Fabio421

I tried a search but nothing came up on this topic.

My 84 5-speed will pop out of 2nd gear whenever I come off of the throttle. I can hold it into 2nd with my hand if I want to, but without that additional help it will pop out almost every single time. Any ideas?
By the way, I also have the grinding problems and difficult downshift problems that seem to be common with these transaxles. Just in case thats related.
Thanks

Styln928

Fab . . . Let me guess. First to second grinds unless you baby it or double clutch it. Same second to third? You need new syncro's. Does you shark have lsd? I just replaced the trans in my 83 euro and was going to send the trans to get rebuilt because it has lsd & the rebuilt one doesn't.

Fabio421

What is the definition of "double clutch"? I know that sounds like a stupid question but I'm not 100% on the true definition. Also, does the popping out of 2nd gear when I let off the gas have anything to do with synchro's? If so, how? thirdly, what is LSD ? Does that mean limited slip? I'm not sure. I will have to check when I have it in the air next time. I have another gearbox that I'm buying for parts. Maybe that one does.

SteveG

LSD = Limited Slip.

Suggest you read the new visitor thread, it's in there + lots of gold. put MY in sig line. Welcome.

fst951

Unlikely that it is the syncros. More likely it has a worn shift rod where the detent isn't fully engaged because it has worn or the shift fork could use adjustment in later transmissions. A faulty slider can also cause this, but I have never seen a worn syncro do this.

Good luck.

docmirror

It's a combination of things. The shift fork moves the dog gear into one of the gear sets. The little tangs on the dog gear align with the tangs on the drive gear, and it engages. The synchro provides a timing alignment with the dog gear and the drive gear set. When you have torque on the gears, the dog stays engaged because the dog gear and drive gear tangs have a slightly less than 90 degree bevel. When you let off the gas, that bevel is released, and torque (anti-torque?) is applied to the opposite side of the dog gear. If that bevel is worn(it is), or the shift fork didn't drive the dog fully into the drive gear(it's also worn) then the dog will pop out of the drive gear cluster.

This happens when a racer speed shifts a car repetitvely. The stress on the fork causes is to flex, and bend, or it may move on the shaft which holds the fork. Or, slop develops because the little fingers of the fork that move the dog gear become worn. Then, the little bevels on the gears become worn from being mashed so hard. The bevels tend to hold okay once they are engaged, but when the torque is removed, they just don't stay together in the locked position. The detent in the shift rod is not what holds the gears together, it's just the locator for the dog gear.

All this boils down to you need a trans rebuild. If the 2nd synchro is gone, the 3rd and 4th are probably worn too. The fork and/or dog gear need to be changed, and the whole thing realigned on the trans jig. If you don't have the tools needed, or the time to learn trans work, this is a job best left to a trans shop. The R&R of the assembly is pretty straightforward.

Sorry,

Doc 90GT in resto

928ntslow

Double clutching is more likely to be used by a big rig driver. You push in the clutch pull the shifter out of gear, pull off the clutch while in nuetral, then push the clutch in again and shift to the next gear. I guess this aligns (normals) the the gears allowing you to effectively shift gears without grinding and making it easier to actually shift into the next gear. Totally sucks when you have to do this in a car.

Fabio421

Well.....................that is the most detailed response so far. Sounds like you know what your talking about. I guess I will have to start saving my dimes and quarters. I will be able to live with it in the mean time. I only drive it about once a week anyway. This car isn't going to drive me to drink but it sure is turning out to be a good excuse

Thanks for the help.

Styln928

Well said Keith & I couldn't agree more. Takes all the fun out of driving.

heinrich

Just buy a good used one from Mark Anderson from a later car ...... the rebuild will not be worth it on an '84.

Fabio421

What is the advantage of replacing it with one from a newer car. I hear they are better, but what makes them so? What modifications need to be made in order to swap it? The price on their website looks pretty good but I'll probably bet that freight to get my core to them and to ship the transmission to me in FL will push the total with tax to around $3,500 or more. In addition, would my 84 case be applicable as a core for an 85-86 case?
I have the opportunity to buy a used transmission for hard parts for $300 localy. Does this sound like a good buy or a waste of money.
Thanks

docmirror

Well, I'm in the minority here, but it seems to me if you go to the trouble to pull the trans it might as well get rebuilt properly. If you do the R&R procedure and let a shop do the labor and setup inside, you 'll have a like new trans at resonable cost. Getting a used unit, you run the risk of one that was abused as bad or worse than the one you have now. I am a bottom feeder and save wherever I can, but this seems like bad economy to me.

The parts you need to rebuild YOUR trans, will likely be hashed in any used trans you get on the market. Think about it, why is a guy selling a used trans from a 928? So, the synchros, shift forks, dog gears, and bearings are the wear items. Buying a used one, with just get you used wear items.

I did this once on a vintage car trying to save a few dollars. It took me two tries to get a decent used trans, and the time I spent under the car wasn't worth the hassle. Have your's taken apart, evaluate the needs, replace what needs replacing, setup the trans by the book, and shfit happily ever after.

Doc

Fabio421

I said that the used transmission was for " hard parts" not "wear parts". I was thinking that if I needed just ONE gear or shaft etc. The $300 would be well spent. But I could be wrong, thats why I'm asking.
I have also wasted lots of time installing and un-installing a used transmission that I bought when I was a kid to try and help my Dad out. I spent waaaaay too much time under that station wagon. But it was a good lesson. By the way, if anyone needs a ford E4OD pulled out of something............. I'm your man ;-)

Fogey1

http://en.wikipedia.org/wiki/Double_clutch

This is a pretty good piece that also links to "heel and toe."

It's not just big-rig drivers. Heel and toe and double clutching are still in use by many who do not want to wear out their synchros. Once the technique is mastered it's both fun and rewarding, as well as being easier on your transmission and less likely to upset the vehicle's balance in rapid driving.

FlyingDog

If it is just a synchro problem, you could try a good synthetic gear oil like Redline 75W90NS (or a mixture of NS and non-NS if you have an LSD). I'd also check out the shifter linkage. If none of that works, you're stuck with a rebuild.