comments about your ZF5 failure

[IDIoit]

i have read a couple of threads about people destroying their ZF5.
just curious as to what breaks on them,
what you were doing when it broke,
and how to keep it from not scattering.
ive destroyed many of aluminum cased manual transmissions in my day with alot less torque and weight.
id like to keep this one in 1 piece (F450 ZF5)

 

[79jasper]

Wrong bearing preload on the pto.

Sent from my SM-T537R4 using Tapatalk

 

[BDCarrillo]

From my net wandering I think I've seen more issues with the DMF failing and clutch hydraulics leaking...

Supposedly the wrong fluid will kill the synchros... I don't remember the details I read on that one but the manufacturer recommends Mobil 1 Synthetic ATF

 

[reklund]

I had a SMF flywheel that was drilled off-center and caused the input bearing to fail, and subsequently munched some synchros.

 

[towcat]

tow a ZF5 equiped truck from the front and the driveshaft connected, and you will burn up a trans from the lack of lubrication. the input shaft MUST BE SPINNING to pump oil through the gears.

 

[IDIoit]

lets hope i dont need to be towed with my rear tires on the ground! lol

 

[Kevin 007]

Seems like the cases crack a lot. Mine was cracked around in two places in the bellhousing when I pulled it. Welded them. Second gear synchros seem to go often, not sure why. I baby my trucks and haven't had that issue but I notice this in other folks rigs who drive em a bit harder, maybe shift alot swifter.
A lot of people seem to overfill them a bit to.

 

[marmot]

If your towing put the tc in neutral right? then the zf5 is not spinning correct? I guess with 2wd thats not an option.

 

[madpogue]

Supposedly the wrong fluid will kill the synchros... I don't remember the details I read on that one but the manufacturer recommends Mobil 1 Synthetic ATF

What I've read is, a LOT of modern manual transmissions, the synchros include the same material that's used in the internal clutches of an automatic transmission. So they require the same fluid for maintenance. ZF and Ford REQUIRE synthetic ATF. The owner's manual, the FSM and the plate on the side of the tranny all agree on that. But I've never seen a recommendation for a specific brand from either manufacturer. My personal experience with Mobil 1 is that it's fine and smooth in warm weather, but makes the tranny very notchy when cold. Next thing I want to try is Castrol Transynd, which I've seen recommended for other manuals that call for ATF.

tow a ZF5 equiped truck from the front and the driveshaft connected, and you will burn up a trans from the lack of lubrication. the input shaft MUST BE SPINNING to pump oil through the gears.

How quickly can this happen? I rarely do so, but coasting with the clutch disengaged will obviously have the same effect.

 

[dunk]

Mine have all been case failures. Main case around the bell or just behind and trans mount pad on tailhousing. Syncros on 3rd seem to wear but it doesn't really affect much. Really the cases are the wear point. I believe the S5-47 has a beefier trans mount area on the tailhousing and more ribs on the main case. For what it's worth never had one leave me stranded, just strap it down and it doesn't move around or twist too much. Also my failures were all behind a 460, with teh rare exceptions IDIs will be putting out a lot less torque. I had one failure trying to pull another fullsize truck out of a mud hole, another while towing accelerating from a toll booth, don't recall on the other failures but it wasn't a memorable "what was that sound and what feels different?" type of moment.

 

[Bashby]

I've got one with a broken ear at the trans mount. Reverse synchro is a common failure.

 

[93blklightning]

When i first purchased my truck, the PO had apparently had the transfer case out, but i didn't know it until it was too late.

I was getting off the interstate one day, here in Virginia the vast majority of our on/off ramps are elevate unlike out west ie Texas, where they just turn off the side.
Anyway i was getting off the interstate, it was a 360° off ramp, and relatively a tight turn, on an angle, and i could a whining noise.
After i got home, i crawled under the truck to check it out.
Only 4 of the original 6 bolts in the transfer case/transmission tunnel where still in, but only finger tight, if i remember i think 2 were ready to fall out.

Where they were so loose they allowed the tc to shift and broke the rear of the trans tunnel into 3-5 pieces.

Luckily all the pieces were still there, with the exception of a few slivers, so i took it and had it welded back together (i weld steel, not aluminium lol).
It held for 5 years until i replaced it

 

[icanfixall]

Coasting with the engine running is causing the imput shaft to turn. Thats what you want happening. Towing with the front wheels off the ground in neutral and the engine off kills the trans. At least thats how I see it from what towcat knows.

 

[G. Mann]

On the subject of failures... I don't have one "yet" but may have one in the making.

Went to check oil level in the transmission and found the fill / check plug can't be unscrewed... put a 3 ft breaker bar on it.. still would not budge.. Anyone have any tricks on how to get it out?

I would like to keep the oil level good, and I've owned the truck for 6 years now.. never changed the trans oil, pretty sure the Previous Owner didn't either.. it's time.. just to be safe.

Suggestions? Heat? How much?

 

[towcat]

On the subject of failures... I don't have one "yet" but may have one in the making.

Went to check oil level in the transmission and found the fill / check plug can't be unscrewed... put a 3 ft breaker bar on it.. still would not budge.. Anyone have any tricks on how to get it out?

I would like to keep the oil level good, and I've owned the truck for 6 years now.. never changed the trans oil, pretty sure the Previous Owner didn't either.. it's time.. just to be safe.

Suggestions? Heat? How much?

you may be the victim of galvanic corrosion. take a short punch and hammer and place the punch at the center of the plug. rap firmly with hammer. try again. if not, hit the alu with a torch.
good luck!