How much torque has your ZF 310/320 endured and for how long? Failures?

[M3GSX]

Hey guys, have not posted in quite some time. Hope all is well.

"How much torque has your ZF 310/320 endured and for how long? Failures?"

Discuss. I had positive experience with mine at the time, withstood some heavy abuse.

How about you guys? Especially interested in guys revving over 8000rpm.

[PEI330Ci]

On my black car, I only rev'd to 7600, but I know of pro-level race cars that used this transmission to 8600 RPM.

The only issue I have with this transmission is not related to power: I can shift faster than it wants to engage 2nd gear. If I pull the 1-2 shift too fast, it seems to bind in some kind of neutral state despite having the gear shift lever roughly where it would be in 2nd gear. This meant that when drag racing, I had to "baby" the 1-2 shift with a noticably slower gear lever movement. Shifting into 3rd and 4th I could do much faster. I've had this problem now on 3 different transmissions, with engine/trans mounts being both poly and billet aluminum. It's not the shifter, or movement of the transmission, it's something inside of the transmission.

As far as power goes, I was only about 420rwtq on the black car, but I would get 1.6 second 60ft times on slicks before other drivetrain stuff started breaking. (Not the transmission)

On my silver car I'm likely to run over 500rwtq, with a beefed up drivetrain on slicks....so we'll see how the 320 handles that.

[pbonsalb]

Samsonas makes much stronger internals for the box, but they are not cheap.

I have broken one ZF320, but it had seen 120k miles with 70k of those forced induction, about 40k supercharged with 350lbs rwtq and about 30k turbocharged with 500+lbs rwtq. Mine broke on the highway, but I had drag raced it on drag radials occasionally for the past few years and the drag racing was abusive enough to have fused clutches, twisted driveshafts and broken 188mm diff output stubs so I suspect that abuse contributed to its demise.

I put another ZF320 in, and bought a 3rd one as a spare. I figure it will happen again -- I am not drag racing much, but have continued modding the car and my torque is probably well over 600 at my maximum pump gas boost setting. I have read of cars making power that I believe to be similar to mine repeatedly breaking 3rd gear in street driving.

I don't think it is rpm that kill the ZF320 -- you read of track guys using them behind S54 to save weight.

An alternative to the Samsonas internals is a trans swap to a T56 Magnum. Not quite as expensive and factory rated to 700 lbs at the crank. When I break my current ZF320, I will probably look at the T56 Magnum. I also have a Getrag 420G as a spare, but I suspect I would break it eventually.

[PEI330Ci]

....

[Butters Stoch]

The ZF trans holds up, until you shoot for a 1.6 or better 60' on drag radials. It will only take that so much. Its best to just treat ZF's as consumables. I prep them and change them every 1-2 years before I have to. Then sell them off to NA guys. They have a nice shifting trans

[Jab31169]

I've been trying to track down a ZF thats in good shape. My 1-2 syncro is on its last leg and its a 50/50 chance it grinds.

[jakermac]

The only issue I have with this transmission is not related to power: I can shift faster than it wants to engage 2nd gear. If I pull the 1-2 shift too fast, it seems to bind in some kind of neutral state despite having the gear shift lever roughly where it would be in 2nd gear. This meant that when drag racing, I had to "baby" the 1-2 shift with a noticably slower gear lever movement. Shifting into 3rd and 4th I could do much faster.

I am not saying that this is your problem, especially since your trans is a ZF and mine is a Getrag, but at autocross I had a co-driver once that could not do the fast 1-2 shift and suffered the same fate/issues as you do. He'd repeatedly get hung up going from 1 to 2. I as well as another co-driver had no issues whatsoever at the same event. We identified that this individual was putting a little bit of "left english" on the shifter as he was pulling back which was catching the edge of the gate between 2nd and reverse. Once he corrected that behavior everything was fine.

[PEI330Ci]

I am not saying that this is your problem, especially since your trans is a ZF and mine is a Getrag, but at autocross I had a co-driver once that could not do the fast 1-2 shift and suffered the same fate/issues as you do. He'd repeatedly get hung up going from 1 to 2. I as well as another co-driver had no issues whatsoever at the same event. We identified that this individual was putting a little bit of "left english" on the shifter as he was pulling back which was catching the edge of the gate between 2nd and reverse. Once he corrected that behavior everything was fine.

Thanks for that, it's really good info!

So now I've got to buy a Ferrari with a gated shifter....the wife isn't going to like losing another spot in the garage....

[JimsR]

^^^Buy me one two, I'll be your wife. Seriously tho zf trans I find at the local pull a part for 150, so just replace if it's done.

[NOTORIOUS VR]

Many times not being able to shift fast enough is because the RPM's aren't able to pull down fast enough on the 1-2... usually an extremely light flywheel/clutch setup rectifies that. Of course you sacrifice other things with doing that. Like driveability.

[PEI330Ci]

Many times not being able to shift fast enough is because the RPM's aren't able to pull down fast enough on the 1-2... usually an extremely light flywheel/clutch setup rectifies that. Of course you sacrifice other things with doing that. Like driveability.

