how tough is a ZF 5speed?

[tractorman86]

i have a question for you guys but not sure how dumb it is. my tranny (zf 5 speed) has been giving me problems latley, it wont hardly ever hit third gear and it pops out of reverse and now second is hard to grab sometimes. my question is, can this be due to extremely bad fluid (it was black, ribbined with metalic but no big chunks) i was thinking that it was syncro's going out and needed a full rebuild but am i getting too far ahead of myself? any input is greatly appreciated!

 

[Double-S-Diesel]

poping out of reverse is a common problem, doesnt need a total rebuld to fix, as for 3rd and 2nd that is a common syncro, problem OR could also be caused by a bad DMF or a bad pressure plate, OR possibility of a bad slave or master cylinder, or even just the bushing in the linkage at the pedal, or in the pedal assembly.
Nick

 

[towcat]

I've seen more than my share of the internals to these monsters
The syncros are a composite of steel and a sintered metal deposited on the inside of the ring. If you see chunks, the trans is prolly in need of some very expensive parts. If you catch it in time, you can get away with bearings and syncros and seals. And yes, they are very tough. My F450 pulled 15k-21k gross frequently for ten years and only went through two transmissions. If you have to nurse it along a litle longer, use 40 or 50 wt oil. It might provide you the band-aid just long enough. Oh yea, ATF is 10 wt.

 

[MIDNIGHT RIDER]

I have witnessed a few ZF-5 self-destruct when used hard heavy towing.

I have read and heard of a few more.

They are tough, just not near tough enough.

 

[Rawpower]

the metal in the oil could also be from worn shift forks, happened to me. I could barely get it in 2nd and 3rd, and 1st, R and 4th werent so hot either... 5th wasn't like it used to be... basically it was a timebomb, so I tore it down and later decided I couldn't rebuild it myself. So I gave it to a shop.

 

[tractorman86]

up date!

well, tore her down a few nights ago and cracked into her lastnight. sure enough worn out syncro's and the shift forks have a little more whear than i like to see so bearings, seals, syncro's and shift forks are comming soon.

 

[towcat]

well, tore her down a few nights ago and cracked into her lastnight. sure enough worn out syncro's and the shift forks have a little more whear than i like to see so bearings, seals, syncro's and shift forks are comming soon.

what did your parts cost set you back? I haven't had to do one in a while.

 

[tractorman86]

havn't got them yet . but ill let you know what the total cost is when i'm done