zf 5 question

[BigRigTech]

ZF's are notchy on a good day, I drive mine like Goofy described, much easier on the trans and it will prolong the life span. I drained the reg ATF out of my ZF and filled it with syn ATF....Mistake....Now I have to be going very slow to downshift into 2nd gear....With the reg ATF it could be done at any speed within reason. My trans works great and I thought the syn ATF would make it shift even better....It does but not being able to downshift into 2nd like I was used to doing really ****'s me off so I'm going back to reg ATF.

 

[BioFarmer93]

ZF's are notchy on a good day, I drive mine like Goofy described, much easier on the trans and it will prolong the life span. I drained the reg ATF out of my ZF and filled it with syn ATF....Mistake....Now I have to be going very slow to downshift into 2nd gear....With the reg ATF it could be done at any speed within reason. My trans works great and I thought the syn ATF would make it shift even better....It does but not being able to downshift into 2nd like I was used to doing really ****'s me off so I'm going back to reg ATF.

Hey BigRig-
What do you attribute that to? I'll be honest and tell that as far as downshifting goes, I probably don't do as much as some folks.. Usually I just slip it into neutral and coast.. Anyway, when I got my truck there was heavy gear oil in it and shifts were slow and required more driver input, I replaced that gear oil with some Castrol synthetic ATF for high milage vehicles and now it shifts great- and downshifts easily as well. Could what you are experiencing with that be caused by synchronizers on their way south?

 

[BigRigTech]

It's almost like the syn ATF is TOO slippery if that makes sense and it won't let the synchro dog in...It shifts better up through the gears - definitely noticable....It's just the downshifting part that bothers me as I like to down shift when I'm loaded heavy

 

[MidnightBlade]

When I first got my truck I used to use a little blip of throttle between 1st & 2nd to smooth things along, or do as Goofy Exponent suggests and hold a little pressure on the shifter up against 2nd and let it slide in (using clutch also) at its own pace. These days I rarely use 1st at all unless I'm sitting stopped on a hill. I was reading the ZF manual a while back and they reccomended starting out in second most of the time unless you are hauling or towing. We have so much torque to work with on these engines that my 2nd gear starts are easily as smooth as my 1st gear starts...

i can pull out in 3rd if i feel ambitios but most of the time it is 2nd i only use first when loaded heavy or just feel like creeping up to a stop sign or ******* off the ******* tailgating me that alway makes them a little happier, doing 7MPH in a 45 zone and not being able to see across the street beside me

 

[alienturtle]

my zf5 has 1st gear????

 

[gatorman21218]

when i'm down shifting, mine hardly will let me grab second until ive slowed way down. it screams until for 2-3 seconds before popping in. I try to avoid that figuring its ******* the syncros. in the mornings ill sometimes get the ZZZZZZZZZZZZZZZ in reverse but once the truck warms up its not a problem. Also when its cold itll click going into second or third but again it goes away.

Also isnt starting in second harder on the clutch?

 

[MidnightBlade]

i dont think so, at least not with a hydraulic clutch.

 

[itsacrazyasian]

Well i have a nonturbo truck, 35in tires with 3.55's. starting out in 1st is NOT gonna happen. Shes shifting well enough i'm gonna leave it alone now and let it be. Might rebuild it next month when i get some $$$. Worse comes to worse i put the C6 back in.

 

[franklin2]

Well i have a nonturbo truck, 35in tires with 3.55's. starting out in 1st is NOT gonna happen. Shes shifting well enough i'm gonna leave it alone now and let it be. Might rebuild it next month when i get some $$$. Worse comes to worse i put the C6 back in.

With that combo you can start out in 2nd? I have 35's with 4.10's, and I have to slip the clutch a little too much for my liking to start out in 2nd. A guy I work with though has the same setup with stock sized tires, and he never uses 1st gear unless it's a special occasion.

 

[itsacrazyasian]

Starting out my truck in 2nd is not gonna happen unless theres LOTS O clutch slippage. I start in 1st. I'm not a tranny guy and i don't pretend to be. I'm sure i can figure out how to replace the syncro's on this thing but i don't feel it needs it. I can get into 2nd gear from 3rd at 35, and 1st at 20. But 1-2 is the only issue. Reverse seems to be good now that i fixed the worn shifter.

 

[OkieTruckerD]

I use B&M Synthetic Trick Shift in my gearbox, shifts like silk