Companion Flange Seal Advice

Scott21 · Post by **Scott21** » Fri Mar 12, 2010 4:50 pm

I have the companion flange out and am replacing/cleaning the hand brake shoes. Does the companion flange seal just need to be pulled out and a new one driven in or do I have to take apart the transfer. It has not leaked but everything is opened up.

Scott

Post by **wesk** » Fri Mar 12, 2010 9:23 pm

Clean and examine the companion flange shaft and splines. Look for a groove worn by the seal lip that can be felt with your finger nail. If there is a perceptable groove you will need a new shaft or a redi sleeve. Pull the old seal. Clean it all up and finish with a grease and oil remover. Put a lite film of sealant on the outer circumference of the new seal. With a seal driver or just a deep socket that matches up with the metal body of the seal drive the new seal in to the same position as the old. Now brush a very lite film of sealant on the splines of the companion flange and slide it on. Install remaining hardware and torque nut.

Scott21 · Post by **Scott21** » Sat Mar 13, 2010 8:37 am

Wes,

The flange is fine. The seal looks good but I am going to replace it this week. Is regular RTV good enough for the sealer? How tight on the torque nut, when I removed it the drum had about 1/2 of movement fore and aft.

Scott

Scott21 · Post by **Scott21** » Tue Mar 23, 2010 7:21 pm

Wes,

I just recieved a gasket set for my spicer 18 transfer. I has felt seals and the rubber/spring oil seal. I cant find a diagram with the felt. Can you help?

Scott

Post by **wesk** » Tue Mar 23, 2010 10:03 pm

It's the last thing on the shaft before the companion flange goes on.

Item 76 front and rear in this blowup.

Full size view at:
http://img.mypicgallery.com/mcrunningge ... ercase.jpg

Scott21 · Post by **Scott21** » Wed Mar 24, 2010 6:03 am

Wes,

Thanks again.

Scott

Scott21 · Post by **Scott21** » Sat Mar 27, 2010 5:24 pm

Wes,

How tight is tight enough with the companion flange?

Scott

Post by **wesk** » Sat Mar 27, 2010 10:54 pm

I usually just run the nuts on with an impact gun which has a torque setting of between 80 and 150 Ft Lbs,

To be technically correct whenever the service manual does not list a specific torque figure for a specific part then you use the standard torque chart spec for that diameter nut/bolt, it's thread pitch and weather it is in tension or shear and what grade hardware it is. With critical automotive bolts/nuts assume grade 8 if the marking are not visible. Also when a specific torque spec is not provided it is safe to assume the standard torque used will be with clean, dry threads. The companion flanges are being utilized in shear. The nut is a 3/4-16-2 NF

Using this chart:

Large view at: http://img.mypicgallery.com/techspecs/a ... -chart.jpg
The correct torque listed is 1300-1500 Inch Pounds which if divided by 12 = 108 to 125 Foot Pounds. That size bolt has a max torque in the 54000 PSI tensile strength range of 250 Foot Pounds. This is the torque used by a lot of the strong arm folks. This is an aviation chart and The Strength ratings are generally much higher for the aircraft hardware vs automotive grade 8.

Scott21 · Post by **Scott21** » Sun Mar 28, 2010 9:18 am

Wes,

Thanks

mtdave · Post by **mtdave** » Tue Mar 30, 2010 7:00 am

I'm enjoying this subject as I'm right in the middle of same repair. It started with replacing the rear pinion seal and cover gasket. Now as long as the driveline is down might as well do the rear transfer case seal and see what the parking brake is missing. What a gooey mess sixty years of gear oil and dirt packed between the skid plate and case, at least it kept the bolts well lubricated. I got the companion flange unbolted and got to the yoke nut that was pinned in place with a piece of stripped household copper electric wire, there's a bubba mod. Also the castle nut was only finger tight I doubt thats the proper torque. Ran out of daylight at this point so we'll hit again tonight. Any further tips from you experts that I need to know at this point?

Scott21 · Post by **Scott21** » Tue Mar 30, 2010 6:25 pm

Dave,
How are things in Big Sky Counrty? I have not been in Montana in 20 years. The last trip we fished fron Glacier to Tuscon AZ. Ctuthroats to Apachi trout.

Make sure both hand brake springs are benind the tabs, even though the right side one(BLACK) looks like it should be on front of the tab. You will get a grinding noise the other way. I pulled and reset the brake shoes 6 times before I realized the noise sounded like a spring. I am now an expert with the hand brake shoes.

Scott

mtdave · Post by **mtdave** » Thu Apr 01, 2010 6:56 am

Scott21 things are great in the Big Sky but not so great under my M38. I finished pulling apart the flange and parking brake assembly and oh what a surprise. Some bubba took all the parking brake hardware out. All I have is the drum,backing plate and adjuster. Why do these knotheads of the past do that? If it's wore out and your not going to fix it at least leave the old parts there. So now the parts search starts. I do have two questions for ya'll, why is there a gasket behind the backing plate and is the symetrical groove on the brake face of the drum normal? That groove looks to perfect to not be there intentionally. Ok three questions, should I have the drum turned to true it up for new shoes?

Post by **wesk** » Thu Apr 01, 2010 7:50 am

Gasket is to help limit moisture access to the companion flange area which would get trapped there so moisture can only have access to the shoe area which will drain right out between the drum and the back plate.

If the interior of the drum is smooth and the runout is acceptable you do not need to get it turned.