Thread: 700R4 Transmission service
03-26-11, 04:28 PM #1
700R4 Transmission service
I just purchased a C4 1987 convertible with only 9,600 original miles on it. I has been driven every summer for only a few hundred miles. I know for certain that the fluids have never been changed. I plan to have this done immediately. My main concern is with the service on the 700R4 automatic transmission. The fluid still has the clean redish color with the normal oder. I am confused since some people say to just have it flushed, some have told me to drop the pan and replace the filter and some have told me to do both.
Can anyone tell me the correct thing to do.
03-26-11, 06:28 PM #2
Can never go wrong with a service.If the car drove that little,probably never got good and warm.Fresh fluid has all proper levels of additives keeps seals soft and shifts nice.Did mine last weekend just to get ready for trouble free summer.
03-26-11, 07:01 PM #3
Regarding the trans, its no emergency. You can just leave it or change the fluid (if it makes you feel better) which can be done by sucking it out thru the filler tube or dropping the pan and changing the filter while in there. I am a fan of full synthetic trans fluids because of fleet reports and stats that indicate a greatly reduced failure rate when a used trans is switched to synthetics. Others here do not agree. Thats just MY opinion...
Trans fluid is different than motor oil; its a high grade hydraulic fluid that is formulated with all kinds of additive to fight corrosion, boiling, viscosity and moisture contamination. Thats why the fluid is colored, so its easier to see contamination. If the trans fluid looks good, it is. The more typical hyd fluids used in most hyd equipment use a clear fluid since they are not a sealed system like an auto-trans. Newer automatic trans are totally sealed, and because the fluid does not actually wear, the unit is sealed against outside contaminants getting in. BMW uses such a trans that has no filler hole, no dipstick. Other mfgs are starting to realize that fluid failures and trans failures are caused by things outside the transmission. Your Corvettes Dana rear end is like this...no drain. Be sure to add the GM limited-slip additive whenever you do service the rear end.
Good luck with your car...9600 miles...thats like finding a winning lottery ticket laying on the sidewalk. I'd have sold a kidney to been able to buy that car !
03-26-11, 07:30 PM #4FISHAWKGuest
WOW! only 9600mi , that's great!... I would have to agree about the trans fluid, if it will make you feel better, go ahead and change it it can't hurt...but I wouldn't sweat it!
Anyway conrats on such a great find, and enjoy yourself driving it!
03-27-11, 07:57 AM #5
Just my 2c but I would not mess with the trans or rear end fluids other than to check and make sure they are full. Unlike gas they do not go bad over time only with use. There is an old saying IF IT IS NOT BROKE DON"T FIX IT. I find keeping that in mind is helpful on these cars. When new to a car like the corvette we tend to read the forums and start imaging all the things that can go wrong and want to do preventative maintenance to avoid the horrors stories we read in the forums.
The real truth is that yes these are real stories of real problems that have been diagnosed and fixed by the great people on these forums. But keep in mind these are the exception and not the norm for our cars. WE are enthusiast and and so we post all we know about the problems and fixes for our love of these cars. The problem as I said earlier is to a newcomer it may seem like they have to worry about all these problems in there cars. On a low milage car like you found the best thing you could do is to put in a fresh tank of gas and take it for a 500 mile day trip. Lots of good things will happen if you do the enjectors will self clean the fluids will all get up to proper temp and you will come home with a grin on your face that will take weeks to go away.
Retired from 30 years in the transmission manufacaturing
03-28-11, 04:49 PM #6
I prefer to change all fluids every so often. Mercedes used to have their "Forever" fluid but even they changed their mind and set a schedule for it. I would not use old fluid. Sure, there are a lot of old wives tales about changing the fluid and the trans dies. Yet nobody has been able to show any science behind that. Of course I know of several people who have been wondering about their trans failure. They do a "Hail Mary" flush because they think it might help. Lo and Behold, the trans fails. As such, they blame the trans flushing or fluid change. I too have flushed the trans as a "Hail Mary" and it failed. But we won't discuss the fact that it was acting erratic and the tech found sludge in the pan.
