Has anyone really used these when they build-up their motor in their own garage? I saw in the latest GMHTP that they talked about them. Does anyone know where to get some knock-offs or besides from the dealers?

 

No knock-offs, you can purchase the the tools off ebay. I use them evry motor build we do here at our shop.

 

Can anyone elaborate on these tools, or why they are needed?

 

Mis-alignment can cause a cracked oil pan which is what happened to me and some other GTO owners. A thread exists on the LS1GTO board but I can't find it at the moment:

http://www.putfile.com/pic.php?img=3260451

Kent-Moore J-41480 - Front and rear cover alignment tool; at oil pan:

Our friend the J 41480 is now tightened to the engine block, leaving the tool-to-front-cover bolts loose at this time. Like when used on the rear cover, these bolts get 18 lb-ft of torque.

http://www.gmhightechperformance.com.../photo_41.html


Kent-Moore J-41476 - Front and rear cover alignment tool:

Unlike the seal in the rear cover, the crankshaft front oil seal is not actually contacting any crank surfaces at this point; instead, it will ride on the harmonic damper (to be installed later). Therefore, the seal isn't doing anything to help align the cover to the block. Enter the J 41476 Front and Rear Cover Alignment Tool (Crankshaft Seal Area), also made by SPX Kent-Moore. This is installed hand tight using an old crank bolt. Note the alignment tabs on the cover that the tool presses up against; this tool aligns the cover side-to-side.

http://www.gmhightechperformance.com.../photo_42.html

 

i never used them, not to say you shouldnt, but mine never leaked or cracked..just torqued them in sequence and with a wrench.

 

Why do they crack?

 

nobody knows?

 

i think witht he ls1 the oil pans a structural part of the engine, wich would mean it sees some stresses from the motor if its not lined up right i could see the pan beeing weaker in the wrong orientation..