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Jag Jaguar IRS into a 46' International Harvester

Discussion in 'The Hokey Ass Message Board' started by IRON MAIDEN, Feb 2, 2011.

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  1. zman
    Joined: Apr 2, 2001
    Posts: 16,731

    zman
    Member
    from Garner, NC

    have you ever done a jag rear? because what you propose is incorrect in this situation. The setup is done by leveling across the bottom of the suspension in this instance.
     
  2. need louvers ?
    Joined: Nov 20, 2008
    Posts: 12,903

    need louvers ?
    Member

    I think in the case of this truck, I would go ahead and use the cage. Simplify mounting a bit, keep everything rubber mounted to absorb vibration, and the honest truth is that it will be so far up under your truck that it won't be visable until you tip the bed. Also, the cage looks kind of "trucky" in my opinion.
     
  3. Not stirring the pot on purpose, but:

    Just measured my 1969 XJ rear for included pinion angle. There is none. The dog bone pivot plane is parallel to the pinion at both the attachment point and at the hub carrier.

    Three degrees of pinion up would put three degrees of positive caster into the IRS.



    So, this made me dig around a bit and I landed on Eng-Tips for some advice without drama. This explains why pinion up and the positive caster is going to help you and maybe why Jaguar built these rear axle assemblies this way:

    http://www.eng-tips.com/viewthread.cfm?qid=36015&page=25

    I'll digest this post for you,

    The positive caster (hub carrier leaning back) will work similar in acceleration as does anti-dive does for an IFS under braking.

    This one deals with drive line and half shaft angles,

    http://www.eng-tips.com/viewthread.cfm?qid=256652&page=5
     
  4. IRON MAIDEN
    Joined: May 28, 2010
    Posts: 517

    IRON MAIDEN
    Member

    See how it comes back to the damn debate on the pinion angle!!!! I'm starting to think there is no right way to do it.
     
  5. Don't stress out man!

    Trust me, I'm not trying to start shit. I just want to give you the information and you can do what ever you want.

    The second post I listed from Eng-Tips discusses drive line angles in a way. We have hashed this out numerous times before on how to kill driveline vibrations with link and leaf suspended solid axles. There are two possible scenarios, pinion up (parallel angle) and pinion down (intersecting angle). Both can work to cancel out vibration so long as the working angles match. The rub with a solid axle in this situation is the axle moves! Unless the pinion rotates in such a manor the working angles match as the axle compresses and rebounds the intersecting angles can cause a vibration. With parallel angles and a rear suspension that doesn't change pinion angle throughout it's travel (or very little) you have a better shot at avoiding the mismatch.

    IRS rears can tolerate a pinion down because nothing moves in regard to the driveline.

    I understand where Scott is coming from making the dogbones level. It would set a neutral rear and work just fine. However, if your engine is more than a degree or two off the pinion axis you "could" get a low rumble from the Universal joints.

    From where I stand, it seems like a natural to put the pinion up 2º or 3º to match the engine. The added benefit is a higher anti-squat line.
     
  6. need louvers ?
    Joined: Nov 20, 2008
    Posts: 12,903

    need louvers ?
    Member

    Listen to this guy above!!!
     
  7. BJR
    Joined: Mar 11, 2005
    Posts: 9,819

    BJR
    Member

    Is there any way to adjust the pinion angle with shims under the differential, separate from adjusting the cage? Another words set the cage on the correct angle for the suspension to work right, and then shim the center section within the cage to get the correct pinion angle. Maybe this is not possible just a thought.
     
  8. Slag Kustom
    Joined: May 10, 2004
    Posts: 4,312

    Slag Kustom
    Member

    no matter what angle you put the engine, pinion there will be the angle that the pinion is offset to the passenger side to make sure the u joints work.

    different model jags have different lower control arm mounts that keep arms parell to the ground and change the pinion angle
     
  9. zman
    Joined: Apr 2, 2001
    Posts: 16,731

    zman
    Member
    from Garner, NC

    both engine/trans and rear are set at zero in the Buick. Never have had an issue with the u-joints, and the degree of offset of the pinion is equal in the u-joints. I could measure it if need be.

    As for anti-squat that is interesting. I have read a lot of how the Jag has it built in.
     
