The new fluid had probably intermixed with some old fluid - probably no problem. If you started the engine, the new fluid would have mixed with old fluid remaining in the torque converter and elsewhere.

It's not really practical to shift through the gear positions during the flushing procedure, since fluid is being constantly expelled via the outlet cooler line when the engine is running. But there's so little fluid contained in the valve body it's not really necessary anyway. It is definitely correct to shift through all the gear positions before setting the final fluid level just to be sure the valve body is full. The engine should be running and your foot on the brake to prevent the vehicle from jerking off the jack stands should the rear wheels suddenly spin violently. Hold each gear position for at least 3 seconds before returning the lever to Park to set the final fluid level.

 

No leaks. I'm thinking the original leak may have been residual oil from removing the lines and refilling from the fill plug. However, I will pump the exact amount of fluid into the pan I originally removed and recheck for any leaks before continuing tomorrow.

Just a note on the fluid removed:

The original fluid removed was black and had been i the car for 6 years. Although the car only has 14,000 miles the thought of having this old fluid churning around never set while with me. Also, most wear and tear on the transmission and contamination would have been during the initial break-in period. When I drained the pan for the second time after pumping 2.3 liters in through the fill plug hole the fluid was brown from mixing with old fluid. The brown particles in the fluid can be seen like mixing dye in water. My first thought was it looked like sand being mixed with water. I'm using Jaguar transmission fluid. If I had not used Jaguar fluid (which, IMO, is identical to ZF 6 fluid) I would I think I was mixing 2 different type of fluids. The old pan had very little deposit on the 2 magnets. I'll try to get a picture of the mixed fluid later today. When I purge the cooler and lines I might be able to get enough original fluid for analysis. It would be good to know what contaminates are in the fluid only after 14,000 miles.

 

Could well be slightly burned clutches.

After about 7,000 miles, after I did a complete flush and fill, my fluid was contaminated with minute black particles.

Now looking at my clutch plates some are black because they are slightly burnt.

 

Should the out going fluid change completely to the in going fluid color? Below are pictures of my lines after exchanging 10.6 liters. I wasted 2.3 liters from removing draining my pan and removing it to fix a leak (or what I thought may be a leak). The 10.6 liters doesn't include the 2.3 liters wasted. I ordered more Jaguar fluid. I started with Jaguar fluid so I'm going to complete the process with Jaguar fluid. Although IMO, ZF 6 fluid is the same. Picture below.

 

Yes. It did for me when I did the flush.

 

Some slight discoloration of the new fluid is normal and you are probably just fine as long as you've set the level correctly.

And yes, Jaguar fluid is ZF Lifeguard 6, which is chemically identical to Motorcraft Mercon SP and Shell Spirax S4 ATF MSP except for the dye color. There is no problem intermixing any of those fluids - they're all the same except for color.

 

Great Don. First time I have seen a statement saying its ok to mix the above.

 

Thanks Don and John for your help. The extra Jaguar fluid should arrive Wednesday.

Don, your innovative way of making the adapters is brilliant. I used a 90 degree Barb to move the tubing away from the exhaust. I never had a drop leak from the adapter connections. The cooler adapters I ordered were not shipped in time due to the supplier closing over the holidays.

I'll also take your advise, Don, of over filling by an estimated 1 liter after I complete the fluid exchange. As you said, it will be a lot easier to drain out any excess fluid when doing the final fill process (or in my case drain process) than to pump in fluid through the fill plug over a hot exhaust pipe. I'm counting liters in and out and expect to add about 1 litre over what is removed to compensate for lost fluid and shrinkage over 6 years.

When I did my ediff I added 1.3 liters after draining about 1.2.

One interesting thing I noticed is my 6HP28 on my XKR only has one "O" ring per cooler line connector. In your pictures, Don, you show 2 "O" rings on each connector which I like.

 

Some people say Ravenol makes the transmission fluid for ZF. Is it Ravenol or Shell? My Jugs of Jaguar fluid have a Shell specification number on it. https://www.ravenol.de/en/product-ra...atf-6hp-fluid/

 

Seems i read Shell came up with the original formula.

 

Our research has established that Royal Dutch Shell makes Shell Spirax S4 ATF MSP/ZF Lifeguard 6 in Belgium, and Shell Energy North America makes Ford Motorcraft Mercon SP in Houston, Texas.

According to our member Box, Mercon SP was originally honey-brown like LG6, but around 2007 Ford asked Shell to add red dye to Mercon SP to avoid confusion with other fluids.

