ZF5 LEAK FROM TOP

Jesus Freak

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I'd definitely " go the distance" if you pull it. I'm with rock, if you ain't got to pull it. I'd definitely do the rectangle shifter bushings if you pull the tower off the top. But dang, who wants to pull a tranny? It's hot out there! Ughhhhhh!!!! It's WMO weather though!
 

NeverHave-I-Ether

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Good points, I'm not getting grinding. Never had the issue before hand either, only after I added a qt of trans fluid. It simply won't allow me to go in gear, no grinding of anything. It won't even go in until I go below 20mph. It's annoying but something I can live with. Waiting for a boot shifter kit to come in, then I'll pressure wash the crap off and get to work!

Never-Have-I-Ether
 

Jesus Freak

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The type of ATF you use has a lot to do with the shifts. (Mixing brands and types could help or hurt.) More so on these trucks than most, members have found certain ATF’s to give better shifting.
Hey, I'm just curious, I know you are ONLY supposed to use ATF in these zf5s, but how big of a difference can it really make? Is it just "I'm a fastidious old man with a preference" difference? (No insult intended, I don't know how else to express it) or is there REALLY a difference in the shift, with different ATF?
 

NeverHave-I-Ether

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Good points, I'm not getting grinding. Never had the issue before hand either, only after I added a qt of trans fluid. It simply won't allow me to go in gear, no grinding of anything. It won't even go in until I go below 20mph. It's annoying but something I can live with. Waiting for a boot shifter kit to come in, then I'll pressure wash the crap off and get to work!

Never-Have-I-Ether
It's the EXACT same as reverse. You know, how it blocks you from going in gear when driving forward or in OD. Yep, same feeling for 1st and 2nd when going over 20mph. You simply don't go in gear like reverse.

Never-Have-I-Ether
 

Jesus Freak

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It's the EXACT same as reverse. You know, how it blocks you from going in gear when driving forward or in OD. Yep, same feeling for 1st and 2nd when going over 20mph. You simply don't go in gear like reverse.

Never-Have-I-Ether
I don't have a speedometer, but 20mph might be too fast for 2ond. I don't know for sure, like I said I don't have a speedometer, but after I'm rolling 3rd is as low as I have to go. 1st gets it rolling, 2ond actually starts you moving, and 3rd is the "here we go" gear. I need to look at what zf5 I have. I know there's like 2 or 3 types of them. It must be newer because there's no speedometer cable hole in it. I guess the speedometer was in the differential or something on whatever truck it came out of.
 

IDIBRONCO

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Hey, I'm just curious, I know you are ONLY supposed to use ATF in these zf5s, but how big of a difference can it really make? Is it just "I'm a fastidious old man with a preference" difference? (No insult intended, I don't know how else to express it) or is there REALLY a difference in the shift, with different ATF?
Well I can say that when I switched from Petro ATF to synthetic ATF here a while back, the shifts were smoother/easier to make and the transmission is quieter.
 

Jesus Freak

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Well I can say that when I switched from Petro ATF to synthetic ATF here a while back, the shifts were smoother/easier to make and the transmission is quieter.
Fasinating, it just seems like there's no way there could be a difference, but I guess there is. I mean, it's just metal gears!
 

Jesus Freak

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I don't remember what I put in mine, it wasn't the cheap stuff but it wasn't the most expensive either. I remember thinking that it was better than usual, but that's it.
 

Big Bart

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Good points, I'm not getting grinding. Never had the issue before hand either, only after I added a qt of trans fluid. It simply won't allow me to go in gear, no grinding of anything. It won't even go in until I go below 20mph. It's annoying but something I can live with. Waiting for a boot shifter kit to come in, then I'll pressure wash the crap off and get to work!

Never-Have-I-Ether
If the problem is brand new, likely it’s the new ATF you put in. So a tranny drain and refill will likely fix it.

FYI don’t pressure wash the shifter area, you do not want any water to get inside the tranny.
 

NeverHave-I-Ether

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If the problem is brand new, likely it’s the new ATF you put in. So a tranny drain and refill will likely fix it.

FYI don’t pressure wash the shifter area, you do not want any water to get inside the tranny.
I was thinking just seal the top and pressure wash it, then drain the fluid? There's supposed to be a breather vent bolt and I can't even see where it's at. Pressure wash then fluid change. Sounds like a good plan to me. How else would I get all the crap off? I would go through 15 cans of brake cleaner easy to get it off.

I admit that you have a point, but seeing that I'm changing the fluid afterwards It shouldn't be problematic.

Waiting for boot shifter kit to come it, something is up with the synchros. I used Motorcraft Mercon V. Maybe dirt? Then I don't understand why it works at low speeds to go in gear but at high speeds it won't go in gear. Very strange. Thoughts?

Never-Have-I-Ether
 

ROCK HARVEY

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The fact that you can’t downshift over 20mph is what made me think your clutch linkages might be worn. It’s almost like you’re floating gears, and can’t get it to “drop in” until you’re in the correct RPM range.

As for cleaning it, are you planning to reach your pressure washer inside the cab and spray through the shifter hole? I bet you’d get some funny looks at the car wash doing that :-D
 

Big Bart

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I was thinking just seal the top and pressure wash it, then drain the fluid? There's supposed to be a breather vent bolt and I can't even see where it's at. Pressure wash then fluid change. Sounds like a good plan to me. How else would I get all the crap off? I would go through 15 cans of brake cleaner easy to get it off.

I admit that you have a point, but seeing that I'm changing the fluid afterwards It shouldn't be problematic.

Waiting for boot shifter kit to come it, something is up with the synchros. I used Motorcraft Mercon V. Maybe dirt? Then I don't understand why it works at low speeds to go in gear but at high speeds it won't go in gear. Very strange. Thoughts?

Never-Have-I-Ether
One would think if you wait 10 minutes the water would collect down at the bottom and drain with the atf. But if it comes in the top it’s going to get caught up on the way down the gearing and stick to things. Later heat up and sweat the case each driving cycle.

Maybe Saran Wrap the boot and top area to help prevent water from getting in the boot and use Simple Green below the boot. Then scrub that area and the sides with a stiff brush to break the atf and dirt loose and gently wash off with the hose on low. VS spraying at the boot with 3,000 psi.
 

Big Bart

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The fact that you can’t downshift over 20mph is what made me think your clutch linkages might be worn. It’s almost like you’re floating gears, and can’t get it to “drop in” until you’re in the correct RPM range.

As for cleaning it, are you planning to reach your pressure washer inside the cab and spray through the shifter hole? I bet you’d get some funny looks at the car wash doing that :-D
I did too at first but he said this happened after pulling the shifter and adding one quart of atf. So potentially something new happened (New issue with linkages) from testing the clutch.

As you may have read different ATF’s improve or degrade shifting in these trucks so perhaps it was mixing atf‘s that caused it. Both are plausible if this was not happening prior.
 
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