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Model A Rear Crossmember
Instructions |
Snow
White Ltd.
4727 E. Hedges
Fresno, CA 93703
(559)255-0527
(559)253-1952 FAX |
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A good deal of common sense must be exercised in the assembly
of this unit, high quality welds are essential, we recommend
Heli-ARC (TIG) Welding. If you are in doubt about your welding
ability, we strongly suggest that you tack weld components
in place and take them to a competent or certified welder
for final welding.
- Frame should be boxed in the area of crossmember
attachment; areas adjacent to welds must be sandblasted
or ground clean.
- Set the frame on sawhorse or a suitable working
area and level the frame from side to side and front to
rear, using a good carpenters level.
a) Front to rear "rake" can be set at this time.
(See Notes)
- Square the frame by cross measuring
a) Frame may be a parallelogram. (one rail behind the
other)
b) Make adjustments as required.
- Measure from the front crossmember centerline
to the rear of the chasis and mark a centerline for the
rear crossmember at 102-3/4 inches (this will be the rear
axle centerline.)
PLEASE NOTE:
a) Mark centerline on ends of weedeater crossmember for
your reference.
b) Stock Model A wheelbase is 103 inches
c) For JAG rears we make W.B. 102-3/4 inches
- Double check crossmember centerline by measuring
to some reference point on frame rails.
- Removing existing rear crossmember:
a) Tack Weld in temporary straps across the top
and bottom of frame rails about 12 inches in front of
crossmember.
b) Measure width of frame through centers of stock bumper
bracket holes on top of rails; outside measurement will
be between 38-1/2 to 3/8-11/16 inches.
c) Trim required amount off frame rails
- Frame rail cut will be at 101-1/4 inches. (102-3/4
W.B. less that half the rear crossmember width = [1-1/2"]
- Bolt Crossmember assembly to top of Jag Pumpkin
using the tapered seat OEM Jag Capscrews. (part # C17024
if you don't have them)
a) Narrower end of center mount plate to the
rear of car.
b) Assemble lower control arms to Jag Pumpkin using fulcrum
mounts, shafts, washers, and spacers. (See our Catalog
or Jag Manual)
c) Bolt Pinion Support Bracket to front of Jag fulcrum
shafts at this time.
d) Centerline of crossmember and centerline of 1/2 shafts
should coincide.
e) Shock bosses on crossmember and Lower Control Arms
(LCA) should be parallel.
f) Jag sedan pinion centerline should be parallel with
both inner and outer fulcrum shaft, and lower shock shaft
centerlines.
g) Jag XKE pinion centerline will point slightly upward
at an angle of 5-60.
(XKE's can be converted to flatter sedan angle: see Note
#5)
- Tack weld crossmember in place: DO
NOT FINAL WELD CM IN AT THIS TIME
- Attach pinion support bars to front pinion support
tybar.
a) Clevis end attach to pinion support tybar.
b)Capture bushing ends with teardrop shape gussets, 1/2" bolts, washers, and nuts supplied.
c) Adjust length of support bars to position capture gussets
to lower edge of frame rails.
d) Tack weld teardrop gussets in place.
- Check that face of shock boss on crossmember
and LCA are essentially parallel.
a) Bolt a shock to crossmember shock boss and Jag LCA.
b) If shock won't line up with both shock bosses: You
Have::
- Assembled Jag Fulcrum Mounts to Jag Pumpkin incorrectly.
- Assembled Jag center crossmember mount plate backwards.
(small end of plate toward rear of car)
- XKE Rear End instead of a Sedan Rear (See Note #5A)
c) Shocks line up correctly: All Right!
- Stand around and eyeball your work; does everything
"look" right and straight?
- Final weld crossmember in frame. (Have you read
the NOTES yet?)
a) Read NOTES before final welding.
b) Read ALL NOTES before final welding.
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NOTES
More than you really want to know |
- We recommend assembling rear fender and running
board or body to frame as a check for rear tire centering
and desired height in wheel arch.
- Approximate measurement form bottom of our crossmember
to half shaft near outer U-Joint is 4 to 4-1/2 inches at
normal ride height.
- Bottom of Hub Carriers should be approximately
parallel to ground with frame at normal rake. (Look at frame
and HC from the side)
- Normal attitude for Jag Half shafts at Ride Height:
Half shafts "Hang Down" approximately 1 to 2 degrees
a) Check with Magnetic Protractor (1 to 1-1/2 degrees down)
- Yes, Dave; This is California: and we can turn
straw into gold: send your old XKE inner fulcrum mounts
and $ = We'll puss em' out so's your pinion will lay flat
too.
a) Pinion centerline and all shafts should be parallel to
each other in a side view.
- Bottom of HC should be parallel with ground.
b) This conversion is not possible with some 61 to 63 XKE's
that have only two holes in each Inner Fulcrum Mount:
NOTE:
Your Fulcrum Mounts must each have 4 countersunk holes for
this modification.
THIS CHANGE TO SEDAN ANGLE IS A VERY IMPORTANT CONVERSION
ON XK JAG REARS IN "A" AND "T" MODELS
WITH QUICK CHANGE COVERS 'CAUSE YOU CAN SEE THE REAR COVER
TILTIING DOWN AT THE FROUND UNDER THE BACK OF THE BODY WHEN
AN UNMODIFIED XKE JAG REAR IS INSTALLED.
c) Remember, the installed angle of the rear end is determined
by the position of the holes drilled in the inner fulcrum
mounts on the 3rd member, the weird angle machined on the
top of the 3rd member is just a mounting surface.
d) The machined surface angle on top of the 3rd Member Pumpkin
is the same on ALL JAG 3RD MEMBERS. (Rear cover surface
angle to top)
- If you are planning to "kick" your frame
for hub carrier clearing we recommend a maximum or 1-3/4
inch at the rear crossmember, any more than this requires
major subframe mods, and in a sedan severely limits the
rear seat height - if the top is chipped you may want to
see about adopting a midget.
a)Vicky Owners: You have a wooden subframe - see your body
man first - steel floor time.
- Wheelbase:
a) Stock Model A wheelbase is 103 inches.
b) For Jag Rears we make W.B. 102-3/4 inches.
- Frame rake: If you run 235/75 or 235/78 x 15 rears*
and 195/50 x 15 front tires, your frame rake measured from
the bottom of the front and rear from horns will be a difference
of approximately 13 inches.
a) *Recently available Goodyear/Goodrich 255 or 245/70 x
15 is still about the same size 28 to 28-1/2 OD.
b) 275/70 x 15 may work with Roadster fenders.
© Snow White Ltd. 1/78 (Rev 8/89;1/90;12/90;3/91;7/92;11/96;7/04)
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