Service Tech told me replacing the trans fluid wou

factoryblue

Registered User
New trans fluid destroying trans???

Went to Oil Express for a chassis lube and rear end service. When they checked the trans fluid it looked very nasty. They told us if the fluid was to be replaced it might jeopordize the auto trans. There are no leaks and it shifts alright. Next fall this car will be getting 300 miles a week through Kentucky backroads, and I do not want the trans to go out. Has anybody tryed Lucas Oil products on their trans? What should I do?
 
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why ?

Never heard of a shop recommending you run old fluid. I'd get a second opinion. I know that the dynamics of the fluid changes overtime just like oil looses its ability to protect and coat over time.
 
Old fluid in a tranny starts leaving deposits that the tranny learns to live with. If you put in new fluid, the detergents start breaking these things down and eventually get located somewhere where they will do something bad :) If your tranny has too many miles and the fluid has never been repalced, leave it in there.

Leimens terms rule!

Al
 
One of my friends back home used to work at the Tires Plus there before he moved to college. He told me that once a guy brought his big old Suburban in and wanted the tranny fluid changed. They looked at the fluid, and it was very dirty and had some metal flecks in it. They warned him that the transmission may fail after the change, but he told them to do it anyway.

Low and behold, after they changed the fluid the transmission would not go into ANY gear. It was toast. So yes, I guess if you don't keep up on fluid changes, don't bother at all unless you want to rebuild the tranny.

-Chris
 
I have heard the same thing. A friend of mine was a manager at a Minute Lube they were told not to change cars in excess of 60K if they had not been serviced prior to this time. He was told that the clutch particles in the trans were the only things holding the clutches together basically without them the trans would slip. I had close to 80K on my car and asked him to change it. I never had a problem with it until about 30K later, so who knows. I’m pretty hard on automatics (just ask the 00’ impala with only 5K)

Jeff
 
So how can you tell if your fluid has been changed or if changing it will screw up your tranny? I have almost 100k miles on my car and I dont know if it has ever been changed, bought the car with 91K. It does shift kinda hard from 3rd to 4th.
 
Oh LORD have I been here before. If you have not, or don't know about the previous owner, been changing the fluid in that trans and it's over 60000 miles and looks brownish or smells a bit burned, just don't touch it. You are at the point where you either drive it til it quits or rebuild it now. I have 160000 miles on my 92 explorer and the fluid was brownish when I got it at 120000. My mechanics told me to leave it alone. I got five years out of that tranny, taking trips 4 times to New England and back until it finally started showing slippage and finally locked up. Rebuilt with a rear main seal installed too for $1600. A friend bought a 35th last summer and the owner had just serviced the transmission thinking he was doing a good thing. 2 weeks after driving it, it locked in overdrive and had to be rebuilt. It had 105000 on it when he bought it. Just add this to the list of opinions.

Good luck to you.
 
trans fluid

I know a couple of transmission enineers, one from Ford and another from GM. I've talked to them about this and both of them said that they wouldn't recommend ever changing trans fluid. Because it's a closed system, there isn't any reason that it would get dirty.
 
I don't know about trans fluid not getting dirty, but... Anyway, about the only way I know to determine if the fluid has or has not been changed is by the little plastic dipstick plug in the pan. Unfortunately you have to pull the pan to find out.
 
When I bought my 1986 Grand Marquis with 150,000 or so on it, the transmission STILL had that plastic factory plug in the pan. Wierd thing is, the fluid still looked pretty good and there was hardly any deposits on the bottom of the pan itself. The transmission still seems to shift fine, and I've been hard on it. I overheated it hardcore when I pulled bushes out of my parent's yard with the car (and there are still tires marks on the driveway to prove it). My dad said he's pay for any damage to the car from that, but despite the fluid accumulating more deposits (still red, but has dark clutch flecks in it) it still works good.

Tough transmission in my opinion. The car has 184,000 on it now and it sometimes shifts just a little rough between 3-4.

-Chris
 
Re: trans fluid

Slysc said:
I know a couple of transmission enineers, one from Ford and another from GM. I've talked to them about this and both of them said that they wouldn't recommend ever changing trans fluid. Because it's a closed system, there isn't any reason that it would get dirty.

