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Crank nut removal

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philipheys Avatar
philipheys Phil Heys
Accrington, Lancashire, UK   GBR
Hi guys,

I want to change my timing chain and tensioner how do I get that crank nut off?
How do I do that rope thing?

When removing the pulley do I need to set the crank to a certain position or does it just pull straight off?

Any information would be helpful as I have not done this before.

Thanks
Phil

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trrdster Avatar
trrdster Wayne Tate
Spencer, NC, USA   USA
The crank is keyed, but take care to set the timing marks on the gears to line up before removal.
The nut is easy enough. Brace the handle of the breaker bar on the driver side frame and bump the starter. Notice I didn't say crank the engine, be sure and disconnect the coil wire.



Wayne
1970 TR6
2000 Jaguar XK8
1949 Triumph Roadster 2000
1978 Spitfire (rust victim)
1971 GT6 (tarp covered for 12 years, rusted inside out)
1980 Spitfire (getting all the good GT6 parts, all poly suspension and Spax shocks)

spitfire50 Avatar
spitfire50 Paul Mugford
Rochester, N.H., USA   USA
In reply to # 1499972 by trrdster The crank is keyed, but take care to set the timing marks on the gears to line up before removal.
The nut is easy enough. Brace the handle of the breaker bar on the driver side frame and bump the starter. Notice I didn't say crank the engine, be sure and disconnect the coil wire.

Wayne,
Phil is in the UK. His "driver's side" is the right side. What you have posted will work, but the spanner will swing across the car as the engine turns before the other side of the chassis frame stops the wrench and the engine unscrews the nut

Phil,
To use the rope trick make sure #1 cylinder is on the firing stroke so both valves are closed. Remove the sparking plug, and feed in as much soft rope as you can fit. When you turn the engine attempting to unscrew the crank nut the rope will stop the piston from going to the top of the bore and the nut will unscrew from the front of the crankshaft.

All the best,
Paul

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tapkaJohnD Avatar
tapkaJohnD John Davies
Lancaster, Lancashire, UK   GBR
The 'shock' strategy of using the starter can work but at risk of damage/injury.

Take the starter off, and put alarge screwdriver between the starter ring teeth, so that the shaft engages with the openeing's edge.
Then use a breaker bar to pull the crank nut loose. You might need to extend the bar with a length of scaffold tube!
No one and nothing will be be hurt that way - except the socket! I've one split doing this, but hey! It's only a socket.

John

grumpicus Steve Jackson
Leicester, Leicestershire, UK   GBR
In reply to # 1500083 by tapkaJohnD The 'shock' strategy of using the starter can work but at risk of damage/injury.

Take the starter off, and put alarge screwdriver between the starter ring teeth, so that the shaft engages with the openeing's edge.
Then use a breaker bar to pull the crank nut loose. You might need to extend the bar with a length of scaffold tube!
No one and nothing will be be hurt that way - except the socket! I've one split doing this, but hey! It's only a socket.

John

+1 to that! Get an assistant to wedge the screwdriver against the ring gear, while you hang onto the scaffold tube!

TR-PI Lee Cunningham
Sardis, BC, Canada   CAN
If you place the transmission in 4th gear and have someone put there foot firmly on the brake pedal, you can undo the nut with a socket and bar.

philipheys Avatar
philipheys Phil Heys
Accrington, Lancashire, UK   GBR
Thanks guys,

Sounds like I need a socket for that nut at the moment I have a large wrench but that sounds like the wrong tool.
What size is the crank nut?

I like the rope trick so I will try that first, what diameter rope works best?

Thanks
Phil

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clshore Carter Shore
Beverly Hills, Florida, USA   USA
In reply to # 1500044 by spitfire50 ...
Wayne,
Phil is in the UK. His "driver's side" is the right side. What you have posted will work, but the spanner will swing across the car as the engine turns before the other side of the chassis frame stops the wrench and the engine unscrews the nut
...
Which is precisely what you WANT to occur.
Just be sure that there is nothing in the path of the swinging wrench handle.

skyking1231 Avatar
skyking1231 Silver Member Frank Strobel
Mt. Sinai, NY, USA   USA
1975 Triumph Spitfire 1500 "Lil' Rose"
shouldn't this be the easiest method ? provided engine is still in the car ....