I can't see any scientific proof that changing the fluids is bad. Fluids, IMO, break down after a while. I don't believe anything is forever. Yes, synthetic might give you a little more stability but you still have to figure that the composition might get stale after a while. I flush my brakes ever couple of years for that very reason. If someone can show me scientific proof that flushing or changing fluids is bad other than anecdotal "evidence" that it cleans the sludge and causes leaks, breaks the trans, causes you teeth to get loose and hair to fall out, etc, etc, I would be glad to review it.Holley Stealth Ram, 42# injectors, AFR 190 heads, 1.6 intake RR and 1.5 exhaust RR, 230/236 - 110 lobe sep, 108 intake centerline (2 deg. advanced), TPIS Long Tube Headers, Random Tech Cat, Borla exhaust, Rossler Trans, HiTech Motorsport tuned ECM.
03-28-11, 08:04 PM #7
03-28-11, 11:42 PM #8
Holley Stealth Ram, 42# injectors, AFR 190 heads, 1.6 intake RR and 1.5 exhaust RR, 230/236 - 110 lobe sep, 108 intake centerline (2 deg. advanced), TPIS Long Tube Headers, Random Tech Cat, Borla exhaust, Rossler Trans, HiTech Motorsport tuned ECM.
03-29-11, 06:17 AM #9
I do understand what aklim is saying about the age of the oil. But I would like to share some thoughts I have on the subject of oil changing in general
Today we have motor oils that are rated for 5, 10, or 15 thousand miles of use before being changed. However because great grandpa advocated changing his oil every 3 thousand miles it became the national standard (remember this was in the days before synthetic or blended oils). And also the manufactures recommended we change the oil this frequently (again because of less effective filtering and short trip driving). Now we fast forward to today’s real world were the engines go 250K instead of 50K as in the days of old.How to reduce our dependency on foreign oil
So let’s try to put this in perspective as to how it impacts our dependency on foreign oil.
If you drive a car 100,000 miles and change the oil every 3,000 miles that will take 33 oil changes. But if you only change every 6,000 miles you only have 16.6 oil changes. Each oil change will take 4 quarts of oil so you have used 33 gallons of oil at 3,000 mile change intervals as opposed to 16.6 gallons at 6,000 miles.
If 1,000,000.00 people every day change their oil at 3,000 miles instead of 6,000 we will be prematurely disposing of 16,600,000.00 gallons of oil a day (Adding to our environment problems). Carrying this further take the daily figure and multiply by 365 days a year and you get 6,059,000,000.00 gallons of oil that has been wasted.
I believe that we out of a lack of knowledge want to cling to the way we have always done it approach. For example I remember when radial tires became the new kid in town people actually bought new cars and then took them directly to a tire store to replace the radials. Or when disk brakes were first introduced the horror stories that were told about how you would have to replace everything but the crank for the passengers window when the brakes needed to be replaced. Or more recently the acceptance of seat belts, air bags, anti lock brakes. So until proven wrong I for one will accept that what I learned as a teenager from grandpa and dad has been improved with technology and the old truisms no longer apply. I will however keep an open mind and if my car goes through a sand storm I would then off course replace the filters and oil regardless of the mileage on them.
03-29-11, 09:21 AM #10
If you want to extend your Oil Change Interval, the answer is very simple. Take a sample and send it to someplace like say Blackstone Labs. Can the oil go 3000 miles or more? IDK. Let the lab results speak. I for one will stick to the old 3000 miles unless I have sent the oil out for testing and then will adjust the OIC to suit the results. I will drive differently from others so just because I can make it 5000 miles doesn't mean you can.Holley Stealth Ram, 42# injectors, AFR 190 heads, 1.6 intake RR and 1.5 exhaust RR, 230/236 - 110 lobe sep, 108 intake centerline (2 deg. advanced), TPIS Long Tube Headers, Random Tech Cat, Borla exhaust, Rossler Trans, HiTech Motorsport tuned ECM.
