ARP main and head bolts

[SilverXJ]

ARP already offers stud kits for the mains and head bolts. For reference: PN 146-5401for the mains and PN 146-4201 for the head. Rod bolts are 146-6001, fly wheel bolts are 146-2801 and flexplate bolts are 146-2901.


However, while doing some research, I found that they now offer main bolts and head bolts. For those of use that don't want to go with studs, but want something better than the stock style.

Head bolts: 146-3601
Main bolts: 146-5001

Head bolts and main bolts:


Also, head studs, main studs and rod bolts:


And flexplate and flywheel bolts:


However, neither kits have the studs on the bolt head. For the head bolts the plastic shell for the wiring harness won't mount to them. For the main bolts that means you can't use the girdle, but you can't use it with studs either.

Here is how I rectified the plastic wiring shell issue: http://www.jeepstrokers.com/forum/viewt ... =24&t=4114

[caveman]

I used this bolt kit on mine and as far as the wiring harness. I had rid the engine of all unnecessary wiring which made for a lot smaller looms and used smaller wire clips and fastened them useing the valve cover bolts.

[00XJ49]

Dumb question upcoming... Please educate me.

Why can't the girdle be used with the main bolts or studs?

[SilverXJ]

The girdle needs the smaller stud on the end of the bolt. The ARP bolts don't have the small stud and the ARP studs are to wide to allow significant material to be retained if the holes in the girdle are enlarged.

[00XJ49]

I didn't realize the studs were differently sized on either end - thanks!

Alright then, follow-up question - is there a source for new factory-sized main studs?

*edit*

Looks like people are just calling the dealership for these... Anyplace else they can be acquired?

[SilverXJ]

Hesco. I don't think I have seen any aftermarket OEM style bolts with the stud head. I wouldn't get new ones unless yours are damaged in some way or want to convert to the main girdle on an earlier block.

[5-90]

ARP already offers stud kits for the mains and head bolts. For reference: PN 146-5401for the mains and PN 146-4201 for the head. Rod bolts are 146-6001, fly wheel bolts are 146-2801 and flexplate bolts are 146-2901.


However, while doing some research, I found that they now offer main bolts and head bolts. For those of use that don't want to go with studs, but want something better than the stock style. http://arp-bolts.com/images/releases/pdfs/146-3601+.pdf

Head bolts: 146-3601
Main bolts: 146-5001

However, neither kits have the studs on the bolt head. For the head bolts the plastic shell for the wiring harness won't mount to them. For the main bolts that means you can't use the girdle, but you can't use it with studs either.

Relocate the engine-chassis ground strap to the rearmost screw mounting the fuel rail, and don't worry about the standoffs for the FI subharness (if you insist on fixing it into place, loose zip-ties to the fuel rail main tube will serve neatly.)

Problem solved!

[SilverXJ]

I never said its was that big of a problem.

[Torqsplit]

I am seriously happy you posted this! I'll be needing new main & head bolts and wasnt looking forward to re-using the original mains. BTW-the hescos i used on the head last time don't have the flange under the bolt head like the originals and i felt the need to source a quality washer. ARP includes these. Don't mean to bash, just saying. Thanks!

[SilverXJ]

I sent an email to ARP asking how many times their bolts can be reused. This is their response:

Hi Chris
As long as our bolts or studs have not been over torqued you can reuse many times.
RonF

[5-90]

I didn't realize the studs were differently sized on either end - thanks!

Alright then, follow-up question - is there a source for new factory-sized main studs?

*edit*

Looks like people are just calling the dealership for these... Anyplace else they can be acquired?

Probably the factory. The mains are threaded 1/2"-13 on the engine end, and 3/8"-16 on the girdle end. The head screws are, I think 1/2"-13x7/16"-14.

However, what's stopping use from using overlength 1/2"-13 studs and fabbing up a brace to fit?

[Cheromaniac]

All available from Summit Racing for easy ordering:

Main studs: http://www.summitracing.com/parts/arp-146-5401
Head studs: http://www.summitracing.com/parts/arp-146-4201
Rod bolts: http://www.summitracing.com/parts/arp-146-6001
Flywheel bolts: http://www.summitracing.com/parts/arp-146-2801
Flexplate bolts: http://www.summitracing.com/parts/arp-146-2901

[Knoxes]

Just received the flexplate bolts 146-2901. It looks like they have a much shorter head than the stock bolts. I didn't get a great look, but I don't think that the ARP's are hex head - maybe they're 12 pt? Does this make sense?

Edited to confirm that the ARP bolt threads are slightly shorter (~1/8") and the head is definitely shorter than the stock bolts from a 2003 WJ. The ARP's also have a 12 point head as opposed to the stock 6 point.

[hoghunter]

While we're on the topic, does anyone know what combination of ARP kits are needed to replace the factory style head bolts/studs/pins on the newer 4.0L's? Below is a picture of Fel-Pro ES71102, which is a direct replacement for the OEM hardware.

[SilverXJ]

Head bolt kit: 146-3601 or head stud kit: 146-4201