I had my shifting problem with both the UUC Ultra light flywheel, and a CM with aluminum flywheel. The CM was lighter than the UUC.

This should give you an idea of what the rev's were like on the black car with the CM:

https://www.youtube.com/watch?v=tdg8C1nN9Uw

I might just really suck at the 1-2 shift. LOL

[jakermac]

Me too. UUC flywheel, 40lb S52 crank, light rods and pistons.

[NY98M3]

A "Stage 2" ZF320 lasted about 400 miles til it let go in 4th gear.

[chikinhed]

A "Stage 2" ZF320 lasted about 400 miles til it let go in 4th gear.

See you should have paid the $49.95 extra for the stage 3 option, they are way stronger

[pbonsalb]

$6000 extra for the Samsonas. Or $3000 extra for the T56 Magnum.

[Gmfwd]

2 seasons drifting at ~400 wtq. Broke a few getrags but ZF is going strong.

4 puck unsprung clutch shifting at 7k I cannot outshift those syncros. Zero boost lag. I would have to check a datalog but I doubt TPS even drops to zero before im back in the gas. I love these transmissions.

Have one in another car with 230k on it. Put new detents in it and the cheapest ATF I can find and it shifts flawless.



BUT cats out of the bag. Everyone knows how great these trannies are for their size and now theres a Miata swap kit and some JZ adapters. Its only a matter of time before prices start going up, stock up now!

Random useless tip. These will go into reverse at decent speed. Ive avoided a few collisions in drifting by backing out of a situation when I was already rolling backwards at 20-30mph.

[M3GSX]

Thanks for all the advice guys!


I ended up doing an auto to manual swap on my Supra and used the ZF 320. Still going strong to this day. The swap was fairly simple and the trans has held up more than a few track days and tons of abuse just as I hoped. Its a street car making ~600whp. It shifts fine at 8000rpm. I just have to remember not to shift too fast or the shift knob will come flying off!! haahha I totally forgot about that little quirk on these cars.

I ended up threading the end of the shifter and using a OEM Evo 8 leather momo style shift knob. Looks and feels great. I cut some serious weight on my Supra doing this swap with an aluminum driveshaft and some other small things. Got her down to 3170lbs on a 1/4 tank of gas and kept the ac. It was 3330 with the auto (verified on scale).

Thanks again and stay boosting.

[Gmfwd]

2 seasons drifting at ~400 wtq. Broke a few getrags but ZF is going strong.

4 puck unsprung clutch shifting at 7k I cannot outshift those syncros. Zero boost lag. I would have to check a datalog but I doubt TPS even drops to zero before im back in the gas. I love these transmissions.

Have one in another car with 230k on it. Put new detents in it and the cheapest ATF I can find and it shifts flawless.



BUT cats out of the bag. Everyone knows how great these trannies are for their size and now theres a Miata swap kit and some JZ adapters. Its only a matter of time before prices start going up, stock up now!

Random useless tip. These will go into reverse at decent speed. Ive avoided a few collisions in drifting by backing out of a situation when I was already rolling backwards at 20-30mph.

Well I spoke too soon. 3rd gear finally exploded last weekend. Ill pull it apart and see what the failure looks like, but I'm not complaining. 2.5 years of hard track and street use. Popped another JY unit in and hope for another 2.5 years.

[Mklock]

My biggest beef of the zf320 is no 6th gear considering 5th is only 1:1. Great that the gears are short but 3600rpm at 80 is anyoing. I'm ready for some OD in my life. Other than that no complaints here.

[M3GSX]

Well I spoke too soon. 3rd gear finally exploded last weekend. Ill pull it apart and see what the failure looks like, but I'm not complaining. 2.5 years of hard track and street use. Popped another JY unit in and hope for another 2.5 years.

3rd gear has always been the weak point. First sign of it going are the infamous dead shifts. <when you bang into 3rd and it goes in but car goes nowhere> 3rd ends up in what I call a black hole. Its the gear itself, the teeth. Liberty gears is working on a set. Hard to do in a E36 but in a e34 or supra we can stuff a 28" tire and combined with my 3.266 rear gear it feels nuts, good for ~200mph

[NOTORIOUS VR]

My ZF has a crazy whine on decel in 1st gear (and a constant light whine in 5th).... pretty sure it will let go this year at some point. I'm guessing a worn out bearing somewhere (possibly on the input shaft?).

[M3GSX]

Once this ZF goes, I will be installing a Getrag 420G. The 6th gear would def be nice for freeway cruising. Still same gearing, just the extra 6th gear for OD

[pbonsalb]

Do the ZF GS6-53 rated for 530NM not the Getrag 420G rated for 420NM. Volosso has a conversion kit to use the GS6 from a 335i. That 530NM is underrated since BMW put it behind the twin turbo V8 F10M5 making much more torque.

[Mklock]

I just smoked one... First gear had a horrible buzzsaw sound at 4500+ Rpms :/ Still shifted fine and whatnot but after taking it out it was quite clear it was an unhappy transmission lol. Popped a local junkyard one in for 100$ and all is well. Guestimated 500whp 500wtrq.