Thoughts on Changing Transmission Fluid

[puddinboo]

my theory in changing tranny fluid is this you have 200000 mile say on your tranny , tranny fluid is life time , but with that many miles tell me there isn`t any metal shavings in there, metal parts wear down no matter what so if you keep the fluid in there with all these metal shavings ,this is good for the transmission, don`t think so . so I`m the one that will do regular tranny flushes a piece of mind in my opinion. keep in mind metal doesn`t last for ever and will break down overtime.if its man made its not perfect.

[bigwave2255]

scary thing is that even with the advances in technology , fluid or mechanics, its still not possible for one of these "modern cars " to get the life expectancy of older cars,

it seems sad to me that these vehicles are built on a through away model.

what was to bad about having to adjust the points gap, clean the plugs and tweak the mixture screws on the good old 4 bbl holley, AND occasionally check the oil in the turbo 400, as for the diff, never looked at it.

same story with batteries, when i was young if i ever had to buy a battery it was a big thing, now anything over 2 years and your on borrowed time.

seems sad to pay so much money for a vehicle that has such a relative short life expectancy

my '94 XJ Cherokee has 400,000 km on it and has had the trans oil changed once, i can easily fix it and its super reliable, when i retire the 2005 3.0d X5 goes and i,ll keep the Jeep, and theres every reason to believe i will get another 200,000 out of it

did a compression test on it and all cylinders were within 3 lb of each other so not bad after nearly 20 years

[bmw3er]

The tranny in my 2003 began to shudder during shifts just after I bought it. I did a fluid flush first, then a flush and filter about a month later. It's been about a year since then and the tranny shifts like new, even after pulling my boat around all summer. Now that it has been done twice I will keep doing it at regular intervals to keep it fresh. With that being said, I had an auto tranny in my E36 that went 175k miles on original fluid and was still bright red when I drained it out to ship it. So I go both ways on this fight.


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[srmmmm]

I've got 244,000 miles on the original fluid. If I had serviced the transmission every 60,000 miles (fluid flush and refill plus filter for proper procedure), I'd have about $1600 in maintenance costs so far. A factory re-manufactured unit for my vehicle is $2245 which comes with a three year warranty. So if I can get to 360,000 miles without a breakdown, I'm money ahead to not change fluid for sure.

The question really is would those 60,000 miles servicings get me much past 360,000 miles before a replacement is needed anyway?

2002 X5 3.0 244,000 miles
2004 325i 109,000 miles

[J.Belknap]

Originally Posted by JCL

So, 10 years for normal use. Sooner for severe service. I'd put J. Belknap's supercharged 4.6 in that category, myself.

Damned if I do, damned if I don't.

[JCL]

Originally Posted by bigwave2255

Scary thing is that even with the advances in technology , fluid or mechanics, it's still not possible for one of these "modern cars " to get the life expectancy of older cars....

I think perhaps we all suffer from selective memory loss over these issues. Not picking on you, I hear what you are saying, but in the seventies and eighties batteries were sold in North America with 36, 48, or 60 month guarantees, prorated. The battery companies were very good at designing them to fail at 35, 47, or 59 months, so the customer came back with a three year version that was failing and got 1/36th off a new battery and thought he was winning. Happened consistently. Our 2007 X3 is coming up on 6.5 years, on the original battery. Yes, it is on borrowed time. But since it has a manual trans, and I can bump start it, I haven't done the smart thing and replaced it yet. But we never used to get that life on batteries.

I used to like annual tune-ups and twice per year oil and lube services, they were good for the garage business. I think cars today are much more durable. If there are reliability issues in some areas, and there are, it isn't due to durability so much as it is a consequence of the complexity, not the quality of design and manufacturing, in many cases. The manufacturers accept that complexity, but we the consumers are the ones who insist on the latest gadgets and features. Just my $0.02.

[JCL]

Originally Posted by srmmmm

I've got 244,000 miles on the original fluid. If I had serviced the transmission every 60,000 miles (fluid flush and refill plus filter for proper procedure), I'd have about $1600 in maintenance costs so far. A factory re-manufactured unit for my vehicle is $2245 which comes with a three year warranty. So if I can get to 360,000 miles without a breakdown, I'm money ahead to not change fluid for sure.

The question really is would those 60,000 miles servicings get me much past 360,000 miles before a replacement is needed anyway?

2002 X5 3.0 244,000 miles
2004 325i 109,000 miles

That is precisely the question. I would rephrase it as how much past 360,000 would you need to get.

I agree with your cash flow analysis but the problem is that in one of the above scenarios you end up with a new transmission with a three year warranty at the 360,000 mile mark, and in the other scenario you end up with a 360,000 mile used transmission with fresh new fluid in it. Those aren't equivalent situations, as one has greater utility.

