Changing tranny fluid!!
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Changing tranny fluid!!
I'm going to change the tranny fluid in my 90 Bronco. Someone told me that when I change it the new fluid(which is slicker than the old fluid) will cause my truck's tranny to slip. Is this true. Please get back to me as fast as you can! THANKS!!
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From: Minneapolis USA
Changing tranny fluid!!
How many miles are on your Bronco, have you ever done a flush before or has the tranny ever had a flush? I flushed my tranny at about 150,000 and it had never been done before, two days later, my tranny went out. If it's never been done and has high miles i would not recommend it, that's my opinion, others here may disagree.
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From: Cincinnati
Changing tranny fluid!!
Well, many of the new fluids are thinner for better cold start response. The problem some refer to is detergents in the new fluid causing gunk deposited over the years to enter the valve body. I don't think that is much of a problem. Depends on how dirty the fluid is now. Some people prefer to do just the pan drop which replaces only 35% of the fluid and repeat that 6 months later.
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Changing tranny fluid!!
My truck has 150,000 miles. the tranny itself has 30-40,ooo miles! The fluid right now is bright red. The only reason I'm changing it is because I need to replace the gasket on the pan because it's leaking.
The fluid was changed 19,268 miles ago. What do you guys think I should do??
HELP!!!!!!!!!!!:-staun
The fluid was changed 19,268 miles ago. What do you guys think I should do??
HELP!!!!!!!!!!!:-staun
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Joined: Dec 2002
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From: Minneapolis USA
Changing tranny fluid!!
If you've flushed it 19,000 ago you're pretty safe in changing the fluid. Ive only seen tranny's with high miles fail after a flush. Some people recommend flushing every 20,000 and you're less than that on this fluid. 
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From: Dededo, Guam
Changing tranny fluid!!
I would use new just so you know good stuff is going in. If you leave the old fluid sitting around, you might get some contaminants you wouldn't want floating around in your tranny. Just my 3 cents.
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Elder User
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From: Nebraska
Changing tranny fluid!!
There is a friction additive in tranny fluid that is "used up" over time. You should definatly use new fluid and put in a new filter while you have the pan off. (most filters come with a gasket too)
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Changing tranny fluid!!
Somebody should market a reduced detergent fluid. This happens alot, somebody gets a leaky pan or line, gets it fixed, then couple weeks later, gets tranny rebuilt. Come to think of it, now I can see why this isn't offered after all. You also have to watch, whoever changes fluid, pour it in!!! Insist on this, otherwise, you have no idea what went in there. Some of these places only use GM fluid on everything.
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From: Cincinnati
Changing tranny fluid!!
You just don't find caked on sludge like you might find in some old 75 Ford engine. I delayed rebuilding a transmission with a mechanical problem for a long time. Drained the fluid every couple of months and had 5 magnets that would get 1/4 inch of coating on them. When I dropped the valve body, the gasket had 1/8 inch of sediment in the channels. That tranny never missed a beat except the OD which was grinding itself to death. A change in chemical formulations probably has more to do with problems than detergent. And I think these problems are rare. More likely it has to do with the change in driving habits one the fluid is changed. Everyone seeing what the "new" transmission can do.
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Changing tranny fluid!!
If I seen it once, I seen it a dozen times. Someone for some reason or another, changes the fluid, then has to rebuild the tranny shortly thereafter. As a matter of fact, I rarely see it work any other way. It is not the driving habits that change, mine never did anyway. This happened to me twice. I never got on it hard after a fluid change, just drive it like normal. No one I know thinks changing the fluid will have any performance increase no more than changing motor oil would, so who romps on it? There is something with the new fluid that screws things up. You can argue about what that something is if you want, but the best arguement I've heard is the detergent in the new fluid. The best advice I can give is either change it regularly or never change it at all and hope you never get a leak or broken line.
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From: SLC
Changing tranny fluid!!
[updated:LAST EDITED ON 30-Dec-02 AT 03:12 PM (EST)]I would say if you haven't changed it in a while and you have high miles take it somewhere and have them use a fluid changer to do it. It will flush almost all of the fluid out. The problem with changing it yourself is that it is very hard to get all the fluid out of the torque converter. I know there is a way, I'm just not that mechanically inclined and patient enough:-X23 That way you know that you won't have old fluid with new fluid. This is just my humble opinion.
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From: Cincinnati
Changing tranny fluid!!
I bought a 97 Explorer with a 5R55E that had 106K and never a fluid change. Nasty looking fluid. Dropped and cleaned the pan, changed the filter. 10K later did it again and then used the pump out method. Now over a year later and 25K everything still fine. I did find all the valve body bolts loose. The 5R55E is notorious for blowing out gaskets. Just bought a spare transmission to play with that I will probably will never use. I would never hesitate to change fluid. Just don't like things that stirr up the crud in the pan or the TC.
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Changing tranny fluid!!
Automatic Transmission Fluid Change Warning
by Harry Yarnell, Virtual Vairs
Pennzoil is recommending that if an automatic transmission hasn't had an oil change within the first 75,000 miles, NOT to change the oil at all. Allegedly, the transmission is just happy as pig in mud with the old fluid, and by changing the oil will create more trouble than if left alone. Goes against conventional wisdom, but I guess its the sleeping dog syndrome.
Editor: I believe the theory here is that over the years, old transmission fluid looses its cleaning abilities. This allows sludge and debris to collect in various nooks and crannies. These clumps won't cause any problems as long as they stay put. However, fresh transmission fluid will flush this junk from its hiding places and allow it to float freely through the transmission. It then clogs up narrow passages, causing malfunction and damage.
http://www.corvair.org/chapters/chapter017/resources/tips/vv/automatic_transmission_fluid_change_warning.html
by Harry Yarnell, Virtual Vairs
Pennzoil is recommending that if an automatic transmission hasn't had an oil change within the first 75,000 miles, NOT to change the oil at all. Allegedly, the transmission is just happy as pig in mud with the old fluid, and by changing the oil will create more trouble than if left alone. Goes against conventional wisdom, but I guess its the sleeping dog syndrome.
Editor: I believe the theory here is that over the years, old transmission fluid looses its cleaning abilities. This allows sludge and debris to collect in various nooks and crannies. These clumps won't cause any problems as long as they stay put. However, fresh transmission fluid will flush this junk from its hiding places and allow it to float freely through the transmission. It then clogs up narrow passages, causing malfunction and damage.
http://www.corvair.org/chapters/chapter017/resources/tips/vv/automatic_transmission_fluid_change_warning.html