In several other threads I have posted the Material Safety Data Sheets for these different iterations of the same fluid.

This formula was created by Shell to meet the specifications of ZF during the development of its 6-speed automatic transmissions, and the specification is known as Shell M1375.4.

Cheers,

Don

 

Thanks Don

 

In review of my fluid change process to date:

1. I'm surprised how small the transmission cooler is. It's in a location very hard to access and the lines to/from it would be difficult to use for a fluid change.
2. Use of Don's innovative splicer barbs as an adapter is excellent and relatively easy to make and install. They don't leak, not a drop. Use of 90 degree 1/2" to 3/8" barbs helped to keep the fabricated adapters away from the exhaust. Although, I discovered it was not necessary to keep the lines away from the exhaust because the car was running for such a short time during the procedure and the exhaust never had time to heat up.
3. I'm surprised the new fluid (2.3 liters) I pumped in through the fill plug port became so mixed with old fluid in the transmission pan after draining/removing the newly installed pan to check for a leak. It never felt right to reuse the fluid after draining it because it became mixed so much with the old fluid still in the transmission .
4. The 2.3 liters I wasted left me short on fluid to complete the process. More Jaguar fluid has been ordered. I have 7 liters of ZF LG6 which I was originally going to use for the change, but I don't want to mix fluids, even though it is probably the same as the Jaguar C2C8432 fluid. This stop in the process will give the remaining old fluid in the transmission time to mix with the newly pumped in fluid. How much mixing? This will depend on the fluid flow within the transmission. In total I pumped in 10.6 liters of new fluid after wasting 2.3 liters on a second pan drain/drop. I should be very close to a compete fluid change or as close is possible using this method.
5. The stopping and starting to expell/pump in fluid, 1 liter at a time, will give the remaining old fluid in the transmission time to mix with the new fluid pumped in. A continuous flow of old fluid being expelled and new fluid going in at the same rate should serve to limit this mixing.
6. In the 10.6 liters I removed/pumped in I noticed the color going out is considerably lighter. The color is not changing immediately from old dark brown to the light honey color of the new fluid. How much mixing is taking place in the transmission and what degree of fluid will remain in the transmission from not running the transmission through, N,R,1,2,3, which is required in the final fill process? I have no idea. I don't have the knowledge to even estimate this, but I think the flow out/in is not through a closed stream and open pockets of fluid in the transmission and torque converter allow for the old fluid/new fluid to mix somewhat. I have no idea how much of the new fluid going in is mixed and comes back out.
7. When the additional 5 liters arrives, I'll expel another 3 liters, pump in another 3 liters plus 1 more to ensure I have enough fluid in the system so I don't need to add anymore during the final fluid level check through the fill plug. I hope my accounting for the fluid removed and fluid pumped in is accurate.
8. The remaining 1 liter will be used to replace the fluid in the cooler and it's lines before reconnecting them to the transmission.
9. I'll do the final fluid level check according to the ZF 6HP28 procedure. I hope I only need to drain a bit of excess fluid in the system and don't need to add any more fluid through the fill plug hole.
10. Finally, I'll be finished with this Wednesday, until next time in about 6 years. I'll probably do it sooner--it was so much fun,LOL.

I'm pleased John (jackra) referred me to Don's procedure so I could do a more complete fluid change. I was disappointed at first that I was only able to remove 4.6 liters of old fluid by draining and replacing the pan/filter.

 

Based on cutaway drawings of the transmission, there are plenty of areas where old and new fluids can mix, including the torque converter and pan and around the gear sets and clutch packs. But whenever the engine is running the transmission pump runs too, so the general flow of fluid is from the intake in the pan, through the transmission, and toward the cooler line outlet. Transmission fluid is virtually incompressible, so the new fluid does a pretty good job of pushing the old fluid out.


Cheers,

Don

 

Does anyone know the pump rate of the 6HP26 and 6HP28 NA/SC (if different) transmissions? On my next fluid change I'll match the expulsion rate of old fluid with a pump to load new fluid into the transmission. This should serve to minimize the mixing of old/new fluid. Having to start/stop the engine (transmission pump) disrupts the flow and will give the fluids time to mix. I'll use 2 measuring buckets. I'll put about 12 liters of new fluid in a bucket connected to a pump matched closely to the rate of the pump in the transmission and connect it to the in port. Another similar empty bucket connect to the transmission's out port will be used to capture the old fluid at the same rate as new fluid is being pumped in to minimize the mixing of the new fluid with the old fluid during the change. This will require starting the car (or pump) once and the change will happen at about the same rate in one cycle with no need to start/stop the car (transmission pump) for every liter.

