Axle Bearings and Spark Plugs

[Bill Lalk]

I was going to start 2 threads seeing these are unrelated but.........

1) I just read in Popular Mechanics that the 4.6/5.4 and V10 OHC's from 1999 to 2004 only have 4 threads for the spark plugs and that they sometimes blow out. Is this something I need to worry about on my 04' MM? I am planning on replacing plugs this Sat. And what plugs do you guys recommend? And anything I need to watch out for? Car has 56k on it and I have done nothing under the hood besides oil/air changes.

2) I also am planning on installing 4:10's this Sat. I did some reading about the axles, what fluid to use, etc. Lot of good info here(thanks everyone who sent me pics and such). My question is about replacing carrier/axle bearings. It seems the concensus here is to rebuild the entire rearend while its apart. I have no problem with that but I worry about the quality of the new bearings. I pulled both axles last week and they look smooth - no grooves. Would you still replace the carrier and axle bearings? And, if so, are Fords(motorcraft) good enough or is there another brand you would recommend.

Thanks ahead of time for all your informative and invaluable input.

[Got_1]

just make sure when changing spark plugs that you don't over torque them. the torque value is very low, (11ft/lbs IIRC)

Its a good ideal if you have the rear differential apart to replace all bearings and yes, motorcraft makes an excellent bearing.

[babbage]

Plugs = NGK TR6

Axles - Get a Richmond master 8.8 install kit. Good quality bearings (timken) , comes with everything you'll need - seals, gasket, bearings - the works.

4.10s - drive normally for 10 minutes - let cool for 30 - repeat 3 times. After 500 miles I'd drain the cheap mineral oil from pumpkin and fill (2.5 quarts) go with a quality synthetic. This is the most anal way to do it.

You could also install a girdle with magnetic drain plug. Good luck.

[MOTOWN]

when you change your plugs make certain your engine is cold!! do not attempt to change the plugs after you have driven it, the treads may strip out.

and dont forget the anti sieze

[SpartaPerformance]

When changing the gears I recommend FRPP part M-4210-C

[RF Overlord]

just make sure when changing spark plugs that you don't over torque them. the torque value is very low, (11ft/lbs IIRC)


when you change your plugs make certain your engine is cold!! do not attempt to change the plugs after you have driven it, the treads may strip out.

and dont forget the anti sieze^^^what they said^^^

and USE A TORQUE WRENCH. This is not your father's Oldsmo-pile. The lack of threads and being an aluminium head make this very important.

[Rockettman]

My torque wrench is 1/2" drive = ft/lbs.
My other torque wrench is 3/8" drive = in/lbs.

Can I even get a 3/8" drive wrench with the ft/lbs readings on it? I don't want to use the giant one for only 11 ft/lbs.

[RF Overlord]

11 ft/lbs is 132 in/lbs.

[CBT]

I would like to go on record as saying I think it is impossible for a spark plug to unthread itself. I just don't buy it. Even if it only has four threads, or four turns, however you want to say it. If your plugs are so loose that they can turn 4 complete circles, while being held down by a coil, which is held down by a coil cover, you have way bigger problems than you know.

I've never torqued spark plugs on any vehicle, but if it gives you piece of mind, why not.

[fastblackmerc]

I would like to go on record as saying I think it is impossible for a spark plug to unthread itself. I just don't buy it. Even if it only has four threads, or four turns, however you want to say it. If your plugs are so loose that they can turn 4 complete circles, while being held down by a coil, which is held down by a coil cover, you have way bigger problems than you know.

I've never torqued spark plugs on any vehicle, but if it gives you piece of mind, why not.

Torquing the plugs not only stops the plugs from backing out, you don't want to over-stress the aluminum threads in the heads which could lead to a failure of the threads. Then your in deep doo doo.:eek:

[Rockettman]

...deep doo doo.

you said doo doo. :P

[RF Overlord]

I would like to go on record as saying I think it is impossible for a spark plug to unthread itself. I just don't buy it. Even if it only has four threads, or four turns, however you want to say it. If your plugs are so loose that they can turn 4 complete circles, while being held down by a coil, which is held down by a coil cover, you have way bigger problems than you know.

I've never torqued spark plugs on any vehicle, but if it gives you piece of mind, why not.Casey, the issue is not the spark plug unscrewing itself, it's that if the threads (which are the only things holding the plug in the head) get damaged, the plug can simply be forced straight out of the head by the pressure of combustion.

You're correct in thinking that it won't come flying out of the motor and ding the hood, but it can be dislodged enough to destroy the coil. It's less common on the 4V, but the 2V motors have a disturbingly high rate of plug ejection, usually caused by over-tightening due to the operator believing he has a calibrated wrist and doesn't need a torque wrench.

The problem is further exacerbated by the use of taper-seat plugs which only require snugging, as opposed to the old gasket-seat plugs which needed to be snugged, then turned a certain amount more to load the gasket to the right compression. Reefing down on a taper-seat plug in an aluminium head is just asking for trouble...you may not have encountered it yet, but if you do it enough times, you will.

[tbone]

You're wasting your money changing the plugs at 56K. They last for 100K.

[fastblackmerc]

You're wasting your money changing the plugs at 56K. They last for 100K.

I change my plugs (TR6) once a year. Cheap insurance.

[tbone]

I change my plugs (TR6) once a year. Cheap insurance.

Insurance against what?

[fastblackmerc]

Insurance against what?

Combustion chamber problems.

[tbone]

Just curious. What do you think could happen?

[Bill Lalk]

I was told by 2 family mechanics that if I wait until closer to 100K that I may not get all of the plugs out.

[CBT]

I was told by 2 family mechanics that if I wait until closer to 100K that I may not get all of the plugs out.

That I can believe.

[76719]

I was told by 2 family mechanics that if I wait until closer to 100K that I may not get all of the plugs out.

100k when do they change there oil then every 30k haha

[SC Cheesehead]

100k when do they change there oil then every 30k haha


Who's doing oil changes every 30,000 miles? :confused: