Crankshaft Plugs

[David James]

2nd attempt to post - lost the last one!

 

Can any one advise on the availability of the X4 crankshaft plugs and tips for removing?

 

I will be starting the winter build of my T4/4A engine which I had machined earlier this year.

I would like to remove the plugs and thoroughly clean the crank oil ways before rebuilding the lump.

The plugs have hex socket heads. I am not sure whether these are original as the car had come in from the USA with evidence of some engineering work such as cleverly crafted stitching on the cylinder head.

In a previous attempt to remove a plug the hex head cracked across the diameter!

I feel it is now the point of no return and I must at least continue to remove this plug though it is clearly not loose.

Any help would be much appreciated - thanks in advance

David

 

[Stanpartmanpartwolf]

Plugs are 1/4"BSPT- I usually have some around.

They can become brittle if the crank has been Nitrided & are rarely easy to remove.

To start, try a heavy blow with hammer & bronze punch, take a short 1/4" mounted hex bit & wrench & tighten the plug. If you're lucky, this will spring the threads & out it comes. If not, apply some heat & repeat. Next, start undoing; you've nothing to lose now. Either the plug plays ball or it splits, rounds out, or the hex bit yields.

Next, drill the wounded plug out to 5/16" or 8mm, get hold of a really high-quality 4-point fluted extractor (Mac Tools are best, then Snap-On).

Never, EVER use Sunday market £1 specials or you'll be into spark erosion territory.

In with the extractor, don't be shy, & unwind the plug with a large tap wrench or a 12 point socket & wrench (fits a square fine).

If you are having the crank Tuftrided or Nitrided, tidy the threads up & refit any surviving or fresh plugs just nipped in- this protects the threads from filling with grud, which is a swine to tap out after.

True the crank after hardening.

If you're a proper fuss-pot, rebalance the crank once the new plugs are threadlocked in.

Er, that's it

[David James]

Many thanks for the reply - most informative.

Best Regards

David

[Steveb19]

Plugs are 1/4"BSPT- I usually have some around.

They can become brittle if the crank has been Nitrided & are rarely easy to remove.

To start, try a heavy blow with hammer & bronze punch, take a short 1/4" mounted hex bit & wrench & tighten the plug. If you're lucky, this will spring the threads & out it comes. If not, apply some heat & repeat. Next, start undoing; you've nothing to lose now. Either the plug plays ball or it splits, rounds out, or the hex bit yields.

Next, drill the wounded plug out to 5/16" or 8mm, get hold of a really high-quality 4-point fluted extractor (Mac Tools are best, then Snap-On).

Never, EVER use Sunday market £1 specials or you'll be into spark erosion territory.

In with the extractor, don't be shy, & unwind the plug with a large tap wrench or a 12 point socket & wrench (fits a square fine).

If you are having the crank Tuftrided or Nitrided, tidy the threads up & refit any surviving or fresh plugs just nipped in- this protects the threads from filling with grud, which is a swine to tap out after.

True the crank after hardening.

If you're a proper fuss-pot, rebalance the crank once the new plugs are threadlocked in.

Er, that's it

Just searching to find thread size for these plugs and wasnt dissappointed! Ive just had to drill mine out and need to retap and make new plug,.

Dont know what Id do without this forum!

Another answer I need is clutch friction plate, maybe I should start new topic but here goes.

My 64 TR4 was a basket case and gearbox was not original. It has a A type O/D but standard 8.5 " Tr plate slightly too small for to fit gearbox splined shaft. My parts supplier is baffled. Need to find one that fits, Any ideas?