In reply to # 1500113 by TR-PI If you place the transmission in 4th gear and have someone put there foot firmly on the brake pedal, you can undo the nut with a socket and bar.

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Andy-Sherry Avatar
Andy-Sherry Gold Member Andy Martin
Portland, OR, USA   USA
I just hit mine with an impact wrench



Andy&Sherry
1974 Spit 1500 Carmine Red
1977 Spit 1500 Pink Panther Pink

Always learning something

GottaSpit Avatar
GottaSpit Duncan A
Folsom, California, USA   USA
Mine came right off using my $50 electric impact wrench from Harbor Freight. Also has worked great for rusted lug nuts.

https://www.harborfreight.com/12-in-heavy-duty-electric-impact-wrench-61173.html

I spent nearly $30 for the impact socket!

https://www.amazon.com/gp/product/B006L2320G/ref=oh_aui_detailpage_o07_s00?ie=UTF8&psc=1

Bigger problem was getting 150 ft. lbs. of torque on the nut when I put it back. Had the oil pan off, so I put a wooden mallet handle between the crank and the casing.



Edited 1 time(s). Last edit at 2017-11-28 12:28 AM by GottaSpit.

grumpicus Steve Jackson
Leicester, Leicestershire, UK   GBR
In reply to # 1500219 by skyking1231 shouldn't this be the easiest method ? provided engine is still in the car ....

In reply to # 1500113 by TR-PI If you place the transmission in 4th gear and have someone put there foot firmly on the brake pedal, you can undo the nut with a socket and bar.

It should be the easiest method.......however......

It all depends on the amount of torque required to undo the nut - and the size of clutch fitted to the engine. It may well work on larger capacity engines, with a clutch designed to transmit larger amounts of torque without slipping, Try this on a 1300 Spit with its 6.5" diameter clutch, and you'll probably get the clutch to slip without budging the nut. I seem to remember I tried that once, hence the recommendation for the large screwdriver jammed in the ring gear.

Impact wrenches are the easiest solution - maybe hiring one is the best idea, unless you have other uses for it!

clshore Carter Shore
Beverly Hills, Florida, USA   USA
In reply to # 1500248 by grumpicus
In reply to # 1500219 by skyking1231 shouldn't this be the easiest method ? provided engine is still in the car ....

In reply to # 1500113 by TR-PI If you place the transmission in 4th gear and have someone put there foot firmly on the brake pedal, you can undo the nut with a socket and bar.

It should be the easiest method.......however......

It all depends on the amount of torque required to undo the nut - and the size of clutch fitted to the engine. It may well work on larger capacity engines, with a clutch designed to transmit larger amounts of torque without slipping, Try this on a 1300 Spit with its 6.5" diameter clutch, and you'll probably get the clutch to slip without budging the nut. I seem to remember I tried that once, hence the recommendation for the large screwdriver jammed in the ring gear.

Impact wrenches are the easiest solution - maybe hiring one is the best idea, unless you have other uses for it!

A big wrench is the easiest solution.
No wires, no airlines, no need to remove the radiator for access, no need to immobilize the crank.
Place it on the nut, position the handle, hit the starter ....
Somewhere between 30 seconds and 1 minute, all in.

skyking1231 Avatar
skyking1231 Silver Member Frank Strobel
Mt. Sinai, NY, USA   USA
1975 Triumph Spitfire 1500 "Lil' Rose"
hmm...i was figuring the clutch slipping would be the weakest link.

Mark Jones Avatar
Close to Sarnia, Ontario, Canada   CAN
1995 MG MGF "Barney"
1996 Land Rover Discovery
I tried the 4th gear and STANDING on the brake pedal trick, it didn't work.

I figured my safety was worth more than the risky bump the starter suggestion. I can envision the breaker bar handle flying somewhere you don't want it to, no thanks.

I, like many others, have used an impact wrench with great success: works well and is safe.





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