Can Someone Help Me? I'm Thoroughly Confused on the ZF!!

Can Someone Help Me? I\'m Thoroughly Confused on the ZF!!

I ordered a bellhousing from Kennedy Engineered Products. it is non-flipped. Lloyd at RBT said I should have bought the flipped version. I talked with Mr. Kennedy himself and he tried to explain the difference to me. I must be completely dumb, as it just doesn't make sense.

here is what he said:
The flipped version moves the transaxle back up in the chassis. The non-flipped design moves the transmission lower requiring the use of a dry sump oiling system. He said the one I bought can be modified. I just don't see how. He said it had to do with the crank centerline.

At this point, I'm thoroughly confused.

Bill D /ubbthreads/images/graemlins/frown.gif
 
Re: Can Someone Help Me? I\'m Thoroughly Confused on the ZF!!

I think I've figured it out. Please correct me if I'm wrong.

It appears the "fliping" and "redrilling" pertains to the mounting holes for the transmission to the bellhousing. Am I correct?

Bill D
Confused but determined
 
Re: Can Someone Help Me? I\'m Thoroughly Confused on the ZF!!

The transaxle rotates around it's input shaft centerline relative to the bellhousing. In a Pantera the axle drive flanges are situated BELOW the input shaft centerline. In a GT40 the axle drive flanges are situated ABOVE the input shaft centerline. Usually the terminology "flipped" comes from the Pantera perspective, meaning you take a Pantera style ZF-2 box with the drive flanges located below input shaft centerline and flip it over to the GT40 configuration putting the axle flanges above the input shaft centerline. Keep in mind that the transaxle input shaft centers itself in the engine crankshaft at the pilot bushing. Any rotation happens around that centerline. Do yourself a favor and spend some time on the ERA web site reading the transaxle section. ERA sells a complete bellhousing kit for the -2 box and the CAV bellhousing is basically the same thing. I just posted some pictures on another thread that may also help. Oh, one last thing, when putting a flipped ZF in a GT40 the bottom of the bellhousing is machined flat for ground clearence because the flipped configuration allows the engine to sit very low in the chassis. The lower position limits the flywheel diameter and the maximum clutch size is 10.5" and not 11" as in the Pantera.
 
Re: Can Someone Help Me? I\'m Thoroughly Confused on the ZF!!

Thanks for the quick reply Patrick. Using your picture from the other thread, the bellhousing is not flipped, but the transmission mounting holes are "flipped" so the transmission can mount to the bellhousing. The bellhousing is trimmed along the bottom for clearance (that one was easy).

If I'm correct, then it all makes sense (finally). At least I can have my bellhousing reworked by Kennedy.

Thanks again
Bill D
 

Lynn Larsen

Lynn Larsen
Re: Can Someone Help Me? I\'m Thoroughly Confused on the ZF!

Bill D.

Yes the bell housing/engine mating surface never changes. What changes are, as you said, the position of the holes that allow the transaxle to mate to the bell housing. In your case, the transaxle is in the position described by Patrick D., which should be upside down as compared to the way the transaxle sits in a Pantera. Since, as Patrick D. stated, the transaxle rotates about the input shaft, the trans side opening in the bell housing for a flipped transaxle is higher than a Pantera bellhousing.

I think where you (or who you were talking to) got into trouble is talking about a flipped bellhousing or non-flipped bellhousing. I think the better way to term it is a "bell housing for a flipped transaxle" or a "bellhousing for a standard (non-flipped) transaxle."

Don't be concerned over this; we have all been there, done that and got the T-Shirt! Somewhere I have a post describing a comical scene that would have gotten me thrown in the luney bin if I had been seen by my neighbors. It involves me spinning my fingers, pointed out to either side me, then turning around and then rotating my self upside down. All of this to prove to myself that a Porsche when turned to the midengine position and then flipped upside down will, indeed, provide 5 speed FORWARD.

With a ZF, its already in the midengine position normally, so when you flip it upside down, you get 5 speeds in reverse. Thus, you have to flip the ring gear over to make it 5 speeds in forward once again. Following Patricks description, a quick glance at where the output flanges are will immediately tell you if the tranny is flipped or not - this is true for the Porsche or ZF boxes (I don't think the Audi can be flipped since there is no way to flip the ring gear. From this you can deduce that they, like the ZF, also normally sit with the input facing the front of the car.)

Regards,
Lynn
 
Re: Can Someone Help Me? I\'m Thoroughly Confused on the ZF!

Lynn - when my G50 goes inverted for the install, are you saying that the ring gear needs to be as well? Or was that just the case for the ZF, or... hmmmmmmmm

Chris
 
Re: Can Someone Help Me? I\'m Thoroughly Confused on the ZF!

Should I complicate things further? Since the GT40 came before the Pantera, the ZF is actually not flipped for the GT40. It was flipped for the Pantera and all you have to do is flip it backover to make it "unflipped" for the GT40. Think of it as making things right again. /ubbthreads/images/graemlins/grin.gif
 

Lynn Larsen

Lynn Larsen
Re: Can Someone Help Me? I\'m Thoroughly Confused on the ZF!

Chris,

What I was saying is that turning the transaxle around from the "in Porsche" position makes the transaxle have 5 speeds in reverse. Then flipping it makes it have 5 speeds forward again. All you have to do is make the drain the vent and make the vent the drain. Then, loosen one of the output flanges and fill it will gear oil just until you get leakage, so you'll know how much to put in. If you'd like, you can then make a right angle dip stick with which to check the level via the existing fill level port. Chris, there is one downside to flipping the tranny: the input shaft is now below the oil level. So, I would, by all means, put a new input shaft seal in before you bolt everything together. If the one you have has much wear, it will leak sooner rather than later.

I understood that Patrick, but I think Bill failed to see the humor ;^). Again, don't worry about it Bill, I've been through the wirrly bird exercise more than once, and you will too 'till you firmly "get it."

Regards,
Lynn
 
Re: Can Someone Help Me? I\'m Thoroughly Confused on the ZF!

Got it - I think the grey matter is fading a little earlier today. Well, 28K is what's on the unit but I may just replace it while I have on the stand.

Good to know - thanks again.

Chris
 
Re: Can Someone Help Me? I\'m Thoroughly Confused on the ZF!

Lynn-

I got Patrick's humor. I was just being a smart a**
 

Ross Nicol

GT40s Supporter
Re: Can Someone Help Me? I\'m Thoroughly Confused on the ZF!

Flippin heck, see what you started Bill.I like Patrick's explanation the thing was correctly orientated in the original GT40 and then some idiot thought oh why don't we turn it upside down so we can raise the motor and ruin the centre of gravity and because all Ford motors leak oil out of the rear seal we'll have a bolted on cover plate under the crown wheel that will leak oil sooner or later too.Moral 2 leaks must be better than 1.Well done on the detail explanation though Lynn I'm still dizzy.
Ross
 
Re: Can Someone Help Me? I\'m Thoroughly Confused on the ZF!

lmao, its good to see I'm not alone in getting so confused over these ZFs /ubbthreads/images/graemlins/tongue.gif
 
Re: Can Someone Help Me? I\'m Thoroughly Confused on the ZF!

/ubbthreads/images/graemlins/tongue.gif you guys are givin me a flippen headache!!! /ubbthreads/images/graemlins/grin.gif
 
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