Re: ATF change - Mandalorian way. - Saab 9-5 Bulletin Board - Saabnet.com
NG900 & OG93 |
Vintage Models |
Clubs & SOC |
Other Cars |
Member Photo Galleries |
Member Directory |
*Buddy Registry |
*Mileage Registry |
What's New |
Photo of the Month |
[Main 95 Bulletin Board | Post Followup | BBFAQ ]
[ Prev by Date ] [ Next by Date ] Member Login / Signup [Latest Member Gallery Photos]
Re: ATF change - Mandalorian way.
1 Saabers Like This Post!
Posted by siwyjohn (more from siwyjohn) on Wed, 13 Jan 2021 01:45:16
In Reply to: Re: ATF change - Mandalorian way., Boris Bubbanov, Tue, 12 Jan 2021 07:38:05
Yes, mixing old fluid with new one is bad - it degrades new fluid. It's obvious. Of course in your case when you are refilling the tranny so often it simply doesn't matter (it's just like mixing new one with new one). However if you change fluid after 100.000 miles and 10 years of service then "not to mix" matters a lot. IMHO it's simply not necessary to change the ATF too often, because, as I said before, the environment in the transmission is much more oil friendly then in engine. Changing too often is simply waste of oil, time and money (not to mention the environment). It's similar to changing brake fluid each 6 months instead of 2 years without any actual reason. It will not help technically, but only to keep your mind in peace. Unnecessary waste is the cost of such thinking.
Factory sealed transmissions (and other "unrepairable by design" things) are typical solution to sell a new thing instead of keeping old one longer than manufacturer wants. Nowadays each part of the vehicle is designed to last for certain amount of time. For a part supplier = just to pass the OEM specification. If you've designed a part which can survive twice the spec you will be asked to redesign it to make it cheaper. I worked many years in automotive, so believe me - it's just like that. Look at manual transmissions. In 90's each manufacturer specified the oil change interval for about 60.000km (Saab 9000). Later they did not recommended oil change at all (Saab 9-5). Was the tranny construction significantly different? No. It was only claimed that it is due to new magnificent synthetic oil, what was only partially true. Synthetics really lasts longer but not forever. Plus there are additional reasons to refresh fluid, like to flush out the particles (magnetic plug capacity is limited). But for a given time/mileage of typical first ownership it was fine ("fine" criteria for car manufacturer: failure probability peak over warranty). To be sure that user will not outsmart the manufacturer we will delete the plugs. Simple and effective. Usually users blame engineers for such design evolution - yes technically they did it but not driven by themselves - they were told by management to do it (three plugs less - we will maximize profit!).
PS. Hey, absolutely no other books than SAE journal in the childhood? ;)
posted by 80.50.141...
Posts in this Thread:
- Are there any Auto-Trans conditioning additives?, thewheell22 , Fri, 1 Jan 2021 10:57:07
- Twenty-five years working for GM's Hydra-matic, MI-Roger , Tue, 5 Jan 2021 10:17:571
- Re: Are there any Auto-Trans conditioning additives?, siwyjohn, Mon, 4 Jan 2021 01:34:40
- Re: Are there any Auto-Trans conditioning additives?, Boris Bubbanov, Sat, 2 Jan 2021 18:02:571
- Please don't use that crap!, jimmy, Sat, 2 Jan 2021 08:50:43
- Re: Are there any Auto-Trans conditioning additives?, JerseySaab , Fri, 1 Jan 2021 11:23:55
Post a Followup
No Site Registration is Required to Post - Site Membership is optional (Member Features List), but helps to keep the site online
for all Saabers. If the site helps you, please consider helping the site by becoming a member.
This is a moderated bulletin board - Posting is a privilege, not a right.
Unsolicited commercial postings are not allowed (no spam). Please, no For Sale or Wanted postings, SERIOUSLY.
Classifieds are to be listed in The Saab Network Classifieds pages.
This is a problem solving forum for over 250,000 Saab owners, so expect to see
problems discussed here even though our cars are generally very reliable. This is not an anything goes
type of forum. Saabnet.com has been a moderated forum since 1988. For usage guidelines, see the
Saabnet.com Mission and Purpose Page. Please remember that you are
not anonymous. Site Contact | Site Donations | Other Sites by SP -
Your address is: 22.214.171.124 - Using CCBot/2.0 (https://commoncrawl.org/faq/) - Logged.
Site Members do not see red text instructions, bottom of the page anchor ads, or box ads.
Click here to see all
the Site Membership Benefits!