2nd gear ZF

[bird hunter]

Just curious does anyone else find 2nd gear shifts harder than all other gears in the ZF? Mine has always shifted a little hard even with synthetic ATF into 2nd but fine in all others. Not overly hard, but definitely noticeable. Or could this be related to my original dual mass that has been rattling on startup occasionally for 2 years?

 

[flareside_thun]

Yup, but my trans has bad syncros.

 

[Diesel_brad]

Sounds like you got a worn 2nd gear syncro

 

[Sycostang67]

Third gear has always been noisy in my zf's.

 

[Midwest_Mudder]

ya third is my noisy gear.

 

[RLDSL]

Sounds like your 2nd gear synchro is trashed from when the previous owner failed to follow the upgraded ZF spec and didn't have synthetic in the thing before you got it.
My tranny suffers from the same malady

 

[franklin2]

We had a thread about this before about a year ago. There is too much spread between 1st gear and 2nd gear ratios, so if you rev the engine way up in 1st, the 2nd gear synchro has a hard time matching up the revs for 2nd gear. The trick is only just get the truck moving in 1st gear, and then short shift into 2nd.

Most people with normal sized tires don't even start out in 1st, but start out in 2nd. But I have 35 inch tires, so I need to use 1st to get going to keep from slipping the clutch too much, and I shift from 1st to 2nd all the time, by just getting a couple 100 rpm in 1st, and then going to 2nd.

 

[Goofyexponent]

When I had 4.10's I found first gear USELESS!!!!

I usually start off in second....no fuel until the truck is moving and the clutch is all the way out. No issues with stalling or anything.

My first to second gear shift is smooth and flawless if I just use first gear for like 5 feet then plant her into second....however second to third or fourth to third is another story....just another thing to add to the list when I put that trans into the crew cab.

If you find shifter has a hard time matching gears due to worn syncros....just double clutch that shift like you would in a big rig, or give yourself LOTS of time to shift and just ease the shifter into gear....either way your transmission will thank you.

 

[Diesel_brad]

We had a thread about this before about a year ago. There is too much spread between 1st gear and 2nd gear ratios, so if you rev the engine way up in 1st, the 2nd gear synchro has a hard time matching up the revs for 2nd gear. The trick is only just get the truck moving in 1st gear, and then short shift into 2nd.

Most people with normal sized tires don't even start out in 1st, but start out in 2nd. But I have 35 inch tires, so I need to use 1st to get going to keep from slipping the clutch too much, and I shift from 1st to 2nd all the time, by just getting a couple 100 rpm in 1st, and then going to 2nd.

If you think there is a big jump between 1st and 2nd in a diesel S42 trans, you should try a S47 or Gasser trans(they re even a bigger jump)

 

[Goofyexponent]

If you think there is a big jump between 1st and 2nd in a diesel S42 trans, you should try a S47 or Gasser trans(they re even a bigger jump)

That's what I got in my old girl....S5-47. I can put the truck in 4 low, first gear and walk faster than the truck will idle along lol.

 

[bird hunter]

Thanks for all the help guys, I guess I'll try to just get moving in first and then ease her into second and see if that helps.

Also, is replacing the 2nd gear synchros even possible, cheap, or easy??

 

[RLDSL]

Thanks for all the help guys, I guess I'll try to just get moving in first and then ease her into second and see if that helps.

Also, is replacing the 2nd gear synchros even possible, cheap, or easy??

If youre running synthetic now, chances are it will stay running at the same level for an extremely long time and you wont need to replace the synchros . Mine hasn't got any worse in the last 100k miles since I've owned it. It just helps to lmatch your rpms up when shifting so the synchro in 2nd doesn't have to work so hard .
I run Amsoil 50wt synthetic ATF and once it gets warmed up now even teh 2nd gear shift goes smooth by itself

 

[MidnightBlade]

If youre running synthetic now, chances are it will stay running at the same level for an extremely long time and you wont need to replace the synchros . Mine hasn't got any worse in the last 100k miles since I've owned it. It just helps to lmatch your rpms up when shifting so the synchro in 2nd doesn't have to work so hard .
I run Amsoil 50wt synthetic ATF and once it gets warmed up now even teh 2nd gear shift goes smooth by itself

can you get the 50W syn at any HD truck shop?

 

[Diesel_brad]

Thanks for all the help guys, I guess I'll try to just get moving in first and then ease her into second and see if that helps.

Also, is replacing the 2nd gear synchros even possible, cheap, or easy??

It would be foolish to just replace the 2nd gear synco.

In order to do syncros, the trans has to com out of the truck and com completely apart. They make a bearing, seal and syncro kit for about $150-200

 

[92F350CC]

My second gear grinds like a slutty dancer everytime I downshift from 3rd. I usually have to take it out of third and then let it slow down a bit before finishing the shift. This of course is in a gasser trans behind a 351. First is pretty damn low in the gasser trans and I just start in 2nd most of the time. The spread is pretty far.