So I posted a couple years ago on whether or not to change the trans fluid, and the consensus was that since that it was cherry red, smelled fresh, and there were no shifting issues that there was no immediate need to change it. It's still cherry red etc, but it's the original fluid -- now 32 years old, and I just can't imagine that is a good thing.

There are stories posted elsewhere claiming that a fluid flush on an older transmission actually ruined the transmission, sounds more like a correlation does not equal causation fallacy, but I'm no expert. I've also read several threads here and I'm aware that you can only drain a fraction of the fluid at a time, and to fully replace the fluid takes several cycles of drain/fill/drive/repeat.

I now have a nice fluid extractor which would make the above easier as I wouldn't have to drop the pan each cycle.

Here are my questions:

1. Should I worry about the 'trans flush ruined my transmission' stories?
2. Should I start by dropping the pan and replace the filter?
3. Should I instead start gradually replacing the fluid a few liters at a time, and after several cycles then replace the filter?
4. Do #2, then after multiple cycles, replace the filter again?
5. Anything I should know beforehand about dropping the pan and replacing the filter and gasket?

Thanks all!

 

#1 YES, a 100% NO NO from me. Seen too many issues, and NOT only Jags.
#2 NO
#3 YES. About 60 kms or so between procedures. I just used work and back for 3 days a sy rough (Auussie speak here) guide, with as many gear changes as possible.
#4 YES, sort of. Once the colour coming out is the same colour as whats going in, JOB DONE. Most of mine took 8 times.
#5 NOPE, just taht you will get an ATF bath, especially if teh car still has that Collision Bracket nonense installled. Ensure the pan face, particularly around the holes is FLAT, and even. Finger tighten the bolts, then tighten 2 FLATS ONLY and STOP., its a cork gasket, common sense must prevail. Ensure the filter suction tube o/ring is renewed, or you will be in there again within hours.

Have fun.

 

Mac,

You know my views on fluid changes. You can never do too many. Fluid is cheap. Drivetrains are expensive.

I would do a "3 plus" from your list.

1. Syphon out fluid (or drain if you have the drain plug fitted on your sump. Some don't have it). Refill
2. Drive 10 miles
3. Repeat 1. & 2. twice more.
4. Syphon / Drain fluid, Drop sump, Replace filter. Refill
5. Drive 10 miles
6. Syphon / Drain & Refill
7. Drive 10 miles
8. Repeat 6. & 7. twice more

Wait 12 months. Drain & Refill. Repeat every 12 months until you've done 10k. Then go through whole sequence again.

Cheers

Paul

 

Add a drain plug to your oil pan. It's easier than siphoning/suction method for future fluid changes in my experience.

Cheers
DD

 

I'll add that, personally, I don't see much need for repeated filter changes down the road.

I've changed more trans filters than I can remember and the very few I've seen with any accumulation of debris are in cases where the transmission is on it's last legs. At that point no amount of new filters and fluid will save the transmission. Get it overhauled before any serious internal damage is done....which greatly increases the cost of the overhaul. It's the difference between a "soft parts overhaul" and a "hard parts overhaul".

So, do the whole process as you've planned, including a new filter, and then just do regular and frequent fluid changes down the road. If you install a transmission drain plug this is very fast and easy and your trans oil is continually being 'refreshed' 3-4 quarts at a time.

When you drain the trans oil measure what has been drained and then you'll know exactly how much new fluid to put in. This saves the somewhat annoying process of getting the fluid level correct each time. After a couple times you'll have this down to 15 minutes or less.

Until or unless the transmission develops a problem you won't need a new filter, IMO. Dropping the pan isn't the most pleasant task. I see no reason to do it needlessly

All of the above is "IMO" and not everyone will agree.

Cheers
DD

 

I don't know about the V12 but the ZF box in the 4 litre just uses a gauze mesh in a crimped filter enclosure.

IMHO, it's perfectly ok to do a full wash of that canister and reuse it most of the time.

Paul

 

TH400 is a Dacron? medium, and floats on top of the fluid.

Life span, NO idea.

I do as Doug has mentioned, then every 2 years, ATF drop and fill, and Brake Fluid Refresh, followed by Steer fluid suck and refill..

Never had an issue with either component in any Jag.

 

Any recommendations for Trans Fluid I should use?

Thanks

 

Dex 3,

Whatever is on sale on the day, the TH400 is NOT fussy.

 

BTW - if your pan does not have a drain plug - here's a tip to avoid the "big spill".

1 - Use a suction device to get fluid out (Mighty Vac for example)
2 - As you undo the bolts securing the pan, replace the corner ones with longer bolts.
3 - Drop the pan 1" or so - held up by the corner bolts
4 - Use the suction device through the gap to clean out what ever is left in the pan
5 - Drop the pan - its got almost no oil and is quite light & easy to control
6 - Consider adding a drain plug

I've been doing 1-5 every couple of years along with the other fluids as suggested above by Grant.

HTH, Dave

 

What’s the best or recommend fluid,for 1995 xjs 4.0L ZF automatic. I used ZF fluid.

 

Dexron 3 again

Paul

 

The extractor works a treat, and I was able to pull out ~4.75 liters.

Though the fluid looked cherry red on the dipstick or a finger, it wasn't quite so when extracted. I should have done this sooner.

 

Well done Mac!

A quick 10 mile run, then do it again!

Paul

 

Ha, I was out driving when you posted that. 2 cycles of extract/fill/drive today will do some more next weekend.

Cheers

 

Mac
Which extractor did you use please?

 

Greg,

FWIW, I use a 7l pneumatic extractor linked to my compressor, that I've had for 15 years for engine and autobox oils. Simple bits of kit.

There's lots of both Manual & Pneumatic versions on the market with huge variations in price. But they all work in broadly the same way, so it's difficult to see the justification in the very expensive ones.

Cheapest widely available one seems to be £35 and cheapest dual one I found was £48. See here:



The only thing that people should consider is taping the thin extraction pipe to the next size up, to create a longer pipe, as the length of the pipes can sometimes be problematic depending on the position and the length of the oil dispstick.

Cheers

Paul

 

Like Paul I use a pneumatic extractor. I picked it up when it was discounted during prime days on Amazon because I was thinking it would be handy for a coolant flush without having to mess with the bottom hose. It worked great for that task using Grant's tubing down the banjo bolt hole trick.

Here is a link to the one I bought on the US Amazon site:

 

Oh interesting what trick? Is it written up somewhere? I'm collecting a library of information haha.

 

Here is a link to one of the times Grant mentioned it:

https://www.jaguarforums.com/forum/x...2/#post2406838