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View Full Version : 80 Series Knuckle Studs...How tight?


corsair23
10-26-2009, 04:03 PM
As part of my front end service, I am replacing my DS knuckle (the one with the caliper bolt hole that had been heliocoiled as a "temp" fix) so it will get new studs. I decided to go ahead and put new studs into the other knuckle and bought new cone washers, washers, and nuts as well...

So I'm wondering what to torque the new studs to? In Timm's thread on MUD the question came up and there doesn't appear to be any definitive answer. One guy states he found a section in the FSM that covers torque specs and based on the classification for the stud it should be torqued to 53 ft-lbs. Other than that the FSM doesn't state.

What do you guys do? I was figuring to just crank them down until the non-threaded area hits the knuckle and call it good. I still planning on putting some red Loctite on each stud and maybe a little bit of blue on the nuts.

Romer
10-26-2009, 04:18 PM
Good time to swap the studs out for the new torx heads. I don't recall the torque. Is that what your doing, replacing with the new style? Is it not in the FSM?

There is a method when you put the nuts on to keep them from loosening up

as you bolt the linkage on and tighten. keep hitting the bottom with a hammer to ensure they go up all the way

nakman
10-26-2009, 04:25 PM
That's probably what I'd do, double nut them then drive them in until the threads bottom out and give them a pretty good oomph and call it good. Also do it on the bench, before you attach it to the knuckle. ;)


53? No way man, try 71... heck 72 for good measure. Also this is one spot where you want everything super clean, then tighten them like 3x - once just snug with the little ratchet, then torque them all to 35-40 or so, then torque them all again to spec. I also criss-cross like a tire- so far so good I've never had one come loose and that seems to be a shrinking list lately..

Here's the spec chart:

corsair23
10-26-2009, 04:48 PM
Good time to swap the studs out for the new torx heads. I don't recall the torque. Is that what your doing, replacing with the new style? Is it not in the FSM?

There is a method when you put the nuts on to keep them from loosening up - as you bolt the linkage on and tighten. keep hitting the bottom with a hammer to ensure they go up all the way

Yep, new torx head studs all around...I'll look again in the FSM (looked at my computer one here and didn't see it) but IIRC there is no specification in the diagrams where you find a lot of the torque specs. Someone on MUD (think it was Tools) mentioned "pinging" the studs which is what I think you are mentioning...Said he's never had a stud come loose.

In addition to the new studs I decided to get all new cone washers, washers, and nuts. Since I'll be using the double nut method to get the old ones off, figured it would be best to get all new hardware...I'm going to have a LOT of trail spares once I done :rolleyes:

53? No way man, try 71... heck 72 for good measure. Also this is one spot where you want everything super clean, then tighten them like 3x - once just snug with the little ratchet, then torque them all to 35-40 or so, then torque them all again to spec. I also criss-cross like a tire- so far so good I've never had one come loose and that seems to be a shrinking list lately..

You sure that 71 isn't for the nut vs. the stud? Guy on MUD just did this and say at 50 (responding to the suggestion to go to 53) he felt he was getting "too tight" - Definitely on the "super clean" drill...Luckily one side is new so it will meet the super clean requirement for sure. The other one...Well I'll do my best but it is nasty :hill:. I'll also try the gradual torquing and criss crossing as well...I tend to do that automatically anyway for some reason :)

nakman
10-26-2009, 04:59 PM
71 is for the nut, not the stud, sorry if I misunderstood. On the stud I'd go for guddentight.

And keep those spares! you should see my drive flange stud collection... :hill:

corsair23
10-26-2009, 05:46 PM
71 is for the nut, not the stud, sorry if I misunderstood. On the stud I'd go for guddentight.

And keep those spares! you should see my drive flange stud collection... :hill:

Roger dodger :thumb: - Thanks for the confirmation guys...This whole thing has been a huge learning experience. The rear axle work doesn't scare me any more - The :Princess: also now knows what is meant when people say "Nothing like the smell of 90 weight in the morning"...We have been getting to smell it everyday now for a couple weeks :cool: