hey got a 4 speed that grinds going into reverse it only does this when i put the clutch in and shift right into reverse but if i was to go to first gear then shift to reverse it woundnt grind what could be the prob on this situation

[This message has been edited by pontiacfierokid1985 (edited 03-25-2010).]

Same problem here sometimes it grinds goin into reverse but if i shift up to fifth with clutch in then back to reverse while idling it goes right in

There is no synchro for the reverse .

Your clutch is not fully releasing. When you shift to 5th you use the syncros to get the transmission's input shaft to spin the correct speed compared to the rear wheels (stopped the correct speed would be 0 rpms). GM like most manufactures didn't use syncros for reverse since you shift into reverse stopped, and a fully released clutch on a stopped car needs nothing to get the transmission input shaft to stop rotating.

So shifting to 5th first stops the input shaft, and then when you shift to reverse it doesn't grind.

So your clutch isn't fully releasing. It's most likelly engaging quite closee to the floor. And yes, there's something wrong with how its working. That is most likely air in the system.

With a 4speed it could also be the shift cables slightly out of adjustment. This or clutch not fully disengaging.

Like the man said. The Muncie 4 speed has no synchroes in reverse. It has to either reduce rpms or get cleared through the synchroes in another gear first.

BTW. You'll find the tansmission will work WAY BETTER with Syncromesh fluid vs. other oils.

Arn

Other things to look for other than air in the fluid for a non-fully disengaging clutch - Bent clutch pedal, bent pin bracket on the clutch pedal, bent banjo arm, misinstalled banjo arm, improper lenght push rod at the slave, bent clutch lever on the tranny, bent clutch lever shaft, Clutch having internal problems that prevent it from fully releasing.

I do not believe a misadjusted shift linkage could cause the grinding into reverse. With the clutch pushed, the input shaft should not be spinning. Assuming the car is also not moving there should be NO spinning parts in the tranny. If you are indeed at this point, I'm not sure how anything you do with the tranny will make it grind.

Let's not get ahead of ourselves here. Reverse has no synchroes. It is that simple. What he is talking about is normal, normal, normal.

Arn

Yep, my 4 spd did it for the whole time I owned it for 100,000 miles. Completely normal. I just put it in first or second first, then reverse.

quote Originally posted by phonedawgz: With the clutch pushed, the input shaft should not be spinning. Assuming the car is also not moving there should be NO spinning parts in the tranny. If you are indeed at this point, I'm not sure how anything you do with the tranny will make it grind.

The input shaft has inertia. It will continue to spin even after clutch disengagement. If you're in neutral that is.

To shift into reverse, you either have to halt the input shaft using another gear's synchro, or you must wait several seconds until the input shaft slows on its own.

If reverse still grinds after halting the input shaft, then yes, it is a sign of the clutch not fully disengaging.

[This message has been edited by pmbrunelle (edited 03-25-2010).]

Don't be looking for problems where they don't exist. The clearance between the clutch friction disk and the pressure plate and flywheel, with the clutch pedal pushed all the way in is very small. All it takes is a new, thicker clutch disk, or a couple of high spots on either the flywheel or the pressure plate to keep the friction disk turning a hundred RPM or so, much slower than the engine. But it's only free-wheeling with no torque being applied to it. Because reverse isn't syncro'ed, a slight grinding as you select reverse is perfectly acceptable since you're effectively stopping the clutch disk from spinning by forcing the teeth of the stationary reverse gear into the teeth that it mates with on the slowly spinning input shaft. Selecting reverse usually only baulks a little and then slides in. If on the other hand you get a solid "clunk" when reverse is selected, then you should look into whether your clutch is fully releasing because the clunk comes from the small amount of torque actually being transmitted from the engine to the clutch disk, rather than it just free-wheeling.

If what we are talking about it pushing the clutch and the popping it into reverse and it grinds then i do agree with you guys. However I take it as it grinds into reverse always unless you get the input shaft stopped by useing the syncros of a different gear and then quickly going for reverse. With the clutch depressed the clutch shouldn't drag enough to start the input shaft rotating assuming your starting from a stopped position.

The issue is the inertia of the neutral gear. After you depress the clutch, it continues to spin. This is the reason for the grinding. If you wait for it to stop you or at least slow way down you have a minimal problem. Clearing it through the synchros of a neighbouring gear is the quick way and is the common way to deal with it. I've had a sticky clutch and it affects more than reverse.

It is as simple as clearing the stick through 1st or 2nd before going into reverse.

Arn

Oh good, it's that simple? I've had this problem for a while, and I look like a pretty terrible driver with the large grinds...

This topic gets discussed continuously on this forum and I even remember the topic on the Fiero Mailing List Waaaaay before forums like this existed.

HERE is one of the more lively discussions.

I find it ironic that the Title of the threads are almost identical.

Grinding the gears going into reverse? vs. gears grind going into reverse

[This message has been edited by Jefrysuko (edited 03-25-2010).]

If shifting into First gear and then into Reverse stops the grinding, then there's nothing wrong. That's just how the manual transmissions in the Fiero work. If the car is rolling and/or the tranny input shaft is still spinning while you're trying to shift into Reverse, you will grind gears.

Like mentioned above, throw it into another gear first, or count "thousand one, thousand two" before throwing it into Reverse. Also, make sure the car is completely stopped.

alright so this is normal so i will just remember to go to first gear then reverse where could u find that sycnromesh fluid u were talking about can u get it at a local autozone or a advance auto part store

I just realized how your name is eerily similar to "pontiackid86". You also talk the same

quote Originally posted by grkboy707: I just realized how your name is eerily similar to "pontiackid86". You also talk the same

And one kid is from from 'ma' and the other is from 'pa'

Sounds like the whole Pontiac family

Where do i check my tranny fluid at it just dawnd on me reading this that ive never check'd it lol its a 85 2m4 5spd. thanx ...Tim Reed

The dipstick is on the VSS, just be careful when pulling it up that you don't accidentally pop the gear off the end of the VSS and have it fall into the tranny.

[This message has been edited by Bloozberry (edited 03-26-2010).]

kool thanx alot man i hope i dont do that, it's not easy to do is it lol?

It is easy to do. Pull it straight out. Be ready with a needle nose pliers to get it if falls. Not like you are going to catch it as it falls but to pick it up before it goes further. Mine fell off but had landed right there on the gears and not fallen further. I was able to just pick it up. Kinda crappy design, but as long as your aware of it, a reasonable person should be able to keep it from going way bad.

quote Originally posted by phonedawgz: It is easy to do. Pull it straight out. Be ready with a needle nose pliers to get it if falls. Not like you are going to catch it as it falls but to pick it up before it goes further. Mine fell off but had landed right there on the gears and not fallen further. I was able to just pick it up. Kinda crappy design, but as long as your aware of it, a reasonable person should be able to keep it from going way bad.

I did that, but I was scared of knocking it in by accident, so I used a vacuum cleaner...