[DeTomaso] : Back in the saddle

Corey Price coreyjprice at gmail.com
Wed Sep 10 13:53:08 EDT 2014


Mike,

I just rebuilt my half shafts and won't do it again.  I will be going to CV if these ever give me trouble.  Rebuilding half shafts looks easy but I spent more time on them than on my ZF partial rebuild!  Rebuilding my own including cad plating was a little more than half what a set of CV axles can be pieced together for and I'd rather have the CV axles for the balancing reasons you state.  

A couple "challenges":
1.  I couldn't get the original caps to move.  I had to cut the cross out on one side.
2.  Cleaning them took a while with all of the nasty grease and rust.  
3.  Reassembly took a long time.  The yokes aren't flat on the side you press against and any kinking of the assembly will bind up the caps.  Two people are needed to assemble, really.
4.  If one cap in a yoke binds, the yoke can be bent by the press.  Don't ask me how I know...
5.  Proper assembly means that you have clear scratch marks that identify all eight pieces, in order.  
6.  If you have the yokes plated for corrosion resistance, don't let the plating company plate the splines (or cap bores).  You might have to make another trip back to the plater to get the spline end stripped since the interference will prevent the splines from sliding properly.
7.  Hopefully these things were balanced right at the factory, but I might be taking them to the driveline shop to be balanced now.  
8.  Don't let any of the greasy needle bearings be dislodged and fall into the cap and be crushed.  Don't ask me how I know.

Corey

> On Sep 10, 2014, at 9:44 AM, Mike Drew via DeTomaso <detomaso at poca.com> wrote:
> 
> 
>> Hi guys,
>> 
>> Some of you may remember that my Pantera has been up on my lift for the world's longest brake system upgrade project.  Scott at SACC Restorations has been a dream to work with; on the other hand I have been a pain in his butt because of my unique requirements (must have big brakes, must run stock Campagnolo wheels) along with my own inability to overcome inertia when the project ran around (or more accurately, when the wheels crashed into the calipers).
>> 
>> Months would pass with spiffy new parts sitting on the floor, waiting to be installed, but time constraints coupled with fundamental laziness made it impossible.  And then, just when I thought I was finally done, I discovered my halfshaft U-joints were shot.  An attempt to rectify that situation at a PCNC tech session turned into what the British would term, "a dog's breakfast' with U-joint caps being broken left and right.
>> 
>> After ordering a stack of replacement U-joints, eventually I made the decision to bring my halfshafts to a gen-u-ine driveshaft specialist to have them rebuilt and balanced.  I'm glad I did, because they discovered some of the ends of my halfshafts had been damaged by a previous, long-ago owner and were bored out and sleeved, so the new U-joints wouldn't fit properly.  Fortunately I had some spare driveshaft bits in my parts stash that I had thoughtfully brought with me, so among all the parts, they were able to generate two good halfshafts with new U-joints installed.
>> 
>> (If anybody has a desire for random halfshaft ends with U-joint holes that are either oversize, or oval, or both, let me know and I'll make you a good deal!).
>> 
>> I noted when I took my halfshafts out that four of the bolts (all four on the inboard passenger side) were barely tight--this despite the fact that they had been installed and tightened properly just a few hundred miles earlier.  I played it safe and bought new lockwashers and new Grade 8 nylock nuts for reinstallation (curiously, the factory application calls for use of both split washers and nylock nuts; the bolts are just barely long enough for the nylock to engage the threads on the bolt as a result).
>> 
>> I finally got the car back on the ground and drove it around the block a couple of days ago; last night I took it on its maiden voyage, about 45 minutes up to the Capitol Panteras monthly meeting.
>> 
>> I haven't had the opportunity to fully test the brakes yet (for now I can say that they work, but the old ones seemed to work too, until I learned the balance was AFU).  I need to break in the new pads and rotors properly, something I'll likely do next week.  Bob Benson and I are going to be running at Laguna Seca on the 21st (Brent Stewart is supposed to be running with us but he wimped out!) so I will definitely put them to the test there, but I plan to have full confidence in them before leaving for the track.
>> 
>> Anyway, the whole point of this missive is that I was shocked at how SMOOTH my car ran last night.  I've always been particularly impressed by my Pantera in comparison to the many others I've driven; thanks to the exorcism of a lot of rust and the substitution of much thicker and stronger steel in the floors and rockers, few feel as solid or buttoned-down as mine does (this despite the somewhat floaty ride from the crappy old 50-series tires).  My car has always had just a slight tinge of vibration; nothing you could put your finger on, but something that I just chalked up to the fact that the tires sit for long periods of time, are 20+ years old, it is a 42-year-old car, and 'they all do that sir'.
>> 
>> While I had the halfshafts out I noted that the passenger side GTS tailpipe was resting against the chassis, and that seemed like a good way to transmit unwanted noise and vibration, so I put the tailpipe into my 20-ton press and 'reprofiled' the pipe slightly, so that it just barely clears the chassis now.  And of course, when I installed the newly balanced halfshafts I made sure everything was good and tight.
>> 
>> I was astounded at the difference.  My Pantera now feels like a brand new car when cruising on the freeway.  I'm convinced that my halfshafts were the source of the feeling I no longer feel (although the exhaust may have played a role as well).  When I took the halfshafts apart originally, I discovered that the outboard U-joints had been replaced, but they were stiff and unhappy, while the inboard U-joints were original, with no provisions for lubrication, and were bone dry and rusty--it's a miracle that I didn't have one of them snap on me!.
>> 
>> While there is no doubt that CV-joint halfshafts are sexy, they are also expensive, and just as heavy as the stock ones.  People have reported great improvements when switching to CV-joint halfshafts, but I am here to tell you that the improvement comes mostly (if not fully) from replacing the old ones, rather than from the fact that they happened to have chosen CV-joint units to replace them with.  I think having my halfshafts rebuilt and balanced was some of the best money I've ever spent!
> 
> I was so happy that I decided to drive the car to work this morning. I actually got to work early as a result!
> 
> <image.jpeg>
> 
>> 
>> Mike
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