Turbo 350 sloppiness

[Bonnewagon]

1980 LeMans, Turbo 350. When you change directions the driveshaft clunks terribly. Watching with the car up on jacks, in park, and turning the rear wheel, the driveshaft yoke turns about 45° at the transmission output shaft. That is wrong, but what would cause that internally? The universal joints are tight and the rear has minimal slop. It shifts and drives nice otherwise.

 

[pagrunt]

The tail end bushing/bearing worn or damaged?

 

[Bonnewagon]

It looked OK, but I can't see inside. Would that allow it to turn that much? It is like there is something inside broken that has a ton of play.

 

[lilbowtie]

The parking paw shouldn't let that happen.

 

[Bonnewagon]

The parking pawl is an aluminum finger that engages indentations on the drum. That is why when you try to put it in park while you are still moving it sounds like a stick being snapped along a picket fence. This looseness is more deeply internal like where the output shaft is inside somewhere. I am thinking someone did a lot of high rpm neutral-to-drive-dumps and ruined something. But I don't know enough about the T-350 innards.

 

[lilbowtie]

The parking paw isn't aluminum it wouldn't live.

How does a parking pawl work?

The parking pawl works by engaging a metal pin "pawl" into one of the notches of a metal ring that is attached to the transmission's output shaft when the shifter level is placed in the Park position. When the pin is in this position, the output shaft is prohibited from turning, which in turn prohibits the drive wheels from turning. Moving the shifter out of Park disengages the pin, which frees the output shaft and drive wheels to turn freely.
Note: Relying solely on the transmission's "P" Park position and the parking pawl to keep the vehicle from rolling when parked places undue stress on the pawl and other driveline components, which can cause excessive wearing of the pawl and lead to premature failure.
Symptoms of a worn or broken parking pawl

If your vehicle rolls forward or backward more than an inch or so after placing the shifter lever into "P" Park, the parking pawl may be badly worn. If your vehicle rolls more than a couple of inches, or rolls freely, after placing the shifter into Park, the parking pawl may be broken.

Note: In a rear wheel drive vehicle, a worn-out universal joint (U-joint) also causes excessive roll after the shifter is placed in the "P" Park position. In fact, a worn out U-joint is much more common than a worn or broken parking pawl. Therefore, you must rule out the universal joint as the cause of excessive roll before replacing a parking pawl. The cost to replace a U-joint is less than $50. The cost to replace a parking pawl is at least $500 (and can be much higher) unless you do-it-yourself.
IMPORTANT
When parking your vehicle, SET THE E-BRAKE BEFORE SHIFTING INTO PARK, especially when parking on an incline. This way, the weight of the vehicle is held by the e-brake rather than the parking pawl. Following this tip will eliminate the parking pawl from becoming lodged and subsequently causing your shifter lever to lock in Park
► What is a parking pawl?
► How does a parking pawl work?
► Symptoms of a worn or broken parking pawl
► Parked on an incline and shifter stuck in Park
► Parking pawl repair information and cost

 

[Bonnewagon]

If it is not aluminum then it is some kind of "pot" metal. I once rebuilt a T-400 and I was amazed at what a POS the pawl was. Look at the last line you posted- "Will wear down and break". I am constantly scolding the idiot women not to rely on the park pawl and to use the damn E-brake. But you know how that goes.... bang head here >>>>>>[X]

 

[lilbowtie]

Hey - no mater what it's make out of I'm just trying to point out something is not right there.

 

[Bonnewagon]

Yeah, I understand, but it does actually hold in PARK.That is what is confusing. In Park you can still turn the output shaft about 45°. Changing direction gets you a loud CLUNK. I don't understand what inside can be that broken yet drive normally.

 

[lilbowtie]

In Park you can still turn the output shaft about 45°

And you know that is not right - the ring gear is splined to the output shaft which the parking paw holds, rotation is minimal unless something is wrong with the paw or broken paw lugs which is all I've tried to point out.