I recently had Loyd over at RBT rebuild my ZF we changed the ring gear to the Euro type and the higher gear ratio is well worth it.

Last edited by George P
Original Post
I'm confused.

I know owners have changed ring and pinion gear sets and fifth gear sets, but I am unfamiliar with the term you used, "euro" gear.

Which gearset did you change out, and what was the ratio of the replacement set?

Larry
4.22 was the common ring gear in all European cars. A factory option was the so called "Le Mans" gear with a 3.77 Ratio. 4.00 was also avaiable. 3.71 was never in the parts books.
you got me 3.77! the variance was related to me from Loyd, anyway the point it is far better in my opinion. thank you for the clarification. May I recommend it again if you have the hp for it. As bond would say thank you M
Only when you drive your Pantera in city's and traffic jams , dont go to 3.77 ratio.

your clutch dont like it .

Simon
It is not so dramatic, traffic jams and traffic?
I assume you have not driven a car with the gearing? I forget sometimes what traffic is all about up hear in the outback, but it is a pleasure and not a problem at all, unless you live in San Francisco.
When you want to drive fast whit a high powered engine a 3.77 ratio is good.
Engine's whit a lot of Hp the torque come's in whit 2000-6000 rpm.but are needed to come to the high speed .
Whit the high gear ratio , it's not relax to stop and go into a traffic jam.

When you choice is a lower HP engine you cannot drive's it really faster than 250km/h

1/2 hour of traffic jam is not unusual in my country.
Simon
It all depends, what car you have. DT claimed a top speed on the old Pantera with the 4.22 Ratio of 249.5 Km/h @ 6000 rpm. On the GT5-S cars with the way less tire diameter it was 232.5 Km/h @ 6000 rpm. Those cars should use the 3.77 ring gear.
I have the 3.77 gearing and I have not experienced any trouble at any speed in any gear and in any kind of traffic. I use my Pantera a lot and twice to France (from Denmark). Tell me what I should look for of problems..... I should mention I have a 393" stroker now but with my standard 351c I did not experience any problems either ever!

I can only recommend it and I usually only shift up to 3rd or 4th on country roads (80km/h) and 5th is a blessing on the highway and keeps the rpm's down to about 3000 at 150km/h
I have the Ford 400 stroked 434. I had mind changed to a 3.44. It is a joy to drive. Ive got 434ftlbs of tq at 2000 rpm so i needed to drop the rpm.

Before, 1st gear was absolutly useless. 60mph was way too much rpm.

Now 1st is in a perfect range and 60mph is is just a little over 2000rpm. Perfect range for this engine.
The worries are overblown, I have had 5.38's in a hot rod truck, 4.11's to higher gears like the 3.44 mentioned, my car weighs 2800 pounds, the difference between this gear and the stock is I shift after I exit the intersection instead of have way through it. I REALLY like it!! I also have a 393 stroker 285x35x18 that's 25.9" in diameter so my original back tire was a 305x50x15 27" in diameter, i" taller.
Appr. 12% difference. Your gearbox should have a data plate with all informations. Otherwise you have to open the bottom plate and count the teeth of the ring an pinion. Number of teeth of the ring divided by the number of teeth of the pinion gives you the ratio.
If you are having your transaxle opened for rebuild/repair anyway then the additional cost for a new ring and pinion is about 2500$.
At Zf direct the ring and pinion is about 3800 euro.
We do a new 4.0 ring and pinion wich is about 50% stronger than the original.
I collect the orders right now.
It is developed by a technical master with have done some transmissions for verry big companies.

My Bora has the 3.77 ring gear.  It drives fine in traffic but drives even better at freeway speeds.  We tend to drive pretty fast here in So Cal when there is no traffic.  Since I never use it for work and such, usually my freeway drives are in the 80 mph range.  It drives great.  The Pantera on the other hand at 80 mph is not as good it revs too much for my liking.  In my opinion since the engine is pretty powerful it would benefit from the 3.77 gear.  Problem is the cost outweighs the benefits.

I‘ve just put in a 12 % longer 5th gear in one of my stock engined Panteras. This is the way it should have come as stock. Relaxed cruising, less noise and better fuel consumption is what you get. My other Pantera, which will have a slightly tuned engine, will get the 3,77 crown and pinion. In my humble opinion the Pantera can handle much longer gearing than we think. Donˋt forget to factor in tire circumference in your calculations.

A 3.77 may be more useful with a big cube engine. With a 4.22 in 5th, it's the equivalent of a 3.00:1 rear. A 3.77 in 5th is a 2.66. Kind of like a Lincoln cruising.

The trade off is that with a 2.20 first gear, you only have a torque multiplication of 8.2. For performance usage you need that number to be between 10 and 11.

Of course a 450 cube engine is a different beast and takes to 'Granny shifting much better.

Where I am and with only 357 cubes, that kind of gearing (3.77) would make 5th pretty useless. This ain't the autobahn for sure. To each his own I suppose?

I like my 3,77 and I certainly don't think 5th is useless I have lowered the rpm at 100km/h (60 Mph) now it is 2100 and it is a comfortable rpm range for cruising at europe highway speed 130 km/h to 180 km/h. As I mentioned in a previous posting 4th is more suitable on country roads at 80 km/h and 5th is only really needed on the highway unless you are ok with cruising as low as 1500 rpm.

If by performance you mean drag race I have no experience and can not comment on that. I have never raced my Pantera and I do not intend to do it either.

Last edited by goodroc

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