real world without drag racing.
And BTW, the fluid ALWAYS turns black with time.
This is due to the black carbon frictional surfaces of the syncronizer.
Allthebest, c4c5

 

[skips1]

I'll see my friend this week at work and get back to you. I'll make sure he provides a more detailed description on what the case actually is with his transmission. However, about my original question, does the Z51 option also include a transmission cooler for the manual/automatic transmission?
Thanks again!
SKIP

HI there,
Actually, I would be VERY VERY interested as to WHAT actually failed.
If it was just seals, then its NOT necessary to overhaul the entire unit.
2, if the car was stored and then driven, there may be leakage from the rear output shaft seal when they take a set.
Clarification is needed here to assist further.
These transmissions are bulletproof in the real world without drag racing.
And BTW, the fluid ALWAYS turns black with time.
This is due to the black carbon frictional surfaces of the syncronizer.
Allthebest, c4c5

 

[c4c5specialist]

HI there,
All Z51 have coolers, auto or manual.
Allthebest, c4c5

 

[vettefan]

The 2008 Z51 includes the following coolers:

Manual or auto automatic trans cooler through the radiator
Engine oil cooler
Power steering fluid cooler
no rear end cooler, only thr Z06 has this

 

[Hib Halverson]

In re: the friends C5 Z06, if the trans fluid was truly "black" upon draining, it had either been severely overheated, was severely contaminated or was the incorrect fluid. Any of those could cause transmission failure.

The C6 w. Z51 has a trans cooler if the transmission is an automatic. If it is a manual, it does not have a cooler. The axle part of the transaxle does not have a cooler.

Generally, the manuals do not require a trans cooler unless the trans is subjected to severe duty (ie: racing) in hot weather.

 

[vettefan]

In re: the friends C5 Z06, if the trans fluid was truly "black" upon draining, it had either been severely overheated, was severely contaminated or was the incorrect fluid. Any of those could cause transmission failure.

The C6 w. Z51 has a trans cooler if the transmission is an automatic. If it is a manual, it does not have a cooler. The axle part of the transaxle does not have a cooler.

Generally, the manuals do not require a trans cooler unless the trans is subjected to severe duty (ie: racing) in hot weather.

I don't know pre 2008, but my 2008 has a transcooler and it's a manual. You can see the coller lines. Here are some pictures:

LINK

 

[skips1]

Hey Guys:
I just talked with my friend who had the transmission problem and he said that it was not the seals that failed, but that the bearings themselves were "shot" (to quote the mechanic).

Sorry about the mix up.
The fluid was jet black. The mechanic did not know just why the failure occured and could not come up with any theories as to why.

My friend has taken his C5 Z06 to Great Lakes dragway in the past about twice and did about 4 runs with it. Could that kind of abuse be the cause?
Again, he does not "beat" his car. I hope that this helps some.

HI there,
Actually, I would be VERY VERY interested as to WHAT actually failed.
If it was just seals, then its NOT necessary to overhaul the entire unit.
2, if the car was stored and then driven, there may be leakage from the rear output shaft seal when they take a set.
Clarification is needed here to assist further.
These transmissions are bulletproof in the real world without drag racing.
And BTW, the fluid ALWAYS turns black with time.
This is due to the black carbon frictional surfaces of the syncronizer.
Allthebest, c4c5

 

[c4c5specialist]

HI there,
Something isnt right here. To fry those bearings, it had to be driven totally low on fluid to overheat the internals, thats why I asked about a leak.
And in 11 years of overhauling these transmissions, I have yet to replace one bearing INTERNAL to this unit.
What were his symptoms prior to bringing the car in to be checked??
Allthebest, c4c5

 

[skips1]

HI there,
Something isnt right here. To fry those bearings, it had to be driven totally low on fluid to overheat the internals, thats why I asked about a leak.
And in 11 years of overhauling these transmissions, I have yet to replace one bearing INTERNAL to this unit.
What were his symptoms prior to bringing the car in to be checked??
Allthebest, c4c5

C4C5:
Reason he took it to the dealer was what appeared to be a "ticking" noise that would occur when running the vehicle at speed. The ticking noise would increase both with speed and revving the engine. Consequently, my friend took it to the dealer expecting a sticky valve or problem with the engine. Difficulty shifting was not an issue from what he says. Additionally, the noise came from what my friend described as from the engine area.