  10. zman
    Joined: Apr 2, 2001
    Posts: 16,731

    zman
    Member
    from Garner, NC

    Not without affecting the rest of the suspension.
     

  11. I thought the engine was pretty level in that car from seeing it in person. I don't remember if you still had the rubber mounted cage also. I could understand using the rubber mounted cage to help isolate the odd shake or rumble and masking any driveline angle issues, like leaf spring suspensions do on "normal" stuff. :)

    I don't have any access to nor have I spent a ton of time researching stock Jags, but I just wonder if the "built in" anti-squat you speak of is related to pinion up...

    hmmm
     
  12. nunattax
    Joined: Jan 10, 2011
    Posts: 3,052

    nunattax
    Member
    from IRELAND

    iron maiden ive just fitted a corvette irs into my 38 chevy.i had similar problems to you .this is how i approached it.before i removed the irs i parked the doner car over a pit and took detailed measurements of trailing arm mounting heights trailing arm angle half shaft angle and pinion angle take plenty of pictures ..even though i thought i had everything covered i still needed to get under another corvette to double check( pinion angle what else)put air in the tyres.my wheel/tyre combo was 26 1/4 inches high make sere you are happy with your tyre sizes before you start
     
  13. nunattax
    Joined: Jan 10, 2011
    Posts: 3,052

    nunattax
    Member
    from IRELAND

    my pinion angle was 0 degrees yes 0 degrees.every book i read said 3 degrees.my vette was 0 degrees (1971) the other corvette was 0 degrees (1974)rang heidts who do there own irs they said 0 degrees for independent rear.i set the engine gearbox falling at 3 degrees as per stock 71 vette.before i set these angles i sat the chassis on two metal tressles and bolted the chassis to the tressles and the tressles to the floor at my finished desired ride height.then i bolted some sheets of m d f to the floor to allow me to draw a centre line for the vehicle and calculate axle centre lines.i sat the frame at the rake i liked and leveled the frame across the frame.bolted on some body work so i could place the wheels in the opes where they looked best.i would unbolt the shocks in your suspension and measure the centre to centre in a set of shocks in a complete car make two struts one for each and bolt them in instead.that will save yoy trying to compress the springs.

    consider this my engine and box are centred in the chassis but thepinion shaft is ofset so looking from above there is a couple of degrees in the drive shaft i was nt expecting

    could i suggest bolting some plates instead of the wheels to stop the unit from rolling around and to hold the axle assembly at ride height while you work on it.once you get going it will get easier good luck im subscribed to this one have a look at my build (www.hotrod.ie) different builds but similar.i set my halfshafts falling 1 degree so they would be level when i sat in and set the trailing arms falling 1 degree so they would be level when i got in.im not saying this is the right way to do just how i approached it.
     
    Last edited: Feb 22, 2011
  14. IRON MAIDEN
    Joined: May 28, 2010
    Posts: 517

    IRON MAIDEN
    Member

    Very nice build. Sounds a lot like mine. I planned on a fenderless Ratrod until I realized how solid the truck was. So here I am.
     
  15. nunattax
    Joined: Jan 10, 2011
    Posts: 3,052

    nunattax
    Member
    from IRELAND

    so did i when i realized how solid my fenders are i had to use them will still need a little panel beating though.lack of fenders wont keep it off the road but will eventually get fitted
     
  16. Slag Kustom
    Joined: May 10, 2004
    Posts: 4,312

    Slag Kustom
    Member

    did the same thing with a dump bed but no cage
     

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  17. Sheep Dip
    Joined: Dec 29, 2010
    Posts: 1,572

    Sheep Dip
    Member
    from Central Ca

    Hey Iron Maiden looking for some info here may be you would know, I've got one of these rear diffs and I was told that it is a Dana 44 and to rebuild it the Jag parts are pricey but the domestic parts will fit except that the ring gear on the domestics are drilled for 7/16 bolts and will have to be drilled out to 1/2" to fit the Jag carrier. I don't know if they do or they don't... never messed with this stuff before just looking to see if anyone knew for sure:confused:
     
  18. If this has been asked and answered then i'm sorry( but i flipped though the thread a couple times and could not find what year Jag this comes from. And maybe the series numbers tells me but i'm not sure.
     
