Monday, December 31, 2012

Fall 2012 MGB suspension, top frame

The fish have left for warmer water- so the winter projects have started on the MGB:

First up was to prepare the old rusty convertible top frame for some new vinyl.  I stripped it down first- removing the retainer seal and gasket (goes against the top of the windshield).  The retainer is held to the header rail with a dozen rivets or so.  I just drilled them out.  The new vinyl will be held between the retainer and the header rail once installed.


old vinyl- at least what's left of it

removing the hardware- this is one of two clamps that hold the frame to the windshield
Next up, it was a basic sand, clean, sand, clean, etc. in prep for some paint.  I taped over the original sticker.

lots of surface rust, but in go solid shape


ready for some new paint

old rivets- I had to fish them out of the header rail or listened to them role around in there, which would have been really nice while driving down the road.






Next up came some paint.  I just hung the frame and header rail from the ceiling and painted them with a brush.  I used the same satin black paint I bought for the floors- very tough stuff that sticks to your hands for about a week- seriously.

done, and ready for a new top in the spring

Looks pretty good
The front suspension rebuild is next:

The car has 40 year old rubber in the suspension, so it's long overdue for a refresh.  On the road, she would hop weirdly over bumps or railroad tracks.  Replacing all bushings will tighten up the handling for sure- so lets get started on this big job.

Let's start with a little description of how the MGB front suspension works.  The entire front suspension and brakes are attached to a large crossmember that is attached to the structure of the car with 4 long bolts.  The MGB is a unibody construction, so there really is no frame and the body of the car is actually the structure- as opposed to a frame construction car where the body, suspension, and drivetrain are hung a large frame.
The front Armstrong lever-arm shocks sit on top of the crossmember and the shock arms are also the upper a-arms.  These arms mount to the top of the king pin (or swivel pin) which has the steering arms and hub/brakes attached and turns the front wheels.  The lower a-arms attach to the bottom of the king pin and also support the bottom of the coil spring.  The top of the coil spring is retained inside a depression in the crossmember- here is a photo of the entire contraption (with the sway bar link, brake disk and brake caliper removed):


prior to removal of the crossmember

So, I am going to remove the crosmmember, clean and paint it, remove and replace all rubber bushings, refresh the shock oil, clean all and paint most of the componants, and put it all back together.

First step was to get the car in the air, loosen all suspension bolts, and drop the crossmember as a complete unit so I can take it apart in the basement where it is a tad warmer than Maine in December in an uninsulated and unheated garage....

It's easier to loosen everything that will eventually be removed while the crossmember is still on the car so I can use the weight of the car as I'm applying quite a bit of torque to remove these old nuts and bolts.  No real trouble with this- just a bunch of penetrating fluid and time.

Once everything is loose- I put my floor jack under the crossmember to support it and loosened the 4 large bolts holding to the structure of the car.  One of these bolts proved more difficult than the other 3 since there was a large oil cooler line right on top of it.  When somebody added air conditioning to the car many years ago, they relocated the oil cooler lines to make way for the AC lines running up to the front of the car.  So, I had to remove the oil cooler line:

you can just see the top of the bolt I need to remove under the large black oil cooler  line

before removing the crossmember, I needed to remove the coilspring...

so I supported it with the jack, undid the bolt holding the top of the king pin to the shock arms, and leaned the king pin out of the way.  This is slightly dangerous considering how much force is held in that spring under compression- so I took it nice ans slow as I lowered the jack and pulled out the spring.

good looking king pin bushing here- that crumbled torn rubber is some of what is being replaced.  You can also see the end of the steering arm dangling by itself on the right- it has been removed from the steering arm below it

brake lines clipped to the back of the crossmember had to be loosened- they stay with the car

the other side taken apart to remove the spring

now I have moved the jack to support the crossmember.  The steering rack is also attached to the crossmember, and it stays with the car as well.  This is easier than splitting the steering column and taking the rack off still attached to the crossmember.  I just used some string to support the rack as I removed the four bolts holding it to the crossmember.  The piece of wood is there to give a little stability to the rack as it comes down- it wouldn't be fun to have it fall off of the jack.

So- dropping it out was next.  No real drama- just a two person job, so Drew helped out here.


you can now see the 4 big bolts holding on the crossmember

It's out!

a rusty greasy mess sees direct sunlight for the first in 40 years

Gone!  You can see the brake caliper hanging on the left, the steering rack held by the rope in the middle, and the silver end of the sway bar on the right pointed up out of the way.

So, next up was to try and clean off some of the grime so it would be easier to work on and not make quite the mess in the basement.  I just put it on a towel and went to work with cleaner,wire brushes, and running water.


looking better.  I just let it dry in the sun before dragging it down into the basement.


I also decided to remove the transmission crossmember from the car while it was in the air.  Not too difficult, just quite a few bolts and rubber mounts.  I'll clean and paint the thing, and replace all of the mounts.  Basically, it's held to the car with bolts and attached to the sides of the transmission with rubber mounts to provide stability to the transmission.

transmission mount- aka butterfly


mount and butterfly again- the trans crossmemer is already dropped out of the way

It's out and filled with years of crud

close-up of the butterfly (now you see why it's called that).  I'll replace those round gooey black bushings with polyurethane.

here is where it sits for reference

the underside of the transmission crossmember after cleaning

somebody had removed the crossmember in the past and decided to use the wrong bolt putting it back in and had stripped one of the attachments in the butterfly- so I tapped in new threads

more cleaning and ready for some paint

painted and ready for new bushings


So, that's all for this post- it's already too long.....  Next up will be cleaning and painting all of the suspension bits

Here is just a little teaser/cliffhanger to keep you interested:




One last thing- I bought a two year old solid state fuel pump and braided lines from a dude who was parting out his 71 MGB.  Original cost was $180 for the pump and $40 for the lines and I got them for $85shipped- not a bad deal! My pump is questionable at best, so this should help with any reliability issues.

Not sure why he included a rusty mounting bracket, but mine is fine.  The pump and lines look brand new- and now I won't need to worry about the old points in my original pump.
















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