impact for the crank nut

[wengr]

I have heard mention here of using impact for the crank nut and of course I always like to use it on any spinning assembly. but how are you using it on the crank nut, as on my car the radiator support is directly in the way. can you lift or drop the engine a bit without to much grief? I've always heard not to use impact with a universal, would you agree? I've got the 38mm nut. can I be sure that it's not reverse thread as was recently reported with a 22mm bolt?

[racydave]

You will need to remove the radiator to get a straight shot with the socket only. Universals may be dangerous on an impact as they can throw a socket or nut and ruin a Radiator.

[wengr]

Dave, Thanks for the reply. My radiator and anything else around there is out. but there is non removeable frame member with the radiator support right at the level of the nut. and there is not enough depth for the gun to fit. Unless you had some kind of ratchet shaped air tool?

[So Cal Mark]

I use a long extension with a swivel adapter on the socket

[htchevyii]

I drilled a "lightening" hole in that support. Now I have a straight shot and the cars lighter!

[wengr]

thanks guys, the way my luck goes, the universal will disentegrate, taking my eye out. then with my good eye, I'll drill the access hole. But seriously, Mark do you also install them with a universal and impact? if so does a universal deliver the torque rating of the gun, or diminish it?

[racydave]

I try to keep impact swivels handy. Any swivel will loose a little torque.

[wengr]

I try to keep impact swivels handy. Any swivel will loose a little torque.

I see. Did'nt know there was such a thing. I'll keep my eye out for one.

[BigShirl]

Just a little tip from someone that wrenches for a living... If the crank bolt is a standard (right hand) thread...The bolt can be removed with a bump of the starter. Place a long breaker bar and appropriately sized socket on the bolt. Rest the handle of the bar on a suitably strong frame/body area. NOTE THE DIRECTION OF ROTATION and STAY CLEAR OF ALL LINES AND WEAK PARTS!!! Remove the wire from the coil to prevent firing. With all things checked, and your body parts out of harms way, have a friend BUMP the starter...usually this is all it takes to break the bolt loose! Saves a ton of time when doing timing belts, crank seals, etc. Unfortunately, tightening is a different story. I usually lock the car in gear with the e-brake applied to prevent the engine from turning, and tighten by hand...

Now, being new to the Fiat world, I'll have to check to see if the crank bolt is standard (right hand) thread.

[alexGS]

That's what I've done too, BigShirl, great guide there Except I flick the starter myself - that way I'm really out of the way.

I have one of those impact guns that just never seems to quite do the job. I should have shelled out for an expensive one. I even have a bigger 16cfm compressor now but STILL the gun never quite gets anything off. Or, it doesn't fit in.

I refit the crank nut with lots of Loctite, especially on the 'wiped' area of the pulley, because I probably don't get quite the same torque on reassembly (but have not had any problems with nuts working loose, and have done 20+ cambelt changes now). I have seen a pulley bolt work loose on a Honda Concerto (I didn't fit it, and it was a silly small bolt) and the pulley chewed the keyway in the crank, losing valve timing - nightmare. I haven't seen that happen on a FIAT.

I think our conclusion is that on the FIAT twin-cam, 38mm nuts are normal right-hand thread, 22mm bolts on mid- to late-80s engines are left-hand-thread.