When my friend returned to the dealer to find out the diagnosis, he was totally taken by the mechanic's explanation of the problem. My friend even tried to tell the mechanic that it was the "engine" noise he was concerned about and not a transmission problem. The mechanic persisted and said it was the transmission that was the problem.

I agree with you on the fluid issue. From all I've read on how these cars are built, transmissions on Corvettes just don't "break" for any reason at all. Maybe the dealer wasn't quite correct in their effort to describe the problem. This was warranty work and meant a substantial amount of money for the dealer.

Thanks,
SKIP

 

[eboch]

Hi;

I recently changed the trans fluid on my '05 Z51 6-spd manual (20K miles on it). The old fluid was indeed surprisingly blackened, but there is nothing wrong with the transmission functionality. It shifts smoothly and makes no odd noises.

Incidentally, it does have a transmission oil cooler.

eboch

 

[Hib Halverson]

I don't know pre 2008, but my 2008 has a transcooler and it's a manual. You can see the coller lines. Here are some pictures:

LINK

"vetteman" is correct.

Earlier I posted inaccurate information which "c4c5specialist" was kind enough to point out to me

All C6 Z51manuals have a trans cooler. It's an oil-to-liquid unit which uses the engine radiator for cooling.

I apologize for any confusion this caused.

 

[RaZr]

Coolers

Anyone know when the various Z51's coolers kick in? Is the fluid flow controlled by a thermostat of some sort that controls a gate, or are they always "on"? Living in South Texas, I got the Z51 pkg. for my '06 M6 coupe in the belief the extra coolers might be useful in ordinary summertime driving when the temperature hits the high 90's (It's 101 degrees as I write this), but I'm not so sure, since my oil temps hit the mid 120's on a fairly frequent basis. Is there any way to know when these coolers are actually engaged?

 

[yellow_2002_germany]

Anyone know when the various Z51's coolers kick in? Is the fluid flow controlled by a thermostat of some sort that controls a gate, or are they always "on"? Living in South Texas, I got the Z51 pkg. for my '06 M6 coupe in the belief the extra coolers might be useful in ordinary summertime driving when the temperature hits the high 90's (It's 101 degrees as I write this), but I'm not so sure, since my oil temps hit the mid 120's on a fairly frequent basis. Is there any way to know when these coolers are actually engaged?

I do believe they are "always on" types with direct piping.

 

[c4c5specialist]

HI there,
That is correct.
Fluid is CONSTANTLY flowing, as long as you are driving the vehicle.
The pump is mounted to the countershaft within the transmission/torque tube assembly.
Allthebest, c4c5

 

[danl72]

Let us know how it turns out with your friend.

 

[darkstar]

On a closely related issue, my clutch reservoir (DOT 4) fluid is very black and my vehicle has only 4400 miles on it. The dealer said it is just due to its (reservoir) location. I do drive the car sportingly and I catch myself resting my left foot on the clutch petal occasionally. Should I be concerned??? Thanks for any advice.

 

[c4c5specialist]

HI there,
It is normal, however, GM service maintenance intervals are 2 years/24000 miles on the clutch fluid.
It is NOT location, however the carbon from the diaphragm leaching into the fluid.
It does not create any reliability issues.
Allthebest, c4c5

 

[darkstar]

Thanks c4c5..

 

[dtammen]

Anyone know when the various Z51's coolers kick in? Is the fluid flow controlled by a thermostat of some sort that controls a gate, or are they always "on"? Living in South Texas, I got the Z51 pkg. for my '06 M6 coupe in the belief the extra coolers might be useful in ordinary summertime driving when the temperature hits the high 90's (It's 101 degrees as I write this), but I'm not so sure, since my oil temps hit the mid 120's on a fairly frequent basis. Is there any way to know when these coolers are actually engaged?

I too have an '05 Z51 MN6. Just curious about your comment on the 'oil temp of mid 120's.' Are you referring to the engine lube oil temp, or do you have a temp gauge on your trans cooler? I see only the lube oil temp on the DIC, which typically runs at 200 deg. when up to normal temp.