Well, it only happens when I shift into reverse. Clutch is completely, all the way in, and I go to shift and it either binds a little, and doesn't want to go in or it grinds a little, and finally shifts into reverse. Any ideas?


Oh, ps, it's a getrag.

[This message has been edited by Hornet (edited 07-09-2008).]

No reverse syncro's, you need to shift into first then into reverse.

Bleed the clutch ... *yells* NEXT!

If it grinds going into reverse with the car not moving, and the engine at idle, the clutch isnt fully disengaging, no two ways about it. There can be more complicated causes, but start by bleeding. Keep in mind this also means you are not fully disengaging in all gears, so you are overworking your syncros in 2-5

Reverse is not syncronized, always shift into a forward gear first.

So, bleed clutch or shift into foward gear first. Who's right here?

Try the foward gear approach first, especially if your clutch works right otherwise.

My bet is try the forward gear first. If the clutch isn't fully engaging it most likely will still grind when put into reverse. You will need to bleed and adjust the clutch. I would also check the oil level of the transmission as this can also cause this type of problem.

Nick

You're not supposed to have to go into first before reverse. You can do it to keep from grinding, but as I said, just because you dont hear noise going through the forward gears doesnt mean there isnt wear and damage occuring.

quote Originally posted by 86GT3.4DOHC: You're not supposed to have to go into first before reverse. You can do it to keep from grinding, but as I said, just because you dont hear noise going through the forward gears doesnt mean there isnt wear and damage occuring.

You would be correct if reverse had a synchro. When you are sitting at an idle, with the clutch out, the inside gears are spinning. When you push in the clutch, inertia will keep them moving. You have to stop them, the synchro does that, without grinding. It is the reason why when driving a old truck with a granny gear that it will not go into first without going into another gear first. Granny was not synchroed. The thinner the oil is in the tranny, the more this issue is evidant. You could drain out the proper fluid and fill it with 140w gear oil, then the resistance of the oil would stop the gears from turning.

There will be some movement, but if the clutch is fully released, there will not be enough to cause any noise, much less grinding. Ive had 4 manual fieros, plus other cars, never once have I had to shift into first before reverse, EXCEPT when the clutch needed bled. The tell all diagnostic step for clutch issues is, does it grind when going into reverse. If you are idling at 1000 RPM or less, and the car isnt moving, and you've had the clutch in for a second or so, and it grinds, then the clutch is not fully disengaging. I can go out to any of my manual cars right now and rev the engine to 2k and shift into reverse with no noise.

If the clutch is dragging enough (or the engine is causing the gears to move with the clutch "disengaged" then your syncros will be working extra hard to match up speeds every time you shift.

If reverse had a syncro, you would never hear grinding under any realistic circumstances, you just wouldnt be able to get into gear.

[This message has been edited by 86GT3.4DOHC (edited 07-09-2008).]

When I improved the lubricant in the tranny, the reverse grinding got worse. The reverse gear has no synchroes. If the neutral gear is revved at all it is going to grind. When you engage the neutral gear in one of the synchroed gears the neutral gear stops turning. You can then put it into reverse while it is not spinning, or spinning very slowly. The reverse gear grind is an old Fiero problem. No amount of clutch bleeding will fix it, unless your clutch is also clashing going into other gears.

Arn

quote Originally posted by 86GT3.4DOHC: I can go out to any of my manual cars right now and rev the engine to 2k and shift into reverse with no noise.

Try this...

Start your car with the clutch fully depressed and rev it to 2k and shift into reverse without engaging the clutch.

Then...

With the car in neutral rev it to 2k then depress the clutch and shift the car into reverse.

Let us know if you notice anything. BTW: what kind of fluid do you run in those transmissions?

Is this for me or 86GT3.4DOHC? I can get more descriptive if it helps. Most of the time, this doesn't happen. It shifts smoothly into reverse and all the other gears. If my clutch isn't fully disengaging, I'd really like to know. What are some other symptoms?

