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companion flange bolts
Posted: Tue Apr 12, 2011 5:44 pm
by monkeymissile
Gents,
I need to replace all the companion flange bolts on the propeller shafts and just want to confirm that the total required is 8.
thanks!
Re: companion flange bolts
Posted: Tue Apr 12, 2011 6:54 pm
by m37jarhead
See TM 9-8031-2,
Pages 112 &118 for differential.
Pages 193, 198, 204, 205, 206, & 215 for the transfer case.
Pages 146, 156, & 171 for the transmission.
Might not hurt to replace the seals while you're in there.
Probably want to get grade 8 bolts (might be overkill) and new lock washers.
Torque spec's are in the TM.
Thread sealer would help prevent "weeping".
m37jarhead
Re: companion flange bolts
Posted: Wed Apr 13, 2011 5:22 pm
by monkeymissile
thanks, but perhaps I don't understand. Why do I need to replace seals when I'm just replacing a few questionable bolts that hold 2 flanges together? Flanges are fine, it just looks like someone replaced some of the bolts with junk ones.
Re: companion flange bolts
Posted: Thu Apr 14, 2011 4:21 am
by m37jarhead
The companion flanges are at the end of shafts coming out of the transmission and the transfer case which, as you know,
attach to the propellar shafts. If the units are leaking/weeping oil you may want to replace the seals on these shafts. You'll have to remove the companion flanges to get at the seals. If new seals are not required and you only want to replace the
bolts, nuts and lock washers, that's an easy fix. Four bolts per flange. Again, check TM 9-8031-2, "Power Train, Body and Frame" for additional detail, torque values, spec's. etc. One companion flange on the tranny and four on the transfer case.
Hope that helps.
Re: companion flange bolts
Posted: Thu Apr 14, 2011 4:51 am
by monkeymissile
m37jarhead wrote:The companion flanges are at the end of shafts coming out of the transmission and the transfer case which, as you know,
attach to the propellar shafts. If the units are leaking/weeping oil you may want to replace the seals on these shafts. You'll have to remove the companion flanges to get at the seals. If new seals are not required and you only want to replace the
bolts, nuts and lock washers, that's an easy fix. Four bolts per flange. Again, check TM 9-8031-2, "Power Train, Body and Frame" for additional detail, torque values, spec's. etc. One companion flange on the tranny and four on the transfer case.
Hope that helps.
thanks, will do
Re: companion flange bolts
Posted: Thu Apr 14, 2011 7:31 am
by Sal
M/M Don't forget about the 8 on the shaft that's between the tranny and the transfer case.
Sal

Re: companion flange bolts
Posted: Thu Apr 14, 2011 12:00 pm
by monkeymissile
Sal wrote:M/M Don't forget about the 8 on the shaft that's between the tranny and the transfer case.
Sal

thanks, looking through the manuals, I noted there are a lot more than 8 and some different lengths.
Re: companion flange bolts
Posted: Thu Apr 14, 2011 12:35 pm
by Sal
I had to replace all of mine. I found a lot of mis-matched bolts when I was replacing the universals on my truck.
Sal

Re: companion flange bolts
Posted: Thu Apr 14, 2011 2:26 pm
by powerwagontim
Different lengths? Unless we are all talking about different things, they were all the same on my truck. And there were 24 of them. Each driveshaft has a flange at each end, with 4 bolts per flange. Six flanges x 4 bolts = 24 bolts. Also, the bolts are special, although I cant recall what was special about them. I bought them in a military package, labeled "Driveshaft Flange Bolts" or something to that effect.
Tim
Re: companion flange bolts
Posted: Thu Apr 14, 2011 3:03 pm
by MSeriesRebuild
The companion flange bolts are splined, they are indeed a special bolt; and should be installed using crush type self locking nuts.
Re: companion flange bolts
Posted: Thu Apr 14, 2011 4:08 pm
by monkeymissile
powerwagontim wrote:Different lengths? Unless we are all talking about different things, they were all the same on my truck. And there were 24 of them. Each driveshaft has a flange at each end, with 4 bolts per flange. Six flanges x 4 bolts = 24 bolts. Also, the bolts are special, although I cant recall what was special about them. I bought them in a military package, labeled "Driveshaft Flange Bolts" or something to that effect.
Tim
I may have misread the parts list....
Re: companion flange bolts
Posted: Thu Apr 14, 2011 11:11 pm
by M37UK
MSeriesRebuild wrote:The companion flange bolts are splined, they are indeed a special bolt; and should be installed using crush type self locking nuts.
How important is it that we use these splined bolts?
Are regular bolts with nyloc nuts sufficient?
Re: companion flange bolts
Posted: Fri Apr 15, 2011 2:46 am
by monkeymissile
M37UK wrote:MSeriesRebuild wrote:The companion flange bolts are splined, they are indeed a special bolt; and should be installed using crush type self locking nuts.
How important is it that we use these splined bolts?
Are regular bolts with nyloc nuts sufficient?
I think the splines keep the bolts from spinning and shearing off
Re: companion flange bolts
Posted: Fri Apr 15, 2011 3:10 am
by Cal_Gary
I use standard grade 8 bolts on mine-never have had any problems.
Gary
Re: companion flange bolts
Posted: Fri Apr 15, 2011 3:52 am
by MSeriesRebuild
The correct splined bolts make them much easier to handle as far as nut installation and removal. It has nothing whatever to do with keeping a bolt from shearing off.
Nylock nuts are simply a cheap excuse for self locking, must have protruding threads, and you can only use them once and toss them. There are 2 crush types that work great and can be reused in most cases. The cone style must have at least a couple of threads protruding in order to work. The center crush type actually lock at the center point of the nut allowing for flush mounting . The fact that no threads protrude stops the rust / paint issues in protruding threads that can can be very frustrating at removal time.