Guess they got tired of people grinding off the teeth

 

My guess is that the 6-speed has the shifter poorly design. I always have trouble with shifting from higher gears into low, but it goes smoothly between low and reverse when I do multipoint turns.
Than shifting from low to 1 while moving on steep grade is a skill on its own.

 

I don't want to be argumentative. Nor do I want to hijack the OP's post.

But I'm a curious sort. I just went down and had some lunch and got a few groceries. In my driveway I got the truck rolling slowly forward. I then put the transmission into Low and then into Reverse, without grinding in either case.

This would indicate to me, anyway, that those two gears are synchronized. They certainly didn't go in easy. But they went in without grinding.

It's odd though, because others are reporting non-synchronized Reverse. I would've thought a ZF-6 would be a ZF-6, regardless of year. I may be wrong though.

It's just interesting, I guess. Not really relevant to the OP.

 

I've found much of the same thing you have. I'm not sure if it's a poor design, or simply that it's a monstrous tranny designed to handle a ****-load of torque and horsepower. It's a lot harder to shift when it's cold. It gets a lot better when it warms up. And it seems to be getting better as it gets older.

 

I thought i had read some technical info that the low gear was non-syncronized which is why it's a little more difficult to engage but i guess not. Who knows.

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

 

Non synch gear would grind when engaged at wrong speed while mine is not. The Low will just not click in when I push the level.
I drive stick most of my life and on cars I was shifting in less than 1/4 sec necessary when you shift with gas pedal firmly on the floor.

 

Owners manual for MY 2003 states "Make sure that your vehicle is at a complete stop before you shift into reverse." and "Only shift to LO when at a stop."

 

That's to be expected when the input and output shafts are not spinning at a rate that makes the gear "want" to go in, if the gear is synchronized. The synchro basically gets the input shaft spinning faster, or slower to match the output shaft (plus the gear ratio). At the point where the input shaft speed matches the gear ratio versus the output shaft speed, the gear will just slip in.

The thicker the gear oil, the slower the synchro works (and the harder you have to push to get it to sync up), so the colder the tranny is, the thicker the oil, and the slower the syncro "syncs".

Also, like a brake pad bedding into a brake rotor, the syncro will, over time, "bed in" and over time will work better. It's particularly bad when you put a new synchro ring on an original gear. With synthetics, that can take a long time to happen

And back to the OP, sounds like a shifter issue, or fork/linkage. I'm curious to see what he says.

 

I'm not familiar with with the newer manual trans. As a matter of fact I never had a manual with a hydraulic clutch until now, but does the ZF-6 have wear pads on the shifting forks?

On my '79 with the New Process 4sp, the wear pad on the left side of one of the shift forks wore off and eventually the metal fork wore out on that side and made shifting into 3rd hard and sometimes it would go in.

I don't know if that's relevant here but I'd thought I would post anyway just in case it does.

 

same thing here, if you dont have a twist, the truck stop before 1 is engaged

My 2002 is hard to put into reverse and low, no grinding just long to engage even if I release the clutch a little.

And when the engine is stop, reverse to 6 go in like a champ whit only one finger on the stick, and my clutch is brand new, disengage completely....

i just dont understand why its a little hard with the left gear

 

I have solved problem of 6-speed not shifting into Low or Reverse.
I pulled shifter. This is what I found.
Small tear in inner boot that seals Shifter to casing.
There is a steel ring in the bottom of the boot that sto-pos boot from being pulled up through shifter hole in casing.
Boot was ripped and had dropped ring onto brass collar in.
Ring was binding between collar and casing when trying to shift into reverse and low.
Solution: Bought new boot and installed. $23.00 solution.
Prblrm solved. Gears work great.

 

Thanks for reporting back. A lot of people don't do that and we never find out what the solution was.

Now if someone is ever searching for the same problem, they might find this thread and a possible solution.

 

Amazing, rep points given!

 

You get some rep from me as well.Thanks for posting the solution.

 

First: I'm the new guy and I know that.

Second: I realize what it means to be the new guy and ask for help.

Third: I'm happy to say I've never needed that much help (other than a good Bullet Proofing) with my Ford.

Finally: I've got the same problem - 1999 F-350 ZF won't go in Low or Reverse. I pulled the shifter and everything looks fine. Boot is good and all is intact. Shifter (top part) while out seems to move far enough that the shift forks would move the Low/Reverse fork. Transmission is not locked and shifts the other 5 gears fine. Just can't move the shifter past the 1/2 gate over to the Low/Reverse gate (like it's just a 5 speed shifter).

Thanks in advance for the help. Hopefully I can return the favor someday.

Joe