  19. mossback44
    Joined: Apr 4, 2006
    Posts: 95

    mossback44
    Member

    I recently had the same concern about the pinion angle when installing a Jag rear in my '36 Ford convertible sedan. My research indicated that the pinion shaft needed to be level for the suspension to work right, so my first thought was to also set the engine and trans level. Unfortunately, that had my oil pan nearly touching the ground if the the u-joint angles were kept at no more than 5 degrees. My solution was to keep the pinion shaft level, set the driveshaft at 2.5 degrees up toward the front and the engine/trans at 5 degrees upward. That got the oil pan off the ground and made the u-joint angles the same at 2.5 degrees. Even though the pinion shaft and crankshaft are not parallel, the angles at the front and rear u-joints are still the same and that's what counts. This solution required a little playing with the motor and trans mount elevations to make it work, but I had a lot of flexibility there. Maybe it will work for you.
     
  20. nunattax
    Joined: Jan 10, 2011
    Posts: 3,052

    nunattax
    Member
    from IRELAND

  21. zman
    Joined: Apr 2, 2001
    Posts: 16,731

    zman
    Member
    from Garner, NC

    I believe that 3 degree number is to take into consideration the movement of the rear end. as the suspension compresses that angle will go to 0. The IRS the center section does not move with the suspension. Hence it doesn't need to compromise. The '85 Jag I took the one for my Buick out of the pinion was 0. the Bottom of the suspension was level.
     
  22. nunattax
    Joined: Jan 10, 2011
    Posts: 3,052

    nunattax
    Member
    from IRELAND

    at last some one making sense.I R S needs a slightly different approach.when i started my rod i expected to fit the engine/box drive shaft and pinion in line,reading up on the subject proved otherwise .the 3 degrees is also to spin the rollers in the harvey spicers so each of the caged bearings in the spicer takes theload and spins the rollers spreading the load preventing the races from groving destroying the bearing prematurly even with the pinion at 0 in an irs the pinion is off centre while the trans is centred .if you think three dimensionally you are gaining pinion angle in three planes

    do i know what i mean
     
  23. BJR
    Joined: Mar 11, 2005
    Posts: 9,819

    BJR
    Member

    Does a Jag rear end have one axle longer then the other, with the center section offset to one side? If so and the engine and trans are centered, the degree of offset would be built in on the horizontal plane, to make the U joints work correctly without flat spots on the rollers. Instead of the vertical plane as on a conventional rear end set up.
     
  24. nunattax
    Joined: Jan 10, 2011
    Posts: 3,052

    nunattax
    Member
    from IRELAND

    i would expect the half shafts to be equal lengths , but the pinion is off to one side in the centre section take one apart and u will understand why
     
  25. zman
    Joined: Apr 2, 2001
    Posts: 16,731

    zman
    Member
    from Garner, NC

    yep.
     
  26. nunattax
    Joined: Jan 10, 2011
    Posts: 3,052

    nunattax
    Member
    from IRELAND

  27. IRON MAIDEN
    Joined: May 28, 2010
    Posts: 517

    IRON MAIDEN
    Member

    So just level the rear? 0 degrees pinion? Motor and trans at "0" or "3"?
     
  28. nunattax
    Joined: Jan 10, 2011
    Posts: 3,052

    nunattax
    Member
    from IRELAND

    I suggest pinion at 0 degrees .engine and tranny falling 3 degrees front of motor up rear of tranny low good luck
     
  29. f100newb
    Joined: Jan 23, 2008
    Posts: 42

    f100newb
    Member

    UK Hot Rods: News, tech, chat, email group for hot rods, street rods and kustoms

    This is different from your build but has a lot of really good information. I am doing a 53 F100 with the same setup and battled with the cage or cageless and the pinion angle. I punted and went with an 8.8 explorer rearend and kept the jag IFS for my build.

    The Dana 44 internals will work inside the pumpkin and there is a kit to make them fit correctly. For the price I would have to pay just for the gears and install kit I bought a 3.73 geared limited slip rear. The jag is a really nice way to go and can be had cheap. Good luck with your build man!!!!
     
  30. IRON MAIDEN
    Joined: May 28, 2010
    Posts: 517

    IRON MAIDEN
    Member

    I already have an Explorer 8.8. I just decided to go all Jag for the ride quality. I'm selling the 8.8 this weekend.
     
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