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ATF To Replace or to Flush

Posted: 24 May 2018 18:52
by jacquesW
Hi All

I started another topic 2 days back for service components and I think I have my shopping basket complete. I now have to decide if I am just going to do regular maintenance ATF change or if I am going to flush. I pulled a little sample of ATF as can be seen in attached image. It is basically caramel in colour with a slight red tinge to it. I am not seeing any particles in the sample so other that the discoloration the fluid appears clean and the smell is what I expect from oil. It does not smell like burn.

I like the idea of a flush so I know it is all good stuff in there but there appears to be many mixed opinions on the topic. Many people says flushing the gearbox can cause damage and the other lot says the fluid flush just exposes a pre-exisiting condition. Interpret it as you wish. Drive it till you can afford fixing or expose the problem rather than get surprised on a long trip..........

Anyway. It is a highly contested topic which does not make my desiscion any easier unfortunatly. So I am putting it out for opinions.

Based on the current state of the oil:

1. Do I flush?
2. Do I do normal 40%- 60% change
3 Do I do normal change over 2 or 3 fairly closely placed intervals.

Also what is the opinion on dropping the pan and cleaning/replacing the ATF filter?
20180524_180516.jpg

Re: ATF To Replace or to Flush

Posted: 25 May 2018 03:36
by Michael
I dont see anything wrong with that oil, if it was mine I would leave it as is

Re: ATF To Replace or to Flush

Posted: 25 May 2018 05:25
by Peter Connan
If there was a serious problem, the oil would not look like that. I see no reason to go through the risk of flushing oil that looks like that.

If it had obviously overheated, I might risk a flush.

But, for real peace of mind, take your sample to a lab and have it analysed.

Re: ATF To Replace or to Flush

Posted: 25 May 2018 06:03
by jacquesW
Thanks guys.

I also thought that oil looked pretty good. I just really wanted to look as the car is already on +300k on the clock. I might then just do a normal oil change

Just one thing. That sample was sucked up from the filler pipe. I assume if the car was left to idle up to temperature evidence of filings and what not would still have been suspended in there? Or is best port of call taking the oil from the drain plug where it is more likely for sediment to collect?

Re: ATF To Replace or to Flush

Posted: 25 May 2018 15:16
by Peter Connan
I would expect that, like the manual gearboxes, the drain plug has a magnet to attract filings? Not sure about that though.

Re: ATF To Replace or to Flush

Posted: 25 May 2018 18:11
by Tinus lotz
Please remember the 4.8 does not use atf but special nissan tipe j

Re: ATF To Replace or to Flush

Posted: 25 May 2018 18:53
by Pieter B
My oil was a lot dirtier with 230k on the clock. Yours look like it was done previously. Nissan claims that this is a lifetime oil, but I find that a bit hard to believe.

Re: ATF To Replace or to Flush

Posted: 25 May 2018 22:00
by Mystical_Beast
If your transmission oil is clean you can barely see it on the dip-stick.

I took my Patrol to ZF transmissions and did what is termed a Flush.

Basically they pump clean oil through the transmission displacing the old and continue to do so until its clean.

ZF will analyse your oil before doing the flush, from the analysis they determine whether it will have an adverse effect or not.
They also recommend a transmission oil change every 60 000 km.

In my experience a rebuilt auto-box is never quite the same as new.

Id rather spend a bit on doing the oil flush if the gearbox is within the parameters to do so.