Does Changing Lifetime Fluid Kill Transmissions?

[Cambridge]

I am thinking about changing the lifetime fluid in my 5hp30. It has never been changed before. Unfortunately, my 540i has 114,000 miles on it.

Everyone says that I should have started changing the fluid every 50-75,000 miles back when the car only had 50 - 75,000 miles on it (unfortunately I didn't own the car back then).

Some say it's too late to start now. (I've heard several reasons, e.g. detergent will disolve the adhesive holding the clutch friction pads or the act of draining the fluid will force junk into the valve body causing problems there, etc, etc.)

Others say, start changing it now and hope for the best - life's a risk.

Hence, my poll. I'd like to know how many who started changing their fluid after 100,000 miles had cars that survived the change for 1000 miles, 5000 miles, 10000 miles.

BTW: when I say "change" it means by whatever procedure you use to get fluid in and out of the tranny. e.g. some just replace the fluid in the pan, others let the car sit overnight or have other methods of extracting as much fluid as possible with each change. This poll is not to study the method of fluid change, rather it is to determine the fatality rate on lifetime fluid transmissions when fluid service starts late in life - by whatever form that service takes.

[632 Regal]

you need to change your poll, the proper way to change it is only drain the pan and change just what comes out and put in a new filter. This is supposed to be done every 30k. I was told this by Kirt Kohller a couple years ago. He also added to never flush it all out and change it, re adding the old crap (appx 4 qts) is ok but new is better.

[mattyb]

is it ok to just leave it in there and never change it as advised by bmw?

[632 Regal]

No. Lifetime means 100k then the car is disposable.

is it ok to just leave it in there and never change it as advised by bmw?

[laguner]

I have never done it because my car does not have it. The whole idea seems idiotic to me. I can't imagine how it could be bad to change fluids. I have read posts on both sides of the issue but never found a realistic arguement against doing it.

[Scott C]

I have never done it because my car does not have it. The whole idea seems idiotic to me. I can't imagine how it could be bad to change fluids. I have read posts on both sides of the issue but never found a realistic arguement against doing it.

Actually the discussion comes up quite frequently - if you do a search you will find some interesting reasons for how to do this or not do this... Regal summarized it well....

[laguner]

Yeah, so he is not advising against it as far as I can tell. He says you can do it but not a total flush. You really can't flush it yourself anyway. Again, a transmission is a mechanical device that requires fluids. There is no such thing as new fluid being bad, if the right type is used. The reason that some people have had failures post fluid change is probably because the grit was providing friction for worn bands in the transmission. In other words, the trannys were already shot.

[Traian]

My car has ~160k mi and it's starting to shift a little rough, it hesitates and then does and abrupt change. I don't really know what to look at and I'm a little weary of taking it to a shop and dropping mucho dinero. I think I will start changing the tranny fluid (it's never been replaced before as far as I know), maybe a couple of quarts at a time. After a few changes, I will drop the pan and change the filter. That's my plan, hope it does something. Well...something good.

[Cambridge]

Yes, from what I've heard (after reading many, many posts), it's actually fairly difficult to get all the fluid out even when when you try. Seems plenty stays in the converter and other areas.

However, some are afraid of any approach to changing fluid in 5hp30's with the so called lifetime fluid; gradually or otherwise. I hope with the poll to get some numbers from folks that have actually taken the plunge successfully.

or... maybe I get no numbers and all the discussions about what and what not to do with the so called "lifetime fluid" is mostly conjecture based on little real life experience.

[High Compression II]

I checked and topped up the fluid in my trans. I was expecting a 5HP18, but the oil-pan has the same shape as the 5HP30--Guess its one of those, I was rather rushed and didnt check the side-plate Doh!........

(Strange, All literature, suggests the 5HP18 for the 1993 525TDs diesel, but it definately didnt have that shape oil pan.......)

The fluid that came out, while it didnt smell burnt/bad, definately looked 'grubby/dirty' It didnt take much, maybe half a litre or so anyway.

The trans does some odd things, but ONLY when warm, hesitant shifts particularly from 2 to 3 and something odd from 5th to direct 'Converter' drive, Almost like its between gears, at around 55-60mph, under light throttle........
Very occasionally it may lose drive when pulling out of a roundabout, say in second, just before third comes in, as if second has released, and third is somethow late in engaging..........

Other times its performance is faultless.......

Guessing it needs a good going-over, and new fluid, valve-block clean, maybe new plastic balls and shift-valves........

BUT where do you get this sort of gear in the UK at a reasonable price, There are specialist auto-trans suppliers here in the UK, but I cant find one, I had some parts for an old Borg-Warner many years ago, but damned if I can remember who or where!..................?

Im quite happy about tearing down a valve body for cleaning/new balls etc, Just need to get the correct kit of parts, after checking that side-plate first! .............

Regarding the fluid changing, personally, I can see no real advantage in leaving dirty fluid in there--My idea is to get as much of the old stuff out and fresh in as possible--All that crud in there, can only add to the general wear of bushings/bearings gears, shaft seals, valves etc.etc. I do see the point where the friction surfaces could benefit from the extra friction these particles could provide, but if its gone that bad it needs overhaul anyway...........