Transmission Woes

[Motorsport3]

Shifting my car into 2nd gear under hard acceleration is a horrible, grinding catastrophe.

Short of getting into a 6 speed swap, what do I need to replace to make the 5 speed good again?

[Wertles]

The transmissions are not easily rebuildable. They take expensive jigs and tools to do it properly and usually more expensive than buying a used unit. I WAS able to get rebuilt ZF 5 speeds with a warranty for a reasonable price but ended up with a 6 speed instead. PM me if you need help.

[rf900rkw]

Try a lighter oil before throwing in the towel on this box. Shoot some cheap ATF in there and see if it cleans up the shifts. If it does, then pick a good oil. If it doesn't, you're not out much.

[BenFenner]

I'm hoping a good fluid change will fix this for me too. It doesn't seem to be a synchro issue for me, since it behaves similarly on the other gears as well. 1st -> 2nd gear just has the largest shaft speed delta (I assume) which makes that shift particularly hairy.

I think I'm also used to transmissions with finer dog teeth (less torque holding) which engage in a more civilized manner.

[turbow92]

I had the exact same problem when I first bought the Z. Hard acceleration in second gear led to intense grinding noises. I replaced the driveshaft and it was gone... Not the most cost efficient option, but sounds like a very similar situation and it worked for me!

[BenFenner]

You've hit a black hole in my brain with the driveshaft info. How could a new/different shaft help? Maybe something else that was replaced/fixed along with it? I'd love to hear theories.

[Motorsport3]

How much fluid does the trans take?

[rf900rkw]

1.3 liters

[jajou318]

Is it hard pulling it out of first to go into 2nd? Does this always happen under hard acceleration - or only sometimes?

[Motorsport3]

It isn't hard to pull it out of first at all. You just have to let the revs fall significantly and very deliberately and carefully put it in 2nd.

[CodyR]

About the drive shaft thing - Turbow92 says his noise was under acceleration in second gear, not shifting into second gear, and the noise was probably more of a vibration / thumping noise, not grinding. I had that issue and it was bad u-joints. I had the u-joints and the center bearing replaced and that fixed it. Replacing the drive shaft is another option for that problem, but I found a vendor that could press out the old and replace with new and saved some $$
That doesn't sound like your issue. Grinding while shifting is completely different. How many miles on the car, and what kind of MTF have you been running?

[Motorsport3]

I've only had the car for a couple of months so I dont know what kind of fluid is in there. It does have 138K on it though. I have a couple bottles of pennzoil synchromesh that I'm going to try. If this doesnt make any difference, I think I'm going to do the six speed.

I'ts a good thing for this car that I have an M Coupe obsession. I spent over a grand on maint issues & replacement parts for it before I made the first payment.

[CodyR]

Man, I hope the previous owner maintained that thing. My 98 2.8 Roadster has 178k on the clock. I've been running Royal Purple Synchromax since 30k, replacing every 30-40k. Made a noticable difference immediately and hasn't missed a beat since. I love that stuff.
Best of luck man!

[rf900rkw]

That Penzoil stuff is a bit chewy for this application, and may be more prone to grinding than the stock stuff. It's probably not a good thing to use for this test.

[Shoe Coupe]

how is your clutch pedal? Maybe your clutch isnt fully disengaging?

[rboehl]

Try the Royal Purple Synchromaxor and see if it helps. It fixed mine in my 2k Roady.
I had trouble 1st to 2nd and also to 3rd.

[Motorsport3]

The clutch pedal took some getting used to as compared to my M3 but other than being heavy, it seems to be fine.

[mva]

I've only had the car for a couple of months so I dont know what kind of fluid is in there. It does have 138K on it though. I have a couple bottles of pennzoil synchromesh that I'm going to try. If this doesnt make any difference, I think I'm going to do the six speed.

Don't use Pennzoil Synchromesh in it. It is too thick and will make the shifting worse.

Like others have said, try Royal Purple Synchromax or ATF.

[SWISS]

The clutch pedal took some getting used to as compared to my M3 but other than being heavy, it seems to be fine.

Whatch u mean "heavy"?

Sounds like a clutch is in your future also. Do you have 5th gear lean at all?

[Ronan1]

I've having some issues with mine too. The 3rd gear synchromesh is gone, and yesterday, I had issues getting the car into first after neutral when I came to a stop. I had to turn the car off, and wait and it wouldn't go into first or second.

The clutch was replaced by the PO and it bits at the very top, so not sure if this has something to do with it. Either way, was thinking of changing the fluid or just getting a 6 speed!

[Motorsport3]

I meant that the pedal feel is heavy.

It turns out that the transmission mounts were both completely shot. With things firmed up as they should be, I would expect there to be a positive effect on shifting.

I tell you, it's a laugh a minute with this car. Definitely a polished turd.

[albrazzi]

Now I need to know if that fixed it, if the trans was moving so much you couldn't find the gear then maybe. Proper fluid needs to be there also and hope the wrong fluid hasn't done too much damage.

[Motorsport3]

The new mounts and fluid change appear to have done the trick. I had a slight vibration at highway speed too. That's gone as well.

[albrazzi]

The new mounts and fluid change appear to have done the trick. I had a slight vibration at highway speed too. That's gone as well.

Thanks for posting results here, I like to follow these threads and offer up what I can. A lot of people post issues, get comments and and dont check back in. I think thats an important part of the process.

[Motorsport3]

how is your clutch pedal? Maybe your clutch isnt fully disengaging?

You sir, were correct. It got to the point where I practically had to cut a hole in the floor to get the car in gear. The Clutch MC piston broke in half, stranding me in DC this weekend. As we speak, I am having a SS clutch line and new Clutch master cylinder / pedal installed. Can't wait to see what the shifting is like after this repair.