The Stovebolt Site Forums The Shop Area Driveline 10 bolt posi rotation

Trying to make my first attempt to adjust rear drum brakes. With the trans in neutral I can't rotate the wheels freely to properly make any kind a brake drum adjustment.

Question, are posi units such that they don't allow free rotation maybe like on open diff would??????

Do I need to drop the driveshaft? But is that normal.

Trans in neutral?

Yes....350cid/TH350

bump

Jack up both rear wheels. Even with the driveshaft removed, if one wheel is on the ground there will be too much drag to turn the other one by hand. With both wheels lifted and the trans in neutral, you should be able to turn one wheel, but be aware the other one will move as well.
Jerry

Hello Jerry,
First, hope your doing much better with the hand. Secondly, trust you and family have a Merry Christmas.

I was hoping you would grab on to this....The truck is on ramps at front and stands rear. It is a posi rear both wheels turn same direction. So why am I having allot of resistance? Can't adjust new shoes w/o being able to spin wheels to feel drag...etc.?

Start with both brakes backed way off, like 20 clicks or so. If that doesn't free things up, you might be experiencing more drag than usual inside the transmission. Bendix brakes need to be tightened up until you can feel a firm drag at the wheel with the tires bolted on (not totally locked up) and back off one full turn of the adjuster wheel. That's 10 clicks on manual adjust brakes, or 20 on the fine-toothed wheel of an automatic adjuster. Once you start backing off, ignore any drag- - - -one shoe will still touch the drum until the brake is applied and the shoe assembly self-centers. Do the same procedure on the other side and you'll be good to go.
Jerry

You see with the shoes backed off with zero drag its still difficult to freewheel the wheels/tires?????

Is it something to do with the fact that its a posi unit??????

There is allot of drag/resistance even with the tires mounted. ???????

How would the TH350 trans be holding things back?????

Should I drop the driveshaft and recheck???????

The driveshaft of the TH 350 will be turning several items inside the transmission, in particular, a one-way roller clutch that will create more drag when turned in one direction (don't remember which way offhand). There will also be at least one multi-disc clutch and a planetary gear set in motion. Disconnecting the driveshaft at the rear end pinion flange will reduce the drag considerably.
Jerry

Make shure your emergency brake cables have enough slack that they are not pulling the shoes off the anchors. If that is OK back the adjustment up a few notches after you get a heavy drag. Once the shoes have seated into the drums it will be fine. You are overthinking this.
George

I'm use to a manual trans when working on brakes....virtually no resistance when in neutral. Jerry, I can certainly understand from your description what I'm trying to overcome. I know for a fact the trans in sound. I will temporarily disconnect the driveshaft in order to make adjustments.

The e-brake cables are in place but were never connected, so no interference there.

Thanks gentlemen

bump

Most likely it's the T350, mine is very hard to move when messing with tires and brakes or trying to push the truck out of the garage. Depending on the gear ratio, you could be trying to turn the pinion quite fast which will make for a tough turn of the wheels. Third member shouldn't have any effect if both tires are off the ground. Pull one drum off while adjusting the other and having just the tire and wheel on will help rotate due to the extra weight and spinning mass.

I will just isolate the axle (disconnect driveshaft) while making the adjustments. Thanks again.