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BRITISH AUTOMOTIVE |
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www.mgbmga.com MGTD Articles |
Technical Information (MGB 14B)
REAR SUSPENSION
CONSIDERATIONS
06/13/01
The following information should be read in conjunction with Technical articles MGB 4, MGB13, MGB 15, and MGB 27.For improved road handling performance we recommend lowering the MGB ride height to the following specifications:
| MGB and MGBGT (chrome bumper -> 74.5) | Front 13.5" to 14" |
| Rear 13.5" to 14" | |
| MGB and MGBGT (rubber bumper 74.5 ->) | Front 14.5" to 15" |
| Rear 14.5" to 15" |
Measurements to be taken from the center of the road wheel to the underside of the chrome strip.
Before replacing rear or front road springs measure the existing ride height. Installing new springs may not achieve the ride height you are looking for. We find that many times MGB owners replace road springs to rectify "leaning" problems. To their amazement some owners are mystified that their MGB is still "leaning" to one side or the other. We discuss this problem in depth within technical article MGB4.
Your MGB rear suspension must be allowed to work.
Maximum rear suspension movement is controlled by the progressive bump-stop making contact with the bump-stop pedestal pad under bump conditions and, under rebound conditions, the axle check strap. The total amount of travel is approximately 5.5" - 6" and will be the same measured distance at the road wheel due to the 1:1 motion ratio.
The amount of rear suspension movement is relative to the rear ride height. Premature contact with the bump-stop could result in "oversteer". We recommend a minimum of 2"-2.5" clearance between the bump stop and the pedestal.
Feedback over the years from customers who have followed the below recommendations has been very positive. You will notice the absence of any recommendation for rear sway bar assemblies. We have found installation of a panhard rod assembly to be more crucial in eliminating rear axle steer over versus trying to control rear body roll by the installation of a rear sway bar assembly. To reduce body roll upgrade to a larger front sway bar.
REAR SUSPENSION RECOMMENDATIONS
Through testing, we believe that fitting the following suspension components represents a major step in the way your MGB vehicle handles.
| Qty | Part | Description |
| 1 | ROAD/SPRNG | 135# All MGBs and MGBGTs See MGB4 for more information. |
| 1 | S/ABS.KIT | KYB Telescopic
Shock Absorber Kit Specially valved for the MGB |
| 1 | S/ABS.MKIT | As above with
modified lower mounting bracket See MGB13 for more information |
| 1 | PANHARD | "Bolt-in"
Panhard Rod Assembly Tube axles only See MGB15 for more information |
| 1 | ANTI/TRAMP | Anti-Tramp Bar
Kit (All MGB roadster and MGBGT) See MGB27 for more information |
HARDWARE INFORMATION
Numerous OEM front suspension, rear suspension and steering bolts were of the shouldered type; these special shouldered bolts are substituted, within the parts order form, with regular grade 8 yellow zinc plated bolts along with lockwashers and regular nuts. Slotted nuts are clear plated.
Replacement bolts may, or may not, have the correct length of shoulder as the OEM type. Similarly specific bolts supplied from within the Moss Motors catalog may, or may not, duplicate the OEM bolts.
All plated bolt and nut threads must be lightly coated with oil before assembly. Do not overtighten.
OEM SHOULDERED BOLT INFORMATION
| THREAD | A | L1 | L2 | L3 | |
| BUMP STOP MOUNT (LONG) | 5/16" SAE | .308" | .565" | .935" | 1.500" |
| STEERING SHAFT U/JOINT | 5/16" SAE | .308" | 1.125" | .500" | 1.625" |
| STEERING RACK MOUNTING | 5/16" SAE | .308" | 1.125" | 1.000" | 2.125" |
| PIVOT ARM ATTACHMENT | 3/8" SAE | .372" | .500" | .750" | 1.125" |
| SHOCK ABSORBER MOUNTING | 3/8" SAE | .372" | .313" | .687" | 1.000" |
| BRAKE DISC TO HUB | 3/8" SAE | .372" | .375" | .750" | 1.125" |
| SWAY BAR LINK ATTACHMENT | 7/16" SAE | .434" | 1.000" | .750" | 1.750" |
| STEERING ARM ATTACHMENT | 7/16" SAE | .434" | 1.188" | .812" | 2.000" |
| BRAKE CALIPER MOUNTING | 7/16" SAE | .434" | .750" | .562" | 1.312" |
| REAR S/ABS. MOUNT | 7/16" SAE | .434" | 2.250" | 1.250" | 3.500" |
| LEAF SPRING FRONT MOUNT | 7/16" SAE | .434" | 2.250" | .687" | 2.937" |
| REAR AXLE CHECK STRAP | 5/15" SAE | .308" | .937" | .937" | 1.875" |
OEM REGULAR THREADED BOLT INFORMATION
| THREAD | L3 | |
| SPRING PAN (INNER) | 5/16" SAE | 1.000" |
| SPRING PAN (OUTER) | 5/16" SAE | .875" |
| BRAKE DISC BACKPLATE | 5/16" SAE | .500" |
| SWAY BAR MOUNTING | 5/16" SAE | .625" |
| BUMP STOP MOUNT (SHORT) | 5/16" SAE | 750" |
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