MG-Cars.info

Welcome to our Site for MG, Triumph and Austin-Healey Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGB Technical - Now what order????ADVICE NEEDED

I need to replace my MGB's floorpans and rockers(maybe sill,etc also).I have the motor out and rebuilt.I want to remove the front,and rear axles,and i have made a "car tilter" or rotator and was wondering if the floorpans and rocker/sills,etc. can be done on the rotator OR should they be done first??????What is the order they should be done.Rockers then floorpans OR floorpans then rockers.Should i weld a brace accross the door openings????I NEED advice on this please.I dont want the body to sag.I have read Porters book BUT sure could use Everyone advice that has done this GREAT FEAT.Thanks in advance,Rich
Rich Osterhout

put the doors on and make sure you have the gaps around the door that you want. THEN weld braces across the openings. Fire the welder up and get dirty. Did mine on a rotator. Cut the floors out one side at a time, rebuilt the sills and full length rockers, welded in the new floor and went to the other side.
tom

Tom,thank you so much!!What size and length "bracing" did you use(like angle iron?)At what places on the car did you weld it too?)and after bracing can the doors come back off the car??I told you i needed ADVICE,:)
Rich Osterhout

I used 1 inch square tubing welded across the inside of the door opening about two thirds of the way up. That way I could still fit the door for alignment when welding up the sills. Mine is a GT. On a roadster I would feel better with two braces per side, one near the top of the door, and one lower down. If you remove the sills/rockers without bracing, especially if you tip the shell over, there is a real risk of the car folding in the middle - not a lot, but boy you'll know it when you try to rehang the door. Do the sills first, then the floors. The floors sit on the edge of the sills and tunnel, so that order makes sense. Be prepepared to fit a new outer chassis extension (the bit with the jacking point on it) as well - you have to cut this anyway to fit the castle rail, and its usually rusty.
Mike Howlett

Do the sills first......(before removing the floors???)Will i be able to remove the sills with floor attached?,thanks,Rich
Rich Osterhout

Drill out the spot welds in the floor at the sill to remove it or cut the floor just past the edge of the sill. Leaving the floor in at this point helps to hold everthing in place. ONLY DO ONE SIDE AT A TIME or you will have a pretzel.
John H

Iam planning on having the MGB acid dipped,so the doors,hood,etc. has to come off.QUESTION:with the doors(only)off is it necessary to brace the opening's(door)before the dipping process????????
Rich Osterhout

Rich why are you taking the doors off for the dipping? I can understand you taking an alloy bonnet off!
David Witham

There is no question of Floors or sills first, they must be done together to be correct. The floor is welded to the stiffener plate, the inner sill boxes the two, and the castle rail goes across the bottom of the assembly. Then the outer sill goes on, creating a double box. I've never had a problem with a B sagging, not even a rusty roadster - the gearbox tunnel is stronger and stiffer than most cars with a separate frame. I am careful to support it on the axle centerlines, and shim the stands so there is equal weight on all four. Then do one side at a time. Check constantly.
DO NOT make the mistake of thinking that seam welding the entire sill assembly across the door openings is a good thing - as a youthful folly, I did that on a BMW, and found when finished that my previously perfect door openings were now 3/8 too short to put the doors in - and yeah, I did both sides before trying to fit the doors, since I KNEW that the doors fit fine! Ever tried to stretch a fully welded Bimmer? = BUMMER! (but I did it)
FRM
FR Millmore

You should be able to dip it with the doors off without bracing unless the body is in very bad shape. Myself, I would install the bracing just to be sure.
John H

David,they wont dip the car with the doors on,and stated that they cant be wired shut either.I was told they might come open during dipping,thus causing body damange.....FRM,thanks for the advice......what do you mean "seam welding the entire sill across the door opening"This IS kinda of SPOOKY TO ME,thanks,Rich
Rich Osterhout

That's when you decide that spot welds should be replaced by a continuous weld the whole length, ala boy racer. Shrinks the whole panel lengthwise, as it heats and cools, worst with gas weld.
FRM
FR Millmore

FRM,thanks so much,I guess i'm being too cautious about cutting parts out,but its a big deal to me,and out of my normal type of work.Welding insnt the problem....its knowing what to do and when...!!Thanks,Rich Osterhout
Rich Osterhout

This thread was discussed between 17/04/2007 and 20/04/2007

MG MGB Technical index

This thread is from the archives. Join the live MG MGB Technical BBS now