Oh now I KNOW that's wrong. Not the part about it being a closed system but rather the part about it not getting dirty. The clutches do wear and that material is deposited in the fluid. That right there is a contaminant.

Another issue is that the slip of various components does overheat a miniscule portion of the fluid each time eventually oxidizing all of it.

Further, the gear-to-gear contact of the planetary gearset will result in breakdown of the fluid due to a process known as shear. The gear contact quite literally breaks the viscosity improvers in oils and lubricants (tranny fluid is equivalent to 20wt in viscosity, BTW) Shear is the reason you don't use automotive oils in motorcycles (gears are lubed by engine oil) and is considered to be the primary reason those Toyota 4 cylinders sludge up so bad if you not right on top of the oil changes.

Also a bit of personal experince. I changed the trans fluid on the Cougar at about 180,000. Burnt black and reeked up the whole garage. Car now has 219,000 on it and no oddness noted about the trans operation just yet. Oh yeah I doubt it was original as there was no plug in the pan but I'd had the car since 143,000 and it was in bad shape then. I was just too lazy to change it until 180K.
 
Welll....WHat I was told many years ago..If anything..change the filter...And put back the old fluid that came out..And thats that..But if its nasty and brown..id say start saving now;O)
 
fluid

The particles of worn transmission parts that ends up in the fluid get trapped in the filter. If their too small to get trapped in the filter, they do not negatively effect the transmission. The older the filter gets, the finer particles it will trap because of the particles it already has trapped over time. You are more likely to contaminate the closed system of your automatic transmission by opening it up to change the fluid and the filter than by leaving the original fluid in it. That's what I've been told by people who design and torture test automatic transmissions for GM and Ford and that's why they don't recommend changing it.
 
Re: fluid

Slysc said:
The particles of worn transmission parts that ends up in the fluid get trapped in the filter. If their too small to get trapped in the filter, they do not negatively effect the transmission.

Sounds good, at least until you've run into some failed trannies. Say you get one with a converter coming apart and contaminating the fluid with fine metal debris. The converter is the last item in the fluid path before heading to the cooler and then to the pan via the rear planets. The pump is the first item in the path after the filter and frequently the pump housing is scored badly enough to require replacement of the pump cover and housing. My point being that the filter obviously allowed particles large enough to damage other components through.

I'm not trying to give you a hard time just pointing out that these reasons given by those engineers are full of holes as I see it. I don't know what they're up to besides perhaps covering their tail about giving car care advice.
 
Dad used to wrench and now is the District manager for a major chain of auto repair shops in the Baltimore Metro area. I wrench now and have learned alot from him, but more the hard way. I changed the trans fluid in my 86 5.0 Bird once and realized that when i pulled it outa the driveway it would slip in first gear. it would rev up and almost neutral drop itself. i asked the master when he got home and he started explaining something to me.

This was stated earlier and is correct!: if it hasnt been changed at the factory recomended intervals then DONT CHANGE IT!
Reason being that there are clutches in the trans. as these clutches wear and wear they deposit more and more fiber in the fluid. this is bad for any metal parts that need the lube of the fluid BUT, when you change it to the new clean fluid the clutches no longer have that fiber floating in the fluid to help them lock up! whew. this thereby causes the slipping and eventualy more and more damage in there. So if you havent changed it or dont know if it has been then DONT CHANGE IT!

chris
 
interesting guys!

Never thought about the old fluid particles helping to engage the clutches....

On the LUCAS TRANSMISSION additive:

I had a guy at Advance Auto (I think it was there, or Azone) said that the local police department mechanics come in and buy it b the case! and they put it in ALL their cars.

Another guy said that used car dealerships come in and by it all the time too!

Several folks at the local parts stores swear by it, but maybe their brother in law owns lucas:)

I said what the hey and out in my tranny couple thousand miles ago...didn't notice a difference, but no problem either.....

I changed my trans fluid BTW, but the "cherry" was gone, so I know it has at least been changed once....

just my .02
 
LUCAS PRODUCTS = GREATNESS

i use their HI TACK additive in my engine and Trans (manual). THis is the only additive taht i have ever tried that actually works. you can feel it and tell its there. it really smoothed her out especially on cold starts.

you can try adding a bottle of the additive but be careful not to overfill the trans too much as fords really hate being overfilled.

Chris
 
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