Transaxle Pull Procedure
February 14th, 2004
by Rick Flores
Valentine's day is one that is largely dedicated to couples and their celebration of love and loved ones. This holiday is extra special as a group of Pantera lovers sacrificed the morning to gather to learn how best to remove and inspect the ZF transaxle from their car. Teaching the inquisitive mob of 20 is Lloyd Butfoy of RBT Transmissions from Anaheim, CA. Hosting the TPOC tech event is Rick Flores at his shop.
Throughout the morning, Lloyd gave us insight into this marvel of automotive technology. It helps our cars work towards optimal weight distribution but, most importantly, it translates the Cleveland power into usable go at the rear wheels.
Pantera transaxles come in two varieties. Most dash one transaxles were wired at the factory while very few of the dash two units are known to be wired at the factory. Early (71-72) cars are either -1 or -2. Easiest way of checking is to look at the tag but there are other means. Dash one units are missing top center bell housing bolt while dash two units always have them. There are transitional dash two units, as in Rick's case, that have the dash one fill hole at the top; so, this is not a certain method of identification. Nor is the presence of the back mounting plate (like Rick's) in lieu of the side mounts since both units have the same rear plate. Dash one also has the reverse detent adjuster upside down but this is not reliable since either position works.
Lloyd tells us that it is easy to neglect these units. Years of no use creates an opportunity for water to form rust inside the case while excessive use and exposure to high temps can burn the oil. Simply, the oil should be changed each year or after any heavy racing. He declines to state the preferred oil but noted that synthetics add value while often subjects the trans to weeping a bit, a condition that is acceptable to some and not others.
Remember that whatever oil you choose, it is a limited slip rear.
The removal procedure itself is outlined elsewhere. Not all the steps in the Pantera manual are necessary. This is normally a two man one and a half hour job but with 20 people helping it took nearly three hours as there was ample supply of manpower, coffee and donuts.
One thing bears repeating: "Do NOT touch the bolt located under the speedo cable. It points out at 45 degrees from the case. Doing so will likely cost you big time." There is this thing-of-a-jig that drops into the case normally causing the need for the entire case to be opened which means more dilly-boppers to drop on the floor and run away. Then you know that it is time to call the experts to properly herd them together.
There are a number of things to note about ZF and their transmissions. ZF is the world's largest gear manufacturer and is noted for both manual and automatic units. Our outdated ones have a direct heritage that starts with the FORD GT40 of the late 60s, through the Mangusta, and finally on to the BMW M1 with in essence a much improved dash 2 unit.
Those of you looking for a used unit should always remove the bottom cover to expose the ring and pinion gear. See removal procedure for how this is done. The ring gear should be wired. If not, have it done. Inspect both gears but the pinion tells the story of how much abuse the transaxle has taken. Make sure that the stamping on both gears match and that the two timing marks also match.
Our application often finds the gearing to be a bit low when cruising down the highway in top gear or as we search for more top end at some of the long straight-aways.
RBT offers three ways to help us. First, a ring gear swap to a 3.77 ratio from 4.22. Second, a replacement 5th gear with .642 overdrive rather than the .705 stocker. Finally, they offer a 6 speed that is used in the Saleen 7 of racing fame. (Check them out at www.rbttrans.com.)
Rick — Feb. 14th, 2004
Rick — Feb. 14th, 2004