Rx7-88na

I am in desperate need of help...
My rx7 (an 86) non turbo, runs fine, I just put a cat-back exhaust on it -- anyway, out killing zx's and si's i noticed if i shifted hard and fast, anywhere close to the 7 grand redline, second gear will GRIND terribly, and it is pretty embarrasing... anyway -- I promise to you my foot is flat on the floor (on the clutch) when trying to shift... This is rediculous, so now i lose half a second giving the car plenty of time to catch up to my shifting into second... wich is no big deal, still plenty of pep to keep in front, but come on!! I used to shift like that when i first got it! Is the tranny is it the syncros? what went wrong, and is anyone else experiencing this phenomenon!??

I heard something about the Honda S2K doing the same thing if u dont **** 1000 RPMS shy of the redline... what is that?

Thank you...

iluvrx7z

Hey,
I am not sure what your problem is since I am not a mechanic but I have an 87 TII with the same problem...It really bummed me for a LONG time since it is loud and embarrassing and the only thing wrong with the car...but for the time being I found a little trick that stops it. Its not really a trick...But I noticed that in between shifting if I tap the gas just SLIGHTLY...just enough to keep the rpms from dropping too much if at all it does not grind AT ALL. Now if I don't do this it will grind for me anywhere over 3200 RPMs or so every single time. But EVERYTIME I give it just a tap it works like a charm. At first when I noticed it...it took me a while to master it. But now I feel totally comfortable bringing her up to 6/7k and throwing her into second. I believe the culprit is the syncro's in my case...I just can't wait to get the tranny rebuilt though! Hope this helps!

Dan

Turbocharged

That would be the second gear synchro, try changing the gear oil in the tranny, that should help quite drastically, if not then it's time for a tranny rebuild!
-nathan-

PaulC

Dont panic its not as bad as you think.

Its called a worn clutch. Grinding at high rpms is the first sign usually.

Next it will start slipping a little when you grind....er..shift into second. Mine was doing the same thing a while back. An OEM clutch is like $150 at pep boys. However get new bolts to put the pressure plate back on, since Mazda skimped on the bolts and the engine heat weakend them over time. I snapped one off. The bad news is they are like $6.80 at the dealership plus the price of washers but well worth the time and money to do the job right.

Or its over a grand at a reliable shop or much less at a questionable one.

PS No more racing or you might find yourself stranded. Cause if when it starts slipping its actually burning and that means youve got a week or two of babing your car around town before it goes completly.

13B_FC3S_T2

Yeah I have that problem too!!
2nd Gear Grinding or clashing. It usually happens to me if the car is not warmed up but then after that its ok.
I probably need some gear oil.

Ryde _Or_Die

I have that in 5th gear & am pretty sure its the synchros. I don't mind so much since its in 5th gear & I only use that for interstate long-distance driving. Oh ya, how do you change your tansmission fluid, I would like to do this to see if it makes shifting all gears easier. Thanks.

Rx7-88na

Well you see, last time i changed the oil (engine), i tried to loose the Tranny fill bolt and could not for the life of me get the damn thing off... So, i guess i will be forced to take it to a shop for, sob, a transmission drain&fill, how ridiculous. But, that is the best thing to do -- thanks alot anyway...

Ryde _Or_Die

I think I could drain it but where do you fill it? There is a bolt on the tranny a little farther back then the oil drain, thats the tranny fluid drain right?

Rx7-88na

I can drain the transmission easy... its the the drain on bottom of the tranny, but i cant get the FILL plug loose, (on the side of the tranny) so my next question is this: can i fill the transmission oil from the shifter? or are they seperate resevoirs?

Ryde _Or_Die

Hmm...I need to look at this. I never knew the tranny fill was under the car. Just assumed you couldn't fill it from there. Where exactly is it?(which side, near what?) Thanks alot.

stiltner@harborside.com

No, you cannot fill the transmition from the gear shift opening, But at the same time, it is important that this be checked!! The shift assembly is lubricated with gear oil, but not from the transmision, you have to add it , and it does leak out and get low. So if you don`t want to buy a shimkit for your shifter, check this out !!
If your car is non turbo, your fill plug is on the driver side on the main body, if it`s a turbo model, then it is on the driver side on the center housing.
In answer to your problem of shifting into second gear, It`s true, try to get your gear lube changed. Don`t have the missconception that synthetic gear lube might solve the problem because it will in all likelyhood make matters worse !!! Sometimes changing over to synthetic gearlube can actually cause this problem.. Synthetic lubes are so slippery that they sometimes{depending on the transmision} cause what`s known as run on, which means that the gears do not slow sufficently to mesh
between shifts.
If you are now using conventional gear lube you might try 85/140 But not if you live in a cold climate !!!
Check your clutch by going about 40 MPH and in 5th gear push in the clutch rev up the moter to about 5 grand and drop the clutch, If it never enguages then you need a clutch !!

