Quite an old thread this one, but an interesting one. Let me tell you how we replaced a broken valve spring on an MGB without removing the head !
First I remembered the excellent suggestion of putting the offending piston down to BDC, filling the pot with nylon string ( and it took about 30 feet ), then raising the piston slowly to near TDC to stop the valve dropping. Removing the old collets / oil seal / spring was easy but we had real trouble fitting the new spring with flat bladed screwdrivers under the rocker shaft. Idea ! Get 6 of the large size tie-wraps and use these to compress the spring off the car ,but only use them on the inner coils so it fits squarely on the head still. A minor tweak with the flat blade screwdriver just to compress the spring another 1mm and there was room to fit cap/ collets and we were away ! The tie wraps can then be carefully removed one by one with wire-cutters ! One thing we found was that the nylon string seemed to get stuck as we were pulling it out. It had actually snagged under the valve head when bringing it up to TDC.
Result !
Cheers All,
Tony.
Special Tools -v- Resourcefulness
-
MIG Wielder
- TDC Member
- Posts: 2336
- Joined: Sun Mar 16, 2008 2:52 pm
-
JPB
Re: Special Tools -v- Resourcefulness
Nylon string isn't the ideal thing for the Indian Rope Trick, I use 6mm cooker cable when there's a stem seal or valve spring job to be done. That won't cause you any trouble. 
-
Spunkymonkey
Re: Special Tools -v- Resourcefulness
Talking of nylon things. Had a problem with Matilda the Daf breaking her propshaft last week (only done 200 miles) which I eventually traced back to this:
That bar is part of the carrier for the variomatic and should be straight - in fact, it would have been until someone jacked the car up under the transmission (NOT me btw!). Removing it is a complete pita so el cheapo nylon ratchet strap was pressed into action, along with a length of angle iron and a couple of axle stands to hold the angle iron "anchor" down using the weight of the car:
On the blatant tool-abuse side, if you look closely you'll see I had to work the ratchet with a trolley jack to get enough tension in it. Not bad for a £4.99 strap!
That bar is part of the carrier for the variomatic and should be straight - in fact, it would have been until someone jacked the car up under the transmission (NOT me btw!). Removing it is a complete pita so el cheapo nylon ratchet strap was pressed into action, along with a length of angle iron and a couple of axle stands to hold the angle iron "anchor" down using the weight of the car:
On the blatant tool-abuse side, if you look closely you'll see I had to work the ratchet with a trolley jack to get enough tension in it. Not bad for a £4.99 strap!