Ok, did a ZF swap in January, haven't had any problem with the transmission (I had it overhauled before I put it in) and everything was working fine. Changed fluid yesterday, from straight Mercon III/Dexron, to a Mercon III/Dexron and Power Punch additive. I went to drive it today, and it acts like the synchro for 2nd is out now, but only during downshifting. If I downshift from 3rd to 2nd, it grinds, and I can put the stick back in neutral, then try again and it goes fine, so whats going on?

Are ZFs really that fickle about what kind of fluid is in them to where this would happen? It only does it in 2nd, and only downshifting to it...

 

Sorry I dont have any idea about the answer to your question, but I do have some questions of my own if you dont mind.

I am interested in doing that swap. Did you get a donor truck with all the trans componenets and pedals and stuff or did you buy mostly all new stuff? How hard was the swap and would you do it again? Are the highway cruising RPMs much less than they were with the A4?

Thanks is advance

Eric

 

There are plenty of threads about doing that swap (including nighthawks). Use to search function to search for zf swap, you'll come up with a lot of results.

Most guys say its easier and cheaper to get a donor truck. The swap is not all too hard in and of itself, nighthawk seemed to have the most trouble just getting it working correctly when he was done (ended up needing a new starter).

-Chris

 

Nighthawk, which Power Punch product did you add and why? I see on their site that they have ATF treatment and some oil additives, but nothing shows for a standard transmission...

-Chris

 

Nighthawk:

Try going back to straight Mercon/DexronIII and see what happens. I swapped from an AOD-E to a T5 in my Mustang and I put synthetic Mercon in it. I had a lot of trouble shifting. It didn't grind but it was hard going in gear. I pulled the trans when swapping in a new engine and upon reinstallation, filled the trans with dino Mercon. Problem solved,the thing shifts great.

My theory wathat the characteristics of the synthetic were different enough that the trans wouldn't shift smoothly. Mybe the additive is doing that to your trans. Does it shift ok if you double clutch it?

Off topic, but does your ZF have a lot of gear roll over noise in neutral with the clutch out?

 

That's what I was thinking. I typically shy away from additives that go into your tranny fluid or engine oil. Just my own pet peeve I guess.

-Chris

 

no noise with clutch out in netural (bearings and shims are new if thats where you were going with that..... everything was awesome until I swapped fluids....

I just put in standard Power Punch oil additive (which says works with ATF) because that is some of the best oil additive I've ever seen. My dad's 3406B Cat engine with Power Punch in the oil, and when he finally destroyed it(not watching temp gauge), we pulled the rod bearings and they looked brand new, same with trans bearings and gears. I just wanted a little more OOMPH to the ATF in there...

I haven't tried double clutching, but it will grind really hard (won't go in) if I just downshift regularly, but if I try it, then let it go back to neutral and try again, it works. I will try going back to the DexIII/Mercon and see if that helps.....crazy that things things are so fickle for being standard transmissions.......

Stanghater, I got the pedal bracket (whole different piece for clutch & brake) out of a donor, got the trans out of another donor, got the hose and master clyinder NEW, new clutch, new slave cylinder, X-members out of another donor, flywheel out of a donor then had it machined, front driveline out of a donor, had the back driveline shortened an inch at a machine shop.......just a word about that starter....if you do it, the manual trans starter is different than the automatic trans starter, so you have to get that, that was the whole problem I had with mine....other than that, it was an easy swap...I would do it a million times over for how much I like it over the AOD, more power, better milage (14AOD to 16 with the ZF), more control....

here are my threads for this swap, if you want any more info, PM me and I'll be happy to help

https://www.ford-trucks.com/forums/5...tch-pedal.html

https://www.ford-trucks.com/forums/5...nual-swap.html

https://www.ford-trucks.com/forums/5...-problems.html

https://www.ford-trucks.com/forums/5...a-zf-swap.html

Thanks, now to go swap fluids again...

 

Why are you using ATF in your standard transmission? I've never had to change a manual tranny's fluid, but isn't there a specific type of MANUAL tranny fluid? I could be wrong here...

-Chris

 

thats what it called for, dont ask me, i dont understand it either.......

it still does it, I can get it to shift into 2nd about 50% of the time by double-clutching, then the other way by letting it go back to neutral, is this looking more and more like 2nd gear synchro going?

 

Nighthawk:

Was there any brass/metal in the oil? If it's still doing it after the oil was changed, it sounds like it could be a bad synchro. That would really suck.


Back in the day manual transmissions used 90 weight gear oil. At some point in the late 80s or so, manual transmissions started using ATF. Was I ever surprised the first time I ran into one of them. One of the reasons is that the lighter oil allows better gas mileage. Some people now run 30 wt in the old transmissions and transfer cases.

 

Should have expected gustang to show up, the tranny guru, lol. But yeah gustang, I don't think he was grinding 2nd before he changed his fluid. Only after he put in new ATF + Power Punch additive. I'm thinkin' that additive is messing up his mixture. Whats your take?

-Chris

 

no there wasnt any metal, the fluid that came out was a dark maroon color (looked good, just figured after the rebuild, it was a good idea to swap fluids)........yes it is still doing it, even though I have swapped back to the straight Dex III/Mercon, so I am really not happy about this, thats about a $600 fix, plus downtime

edit....Can I drain the fluid, take off the PTO covers, and look up in there and see anything? Not that I'd know what to look for, but just an idea, maybe you guys would know

 

My take is that if changing the fluid back to straight Mercon doesn't fix it, then it's a hardware problem. I thought maybe he had changed the fluid and said it was still doing it.

 

The synchros are brass rings that have teeth on them. If the teeth are worn/ground down/missing, then the synchros would need to be replaced. If you took the cover(s) off you would have to find the ones for second gear.

 

are they at the front of the drive gears, or do you know in general where they would be in relation to the rest of the stuff in there?