i use a custom Aluminum driveshaft, HD GM U joints, 700 trans, GM diff yoke at pinion shaft!

works great NO vibes ,and saves weight!

 

Nix has that canister but it's pretty worthless, not even completely connected. Mostly its purpose is to satisfy the SMOG cops.

You might not even need it in your area.
(';')

 

Yeah @lnrb I live in an area with no emissions requirements but that doesnt mean that i will forever! I wonder if they would even care in CA though as it is a 74 model year.

 

Not 1974. The cutoff year is 1975. If your car has a build date of January 1976 like mine does then they Most Certainly Do Care!

As California has among the most stringent emissions rules in the country, I'd say your quite safe.
(';')

 

Indeed, the canister and it's related components are for SMOG purposes. Mine is connected. But, I doubt it's effectiveness. It is intended to deliver fumes from the gas tank to the engine for combustion rather than the old tech way of venting them to the atmosphere. But, in my car, the filler cap seals are pretty raggedy and I doubt they seal... Why it passes CA's tank test, befuddles me.


OTH, My Jeep flunked the EVAP test. OK on the combustion stuff. Failed seal on the filler cap. Offered a replacement at $12 or go get my own. "DEAL" an easy decision.


Carl

 

$100, or the same for an original hood. Thanks, Rob

 

We all have different sensitivities to NVH.

I've driven scores of RWD cars with a one piece driveshaft and never felt (literally or figuratively) that there was an inherent vibration problem. OTOH, a very comment remark from passengers after riding in a Jag for the first time is "Oh my god, this this car is so smooth"

Ages ago a lot of USA luxury cars used 2-piece drive shafts. Perhaps not to correct a problem but, instead, to achieve that extra bit of refinement? Some of the Buicks (and probably others) had not merely two-piece shaft but a *double* u-joint affair joining the two halves. The name of the design escapes me at the moment. But I remember that Dad, who was "A Buick Man", used to curse the design as they didn't hold up very well and were expensive to replace. This was 1960s-1970s.

(Back in the day it was common to be "A Chevrolet Man", or "A Ford Man", or even "A Jag Man". But that's a stroll down a different memory lane)

I also remember, from decades ago, that many full sized Ford products often had giant weights attached to the differential to dampen vibrations. Crude but effective?

Ramble switch "off" for now :-)

Cheers
DD

 

Heh heh.

It's like a great many emissions control devices. Worked effectively....while it was still working. Nothing lasts forever.


Cheers
DD

 

I hear that too, even though my jag is heavily skewed towards performance.


It was called a double carden joint. My 1978 Cadillac Seville had one. The seville was one of my favorite cars...I guess its no accident the design borrows heavily from the Jag sedans that preceded it.

No comparison between the Seville and the Jag mechanically though. The Seville didn't have a rack and pinion but a rather sloppy stearing box and no interdependent rear suspension, it had truck like lief springs.



Understanding Universal Joints and Size Charts







seville driveshaft with double carden joint

 

Doug:


Yes, that memory thing. The double U joint is AKA constant velocity joint. YUP, used amidship in USA critters.


And in the fabulous 36/37 FWD Cords. RZEPA brand. Rumoured to have been a source of trouble.


I'm a bit fuzzy on the theory, but it seems that as the angle of installation of a conventional U joint increased, that the rotational speed of each trunion varied as it turned. Result, a bit of a whip saw motion that translated in to vibration.


And as you say, sensitivities varied.


Ford also used a "pipe within a pipe" member for a drive shaft. The pipes interconnected with a ruberoid layer. Object. Smooth power transmission.


And Ford incorporated "Torque boxes" in strategic locations in it's Unibodied big cars
for the ultimate smooth ride.


Oh, one more, a pipe within a pipe for Lincoln exhaust pipes. Oh, oh, the inner pipe could collapse and drive folks "nuts" as to why the beautiful Lincoln would barely run if at all.


I do have new seals for the Jag filler caps. Far down on the "task list". If it flunks that test next time around, I may install them. It might be wiser to do a preemptive fix !


Band saw to fix in a bit. Then hibernate, heat on the way.....
Carl

 

I guess I messed up. Here goes again.

$100 for the hood, or for an original one.

Rob

 

So the way it works is...

- with a single u-jount...as the it turns, it will shorten and lengthen in
perportion to the angle of the joint.

- with a double joint , the shortening and lenghteing is offset by the double joint's 180 degree offset. As one shortens the other lengthens thus effectively offsetting the vibration or movement in the shaft.

 

Got it. thanks.


Good day in the shop this AM.


1. fixed the band saw. It merely tossed a blade, not busted it. Mea culpa. Wacky feed of a tree limb.


2. Fired up the Jeep to see if it's AC needed a charge. First effort said yes. Cool for a bit, then warm!!! Forgot about the compressor on/off button. sure enough, it was in the "off" position. Engaged, cool air and stayed that way. Rough test. Hold finger tip to outlet. A bit of a bite means OK to cool.


3. My solar topped marker along my drive used to back the Jeep in and leave maximum room on the other side gone??? Made an "elegant" post from a limb from the tree, I severely pruned. Chop saw to make point on one end. Sharp hand saw to clean nubs. Spade bit in old hand drill to bore a hole in tne other. Post of solar lamp fits there. Used big bolt in the bore and a BFH to drive it in toe still somewhat moist soil.


Done, in, t is getting hot. 70 F in my cool breezeway. Away, 80F + and climbing....


Carl

 

that looks good only problem its an xjs and i need one from an xj6/12, let me know if you have a hood from one of those and ill probably pick it up when im back from europe

 

Yes I do. Thanks, Rob

 

seein how this driveshaft/u-joint BS has been beat to death!

i just was reading that for serious performance for the Mustang S197 models,

you have to do away with the 2 piece driveshaft, some of them have been breaking off under hard loads!

they recommend a single piece shaft made from Aluminum along with Heavy Duty U-joints! or a carbon fiber shaft(if you can afford it!).

 

This is becasue the S197 from the factory came with a very thin shaft with a smallish CV joint in the middle so in this case and the small tunnel of the S197 and thin wallets of the owners leave them little choice. My guess is they dont care about vibration either. My googleage suggests some of these cars are modded but the boy racer crowd and shaft breakage is quite common. This is a prime example why I'm a GM guy.


Conversely, the Dodge Demon, a factory 9 second car that launches so hard that it pulls it's front wheels off the ground... it uses a.... 2 piece shaft.

The Dodge Demon's (Drive)line of Defense - Hot Rod Network

Many many many high HP NHRA cars us two piece shafts too. They're sanctioned and some racers believe they are safer and offer an slight advantage. Vibration is lost power to the wheels. Any serious racer understands the advantages. The drive line bloke who want you paid and gone will force a once piece on you becasue its a quick buck. A two piece requires more precision. A one piece can be off by an inch either way and still work.
https://dragillustrated.com/lueck-ra...aft-enclosure/

Frankly anyone doing a convert can use a two piece simply becasue replacing just the front half of the shaft is much cheaper and preserves the XJ refinement we all appreciate. And since converts usually use use a slip yoke it can still be off by an inch or so and still work fine.

 

all i'm sure of is mine works fine ,and no problems in 22 yrs!

KISS(keep it simple stupid).

 

Thinking ahead on my 1985 S3 lump, the drive shaft issue came to mind and I found this old thread that makes me think the stock shaft that came with the car will be OK. Of course there is always a question-what are your thoughts on the rubber isolator connecting two pieces of one of the shafts? Is there an inherent weakness with 300-350hp. I can see where that design could be potentially smoother.
Dave