Automatic Transmission Fluid change or NOT
Safety Car
Joined: May 2006
Posts: 4,290
Likes: 140
From: Salem NH
Let me see if I've got this straight.
Don't service it for 100K miles and when it reaches 100K miles, whatever you do, don't service it then unless it has had regular prior maintenance.
I certainly appreciate that a transmission shop wouldn't want to touch a car that hasn't been serviced for over 100K miles because if anything goes wrong, they will be blamed. Heck, the owner is probably trying the fluid and filter change because it has started to act up. Even more reason to not touch it.
Don't service it for 100K miles and when it reaches 100K miles, whatever you do, don't service it then unless it has had regular prior maintenance.
I certainly appreciate that a transmission shop wouldn't want to touch a car that hasn't been serviced for over 100K miles because if anything goes wrong, they will be blamed. Heck, the owner is probably trying the fluid and filter change because it has started to act up. Even more reason to not touch it.
If I buy a junkyard transmission for someone, with a 30 or 60 day warranty thats the FIRST thing I'll do, because if it survives the flush, then it probably was serviced regularly. If it stops shifting, the junkyard warranties the transmission and labor.
-- Joe
Melting Slicks
Joined: Jul 2004
Posts: 2,018
Likes: 1
From: OR
Well, a 700R4/4L60E is supposed to get a transmission service at like 36k. (Call your dealer, they will tell you). Most people don't touch the thing until 100k, at which point nobody is going to touch it.
If I buy a junkyard transmission for someone, with a 30 or 60 day warranty thats the FIRST thing I'll do, because if it survives the flush, then it probably was serviced regularly. If it stops shifting, the junkyard warranties the transmission and labor.
-- Joe
If I buy a junkyard transmission for someone, with a 30 or 60 day warranty thats the FIRST thing I'll do, because if it survives the flush, then it probably was serviced regularly. If it stops shifting, the junkyard warranties the transmission and labor.
-- Joe
If you do no use your car under any of these conditions, change both the fluid and filter every 100k miles.
There is no controversy. How hard you are on your transmission dictates how often a fluid filter change is required. There is no harm in changing it early under normal conditions. There is no point to it though if you're not hard on it. If the transmission has about a million miles on it and clearly has burned thick fluid in it, then is when you can contemplate whether it's riskier to flush out the old cr*p or leave it in.
Safety Car
Joined: May 2006
Posts: 4,290
Likes: 140
From: Salem NH
That's what oil can henry's says anyway. What the GM shop manual says is to change both fluid and filter every 15k if the car is mainly driven under one or more of the following conditions. (1) In heavy city traffic where the outside temp regularly reaches 90* or higher. (2) In hilly or mountainous terrain. (3) Frequent trailer pulling. (4) Uses such as found in taxi, police car or delivery service.
If you do no use your car under any of these conditions, change both the fluid and filter every 100k miles.
If you do no use your car under any of these conditions, change both the fluid and filter every 100k miles.
The '89 K2500 I just bought has a 700R4 and 120k on it. It shifts fine, so I'm not touching it.
When it does explode, which will happen while plowing, I'll rebuild it and change it every 20k.There is no controversy. How hard you are on your transmission dictates how often a fluid filter change is required. There is no harm in changing it early under normal conditions. There is no point to it though if you're not hard on it. If the transmission has about a million miles on it and clearly has burned thick fluid in it, then is when you can contemplate whether it's riskier to flush out the old cr*p or leave it in.
-- Joe
Advanced
Joined: Sep 2003
Posts: 57
Likes: 3
From: Clover, SC
I'll post somewhat of an opposite story to some of the responses on the topic. I've got a '93 vette with over 240K miles on the ODO, ORIGINAL powertrain never rebuilt. It's been serviced regularly, including tranny fluid replacements every 50K. I was experiencing problems with lack of power on the top end, accompanied with the transmission that did not feel like it wanted to shift into the next gear (I.E. 1-2 shift) at 55oo+ RPM's (I always backed off the throttle out of fear). I changed the tranny fluid (it was definitely burned) and replced with the newer tranny fluid with seal conditioners for high mileage vehicles and it feels like a new car! It's snappy off the line, shifts nice and firm again, and has more power across the band.