We can do a simple life cycle cost analysis, using the numbers provided, just replacing the transmission every 244,000 (assume failure tomorrow, worst case), vs servicing it every 60,000 in order to extend the useful life. You would have to make it 885,900 miles to reach the break even point, on a cost per mile basis. On the original transmission.

Admittedly a very theoretical example. But this is the basis for the approach of not changing the fluid, and putting the funds saved aside for a future transmission replacement.

[bcredliner]

Originally Posted by JCL

That is precisely the question. I would rephrase it as how much past 360,000 would you need to get.

I agree with your cash flow analysis but the problem is that in one of the above scenarios you end up with a new transmission with a three year warranty at the 360,000 mile mark, and in the other scenario you end up with a 360,000 mile used transmission with fresh new fluid in it. Those aren't equivalent situations, as one has greater utility.

We can do a simple life cycle cost analysis, using the numbers provided, just replacing the transmission every 244,000 (assume failure tomorrow, worst case), vs servicing it every 60,000 in order to extend the useful life. You would have to make it 885,900 miles to reach the break even point, on a cost per mile basis. On the original transmission.

Admittedly a very theoretical example. But this is the basis for the approach of not changing the fluid, and putting the funds saved aside for a future transmission replacement.

I would like to meet the person that is putting funds aside for a future transmission failure--talk about a half empty glass.

It is hard to do a payback analysis except by specific example and after the fact. Certainly at 244,000 miles on the fluid I wouldn't change the fluid regardless. That said, I do think a payback should include labor hours of what you think your time is worth, downtime cost and inconvenience, any shipping cost etc.

Seems to me, per the forum, a great number of transmission problems that require going into the transmission happen between 75,000 miles and 150,000 mi. That would be the range of miles I would use for a pre-fail payback. I must admit that even if the payback wasn't there I would still change the fluid because until I have the cost and mileage after the failure of my transmission, my calculations are only a projection, they aren't an actual, accurate payback calculation that means much if anything.

There are changes in some years of a given transmission and within the E53 years different transmissions. Also, these transmissions are coupled with different engines. As an example, I have a 2002 4.6 with 110,000 mi. on the original transmission. I have changed the fluid every 50,000 mi. A projected payback should only be with like vehicles where the transmissions have had internal problems--using those costs and miles to calculate a potential payback comparison for me.

What I think is very unfortunate about the--to change or not to change, that is the question-- fluid threads, is, at least for me, I never have a clue if we ever get close to something that is apples to apples. I am not able to conclude what transmissions are prone to what problems. I assume some are better than others but it is not clear how they individually rank.

Because of that, I come away thinking all E53 transmissions are very poorly engineered and subject to premature failure. Because there are so many threads about transmission problems, I am constantly expecting mine to fail, especially since I am stressing it far more than the norm for a stock 4.6. The worst case of these threads is I believe we cause some newbies to think they have just made a terrible purchase--doom and gloom is at redline heading their way.

[srmmmm]

[QUOTE=bcredliner;966799]I would like to meet the person that is putting funds aside for a future transmission failure--talk about a half empty glass.

Because there are so many threads about transmission problems, I am constantly expecting mine to fail.

Even though the X5 is paid for, I still transfer about 50% of the monthly payment I had into savings to cover repairs & maintenance. As long as the balance stays positive, I'm happy.

The failure point I fear is losing the splines on the front driveshaft again...while pulling the boat out of the water. I've blown the tranmission in my Firebird and Bonneville diesel multiple times, and even though I might have lost a gear, or even cracked the flex plate, the vehicle wasn't totally immobilized. Driveshaft splines are a different story though.

By the way, the Allison 4000 series transmission in my father's 44ft motor home calls for 50,000 mile filter change intervals with a fluid top-off, but no complete fluid change for 500,000 miles!

2002 X5 3.0 244,000 miles
1004 325i 108,000 miles

[bcredliner]

Can't fault budgeting for maintenance and repairs, great to do. You would be close to that one person if your budget for repairs was specifically for front drive shafts.

That said, the thread is about transmissions. My points are concerning the specific topic of transmissions and stemming from forum threads.

As I mentioned, I can't discern what problems happen to what transmission--or when it is apples to apples based on what engine package. I do know that an Allison transmission for a 44ft. motor home is not apples to apples.

My position pays no heed to recommended service intervals. It is my position that changing the fluid every 50,000 cannot currently be dismissed as illogical. If there was a tag on my transmission that said--WARNING WARNING--DO NOT CHANGE THE FLUID FOR ANY REASON. CHANGE OF FLUID WILL RESULT IN PREMATURE TRANSMISSION FAILURE!!!, at that point the there would be no difference of opinion--well maybe there wouldn't.

FYI-If I were towing a boat with my X, the boat wt. would be under max. towing capacity, I would drive like I have an egg under my foot and not be concerned about tearing anything up.