03-29-11, 10:06 AM #11
The "old school" mentality is one of ignorance and lack of keeping ones self educated regarding the things that evolve all around us. We should evolve as well but we don;t because of our arogance. Its more comforting to say to ourselves that "we've mastered automotive technology" of the past, and say it with confidence, than it is to say or admit that we're completely in the dark regarding the new products out there...So we'll try to apply yesterdays skills to todays situation and try to keep that warm fuzzy feeling about our abilities and knowledge,. after all, who wants to admit that they are lost, or simply don't know? I sure don't. Thats human nature.
What we can easily do to help cope with this is to look around and remember that NOBODY was born knowing all this stuff. Every single person out there that does know whats going on today, was trained and had someone else present that info to them. They did'nt just wake up knowing how to maintain a new 2011 vehicle...or understand how oil works and how we work with oil.
As mean as it sounds, old schoolers need to sit down and loose the attitude.
Once a better understanding of a subject comes your way, then you can begin to feel confident about what you know of todays products. Oil changes for example...oil does not wear out, it gets contaminated and dirty. The additives (polymers) in motor might break down after so many cycles and so much contamination, but the base oil is still oil. Its collected, filtered and reused in other applications. The way this works is a matter of molecules...all the things that we want to filter out of dirty oil happen to be as small as the things that make the oil lubricate, so we can only filter out so much until we start to filter away the oil itself, so once its contaminated it can not really be cleaned to be as effective again, at least with the existing technology. Reclaiming oil is expensive and there is not that much savings over new oil, so old oil just is'nt worth pursuing that far. That may change at some point if the price of new crude keeps rising with the sun everyday...
Oil changes are less frequent in new car maint schedules because the oil in a 2011 engine gets less contamination due to better and better engine mngt. In 1965 a car that got 12 mpg was an economy model. It also had a life expectancy of way less than 100,000 miles because the excess (wasted) fuel washed away all the oil and all that fuel and dirt/carbon went to the pan where moisture helped form acids that destroyed the ability to lubricate. It wore itself out prematurely due to excess fuel. Now with precision fuel injection, that does not happen. Its well documented that the majority of engine wear takes place at start up. Once running, engines stay cleaner, longer and so does the lubricating oil.
If the oil is ok...why throw it away? The conspiracy theorist of the world say that the factory maint schedule says to change oil at 6000 miles so they can sell more parts when the engine wears out. Thats what "they" want. Thats hooey. Why would a company want to market a product that wears out? There are plenty of sales out there for new cars, and parts sales will slowly take a backseat to car replacement as laws change and move toward stricter enforcement like Japan and some other countries.
The evolution of things in our lives is like an ongoing education...People did'nt understand the microwave when that came out...drying the dog by nuking it happened a couple times...
Or fuel injection.,..that was going to make tow drivers rich. gas was going to have t o be so clean that it would'nt burn...constant filter problems etc..Then the unleaded issues...wow...lets keep on filling the atmosphere with lead so our grandchildren can be born stupid too....We only acceptted that particular change because we did'nt get a choice. But we tried...I personally punched out the small gas filler tube (my new '77 Ranchero) so I could use leaded fuel...for as long as I could and I'll admit it now, I had NO friggin clue as to why..all I knew was that unleaded fuel was evil. They said so on the news. The guy at the Gulf station said so. They know..right?
Disc brakes...I recall that one well. Won;t stop in the rain, won;t be able to stop a car evenly...all stories originating from fear, ignorance.
Radials...yep. I remember people replacing radials with bias ply for as long as they could and then when they finally started to accept radials and understand that radials were not the devil as the 6:00 news reporter has told them, there was no apology to Goodyear or Firestone...we just went along and used arogance as our shield in our battle with evolution. Jet engines, FM radio, color TV...all suffered the same as they came to market and slowly had to prove themself to the world.
Its like anything else, educate yourself continously or be trapped forever in the time that you choose to end your personal education and evolution, Being unable to relate to today and tomorrows products.
