Transmission Fluid Replacement

[TurdFerguson]

So, although I've asked questions and feel pretty confident about changing the fluid, I want that last bit of peace of mind.

Of the people who have changed their transmission fluid/filter or had it done by a dealer/mechanic, please vote above if you've had positive or negative results. Those with negative results, please post what they were.

Thanks in advance.

 

[TurdFerguson]

Please let me know if you vote over on LRO so I can work out the numbers accurately. I REALLY want to be 100% confident about this change.

I dont have any debris in the fluid so I'm feelin good about that.

 

[daven5735]

We all know that particulate contaminants are the killers of moving mechanical things. However, with auto transmissions this is what I do. With engine running and up to temperature (right after a drive is a good time), pull the dipstick and look at the fluid, then smell it. If it smells burnt, that's bad. If the fluid has a nice red tint and is clear with no little specks or isn't off color, that's good. Trans fluid doesn't pick-up the same acidic contaminants that engine oil picks up so it will last a long time. I don't have it in front of me but I think the factory only recommends one filter change in its life and that is at 15K miles (?). I don't exactly subscribe to that cause I'm like you, I want it to be cleaner.

PT, what say you?

 

[pdogg]

Dipstick for the tranny? whatever for?

much better to crawl under the truck and get dirty to check the oil... no?

 

[JohnB]

Since my D2 had so many other PO problems. I changed the filter and fluid. What a pain in the ass. Why car companies have eliminated the dipstick I have no idea. The procedure outlined in the Rave CD was helpfull although I was on my own and having the landy in drive with the e-brake on(wheels blocked also)was a bit scarry lying under the landy pumping fluid in.

 

[TurdFerguson]

Thanks John!

Which reminds me, its a D1 with 150,200 miles. I'm trying to track down its maint. history since the maint. log is clear.

John, how many miles did your DII have when you replaced the fluid?

 

[macklow]

I posted this awhile back... my disco now has 267K, maybe time for another change?

 

[TurdFerguson]

macklow, i actually came across your thread some time ago when AAXD was asking about fluid changes. Thanks a ton for posting the procedure. It will most likely be the way I do the change.

Has anyone replaced the solid lines with braided S/S lines?

 

[justintoxicated1]

There has been some debate weather to switch out the tranny fluid or not. A lot of people says to do it. Some say not to. The reason not to is due to the detergent effect of tranny fluid. You remove the old fluid with particulates and put new fluid in, it agetates the film of particulates in the tranny that could lead to the valves getting clogged. The guy that I know that deals with a shop in Houston says he's seen a handful of Disco's trannys fail shortly after a fluid and filter change. He's also said that the shop recommends against the fluid change due to the situation above. They have seen trannys with 250,000 with no tranny change finally give way. I on the other hand, had my tranny fluid and filter changed over a year ago, no issues that I'm aware of. Just seems to be one of those subjects where you do as you will. I remember a while back, a guy from ashcroft transmissions touched base with this subject.
http://discoweb.org/forums/showthread.php?t=36230&highlight=transmission+service

 

[justintoxicated1]

But also, hypothetically speaking....if the issue with particulates getting stirred up with new fluid, is there a way to perhaps clean it out (similar to an oil pan with sludge)?

 

[ptschram]

This has got to be one of the more contentious topics!

Let's keep in mind that back in the old days, Land Rover said to flush the tranny every 30K and filters every 60 or 90K (I can't remember which). Now, they say to replace the filter at 30K and flush every 60K (IIRC-the service schedules are out in the shop and it's cold!).

With my Disco, I changed the fluid after every towing job and after wheeling (I beat my truck like I should have beaten Shopboy!). That tranny lasted 214K miles and got beaten on badly. Recently while consulting on a BMW tranny swap, I was told that the BMW guys claim to have never seen a ZF HP-22 last near 200K miles-maybe the load is greater, but all the same, I consider my getting more than 200Kout of a tranny that was heavily towed with (multiple Discos through mountains on heavy trailers, 109s long distances, etc) to have been pretty good.

All that said, I have yet to conduct a tranny fluid swap and have the tranny pack it up within a short period of time and I've done several where I strongly suspect the filter had not been changed at 30K and the fluid never.

YMMV, use parental supervision, wear your safety glasses, drink lots of beer, etc, etc.

PT

 

[robertf]

230k and possibly the original filter (purchased with 70k)

I thought it had finally died last week, but the trans valve cable broke. Seems to be doing fine now, maybe I'll add some more lucas to it for good measure.

 

[JohnB]

Thanks John!

Which reminds me, its a D1 with 150,200 miles. I'm trying to track down its maint. history since the maint. log is clear.

John, how many miles did your DII have when you replaced the fluid?

Landy had 94K when I changed the fluid.
I will say that with 150K it's a good time to change that filter and fluid. What do you have to loose. Most ZF trannys I've been around mostly BMW ZF's tend to go between 120K and 150K. You may be at the trannys end regardless of a fluid change.

 

[Steph]

I played safe and did the filter change without flushing the whole system, thus the torque converter. I just put in Mobil1 synthetic ATF fluid which means that I'm kind of running semi-synthetic fluid. No problems at all.

 

[Spike555]

I change my tranny fluid every 30k and the filter every 60k. It's cheap insurance. If a trans is going to fail it will fail new fluid or not. And the filter will catch any bits that may be loosened by the new fluid.

 

[peter sherman]

He said TRANNY! HE HE HE

 

[ptschram]

I change my tranny fluid every 30k and the filter every 60k. It's cheap insurance. If a trans is going to fail it will fail new fluid or not. And the filter will catch any bits that may be loosened by the new fluid.

I'm with ya Spike. It was good enough for all Rovers up until about '95. I wonder if they didn't change the service interval to reduce costs to owners or stores doing complimentary servicing...

 

[TurdFerguson]

Hmmm...now, when a trans goes bye-bye....it's just the gear box right?

 

[Chris-St Louis]

Transmission fluid, when new is a excellent cleaner. It is chuck full of detergents.

Inside your transmission are paper gaskets, rubber seals, brake pad like friction material, and such.

As a transmission ages, it goes through many hot and cold cycles from use and enviornment. The paper and rubber gets brittle inside the transmission.

Used transmission fluid doesn't clean as well the same as when you wash dishes in a sink. The soap gets dirty and doesn't clean as well.

The problem comes in when you indroduce new, fresh fluid. It cleans away the clutch material and, sometimes, the brittle gaskets and seals inside the transmission. This can cause internal hemroging(Sp?) causing the transmission fluid to go where it isnt needed. Automatic transmissions work on directing fluid, under pressure, to engage gears. Internal fluid leaks bleed off needed pressure and the transmission gives up.

Now that you are scared, let me tell you the good.

The ZF transmissions used in Land Rovers are some of the most stout transmissions I have seen. Usually, I see these types of failures in Domestic products, as they are build "Just good enough".

Smart money is on changing you fluid often on any auto trans... Help keep the fluids detergetnts fresh.


On a Discovery, i would have no problem flushing it.... They are hard core enough to take it.... And, if it kills the trans, frankly, it was on its last leg anyways.

Good reading.
http://www.mightyautoparts.com/pdf/articles/tt107.pdf

 

[hywy61]

what about the filter only being replaced at 30K and then never again, as per the owners manual?

DII - 101K