Two of the things that I feel are important on the matter are: 1) Service the transmission regularly, and you don't get get into issues where you're worrying about changing the fluid when it hasn't been changed in a while 2) When you do change the fluid, drain & replace (flushing the tranny could "kick up" material that had settled out in the pan) and TAKE IT EASY for the first thousand miles and let the o-rings, seals etc bed in with the new fluid..
That's my .02
Two of the things that I feel are important on the matter are: 1) Service the transmission regularly, and you don't get get into issues where you're worrying about changing the fluid when it hasn't been changed in a while 2) When you do change the fluid, drain & replace (flushing the tranny could "kick up" material that had settled out in the pan) and TAKE IT EASY for the first thousand miles and let the o-rings, seals etc bed in with the new fluid..
That's my .02
Melting Slicks
Joined: Oct 2005
Posts: 2,617
Likes: 13
From: Pasadena, CA
Last week At 50k miles I thought it would be good to have the trans fluid and filter changed. I let the dealer do it. I'm sorry I did.
The car is not acting right. Straight acceleration is good, but If, from a stop making a left or right turn and excelerate a little more during the turn it feels as if something grabs and engages... but yet no slippage. it's a little hard to explain and I know if I take it back to the dealer they will either tell me that it won't do it for them or make matters even worse. I think I will just live with it.
The car was running great before. I should have left it alone.
The car is not acting right. Straight acceleration is good, but If, from a stop making a left or right turn and excelerate a little more during the turn it feels as if something grabs and engages... but yet no slippage. it's a little hard to explain and I know if I take it back to the dealer they will either tell me that it won't do it for them or make matters even worse. I think I will just live with it.
The car was running great before. I should have left it alone.
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Racer
Joined: Jul 2007
Posts: 281
Likes: 2
From: Mount Vernon Indiana
Last week At 50k miles I thought it would be good to have the trans fluid and filter changed. I let the dealer do it. I'm sorry I did.
The car is not acting right. Straight acceleration is good, but If, from a stop making a left or right turn and excelerate a little more during the turn it feels as if something grabs and engages... but yet no slippage. it's a little hard to explain and I know if I take it back to the dealer they will either tell me that it won't do it for them or make matters even worse. I think I will just live with it.
The car was running great before. I should have left it alone.
The car is not acting right. Straight acceleration is good, but If, from a stop making a left or right turn and excelerate a little more during the turn it feels as if something grabs and engages... but yet no slippage. it's a little hard to explain and I know if I take it back to the dealer they will either tell me that it won't do it for them or make matters even worse. I think I will just live with it.
The car was running great before. I should have left it alone.
Burning Brakes
Joined: Sep 2006
Posts: 1,202
Likes: 3
From: MD
Last week At 50k miles I thought it would be good to have the trans fluid and filter changed. I let the dealer do it. I'm sorry I did.
The car is not acting right. Straight acceleration is good, but If, from a stop making a left or right turn and excelerate a little more during the turn it feels as if something grabs and engages... but yet no slippage. it's a little hard to explain and I know if I take it back to the dealer they will either tell me that it won't do it for them or make matters even worse. I think I will just live with it.
The car was running great before. I should have left it alone.
The car is not acting right. Straight acceleration is good, but If, from a stop making a left or right turn and excelerate a little more during the turn it feels as if something grabs and engages... but yet no slippage. it's a little hard to explain and I know if I take it back to the dealer they will either tell me that it won't do it for them or make matters even worse. I think I will just live with it.
The car was running great before. I should have left it alone.
