Granted my car needs a clutch desperately, lately while normal driving my transmission will slip out of 4th into neutral. It does it all the time. To me if feels firm like it always has while shifting into 4th gear but it pops right out and I have to pull it back down into 4th. I had a POS Hurst Pro-Billet shifter in the car which was causing the shifts to be hard and sometimes grind while going to the next gear. I re-installed my factory Hurst shifter with the UMI short stick which has corrected most of those issues but it won't stay in 4th gear. Am I heading torwards a rebuild? The car has 97,000 babied miles on it, it's a full bolt on cammed car but has never been to the drag strip. Thoughts on what I may be looking at in the near future? I'm having a monster stage 3 clutch with all new hydraulics installed in two weeks as well. Just wanting to know if this is a clutch or hydraulic related issue or something more expensive. Thanks.

 

If its not a shifter adjustment, its definately inside the unit itself.

 

Could be the Keys shot or possibly one of the Retaining Springs..

 

When you yank teh tranny, it is gonna be in your best interest to have teh tranny gone through.
Sounds like a "key" issue.
If you need help with a tranny rebuild, you can send it to me, and I can get you taken care...give me a call/pm/email.
Thanks

 

Thanks for the help, guess I'll have to get it looked and and see what the issue is. That's strange the transmission would give issues with under 100,000 miles being a manuel. I guess it's one of those freak things that happens.

 

Do you drive a lot in 4th gear?

 

This is an excellent article I read on WC Engineering regarding transmissions popping out of gear and the misinformation that people tend to throw around (ie your synchros are worn, etc). Enjoy and good luck with the rebuild.

"5th Gear (Or Any Other Gear) Pop-Out

Unfortunately, there is a lot of misinformation out there about 5th gear pop-out (or any gear for that matter) being caused by worn syncros or some other problem with the syncros. The truth is, the synchronizer rings have absolutely nothing to do with a transmission staying in a gear or popping out of a gear. Synchronizers only function is to "spin up" the gears as the engagement hub approaches the gear. For a detailed look check out HowStuffWorks: Manual Transmissions. They have an excellent section about manual transmissions and synchronizers.

On the problem of 5th gear pop out, there are two sources of problems that can effect the "pop-out" issue. It doesn't matter if it is 5th gear or 2nd and it doesn't matter if it is a Toyota transaxle or a Renault. Gear pop-out is related to movement in the transmission. This movement can either be external or internal.

External Issues
External issues can be linkage problems or mounting problems. Linkage problems are easy to diagnose and can typically be duplicated. Worn engine/transmission mounts can allow the assembly to move and cause strain on the linkages which can cause the pop-out. This is a little more difficult to find.

Internal Issues
Internal issues are caused by a few items, but the most common one is worn bearings. The helical-cut gears used in production cars put great strain on the bearings. Helical gears are used because they run much more quietly than straight-cut gears. (However, helical gears are much more expensive to produce, so we know cost isn't the factor here.) The two shafts that are engaged with helical-cut gears are always trying to force each other apart along the axis of the shafts. This force is transferred to the bearings and then onto the case. Once the bearings begin to wear, the shafts develop a small amount of play and can then move along their axes. Since the engagement forks and their respective hubs also move in a motion along the axis of the shafts, any movement is going to effect gear engagement. The shift hubs are normally free to move along the shafts and once pushed or pulled into an engagement position they are held in place by only small "detent" springs. These springs need to apply only a minimal force to hold the hubs in place, but if the shaft was to move along its axis, such as in a "power on, power off" application, the detent springs have no chance of holding the hubs in place."

Link to original: http://www.wcengineering.com/articles/popout.html

 

No, not really. I use it around town from time to time but this car normally see's the interstate or highways where I can use 5th or 6th. I noticed my 5th gear seems like it's not engaging all the way but this may be a slave cylinder issue. But the 4th gear pop out beats me, it just started doing it. The transmission feels just as tight as when the car was new with no new noises or any other issues. I guess I'm just going to have it looked at to make sure nothing is broken or worn out internally. These Tremec tranmissions are supposed to be stought aren't they? For a car that has never seen the track or rarely been beaten on this caught me by suprise.

 

Interesting read, thanks.

 

Does it pop out of gear after being in 4th gear for a little while or does it pop out right after you go into 4th gear and let off the clutch to apply pressure to the trans?

 

Well, what you have to realize is that your tranny is mechanical, and at ANY given time, it can go out. That is just the nature of something mechanical. SOmetimes, things last longer than others. I could give you a million examples of this, but how about something recently:

My Cummins Turbo Diesel has @ 160K miles on it. And @ 20K miles ago, I replaced teh left front hub unit bearing. Now, why did I not need to replace the right side one then? Or even after 20k more miles, it is still good? No reason, as it is just mechanical.

What about my passenger side (right side) outer tie rod? I had to replace it, as it was worn...why not the left side (drivers)?

Again, no real reason. Just mechanical items, and unfortunately, you never know when something like this will occur.

 

Does it feel different when you shift it into 4th? If the plastic fork pads are worn or broken the 4th could pop out of gear. Take a look at the plastic pad compared to the bronze aftermarket pad. I have seen too many plastic pads break causing grinding or popping out of gears.

 

4 gear pop out is common with t56 and the cause is bearing wear/improper rebuild

4 gear is most prone to this be cause unlike the rest of the gears in a t56 it is not kept in place with a snap ring or assembled on a shaft

4 gear is your input shaft on your t56 and the only thing keeping it place is your bearing preload and well when you bearing become worn the gear starts to move away from the mainshaft making it easy to "pop" out of gear your slider is not fully engaged on the gear

this problem can be solved two ways
-replace bearing and check preload
-shim input shaft(if bearing are good still) and check preload

 

as soon as I get it in 4 th and let off the clutch it pops right out!
I only have 4 gears and I have a 1996 Toyota Tercel
I had to drive home holding it in place!
it feels almost like it’s out of adjustment but I’m not mechanic but it goes in with out a problem just won’t stay there all of a sudden ty

 

You might get lucky and someone on this site knows your Tercel transmission pretty well. This is a GM enthusiast site. Most of us are knowledgeable regarding the LS platform GM started using in 1993.

I hope you have also posted in Toyota forums...