I'll confess. I still have VHS tapes....I've got all form of disc for video and music, I just won't toss a perfectly good system and all that money spent on magnetic tape...what else is it good for? I keep an old 8mm film projector sitting on a shelf for decor, now guest think the VCR is the same thing..
With the price of gas as it is and we all know its not going to go down much.
I'd sure like to see a few more barrels of crude go toward fuel instead of lubricants.
03-29-11, 11:41 AM #12
But that's the point. If I am understanding the OP, that was the 1987 blend, which is old stuff and certainly not superior to 2011 blend. Further to that, no seal is perfect so it is going to get contaminated over the years and the additives might have broken down. Since it is that old, why take the risk?
Perhaps so but with so many years on it, wouldn't you suspect that somebody has been starting the vehicle from time to time and not moving it so there might be at least some heat cycles in the trans fluid.
If it is ok, I agree that we should not just throw it away. Question. How do you know it is OK without subjecting it to tests? When diesel fuel became ULSD, we had people that can feel it in their hands and know it is not as lubricating. Well, why have those expensive test machines to do that testing then? Why not hire these people with sensitive fingers? Same as trans fluid or fuel injectors. There is no way to know for sure. Only a test can tell. Yet people here will tell you that the snake oils they put in the tank can clean injectors, make your teeth whiter and your "johnson" longer. A lot of anecdotal evidence but not a single scientific test.
Here is another fact. If every car has to change trans fluid at 20K and I can build a trans that changes it ever 100K, I think that will be a bigger selling point. Assuming the cost is about the same, that is.
Like everything else, when you are the new kid on the block, you have to prove yourself. Just because you are new doesn't mean we should wholeheartedly accept you and your claims. After all, there are many new products that looked good on the drawing board but sucked in real world scenarios.
Unfortunately we won't drill what we have or get it from the Bakken Shale fields
03-29-11, 12:41 PM #13
The test have already been done...
by countless fleets, mfgs, UL SAE...you name it. There is no exp date on a qt of oil.
besides, you make an excellent point, thats yesterdays oil, by age, and design. Being in yesterdays design trans is appropiate then is'nt it?
I'm as stuck on changing fluids the old fashioned way as anyone. BUT...
with cost as they are, and knowing of this other information that has become available, I am working to shed my old school ways and embrace the 21th century. It's got to start sometime.
Hell, back when the 2000 mile rule was the reccomended cycle time for motor oil, Western Auto sold a filter kit that used a roll of toilet paper as the element...
Times have changed somewhat.
its just my opinion, but I don;t see the need to change trans fluid thats got less than 300 hrs on it. Hydraulic fluids go by time run or duty cycle, not necessarily miles.
Besides, its his car, if it makes him feel better then fine,, go ahead. It won;t effect the cost of apples in my neighborhood one bit.
03-29-11, 12:58 PM #14
True but perhaps today's fluid in yesterday's trans would be better?
In my diesel Powerstroke, the recommended OCI is 3000 miles. Now, you can use synthetics and extend that but how much is a guessing game. If you want to be sure, simply take an oil sample and have it tested then the recommendation of how much longer you can run it will be known. So, at 5000 miles, I will drain the oil and have a sample sent out and Blackstone will say something to the effect of "You can go another 2000 miles before the next change based on this sample". So, with that information, it can guide you to the correct OCI. I wouldn't simply recommend you embrace everything that comes along simply because it is the latest item. Test it first before accepting it. Anecdotal evidence is not worth a damn when compared to a laboratory test.
Do you know how many hours it has on it? 30 hrs of burnouts is more stressful than 300 hrs of cruising. I am thinking the PO has been running the car every now and then. If so, you might have 300 hrs on it with low miles. Better safe than sorry. When I get a used car, I change all the fluids. I don't know what you did when you owned it so I want to be safe and change it to what I know is good.
03-29-11, 02:50 PM #15
Let's see a picture of the vette it should be cherry unless it was left out in the sun since 1984.
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