My car does the same thing. It needed a new slave cylinder, it was leaking, so i put one on and got the clutch bled well and it still does it. Car is an 88GT, so it has a getrag as well. Goes good into every other gear, just reverse it goes in hard, doesn't want to go at all, or grinds. I just cycle through the gears and go back to try again and sometimes that works, or hold the shifter over far right, not putting it in reverse, wait a few seconds, than go to reverse, sometimes that works. Or when it doesn't want to go at all I will just go forward a bit and it goes in fine.

quote Originally posted by Hornet: Is this for me or 86GT3.4DOHC? I can get more descriptive if it helps. Most of the time, this doesn't happen. It shifts smoothly into reverse and all the other gears. If my clutch isn't fully disengaging, I'd really like to know. What are some other symptoms?

I dont know. BUT if you're saying it only does this on rare occasion, I would ignore it, your initial post implied, to me anyway, that it was all the time. It could happen from time to time depending on circumstances, like if you were rolling, or if the engine is spinning down, etc.

The transmission will always be moving anytime the engine is on and the tranny in neutral, if the clutch is releasing properly, then they will not be spinning fast enough, or actually more importantly, with enough force, to cause noise when engaging reverse. Shifting into forward then reverse only treats the symptom, and ignores the cause. If it was normal, then every fiero and every other manual car out there would be like that. One could argue that its not enough to cause wear on the syncros, personally I think it might be but dont have proof, but you cannot argue that it is the norm or not a problem.

That is pretty much the lowest symptom in the bleeding tree. That is its the first symptom youd get, so other than measuring the throw of the slave, theres nothing else to check.

[This message has been edited by 86GT3.4DOHC (edited 07-09-2008).]

quote Originally posted by Hornet: Is this for me or 86GT3.4DOHC?

Sorry, that was for him. I do hope that he tries it and reports back. Anyone can try it if they want to learn something about rotational inertia.

quote Originally posted by Jefrysuko: Sorry, that was for him. I do hope that he tries it and reports back. Anyone can try it if they want to learn something about rotational inertia.

I am supposed to be learning something? All you did was prove my point. And for the record, at 2k spinning up the internals, I got a "clunk", or loud click, it takes about 3k to get it to grind. However if I wait about a second, I still get nothing. The internals will slow back down because the clutch is released, allowing them to spin down to whatever RPM the slight drag of the clutch allows. If the clutch isnt fully released, the internals spin at 1k, and they have the added force of whatever power is transfered from the engine to keep them spinning some even when grinding.

You know happens if you hold the clutch pedal half way down and shift into reverse? IT GRINDS! Is that inertia? No, thats the clutch not disengaging.

The point is, if you are consistantly grinding going into reverse, the clutch is not fully disengaging, there is no two ways about it. Is there a little sticker on the shifter that reads "shift into 1 before R" No, do you have to do that with every Fiero out there, no. You have a problem, deal with it. You can say its not an important problem, or that it wont cause long term harm, thats debatable, but its a problem.

If its not abnormal, explain to me why the other 300,000 manual Fieros dont require shifting into 1 before R.

Easy fellas, easy. Thanks for everyones help. One last thing, is this going to cost me a new tranny?

quote Originally posted by Hornet: Easy fellas, easy. Thanks for everyones help. One last thing, is this going to cost me a new tranny?

Not at all, it is normal. Just put it in a forward gear first to stop the internal spinning. If it has trouble going into a forward gear, then you have an issue.

quote Originally posted by 86GT3.4DOHC: If it was normal, then every fiero and every other manual car out there would be like that.

You make a great point. I am a tech that worked for GM for over 15 years (early 80's through the 90's). Every GM car does do this.

It is totally normal for all GM and most other cars (every since they went to the light weight tranny fluid). We used to have people come in daily with the complaint. We just taught them how to stop the internal spinning by putting it in a forward gear and the issue was solved. There were a few that could not understand the physics of the thinner fluid and why it was there that would switch the fluid over to gear oil. It hurt the shifting smoothness, affected gas mileage and they no longer had to shift into a forward gear before shifting into reverse, they were happy. There were a few bulletins about this, but that was long ago. Possibly someone that has bulletin lists might be able to find one of them.

quote Originally posted by 86GT3.4DOHC: The point is, if you are consistantly grinding going into reverse, the clutch is not fully disengaging, there is no two ways about it.

That is fine if you want to make that point but do we really know enough to jump to that conclusion?

quote Originally posted by Hornet: I go to shift and it either binds a little, and doesn't want to go in or it grinds a little, and finally shifts into reverse.

