Hard to shift into first

[Jbevs]

while the truck is moving. That pretty much says it all. My tranny (zf5 behind a 6.9) shifts fine except it doesn't want to go into first while moving. I know I really don't need to do this much, but I am trying to find the cause. It became very evident driving it home after buying it with virtually no brakes The clutch seems fine everywhere, so I am thinking syncros?

 

[jonathan]

most sticks ive ever had never cared for going into first while btw how fast are you going when you are tring to down shift?

 

[rhkcommander]

I'm no pro but I'll throw my 2 cents in till the experts can chime in.

Your tranny is fine prolly, First gears usually used for takeoffs ONLY, its locked out during movement so you dont 'accidentally' downshift into 1st i think. If you really need it then double clutch it, just don't do it and save yourself headache unless shes rolling away uncontrollably and you need to .

I got a 4-spd and I can takeoff unloaded in 2nd so IDK why other than slowing down in an emergency you'd need downshifting to 1st while moving.

Fix the brakes

 

[DeepRoots]

are you just trying to stuff it into first? or are you revving the engine to the appropriate RPM to match the speed?

 

[bike-maker]

Mine does the same thing. A little blip of the throttle while putting pressure on the shifter usually gets it to go. Then again, if the truck is still moving at all, I just use 2nd gear

 

[RLDSL]

Unless I'm horribly mistaken, 1st gear isn't synchronized. That;s generally reserved for car trannys. Without a synchro, it's not going to go in easy when moving, it's not supposed to, that means you are the synchronizer and have to match up the rpms as Deeproots mentioned

 

[Jbevs]

Alright then. It doesn't sound like I need to worry about it. I didn't know it wasn't synchronized.

 

[MJlogan]

I was under the impression 1st was syncronized in the ZF's. If its grinding while trying to go into first the syncros are shot. If it is like mine it is hard to push it in unless you match rpms. Mine is even tough at idle.

Pretty positive they are syncrhonized in first, doesnt feel anything like my old T98 in my IH pickup that wasnt syncronized

 

[jam0o0]

first has syncros in a ZF5. it will go in but first is really low. you have to rev it to the moon and be going very slow to get the syncros to be able mach the speeds.

fyi the syncro on first works in forward and reverse. reverse doesn't have a syncro.

 

[Jbevs]

The brakes work, I just was trying to figure out if something was wrong with the zf. Syncronized or not, it doesn't sound like I have a unique issue here.

It shifts into first fine most of the time while stopped. It won't get used much anyhow.

Thanks for the input everyone.

 

[DeepRoots]

if it's an older trans, you'll find 1st 2nd and sometimes 3rd are not so good on the synchro front.