Hi,
I have an 88 Formula with a manual transmission. It is hard to get in gear sometimes and often pops out of first gear.
Is there a common cause for this failure?
Thanks for any info.

I'm not the expert, but could be the shift dogs or shift forks. If the dogs wear round, gears can become disengaged, and if a shift fork is malfunctioning, that could cause the difficulty to get in gear or even popping out of gear. First, try adjusting your shift linkage/cables, improper adjustment might cause this problem, and adjusting it right may correct the problem. Clutch drag could also cause difficulty to shift into gear, but wouldn't explain popping out of gear. Any weird noises comming from the tranny?

[This message has been edited by FieroMan86 (edited 04-20-2005).]

misadjusted shift linkage will deffinatly cause the hard shift, pop out. But so will bad synchors. Order of operations states do the easy one first, try adjusting your shift linkage, if that dosent work, Ill tell you how to replace the synchros.

My 88 was doing that in first also. We have lots of stoplights in Phoenix so I put it in neutral while waiting at the light. Saves my legand the throwout bearing. When putting it back in 1st sometimes it would pop out. Then statred doing it a couple of times every day. I started paying more attention. Sometimes it sems like putting it in gear is like the feel of rowing through a keg of nails with a crowbar. I've never driven another Getrag but suspect mine isn't extremely bad. Probably within the range of normal. I then started putting it in 2nd, then back in first to get a little better feel that it was indeed engaged in 1st fully. A couple of times i thought I felt a little reward movement at the shifter when I took off from the light. Only noticed this a couple of times and it was very minor. I thought engine/trans movement under load was causing this. Maybe the cable was getting tugged to pull the trans out of gear. Not being able to get this to repeat enough times, I couldn't verify this. When accelerating hard in 1st, I couldn't make it do this. I didn't try a clutch dump, I'm not that squirelly. Anyway, the darned thing quit popping ou of gear altogether now. I bought a cable to seeif I could get a more positive feel of it going in gear but its in my kitchen for now! One thing for sure, popping out of gear is horrible for the sharp ingagement teeth on the synchro slider and the mating syncho teeth on 1st gear. Better keep your hand on the shifter and force it to stay in gear 'till it's figured out.

Forcing a transmission to stay in a gear it wants to pop out of will result in a WORN OR BROKEN SHIFT FORK POSSIBLY CAUSING MORE INTERNAL DAMAGE. DO NOT HOLD IT IN FIRST.

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The way the syncronizers are designed in the transmission, normally once it's all the way into a gear it wants to stay in that gear. If it pops out of being fully engaged then the syncrho is trashed. They are very expensive to replace, usually it's cheaper to put in a newer used tranny.

JazzMan

Jazzman is right - a set of synchros for a Getrag / Muncie transaxle is surprisingly expensive. He's also right about it popping out of gear - if that's happening, then it's almost certain that your transaxle needs to have the synchos replaced (along with all the other worn parts).

You can probably find a good used Getrag for much less that it'll cost to rebuild that one...

bologna! You can replace the synchros yourself and have a good transmission for less than 500 bucks. The synchro kits are several hundred, but you can do the work yourself if you have access to a press, and a oven. Ill work you through it if you want me too. I did my first 5 spd rebuild when I was 18, using only the service manual, and some friendly online help.

quote Originally posted by p8ntman442: Forcing a transmission to stay in a gear it wants to pop out of will result in a WORN OR BROKEN SHIFT FORK POSSIBLY CAUSING MORE INTERNAL DAMAGE. DO NOT HOLD IT IN FIRST.

Don't worry, I'm not Arnold Schwartzenegger and I didn't put that kind of pressure on the shifter. Just an open hand on the knob. Not even as much as when as when throwing a fast shift.

right, you dont need to put pressure on it much, the synchro spins and if the fork is held against it, friction does all the work for you. Ive seen it b4. You shouldnt even rest your hand on the shifter if you can avoid doing it.

What I mean is that the fork will be worn down over time and become weak, and when arnold borrows your car, or it pops out of gear fast, you lose the fork ends into the gear box, along with a gear or two.

[This message has been edited by p8ntman442 (edited 04-22-2005).]

Do not listen to everyone that is telling it is a faulty synchronizer, because it is not. The sole purpose of synchros is to equalize idler shaft to mainshaft speed, and also to equalize input shaft to mainshaft speed. Basically just prevents gear clash when shifting. Synchronizers also control 2 gears, not just one. If your synchro was bad, not only would your car pop out of 1st gear - but also in 2nd as well. You would also be having problems with gear clash as mentioned above. The synchronizers are held in place by the shift fork using detents and interlocks. So lets rule that out.