Hope this helps !!

HUMMER

Mykl

I agree with Stiltner, although a bad syncro is a major annoyment, it will not cause the transmission to cease functioning entirely. To get around it, double clutch when you upshift, and/or shift very slowly so that the shifter literally falls into position. My car has this exact same problem in second gear, I've been dealing with it for months.

It also started happening right after I changed it and gave it some Mobil 1 synthetic. I may switch back to dino juice soon to see if that has any effect on it. However, I hear Redline sythetic actually helps with this problem.

If the lube you use is too slippery then the syncros won't catch, if the syncros won't catch then the dog teeth will not mesh. When the dog gears don't mesh, but you force the shifter anyway, they grind.

Read this for a very good write up on how manual transmissions work...

http://www.howstuffworks.com/transmission.htm

skibum9199

Well, damn, which to go with then, dino, or synth? I was going to put in either redline or royal purple synthetics, but after reading this post, I'm not so sure. I had heard that switching to synthetic could only help... So whats the real deal? If I end up like Mykl there, can you switch back to dino lube?

~Jesse

Mykl

Here's the thing, I don't *know* that the syncro is actually screwed. It could just be that the oil in it is too slippery, which after talking to some people I've heard that Mobil 1 is actually some pretty slick stuff compared to others.

Run a search in this forum for "Redline" and see what you come up with. If you can't find anything create a post asking about it, hopefully that'll help you make your decision.

I constantly hear great things about Redline in FC gearboxes, supposedly the stuff works miracles. If you can't come to a good conclusion then regular old dino juice will do the trick.

As for my transmission, I'm partly to blame since I drive it hard. I double clutch downshift, but it was all those redline upshifts that finally did it in. Not to mention that it has 140k on it, so it really is time for a rebuild anyway. Most transmissions don't last that long when driven hard, most of my Honda friends are having the same problem show up in their cars with half the miles.

We drive old cars, we have to deal with these kinds of problems. Sycros are designed to wear down and eventually be replaced.

Rx7-88na

Okay, so I still have the problem with the fill plug and it being f'n rusted stuck in the plug -- and the local shop wouldnt even touch it... so what the hell do I do now? That bastard plug is stuck in good -- i put a 12 inch cheater arm on it and still couldnt they little bitch loose... Im really at a loss here fellas -- I may just park the RX and go back to driving my 73 stang with a 390 -- It doesnt handle nearly as well though...

Ryde _Or_Die

You spray it with any lubricant stuff? Can't think of the name of the stuff I used to take my cat off but it works good.

Mykl

The only thing I can recommend is maybe some WD-40 and a longer cheater bar. 12 inches isn't very long.

88and93

You need to get a can of Kroil to help you remove the plug. It is made by Kano. If anything will penetrate the threads Kroil will. Spray it on liberally, wait a while and spray it again, wait a few minutes, then using as much mechanical advantage as you can get take it out. Using Teflon tape on the threads will prevent the problem in the future. As Mykl mentioned, you don't want a fluid that is too slippery. I tried an Amsoil product that sucked, and one of the Redline products as well. For the last eight years I have been very happy with Synchro Shift made by BG Products. It makes the gearbox when cold during the winter feel as it did during the summer. I change it every two years. Good luck

Mykl

Where can you get that Synchro Shift stuff from?

Ryde _Or_Die

O ya, its some sort of penetrating oil. Worked wonders for my exhaust. Where is the bolt to fill the transmission though. Need to find that before I drain it. Someone said the drivers side on the main body, does that mean under the hood or what? Thanks.

PaulC

forget the synthetic thats out cause of being too slippery. what about ATF??? I just started another thread about trannys cause i didnt read a little farther down

Mykl

You have to get under the car to get to it.

It's really easy to find though. When you're under it look for the tranny drain plug on the bottom of the main body of the transmission. The fill plug is on the drivers side of the gear box, directly above the drain plug. You can't miss it.

If I'm not mistaken, a 14 mm open end wrench will fit the plug.

Could anybody suggest a good brand of dino gear oil? The only thing I can find is the super cheap stuff at Autozone. Would that be good enough?

Ryde _Or_Die

Alright so right above the drain? Sounds good. Just have to make sure to get the fill plug off before the drain one Thanks man.

Mykl

haha, no problem.

Mykl

Oh yeah, before you drain it, make sure it's full so you know that you don't have any leaks.

All you have to do to make sure it's full is stick your finger in the hole (hehe) and hook it down a little. The oil should be filled to the bottom of the hole.

I would strongly recommend that you put all four corners of the car up on jack stands or a lift when you do this. That way the transmission isn't tilted.