To me this very accurately describes the typical no reverse syncro condition but maybe to you it doesn’t hence my post.

quote Originally posted by 86GT3.4DOHC: And for the record, at 2k spinning up the internals, I got a "clunk", or loud click, it takes about 3k to get it to grind. However if I wait about a second, I still get nothing. The internals will slow back down because the clutch is released

Yes but you noticed that something was different. Have you ever thought that there might be some other factors in play? Do you care to answer my other question about the fluid you run in your transmissions? Someone already noted that the no reverse syncro grinding condition was made worse when they changed to a lighter weight oil did you miss that or just disregard it's significance. I noticed a big difference with lighter weight oils as well. With my first Fiero I tried adjusting the shift cables and was actually able to make a significant change somehow. My first Fiero was a fairly low mileage car and since then most of my Fieros have had more miles than that one and I have noticed the problem more on those higher mileage cars. Maybe transmission fluid, shift cable adjustment and age of the transmission could have something to do with why you notice something obviously different than others. Since I learned that the Fiero transmissions don't have a reverse syncro and have changed my driving habits it doesn’t matter what transmission fluid I run, how the cables are adjusted (as long as it still goes in gear) or how worn out my transmission is.

quote Originally posted by 86GT3.4DOHC: BUT if you're saying it only does this on rare occasion, I would ignore it, your initial post implied, to me anyway, that it was all the time. It could happen from time to time depending on circumstances, like if you were rolling, or if the engine is spinning down, etc.

You would ignore it? Come on just admit it, that is just the fact of having a transmission with no reverse syncro and if you simply change your driving style like others have mentioned in this thread the problem goes away. Maybe that goes against what you have experienced with your cars but there are several people in this thread that have obviously noticed that using a syncro from a forward gear before shifting into reverse made a difference. Besides maybe the whole reason for his post was because he doesn't want to ignore it.

quote Originally posted by Hornet: If my clutch isn't fully disengaging, I'd really like to know. What are some other symptoms?

Other symptoms...

Hard to shift into other gears particularly when the car is not moving.

Creeping forward when sitting on flat ground while in gear

Moving forward when starting in gear (Basically same as previous)

Low clutch engagement point (typical is around 1"-2" from the floor)

Engagement point changes with use

Vanishing fluid in clutch reservoir

Fluid present under carpet on drivers side

Fluid present behind boot on slave cyl

Also not a symptom but some Fieros came with an aluminum clutch pedal which is known to bend and cause problems with full disengagement. If a magnet sticks to yours then you have a steel one and can rule that out as well.

Now I really don't think 86GT3.4DOHC is giving you bad advice telling you to make sure that your clutch fully disengaging as it is important but I feel as if the first thing you should try is changing your driving style. If the problems you are noticing go away then your problem is solved, if they don't then you know that the next step is checking that the clutch if fully disengaging.

quote Originally posted by Hornet: Easy fellas, easy. Thanks for everyones help. One last thing, is this going to cost me a new tranny?

I'm not getting worked up and I hope no one else is either. I'm simply trying to point out that there are multiple ways to interpret symptoms and there are other factors which give us all different experiences with the same problems. The only way to work those things out is to have an open mind, share and accept what everyone has to contribute.

When that fails go with the majority

And no if it is simply the no reverse syncro condition it is normal and will have no effect. If changing your driving style dosn't change things then you do have bigger problems and need to look into them to prevent damage.

Edited to add...

quote Originally posted by Electrathon: It is totally normal for all GM and most other cars

Aww, man that sounds so much better that what I said.

[This message has been edited by Jefrysuko (edited 07-10-2008).]

That was very thorough, thank you. Also, I wasn't suggesting that you were getting worked up, it just seemed like it was headed that way. Well, anywho, thanks a bunch.

quote Originally posted by Electrathon: Reverse is not syncronized, always shift into a forward gear first.

What he said. I do that with ALL stick shifts just out of habit.

DOHC, Ive never driven a 4 spd Fiero that didnt grind/grab if you didnt go to another gear first. My Ferrari kit did it from day one until I sold it at 100,000 miles. Thats actually how I got into the habit.

[This message has been edited by rogergarrison (edited 07-11-2008).]