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traingeek087
03-31-2008, 10:15 PM
So today I was installing my LIM after i did a gasket change and i read in a post that the vertical bolts are around 5ftlbs, and the angled bolts are around 9.5ftlbs.

I then read in a different post that they were 9.8ftlbs and 18ftlbs....I already have installed this several hours ago and it is dry. I went by the first specs. Can anyone tell me what the correct specs are?

blario
03-31-2008, 10:42 PM
my haynes book says torque the 4 vertical bolts first to 62 inch-pounds, then the 4 angled bolts to 115 in-lbs....so yes that converts to 5 ft-lbs(vertical bolts) and 9.5 ft-lbs (angled).

traingeek087
03-31-2008, 10:49 PM
ok well i read in another forum that it was suppose to be the second numbers given....the 18ftlbs. I installed it at 4 and it's 30degrees out and the RTV isn't fully cured yet so i went and put them to the 18. I hope i didnt screw myself over......

AaronGTR
03-31-2008, 11:14 PM
You are actually supposed to torque the four center bolts (vertical) to 118 lb/in and the four corner bolts (angle) to 18 lb/ft. There is a certain pattern you are supposed to tighten them in as well... starting from the center lower right bolt, then going to the next bolt up, then down and diagonally to the lower left center bolt, then up, then the far lower right, up, far lower left, and up. After they are all tight you are supposed to go around an re-torque them in the same order. And make sure to use red thread locker on them! GM actually tells their techs to use brand new bolts that have a special locking paste pre-applied on them to make sure they stay tight. Basically if you follow this procedure though you should not have any leaks.

blario
03-31-2008, 11:17 PM
i wouldn't sweat it man. at such low torque values you didn't hurt anything...besides a little tighter is better than loose, no?

traingeek087
03-31-2008, 11:27 PM
ok so i've been doing alot of reading around and there are actually a few threads that kinda talk about it. But in one of them it states that the haynes manual and alldatadiy.com both say ALL LIM bolts are 115....and i did follow the torque pattern

i went back out and poked a bit of the RTV that has seeped out the side and it "popped" so to speak...meaning it hasn't cured b/c of the cold weather...so I set them all to 115 (or 9.5ftlbs)

AaronGTR
04-01-2008, 12:01 AM
i wouldn't sweat it man. at such low torque values you didn't hurt anything...besides a little tighter is better than loose, no?


No... that was the problem GM originally had. The LIM's where getting over tightened, which pulled them down into the V between the heads too far and caused the coolant ports to get slightly out of line, which let coolant leak by and get into the oil.

When they re-designed the gaskets they added metal spacers into them which couldn't be compressed like the original gasket, so that you couldn't tighten them down too far. The angle bolts ARE supposed to be tightened more than before though. However trying to tighten them even more will only stress the aluminum in the heads and possibly strip the threads.

The original factory manual says 115 lb/in for all. Thats where haynes, chilton, and wherever else probably got their info from. The TSB from GM though (what all the service departments use) says 115 lb/in for the center and 18 lb/ft for the outside bolts. That is the revised procedure for the new gaskets, and what the GM TSB says is really the only thing you should be concerned with. Not what some website says. But if you want to have leaks, go ahead and do it however you want.

traingeek087
04-01-2008, 12:18 AM
^^ After reading this post I understand it now. The bolts are set at 18ft/lbs now. I only hope it's not too late because it has been on there for a good 7 hours now...even tho it is 30degrees out.

On a side note tho this is a permatex kit and not a GM kit

AaronGTR
04-01-2008, 01:36 PM
I don't think it will make too much difference on the RTV sealer. It really pulls the LIM down into the RTV when you tighten the vertical bolts, so I think you'll be good there. That RTV really only seals the oil galley from the outside too (not any coolant) and the 3500's actually use a rubber gasket there instead of RTV. The angle bolts should mostly provide clamping force on the gaskets between the cylinder head and the mating surface of the LIM, which is where the coolant ports are and why you want them clamped securely. :) So hopefully it will stay good for you with no leaks.