Zf5 not liking reverse

[gdhillon]

All this tranny talk brings an issue to mind that I should address.

whenever I put my truck in reverse it seems like it goes in halfway then a second later itll pop right into reverse. This is all with the clutch fully depressed ofcourse . This happens when I reverse from being parked or when I'm backing in a parking stall. Now if after it fully pops into reverse I let go of the stick and reverse itll pop out to that half way point andake very angry grinding noises. I now just always have my hand on the shifter when reversing but I just thought I should bring this up. O and the master was changed ~ 5 months ago and the slave was changed about 3 months ago......b/c the mc bushing broke and the slave decided to spring a leak One day. And the system was bench bled both times. Iirc this.reverese thing was happening with the old mc and slave to.

And from time to timr I have to hold the clutch in briefly then it goes into first. All other gears are fine.

 

[lindstromjd]

Sounds to me more like your reverse gear itself is bad.

 

[mobilemech]

reverse slider and syncro are bad

 

[gdhillon]

so over time it will just stop going into reverse?

 

[mobilemech]

yes, and then other gears will start to do the same thing. hard to say how long it will be, too many variables. I had a ZF5 in my 93 that had a bad reverse slider when I bought the truck and it was still drivable 3 years later when I changed the trans, but it was getting worse. I use my truck for everything from towing boats to back hoes, 1500lbs to 15000lbs.

 

[mobilemech]

one thing that kills thease reverse syncro / slider combo's is not being completely stopped, no motion before shifting to reverse

 

[bullwhip]

Same thing happen in my 91 it was the bushing in the cluch pedel. if u can move ur pedel up and down that mite be ur problem

 

[mobilemech]

All this tranny talk brings an issue to mind that I should address.

whenever I put my truck in reverse it seems like it goes in halfway then a second later itll pop right into reverse. This is all with the clutch fully depressed ofcourse . This happens when I reverse from being parked or when I'm backing in a parking stall. Now if after it fully pops into reverse I let go of the stick and reverse itll pop out to that half way point andake very angry grinding noises. I now just always have my hand on the shifter when reversing but I just thought I should bring this up. O and the master was changed ~ 5 months ago and the slave was changed about 3 months ago......b/c the mc bushing broke and the slave decided to spring a leak One day. And the system was bench bled both times. Iirc this.reverese thing was happening with the old mc and slave to.

And from time to timr I have to hold the clutch in briefly then it goes into first. All other gears are fine.

Bushing already done, but the bushing will typicaly cause problems in most gears. but it is possible and should be checked again. The syncro reverse in these trannies is crap and their weak point.

 

[Rxracer]

I have the same problem with my current ZF, i just got a replacemnt just have to install it.
Rob

 

[Iowa 73]

The syncro reverse in these trannies is crap and their weak point.

Yup.

 

[Goofyexponent]

Mine did that t a couple times, then it started something else. If you were moving even the timest bit foreward and tried to go into reverse...it would just lock you out of reverse. No matter how many times you push and let go of the clutch before trying to stick it into reverse it simply would NOT go in. You had to roll foreward about 3 feet, STOP and THEN go into reverse. It only did it 5 or 6 times in the year I had it 5 speed.

It just hints at a slight grind going into third now....no big deal.

 

[franklin2]

Every zf I have driven has had a stubborn reverse gear. I think it's a common problem. All you have to do is push in on the clutch, put it in reverse, and keep pressure on the lever as you slowly release the clutch pedal. If it's not in all the way, it will go ahead and drop in as you keep pressure on the lever and release the clutch. Once you get into this routine, you do it without thinking about it. Not a reason to tear down the tranny in my opinion.

 

[gdhillon]

Thanks for the replies guys,
I don't really haul anything heavy. heaviest id say it sees is firewood or two sleds.

What.are the signs that indicate I'm about to completely lose reverse? I guess I have to.budget a tranny rebuild and clutch in the near.future


Edit: just read the new posts, I do know always keep pressure on the lever...bc I haaate that grinding. Mine occasionally has the third gear bad synceo noise to.

 

[John Deere]

I have torn apart a few of these zf5's, the first one was to replace the reverse gear and syncro, and it was due to my dad not coming to a complete stop before attempting going into reverse. These transmissions are more intimidating than complicated, especially if you use a manual. If you due the work yourself and get the parts from a drivetrain shop, I use Drivetrain Ind., the cost might run you 250-400 for the gear and all new syncros.

I have found that for some reason a Luk flywheel and clutch will make some syncros seem worse than they were before the swap. Not always the case, but in two out of the three pickups I have done the swap in, second and third gear began grinding as you were shifting into them, unless you made a perfect shift.

 

[franklin2]

What.are the signs that indicate I'm about to completely lose reverse? I guess I have to.budget a tranny rebuild and clutch in the near.future
...... Mine occasionally has the third gear bad synceo noise to.

I have been driving mine for several years now, and it doesn't seem to be any worse than it was in the beginning.

I will tell you a big factor in the shifting of this tranny is the oil you use. With most trannies the factory recommends a certain type of oil, and people follow their recommendations. People like to experiment with different oils in this tranny to try and "cover up" all the noise it makes when you convert to a solid flywheel. If you get into experimentation with different oils to cover up the noise, you will find some of these have side effects, like poor shifting, especially when cold. For the best shifting performance of this tranny, you shoudl run the factory recommended red Dexron automatic tranny fluid, or for even better shifting, the synthetic equivalent.