HELP!!!! Need ZF-5 Tailshaft housing like yesterday

[icanfixall]

That really looks like it would weld fine but.... The machined bearing surfaces would need to be cleaned up and that may not be inline after that much welding. So how does towing it with the drive shaft kill it like this???

 

[tonkadoctor]

That really looks like it would weld fine but.... The machined bearing surfaces would need to be cleaned up and that may not be inline after that much welding. So how does towing it with the drive shaft kill it like this???

Sure it could be welded and machined but at $60 per hour or more it isn't worth the $$$$$$ to repair it properly. Aluminum alloys also have roughly a 6% shrinkage problem to deal with too when welding them.

Even though I am selling the truck I am going to fix it right which IMHO is to replace it now that I have taken a really hard look at how bad the housing really is. The Pics are hiding a lot of the damage.

The ZF transmissions don't get lube when the engine isn't running or when the clutch is disengaged. It's simply the way they were designed and Towcat or somebody more knowlegable than me would have to explain it further.

Transmissions in big trucks have the same problem which is one reason they tell you to not coast them to stops or push the clucth in to let them coast down a mountain.....besides the safety factors of driving them wrong like this.

Some trannys are OK to flat tow with a tow bar which is why I did it because I thought the ZF was OK to tow but I was wrong for once in my life

 

[Rawpower]

If you want to convert to a 4x4 I have the Mainshaft and Tailhousing from one...

Or if you don't want to do that... I got my 2wd tailhousing from Blumenthal's in OKC, OK. They have all the parts in the world, I'm sure they will ship, they told me that they would if I needed anymore parts and wasn't going to be up in that area again (wasn't going to be) and sure enough I needed a part... so they shipped it. If you can't find them on Google, tell me and I can check for a number.

 

[SKimballC]

Transmissions in big trucks have the same problem which is one reason they tell you to not coast them to stops or push the clucth in to let them coast down a mountain.....besides the safety factors of driving them wrong like this.

So you're saying its not OK to even coast to a stop with a ZF-5?

 

[tonkadoctor]

Thanks for the info Rob.

Shane,

Been studying how this thing works a bit trying to figure out why it's like this and here it is to the best of my abilities.

There are 4 shafts in this transmission, the input shaft, the mainshaft which is also the tailshaft, the countershaft and the reverse idler.

The input shaft drives the countershaft which rides in the oil bath in the bottom half of the transmission case and provides the lubrication. All of the gears on the mainshaft are on bearings and spin free until they are engaged with the countershaft, the only thing actually locked onto the mainshaft are the syncro assemblies.

If the countershaft is not rotating because the clutch is disengaged and the transmission is in neutral no oil is getting to the bearings on the mainshaft or the input shaft.

For those of you who didn't read about the trip when I towed this truck home a few months back there are possibly more factors than just lubrication that contributed to this failure as I was nearly in an accident and had to lock up the brakes on the interstate at 65 mph when a horse ran across the highway about 2 miles from where I picked up my new Stuperduty. This caused my already at max capacity towbar to bend as well as mangle the chains and locks providing me with a very rough slam bang white knucle 750 mile 55 mph drive across twisty hilly I-40 in Tennessee and North Carolina. While the lack of lubrication hurt I'm sure the beating didn't help either.

I will give the ZF5 transmission its due though, I probably put 200 miles on it hauling firewood in the bed and pulling a 6' x 16' trailer loaded with firewood after the bearing failed and it didn't even give me a sign like hard shifting or more noise. The gears and syncros after all these years and miles look like new. I'd definatly buy a truck with ZF5 or ZF6 transmission again.