Hey all, I am going to be looking at and test driving a 2000 F-350 ZF-6 truck within the next few weeks. I am just wondering what I should look out for upon inspecting the ZF-6 itself and clutch. The truck itself is pretty much 100% stock. It has 182K on it. I have only owned and driven automatic 7.3 trucks. Given that I don't drive a manual vehicle often, the last manual vehicle I have driven was a 5 speed 4 cylinder Tacoma this past May. And I do drive tractors that are manual occasionally. So with the Tacoma being the last experience I had, what will driving one of these trucks with the ZF-6 be like?

The Tacoma required a real feel for the amount of gas pedal input it needed to start in 1st gear without stalling (my Milwaukee cordless impact probably has more torque than that 2.7 I stalled that thing more times than I can count on one hand until I got the hang of it. Now for test driving this truck: What will the 7.3/ZF-6 be like? Will it start in 1st or 2nd without much engine input? What is the clutch feel/release like? I'm also aware that the throttle response is pretty relaxed and linear on a stock truck.

 

To start out in 1st or granny/Low you don't even need to touch the far right peddle

 

As Wesley said, no fuel pedal necessary to get it moving with a diesel. I can't help you any with the ZF6 characteristics.

 

Depending on the condition of the clutch, to bearing and/or input bearing, will determine how the clutch "feels". I just installed a stock power LUK clutch over the weekend, only because A)had it on shelf, B) heard a "whirl" sound 2wks ago when turning motor off. Clutch, to me, still worked and felt great, that was until, the new 1 went in. The pedal now has absolutely NO EFFORT to being depressed vs what i "thought" was normal...ive installed a few and at 1 point, i was blasting thru master/slave assy because what i YHOUGHT was normal pedal action was infact an issue down inside..

Ask if ever the clutchfork has been upgraded/clutch been replaced

Keep a spare master/slave prebled assy on you/in garage..part number pf9021/brute force from RockAuto or Advanced Auto..its an all aluminum construction

Be ready to weld or "mod" the clutch rod post on the pedal. Itll break eventually.

Use only mercV 6.5qts when changing fluid.

As for driving characteristics, just drive it. Within a few gears, itll be 2nd nature. Dont try and match rpm shifting, its why you have a clutch.

 

I've never heard of the ZF6's clutch pedal breaking, my trucks at 310K no issues, I know many other people without issues as well. I think that's an OBS problem.

 

not the pedal itself, but the protruding rod from the pedal, that the master assy rod attaches to via the "birdcage"

 

 

Do your best to ensure it does not have clutch chatter or hot spots on the flywheel. You can attempt to do this by backing up an incline after the truck is good and warm. You will sometimes see it in low gear (not 1st) going forward, but it is a very easily identifiable when backing up a hill or a load.

Here is a video of clutch chatter that I was experiencing without know what it was called until the fellas here helped me out.

Moving our 2011 Montana High Country at a campground...


Here is the video of the parts that were bad and worn, then some of the new parts that were installed.


When I first bought my truck, I knew nothing about a ZF6 (other than I wanted one) and how to drive it. The guy I bought it from knew this and told me the truck bucked like that because the torque was so high. I later learned he was a liar, but I got the truck for a great deal and in great condition, so I let it be water under the bridge.

See if it clunks or grinds going into the gears. There should be a firm click or confident feeling when going into gear, but not a push back or hard push of the lever to get into gear.

If you do get the truck, check the fill plug on the side of the case before you empty the case. Some of us fill from the top at the shifter anyway, but it is nice to know the fill plug is not seized up, like mine was...

I have used all sorts of fluids and settled on Redline High Temp ATF. It is a very smooth performing fluid in the transmission and I have zero roll over noise. It is pricey, but I have complete confidence in the fluid.

As for starting out in reverse, 1st and low, the fellas have you on the right track. Zero, I mean no throttle input until your foot is free from the clutch pedal. If you are on an incline and have the urge to use the throttle to keep yourself from rolling, use the brake instead of the throttle. The brake will hold you in place until the clutch is fully engaged and you are headed the direction you want to go. It takes a bit of practice and I didn't believe it, but now I do and my truck is much happier since the FTE educated me.

Keep the questions or concerns coming, we like to help and would rather have you ask before making a mistake than ask afterward and learning the hard way.

One last thing, the ZF6 is a beast of a transmission and when mated to the 7.3 it is even better...

 

What kind of MPG you guys get with the ZF6?

 

I get 18.5 MPG's with mixed city/highway driving unloaded and 13 MPG's with our 10K lbs 5th wheel in tow.

Edit: I guess I should also mention stock sized tires and wheels with a 3.73 differential.

 

 

Depends on the driving involved. Empty city 15-16mpg, empty highway 19-21mpg, 10k# 5th wheel 11-12mpg depending on terrain, car hauler with 4500# 1971 F100 16mpg, car hauler with 3200# corvette 18mpg. All on 265/75/16 tires 3.73 rear

 

My rod was broken where the pedal attaches to the master cylinder rod when I got the truck. One of the many issues I had overlooked as it felt mostly fine. The PO fixed it with a nut and bolt. I had to get a new pedal assembly and bushing. It's definitely not an OBS only problem, but probably more of a dip**** operator problem.

 

I highly recommend you pull the trans fill port and inspect the trans fluid for coolant infiltration. A bad radiator will toast it pretty quick. Fluid should be red and not milky at all. My truck, lemon of all lemons. also had this issue. The fluid is cooled (and heated) by the radiator. If the internal separation fails at the radiator, coolant will seep into the trans fluid and likely toast your synchros.

Honestly, beyond all that, if you are serious about the truck take it to a good Powerstroke mechanic and pay $150-200, whatever dollars, to have it inspected. Well worth it. There are many things that can go wrong on these trucks that are not immediately obvious.

 

Thank for the tip! My friend recently had the same issue with his '06 and was a mess to get the system all flushed out. Is the fill port just a square plug?

The issue with taking it to a mechanic is that this truck is 3 hours from home and out in a rural area that I'm not all that familiar with. I may do some research and see if I can find a mechanic near by it. I also have a bit of experience wrenching on these and what to look for from the experience of searching for my other two trucks, and I will definitely be going over the checklist of what to look for.