Transmission fluid again...

[JCL]

Originally Posted by sfcl

Reading and re-reading all the threads on the subject everywhere in several forums, choice is still not easy!
Roughly 3 options:
1- Drain the old fluid, replace the filter and the solenoid, and put again the old fluid in the tranny. Should avoid to move the old sediments which could cause new problems BUT the fluid is still old...
2- Drain the old fluid, change the filter, put in new Dexron III, VI or full synth fluid, so about 50 or 60% of the old fluid is changed, a part of it staying in the converter. Could cause new problems (limited as there is only a few new fluid) but could also extend the life of the transmission if it is not too dirty inside. A sort of compromise...
3- Drain the fluid several times (say 3 or 4 times every 50 miles or so), so get about 90% of new fluid. Major risk to let the new fluid dislodge old crap and cause new problems, but could be also the best option if the tranny is not too dirty by having a whole best quality new fluid in it...
Don't want to open a new poll on that but would be interested to know your thoughts! Curious too to know what a automatic transmission real specialist (no one around here) thinks of that...

If the fluid is that old, I wouldn't reuse it but rather put new fluid in. I wouldn't worry about Dexron VI, I would try and get a fluid that was current when the vehicle was built (given your lack of alternatives in your location). Definitely replace the filter. It isn't new fluid that causes problems as much as the process of changing it, and you don't have a choice there, once you have dropped the pan and drained it. Get as much out as you can, refill it, and see how it works. If you want to, do a second change in two weeks. You have a real possibility of this solenoid not curing the problem, so go a step at a time and see how it responds before spending too much money on it. Just my $0.02.

[sfcl]

FYI I contacted directly GM to get a proper response, here is what they say as a first notice (I'm still waiting for an individual reply):

GeneralMotors DEXRON®-VI Global Service-Fill Specification

During early 2005 General Motors released a newly developed automatic transmission fluid (ATF) for the factory fill of all GM Powertrain stepped gear automatic transmissions. The new fluid provides significantly improved performance in terms of friction durability, viscosity stability, aeration and foam control and oxidation resistance. In addition, the fluid has the potential to enable improved fuel economy and extended drain intervals. Since the performance of the new fluid far exceeded that of the DEXRON®-III service-fill fluids available at the time it became necessary to upgrade the DEXRON® service-fill specification in order to ensure that similar fluids were available in the market for service situations. This latest upgrade to the service- fill specification is designated DEXRON®-VI.
Since General Motors introduced the first ATF service-fill specification in 1949 it has been periodically necessary to upgrade the specification. This upgrading process ensures that available service fill fluids are of an appropriate quality for use in transmissions that have been designed around the factory fill fluid performance. It should be noted that, as with previous upgrades, DEXRON®-VI fluids are designed to be backward compatible with earlier transmission hardware. More importantly, earlier type fluids are not forward compatible with transmission hardware that was designed to use DEXRON®-VI fluid, i.e. DEXRON®-III is not compatible with the most recently designed transmissions, and the use of these earlier type fluids could result in transmission damage. All current calibrations and certification tests are now conducted with DEXRON®-VI ATF. DEXRON®-III fluids should not be used for these applications where the owners manual recommends the use of DEXRON®-VI. GM does not license or support obsolete ATF specifications or the use of fluids that are being marketed against cancelled specifications.
All DEXRON®-III licenses expire at the end of 2006 and will not be renewed. Beyond that date GM will only support the use of DEXRON®-VI fluids for use in Hydra-Matic transmissions. Fluids sold in the market after that date bearing claims such as “suitable for use in DEXRON®-III applications” or similar wording should be avoided. DEXRON®-VI licensed fluids are fully backward compatible and can be used in all applications covered by earlier GM ATF specifications.
The use of unlicensed fluids and/or non GM approved aftermarket additives may prove detrimental to transmission performance and void warranty coverage.
There is a published list of GM-approved brands of DEXRON®-VI (see page two of this release). This list represents the companies who have conducted the appropriate testing and received GM approval. Company name, license number, and brand name are shown. This list will be updated on a regular basis as more approved products are added.

[sfcl]

Individual response not very helpful...:

Thank you for contacting the General Motors Customer Assistance Center. We appreciate you taking the time to write us about the GM transmission that your BMW X5 has.

I apologize but the General Motors Customer Assistance Center does not have any information about BMW vehicles even though as you said, it was equipped with a GM transmission. I would like to suggest that you contact BMW of North America at (800) 831-1117 for assistance on your inquiry.

Again, thank you for contacting General Motors.

Sincerely,

The General Motors Consumer Support Team

[John Galt]

Originally Posted by sfcl

Individual response not very helpful...

I suspect that BMW will not be much more helpful than GM; they will probably just tell you to use the BMW Dexron VI fluid (83220397114). On the other hand, they might be able to help you with a local source for it, so I would give them a call.