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Putting the front subframe back on an MGB?
mr henderson - 2/9/08 at 04:07 PM

Actually it's an NG TC that I'm attempting to put it on, but very much the same principle.

The basic problem is that I can't get to the front bolts that have dropped inside the hollow subframe without taking the front springs off, and it would seem that a special spring copmpressor is required for that (which I don't have).

If there is a trick to this I really would like to know about it

TIA

John


r1_pete - 2/9/08 at 04:18 PM

Common problem, basically, without a spring compressor you need to assemble the cross member on the car:

1. Fit the double ended bolts to the car, they are a tapered fit into the chassis, and tighten the top nuts.

2. Fit rubber pad to each point on the cross member, locating collar downwards.

3. Jack cross member into place.

4 Ruber isolator bush, followed by the small steel plate on each bolt, followed by the nuts.

You access the front mounting nuts via the area where the spring is, there are holes below but they dont line up and many a socket UJ has been lost in there. If you dont do the job in that order the crossmember can end up missaligned, and the wrong pressure on the rubbers due to the tapers not being set right - the Mark Evans MGB rebuild shows the incorrect method being used.

Re-assemble everything, you can now use the cars weight to compress the springs.

[Edited on 2/9/08 by r1_pete]


mr henderson - 2/9/08 at 04:26 PM

quote:
Originally posted by r1_pete
Common problem, basically, without a spring compressor you need to assemble the cross member on the car:

1. Fit the double ended bolts to the car, they are a tapered fit into the chassis, and tighten the top nuts.

2. Fit rubber pad to each point on the cross member, locating collar downwards.

3. Jack cross member into place.

4 Ruber isolator bush, followed by the small steel plate on each bolt, followed by the nuts.

You access the front mounting nuts via the area where the spring is, there are holes below but they dont line up and many a socket UJ has been lost in there. If you dont do the job in that order the crossmember can end up missaligned, and the wrong pressure on the rubbers due to the tapers not being set right - the Mark Evans MGB rebuild shows the incorrect method being used.

Re-assemble everything, you can now use the cars weight to compress the springs.

[Edited on 2/9/08 by r1_pete]


Somehow you can just tell when someone really knows about something. Just a feeling that one gets.


Thanks

Now I need to locate the correct spring compressor. Haven't found anything on Ebay so I'm trying google

John


Bigheppy - 2/9/08 at 05:40 PM

On the program an MGB is reborn mark evans made a spring compressor from an old steering rack.


r1_pete - 2/9/08 at 06:25 PM

Fraid so John, my current Zetec B must be the 10th Ive done, ans always started with a bare crossmember.

You could mock the crossmember onto the car, then use its weight to remove the springs, fit it properly then rebuild.


britishtrident - 2/9/08 at 08:30 PM

quote:
Originally posted by r1_pete
Fraid so John, my current Zetec B must be the 10th Ive done, ans always started with a bare crossmember.

You could mock the crossmember onto the car, then use its weight to remove the springs, fit it properly then rebuild.


Yep trolley jack under the spring pan thats the way we used when changing MGB wishbone bushes and springs --- wouldn't have been too tough to make a spring compressor up from threaded bar.


britishtrident - 2/9/08 at 08:31 PM

quote:
Originally posted by r1_pete
Fraid so John, my current Zetec B must be the 10th Ive done, ans always started with a bare crossmember.

You could mock the crossmember onto the car, then use its weight to remove the springs, fit it properly then rebuild.


mr henderson - 2/9/08 at 08:49 PM

So is it best to undo the nuts and bolts on the spring pan, or the one at the bottom of the upright?

John


r1_pete - 3/9/08 at 07:23 AM

Remove the bolt at the top of the king pin, the one which secures it to the lever arm damper, the kingpin will swing down out of the way.

That way its easier to re-assemble, you have the in and out movement on the pin, and up and down on the shock to line the bolt back up.

Rgds.
Pete.


:{THC}:YosamiteSam - 4/9/08 at 11:22 PM

quote:
Originally posted by Bigheppy
On the program an MGB is reborn mark evans made a spring compressor from an old steering rack.


that was on today - he used a long 14mm bolt and few welded on bits to wind spring in.. or he said use the weight of the car to compress it if on the car using the jack

he did mention about the bolts too


mr henderson - 5/9/08 at 07:03 AM

All done now, thanks, chaps.

John