That actually sounds to me like a problem with the posi-clutches in the rear of the car. A transmission problem should be the same regardless of turning or straight. That really sounds like a posi-clutch is hanging and/or slipping. Did the dealer add any fluid to the rear while they were doing the tranny? If the rear leaked, and they added oil to it without adding posi-additive it would do this...
Burning Brakes
Joined: Sep 2006
Posts: 1,202
Likes: 3
From: MD
On the subject of tranny fluid changes, I've got my $.02 to add as well. I always change my autos at 25k. My boss recently bought a brand new '08 Tundra (for like $42k 
). He knows I'm real into old cars, so he was bragging about his "lifetime transmission fluid". Seems the Tundra owners manual actually says not to change the tranny fluid. I couldn't get him to understand, though, that his powertrain warranty is only 100k. Toyota can easily design a tranny to last 100k on the original fluid, but I predict his tranny is gonna drop out soon after his warranty is up and he'll be stuck. Anything I buy is gonna be serviced regularly, properly, and with high-quality filters and lubricants...
). He knows I'm real into old cars, so he was bragging about his "lifetime transmission fluid". Seems the Tundra owners manual actually says not to change the tranny fluid. I couldn't get him to understand, though, that his powertrain warranty is only 100k. Toyota can easily design a tranny to last 100k on the original fluid, but I predict his tranny is gonna drop out soon after his warranty is up and he'll be stuck. Anything I buy is gonna be serviced regularly, properly, and with high-quality filters and lubricants...
Premium Supporting Vendor
Joined: Aug 2001
Posts: 5,364
Likes: 38
From: King George VA
Jim,
That actually sounds to me like a problem with the posi-clutches in the rear of the car. A transmission problem should be the same regardless of turning or straight. That really sounds like a posi-clutch is hanging and/or slipping. Did the dealer add any fluid to the rear while they were doing the tranny? If the rear leaked, and they added oil to it without adding posi-additive it would do this...
That actually sounds to me like a problem with the posi-clutches in the rear of the car. A transmission problem should be the same regardless of turning or straight. That really sounds like a posi-clutch is hanging and/or slipping. Did the dealer add any fluid to the rear while they were doing the tranny? If the rear leaked, and they added oil to it without adding posi-additive it would do this...
I'd check with the dealer and see what, if anything, they might have done with the diff. 
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AMSOIL Preferred Customer Program (Members buy at Wholesale - a savings of about 25%)
Premium Supporting Vendor
Joined: Aug 2001
Posts: 5,364
Likes: 38
From: King George VA
Adding to the debate on the side of those favoring regularly tranny fluid changes (which I favor myself), check out how poorly the Texaco Havoline ATF did in this AMSOIL commissioned test:
AMSOIL vs Havoline ATF Viscosity Testing
1000 hrs even at a highway average of 60 mph is only 60,000 miles. Wonder what its viscosity would be at 100k.
AMSOIL vs Havoline ATF Viscosity Testing
1000 hrs even at a highway average of 60 mph is only 60,000 miles. Wonder what its viscosity would be at 100k.
Melting Slicks
Joined: Oct 2005
Posts: 2,617
Likes: 13
From: Pasadena, CA
Jim,
That actually sounds to me like a problem with the posi-clutches in the rear of the car. A transmission problem should be the same regardless of turning or straight. That really sounds like a posi-clutch is hanging and/or slipping. Did the dealer add any fluid to the rear while they were doing the tranny? If the rear leaked, and they added oil to it without adding posi-additive it would do this...
That actually sounds to me like a problem with the posi-clutches in the rear of the car. A transmission problem should be the same regardless of turning or straight. That really sounds like a posi-clutch is hanging and/or slipping. Did the dealer add any fluid to the rear while they were doing the tranny? If the rear leaked, and they added oil to it without adding posi-additive it would do this...
The dealer did not do any service on the rearend. I had the additive added about 30,000 miles ago, which cured an earlier growling and clunking problem. I'm at 50,000 miles now so maybe it's time to change the differental fluid again. Thoughts?
