zf ?

[DeepRoots]

I'm new to having this trans.
two comments:

While rolling to a stop, I can't really get it to shift into 1st or 2nd until I'm nearly at a stop. Makes city driving a little tricky. I can force it into second but it doesn't go easily and sometimes there is a little grind.

at certain speeds/gears there is a spring rattle sound that seems like its coming from the flywheel. Especially 3rd gear 2k rpms. Not just when getting into gear, but often while cruising.

is it just a sign of the trans/flywheel being old/worn? I was told the flywheel/clutch were in good condition, and visually they appeared to be so, I have no reason to doubt it.
Just wondering if this is normal, or what.

and man, 1st gear with 3.55's is a little high of a gear to start out in... I'm used to more of a granny I guess.

thanks,
Drew

 

[Agnem]

Really? You think that first is high? If I can pull a 30' 5th wheel without haveing to give it any throttle in first, that doesn't seem high to me. You sure your not in 3rd? Your noise is probably the DMF going out on you. Maybe you are also trying to downshift too early. Idle forward in first and second, and make a mental note of the road speed. This is the speed you should expect it to downshift into without giving it any throttle. If you want it to go into that gear earlier, your going to have to rev up to match the speed. Of course there is always a posibilitiy your clutch isn't 100% disengaging also.

 

[92F350CC]

Mine has the exact same problem that you describe in the first paragraph. I haven't figured out why yet though. 1st is plently low for me, and my truck doesn't even have the torque that the diesels do. But i do have 4.10's. Another problem my trans has is that after you push the clutch in, you have to pop it back out with your foot, it doesn't come all the way out by itself.

 

[h2odrx]

Of course there is always a posibilitiy your clutch isn't 100% disengaging also.

What would be the fix for this?

 

[Agnem]

...Another problem my trans has is that after you push the clutch in, you have to pop it back out with your foot, it doesn't come all the way out by itself.

Oh that's definitely bad. That means the presure plate isn't pushing the slave cylinder rod back in far enough. Most likely cause is you have air in your hydraulics or a major malfunction the slave or master cylinders.

In most cases failure of the clutch to disengage properly (as seems to be the case with both of you) is due to either a cracked firewall (preventing full travel of master cylinder), air in the hydraulics (not likey to develope if the system was formerly working OK), A bad slave or master cylinder, a bad clutch fork or pivot ball (not usually the problem), failure of the throw out bearing to slide on the input shaft collar freely, or a bad presure plate. A cracked bell housing could cause this also.

 

[92F350CC]

I hope it's just a crack or the cylinders. I do not have time right now to tear into the tranny and don't want to pay a mechanic to do it. I may end up trading for something newer in the next couple years. A nice diesel SD or a 94 IDI sounds real nice.

 

[DeepRoots]

well, If I were to let off the clutch in first gear, the truck promptly stalls, or at best rattles and bucks until it gets moving. Thus my view on that. On another note, My truck still idles at 600, I seem to recall the idle speed for a manual being higher... I may change it to 700 and see what it does.

The master/slave seems to be releasing fine, as I've gotten to view it from under the truck and the movement is good. Firewall isn't cracked, tho it does flex. This was until 80 miles ago a truck with a c6. The throwout bearing slides freely. I'll check into reinforcing the master and double check on air.

The spring/rattle noise is not while shifting, so I doubt it's from shifting too early, 2k rpms cruising in 3rd doesn't seem like it should be too low an engine speed.
Shoot, if I need a new flywheel, I'd probably sooner put the auto back in it.

 

[Agnem]

You could do a lucky mod. I've gotten to the point now where I wouldn't touch a DMF without doing the mod. We built Matthias' truck the NightMoose with that thing from the get go. No DMF worries then. I'm curious about that stalling. Idle is 650 RPM. In the Moose Truck, I once accidentally popped the clutch in first at a boat ramp with a boat trailer attached. Thought I was in neutral but was in first. Smacked my head on the back window but good. When I woke up a couple seconds later, the truck had walked up the ramp with the trailer in tow. Now I realize, that was a T-19, but still. The ZF seems about the same to me.

 

[dyoung14]

wow thats kinda weird, cause mine seems kinda high and its got a t-19 and supose to be 3.55 gears, mel whats your tops speed in first second and third? mine is 1. 25 2. 38-40 3. 68-70, 4. speedo burried in fourth, i dont have a tach so god only knows what im taching. and mine usauall wont stall but i got to take off in first just about every were i mean it will take off in second but it will jump and buck and try to die until it gets rolling so i just take off in first

 

[Optikalillushun]

lucky mod? whats that?

on a side note, i can pull out in 1st without giving it any throttle with 3:55 gears and 315/75/15 tires...

 

[redneckaggie]

I can take off in second without hurtin anything just got to be easy and my is 5 speed with 373s i think 2k in 5th is like 63

 

[jtate]

i think the lucky mod that hes talking about is taking a dmf, taking it apart and doing some modifications to it to make it alot beefier. i think your hard going into 1st and 2nd problem is do to air in the system ,that hasnt worked its way out yet.

 

[DeepRoots]

roger on that,
I'll tear into it.
I only bled it when I installed it last time I was home, 5 weeks ago.
Might try re-bleeding and topping it off.
or when capt roger gets home, have him help me bleed it out.
hard to do by yourself, ya know.

 

[92F350CC]

Unless gasser and diesel trannies are geared differently, you should have plenty low of a first. I can idle it in first and it will move, granted i have 4.10's. I start out in second quite regularly.

 

[towcat]

bringing a linky back from the dead.....
ckicky here
http://www.oilburners.net/forums/showthread.php?t=9851
look up my comments in post #10