Shifter linkages are the number one and most common problem when dealing with manual transmissions. Whether it be a bad cable, or just simply needing an adjustment - remember your car is at least 17 years old! You need to follow OEM procedures when checking/adjusting linkages and cables. If you do not have access to the proper procedures and specs, I can have them for you no later than monday. Thats where I would start the diagnosis first.....

There are more possibilities as there are more things invovled, so if everything checks out fine there, just let me know and I will let you know where to go from there. I think a simple adjustment is all that is needed though.

-Mark

My guess was that the trans wasn't going into gear fully at times, however poping out does nasty things to those synchro teeth on the gear and the slider as they part company just as the power gets applied. Their what actually transfers the power so keeping them meashed is important. Hence I'm keeping a firm hand on the shifter for now. Detents keep the fork, slider engaged and to some degree the ramping effect of the detent actually helps pull the slider futher over the synchro teeth on the gear after it passesover the synchro ring. Back in the 60s when info was in the magazines about improving shiftabilily for Muncie 4 speeds, people put in the earlier detent springs which had less pressure. Things shifted easier and less notchy, more like the feel a woman might prefer, but ocassionally the trans would pop out of gear. Like when the clutch got dumped in first and the tires bounced a little. In extreme cases of wear or loose fitting sliders over the hubs, the sliders would wobble off center at speed and work their off the steel synchro teeth on the gear and you would have a popout! I never had any interest in transmissions but broke them regularly and learned to fix them and learned how to due some synchro blueprinting.

quote Originally posted by MikeW: My guess was that the trans wasn't going into gear fully at times, however poping out does nasty things to those synchro teeth on the gear and the slider as they part company just as the power gets applied.

That is exactly what I was thinking as well, the hub sleeve is just simply not sliding over enough. Maintaining pressure so that it does not pop out of gear is also a good idea - why cause more headache down the road when your clutching teeth round out and your hub sleeve is shot......

Like I said before, I think its probably just a simple linkage adjustment....

quote Originally posted by AutoTech: Do not listen to everyone that is telling it is a faulty synchronizer, because it is not. The sole purpose of synchros is to equalize idler shaft to mainshaft speed, and also to equalize input shaft to mainshaft speed. Basically just prevents gear clash when shifting. Synchronizers also control 2 gears, not just one. If your synchro was bad, not only would your car pop out of 1st gear - but also in 2nd as well. You would also be having problems with gear clash as mentioned above. The synchronizers are held in place by the shift fork using detents and interlocks. So lets rule that out. Shifter linkages are the number one and most common problem when dealing with manual transmissions. Whether it be a bad cable, or just simply needing an adjustment - remember your car is at least 17 years old! You need to follow OEM procedures when checking/adjusting linkages and cables. If you do not have access to the proper procedures and specs, I can have them for you no later than monday. Thats where I would start the diagnosis first..... There are more possibilities as there are more things invovled, so if everything checks out fine there, just let me know and I will let you know where to go from there. I think a simple adjustment is all that is needed though. -Mark

Your description of the synchros is inadequate and erroneous to some extent. The synchronizer has reverse beveled teeth that engage and lock each gear to the driven shaft. You can have a bad synchro that only affects one gear. The part that matches speed is called a blocker ring, that's the part that actually matches the speed of the driven and drive parts of the synchronizer assembly. If the blocker ring, really a cone clutch inside the synchro assembly, goes bad then you get grinding of the synchro teeth which will eventually damage the teeth enough to eliminate the reverse bevel that locks the teeth together. At that point the tranny will pop out of gear under accelleration.

The CD that was being sold in the mall a few months ago with the training manual for the Getrag goes into all of this in detail.

JazzMan

It would be interesting to see a picture of these reverse bevelled teeth, I'm behind on transmissions. Last one I did was a ZF 6spd out of the Corvette.

Before you get too carried away...

My 86 4 SPD kept jumping out of 4th. I found the damper on the front of the engine was not bolted down. This may not be the case, but it's easy to check and a lot cheaper than digging into the tranny!

If it is a syncro issue, I've been told that Royal Purple Syncromesh can help improve the shifting. I put it in mine and it made a big improvement. Since I found the damper at the same time, I'm not sure wich helped the most.

Thanks for all of the input. I guess I will have to pull it out and have a look, but it seems it might be easier to get a good used FWD
getrag and swap it in.

quote Originally posted by MikeW: It would be interesting to see a picture of these reverse bevelled teeth, I'm behind on transmissions. Last one I did was a ZF 6spd out of the Corvette.

Here ya go, right out of the Getrag training manual. Do a search in the mall, you can still buy one on CD.

JazzMan

it is NOT the linkage........ (been there done that)

Time for a tranny rebuild...start saving you $$ up !!