 

That would be easy enough to approximate by measuring the amount of time the engine has to run at idle to expel one liter of fluid. But it will be impossible to avoid some fluid intermixing. Think of the way the fluid is slung around in the torque converter as just one example of why avoiding intermixing is impossible. Some mixing is really not a problem as long as most of the old fluid is replaced with new.

 

Yes, I very roughly estimate it to be 12 l/min or about 200 gph. I realize mixing can not be avoided, but it can be minimized or managed. A cheap pond/fountain pump should be able to handle this. If either the in flow or out flow gets too far ahead in a 12 liter fluid change the engine can be stopped/restarted (transmission pump) for the out going fluid or pump stopped to and restarted to slow down the new fluid going in. It would be much better to have a slightly faster flow rating inbound pump so the transmission pump can run continuously.

 

This method is always mixing the new fluid pumped in with old remaining fluid left in the transmission and new fluid which has already been mixed. A lot of new fluid is mixed and removed with the old fluid through the outbound port at an increasing percentage and the old fluid is expelled at a decreasing percentage. One would never reach a 100% change and would waste a lot of oil to even achieve > 80% new fluid.

Pictures show the change in color from original oil drained to cycling 13 liters in. The lines show the color of the new fluid and the last oil being removed which consists of more new fluid than original fluid. Early in the procedure the ratio of original fluid being expelled to new fluid pumped in would be 1:1 and then as the new fluid mixes with the fluid in the transmission (new and remaining original) a deminishing return is to be expected.

 

 

I like to read this forum even though my cars are from VAG Group. There is a lot of good info here but sometimes you overthink things.
The pictures from my previous post show HOW and HOW MUCH fluid goes to the oil cooler. In a flush procedure the path would be with the TCC open and, depending on where is the gear shifter, it will flow between 1.5-2.5 GPM at idle. Do not forget that once cooled or warmed up the fluid goes to lubrication so it is important to have pressure on the return line all the time. That is one of the reason I don't like the flush procedure that does not use constant pressure to the return line when the trans/engine is turning. There are machines that use the cooling lines to flush the fluid using the trans pump to do the job but few shops are willing to do the correct steps on these transmissions. I read the posts on the other Jaguar forum in the UK and shops using the Launch machine were trying to do a good job. While being a better alternative to drain and replace filter procedure, I don't think it is the best one. It may be for shops that do not have the time to spend like us enthusiasts do.

I still believe that the best procedure is by draining the fluid, removing the pan and filter, hook up a no pan flush tube like tomoco described in earlier posts. At this point, before starting the engine, I would install a clear hose to the cooler return line so I can see when the fluid gets clearer. This way the only mixing is done in the Torque Converter which is quite a bit of mixing. Once the fluid gets clean it will also wash the clutches and discs after lubrication. Then I would remove the valve body and replace the square seal and tubes if available. At this point about 8 Litres of fluid is needed to complete the job. So whatever you are willing to use to flush the converter and cooler circuit is on top of that 8 Litres. It is difficult to say how much fluid is needed to remove 2-3 litres of dirty fluid in the converter and cooling system but probably at least 5-6 litres.

Unfortunately, after reading the threads with the cooler lines leaks and repair, I see that on Jags there are no intermediate connections like you find in the VAG group so it is not easy to hook up machines, clear tubes or other flushing gadgets. So using Don's method of connecting to the cooler ports is the best way for your cars.

If you insist using Don's procedure I recommend draining the fluid and removing the valve body to replace the square seal and the tube seal, re-assemble everything and fill the pan with fresh fluid. At this point a flush machine that uses old fluid from the converter to push clean fluid back to lubrication and than into the already clean pan would be best. If the machine is not available, I recommend using a fill pump that can be pressurised to push the fluid back to lubrication. I would leave the fill plug out and regulate the fluid return pressure so not a lot of fluid comes out of the fill plug once the engine is running but never shut down the supply. It should only take about 30 seconds to flush 4-6 litres of fluid through the converter. One big problem here is cleanliness: how clean and free of debris is the fill pump? I use Magnom and Magnefine magnetic filters on my fill pump lines. It would be a good idea to use these after a cooler lines repair procedure. Then flush the cooler on its own.