TR4/4A Fan Hub Extension removal early tr4 HELP

[Willie_P]

Hi. I know you've answered this for someone, somewhere before.

I recognize there is a dog-key nut at the tip of the fan hub extension. However, I cannot find a way to keep the crank from turning and thus get enough leverage to unset the nut.

body is in-situ from a very fresh and expensive paint job, so care and precaution are on my mind.

I am moving to an electric fan and will be installing a stub/balancer. thanks in advance! -wes

 

[CJD]

The best way is to use and impact wrench. It works the bolt without turning the crank. Alternate option is 4th gear with the handbrake on.

 

[TR3driver]

The best way is to use and impact wrench. It works the bolt without turning the crank. Alternate option is 4th gear with the handbrake on.

I agree on the impact wrench, that's what I use. However, I couldn't get the handbrake to hold hard enough to do it that way.

Some other possibilities:
Set up a breaker bar so it lays against the frame (with suitable padding if you are worried about damaging the paint), then hit the starter.

I've not tried this sequence, but it should work (and be less risk than the "rope trick"): Turn the engine to TDC with #1 firing, then pour a cup of motor oil through the plug hole on #2. Now turn the engine slowly backwards (with the breaker bar on the dog) until #2 hydrolocks. Using oil instead of rope ensures that the force is spread across the piston, no chance of concentrating in one spot. After removing the crank bolt, remove the #2 plug again and hold a wad of rags to catch the oil as you turn the engine. Probably easier (and certainly less mess) to use rope instead, but some people are scared of it.

 

[Geo Hahn]

...Set up a breaker bar so it lays against the frame (with suitable padding if you are worried about damaging the paint), then hit the starter...

That is how I have done it - quick and not much drama. Just be sure you think through which way the bar will ant to go.

 

[titanic]

+2 on the breaker bar-starter trick. I remember that was the way a VW shop removed the pulley hub nut on a bug I was driving at the time. Since the TR engine turns clockwise as viewed from the front, the breaker bar should rest on the drivers side frame rail.
Berry

 

[Willie_P]

Thanks to all. My neighbor has an impact wrench and the more I think about the physics...the wrench should overcome the initial cranking force required by the engine to turn. will try this weekend.

 

[KVH]

Thanks to all. My neighbor has an impact wrench and the more I think about the physics...the wrench should overcome the initial cranking force required by the engine to turn. will try this weekend.

Impact wrench wouldn't work for me. It was too weak. Whenever I remove my timing cover, It seems the car is up on jacks anyway, and it seems I'm inevitably trying to stop oil leaks and decide I might as well put a new gasket on the sump. Then it's really easy to get that dogbolt out. Just drop the pan and put a block of wood between the crank and block and turn away on your breaker bar.

 

[TR3driver]

Impact wrench wouldn't work for me. It was too weak.

This may be obvious, but they aren't all the same by any means. Running up the pressure will get more force, as well. My cheap 1/2" gun won't reach even 100 ftlbs on 90 psi but does noticeably better on 150. However, for anything stubborn, I reach for the "high torque" 1/2" (which ISTR was rated something like 450 ftlb).

 

[KVH]

This may be obvious, but they aren't all the same by any means. Running up the pressure will get more force, as well. My cheap 1/2" gun won't reach even 100 ftlbs on 90 psi but does noticeably better on 150. However, for anything stubborn, I reach for the "high torque" 1/2" (which ISTR was rated something like 450 ftlb).

Would that require a high pressure compressor? I think mine will max out at 100 PSI. My impact wrench is Chicago Brand/HF, so maybe that says a bit.

 

[TR3driver]

Nope, they're all rated for use at 90 psi. Even HF offers models rated at 250, 450 and 700 ftlb in 1/2" drive (and 90 psi). I suspect the torque figures are wildly inflated, but maybe they bear some relationship to real world torque.
Eg, https://www.harborfreight.com/12-in-professional-air-impact-wrench-68424.html