Melting Slicks
Joined: Jul 2004
Posts: 2,018
Likes: 1
From: OR
That's what oil can henry's says anyway. What the GM shop manual says is to change both fluid and filter every 15k if the car is mainly driven under one or more of the following conditions. (1) In heavy city traffic where the outside temp regularly reaches 90* or higher. (2) In hilly or mountainous terrain. (3) Frequent trailer pulling. (4) Uses such as found in taxi, police car or delivery service.
If you do no use your car under any of these conditions, change both the fluid and filter every 100k miles.
There is no controversy. How hard you are on your transmission dictates how often a fluid filter change is required. There is no harm in changing it early under normal conditions. There is no point to it though if you're not hard on it. If the transmission has about a million miles on it and clearly has burned thick fluid in it, then is when you can contemplate whether it's riskier to flush out the old cr*p or leave it in.
If you do no use your car under any of these conditions, change both the fluid and filter every 100k miles.
There is no controversy. How hard you are on your transmission dictates how often a fluid filter change is required. There is no harm in changing it early under normal conditions. There is no point to it though if you're not hard on it. If the transmission has about a million miles on it and clearly has burned thick fluid in it, then is when you can contemplate whether it's riskier to flush out the old cr*p or leave it in.
Yes, that's what it says in my vette owners manual as well.
And yes, it makes sense to leave a tranny with badly contaminated and burned fluid alone if you want to continue to get more use out of it. As the material on the clutch packs sluffs off into the fluid, the space between the friction discs and steels gets larger. At the same time the tranny fluid is getting thicker which makes up for the extra space. If this is the condition the tranny is in, it may not function as long after replacing the 'thick' old fluid with 'thin' new fluid as it would have if left alone.
Racer
Joined: Sep 2008
Posts: 456
Likes: 0
From: FL
Problem with not changing is that fluid is slowly going bad. So transmission will die sooner or later. There is a way to stop fluing going bad w/o changing it. Pump out 2 bottles thru dipstick pipe and fill 2 bottles. If you do that there will not be radical changes in fluid condition.
That is what we decided to do with my dad's van at 120K. It was fine.
That is what we decided to do with my dad's van at 120K. It was fine.
Pro
Joined: May 2001
Posts: 578
Likes: 2
From: River Ridge LA
Trans fluid change
Hi All
I am on the side of over kill I pull the drain plug on my trani
and refill with Amsoil ATF with every oil change Thats is twice a year
event on my GMC Yukon. I do a LOT of towing Mostly open car trailers
with one of the Vetts I also have added a 28k lb.. Trans cooler after the factory trans cooler. HEAT is the downfall of any transmission.
My trans fluid stays bright and clear But note in a modern transmissions
by the time the fluid is dark and smells you have already got problems
Fluid is VERY CHEEP even synthetic. A new or rebuilt transmission is VERY expensive The bottom line put a drain plug and change it often
One other thing i have sent samples to Blackstone Labs The reports
show little or no wear with 135k miles
The bottom line 5 quarts of fluid is MUCH CHEPER than a new transmission and give piece of mind
Good luck
Michael
I am on the side of over kill I pull the drain plug on my trani
and refill with Amsoil ATF with every oil change Thats is twice a year
event on my GMC Yukon. I do a LOT of towing Mostly open car trailers
with one of the Vetts I also have added a 28k lb.. Trans cooler after the factory trans cooler. HEAT is the downfall of any transmission.
My trans fluid stays bright and clear But note in a modern transmissions
by the time the fluid is dark and smells you have already got problems
Fluid is VERY CHEEP even synthetic. A new or rebuilt transmission is VERY expensive The bottom line put a drain plug and change it often
One other thing i have sent samples to Blackstone Labs The reports
show little or no wear with 135k miles
The bottom line 5 quarts of fluid is MUCH CHEPER than a new transmission and give piece of mind
Good luck
Michael