Can this ZF be saved?

So I picked up this 2005 Passat, cheap. Lots of maintenance and repairs including BSM delete. One of the services was the transmission fluid 10K miles ago. The car now has 230K kms, or 144K miles.

But, the transmission is "toast". Or so the mechanic told the PO.
I checked it with VCDS and found no codes.
The symptom seemed to be mostly that it would engage into reverse normally, then disengage after a second or two. Forward gears appeared to work ok, but I didn't do a lot of test driving.

I found a replacement trans, but thought, why not see if it can be saved?

I dropped the fluid (about 3qts) and it didn't smell as I would have expected (didn't have that strong ATF smell) and was dark.
So now I'm thinking that the mechanic that did the fluid change may have used the incorrect fluid and/or wrong fill procedure. There's hope!

I then refilled with Valvoline Maxlife using the correct procedure.

Now it engages reverse with two fairly harsh clunks, but actually stays engaged!
Forward gears are working well (I don't have a great comparison here on the before and after, but it shifts very well now). Still no codes.

So here's the question for those ZF 5HP19 experienced folk:
Do I:
A)accept that it's failing and start yanking it out, or do I
B)drop the pan, do the filter, and refill again with a Pentosin fluid.
Or option C) suggestions..

C) swap out for a manual 5 or 6 speed.

It's already bolted in. So option B, you'll know if the filter is plugged with its own grindings (or not, and it could be super clean) , so that'll cover more findings of option A.

Then option d, drive it until it's officially roached. Then move onto suggested option C, manual.

Of course the manual trans is the ultimate, but the fact that it is already bolted in is a huge factor.

For now, I will consider option B. Anyone else want to weigh in on option B?

I just didn't want to waste a bunch of time and money on filter, gasket, and fluid.

But it's true, I will know more once the filter is out.

Is this a good sign that there are no stored codes? I wasn't able to conclusively find out if R/D drum failure (although it stays engaged now) or VB issues that cause problems with reverse always throw a code.

Option "C" all the way for me. I bought a perfectly good car with working trans & promptly removed it in favor of the 6 speed. Selling the slushbox paid for most of the swap.

If you don't mind sharing, I would be interested in the numbers and process you followed. Thanks.

At least in the BMW world, these transmissions are somewhat notorious for a Reverse/D drum that starts breaking apart. I'd guess that's probably what's going on here.

Uberhare said:

Option "C" all the way for me. I bought a perfectly good car with working trans & promptly removed it in favor of the 6 speed. Selling the slushbox paid for most of the swap.

Click to expand...

I love the sounds of that, selling it to help pay for the swap. I think I'll try option "B", in hopes of a cost offset moving into Option "C".

mightyquinn, although there's a good chance you're guess is right, it is unusual that it now stays engaged and has improved shifting after just swapping a bit of fluid alone.

And besides, if I drop the pan and find all kinds of goodies, I won't bother with filter, gasket, or fluid...
No drum chunks and looks cleanish? Ok..now I'll try new filter and fluid.
I think this is what Jason_ was suggesting. Drop the pan at least.

If you want to keep the car for more than a few months, save the potential throwaway cost and just replace the transmission with either a manual or a good used, maybe rebuilt, automatic. This transmission is on it's last leg. The chance of a fluid change fixing it very slim.

imo000 said:

If you want to keep the car for more than a few months, save the potential throwaway cost and just replace the transmission with either a manual or a good used, maybe rebuilt, automatic. This transmission is on it's last leg. The chance of a fluid change fixing it very slim.

Click to expand...

Ya wishful thinking on my part.

I'm sure I'm in a long list of those that have sang this song..

Cut the filter open and check for contamination such as metal or clutch material. That'll help which direction to go

There's also "plungers" in the valve body (rubber boots, not the valves themselves) that deteriorate, once they do it causes harsh shifting also

Ya I think I'll explore. I'm a curious type.
What's the worst that can happen?
Might even learn something!
But it seems wise to look toward a third pedal.

Here is another possible cost/benefit view: estimate approximately for $3500 for a complete (parts/labor) five speed swap done by one of our honest and competent TDI mechanics (search through this forum or other means, word of mouth, etc.). You might get a few hundred dollars back from the replaced ZF transmission but just in case do not count on it.

Look at the 'pain' of the above cost vs. the known unreliability (+schedule maintenance costs) of the B5.5 automatic transmission IF you are planning to keep the car for years to come.


Which one is less painful to you?