Autopark?

[codgerbill]

I was just browsing the threads and I noticed several discussions regarding the Autopark thingy. I really dont fully understand its purpose or operation. I have a 2005 Winnebago Suncruiser on a W22 chassis. The discussions were stating that there is a yellow knob for the auto park feature. My coach does not have the yellow knob. Does that mean I do not have that feature?

[DriVer]

Quote:

Originally Posted by codgerbill Does that mean I do not have that feature?

codgerbill, You do not have an Auto Park feature on your motorhome. No worries!

[codgerbill]

Hmmmm....do I need to hire someone to auto park my coach for me?

[DriVer]

Quote:

Originally Posted by codgerbill Hmmmm....do I need to hire someone to auto park my coach for me?

Cars park themselves nowdays .... why not motorhomes !!!

[wa8yxm]

Auto park was a feature on the Workhorse "P" series chassis and on some GM's before that I think (not sure on the GM's)

Since you have a "W", same as I do, you can rest secure in the knowledge that you will NEVER have any problems with the Auto Park system.. Since you do not have one.

It's that simple.

Perhaps you want to know what Auto-park was.

Well, on our car (or pick up) and on your "W" series the transmission has a "PARK" "gear" in which a pin (Called a pall) is inserted into a gear to keep the drive shaft from turning.... This is a good system, normally, however for a vehicle that weighs thousands of pounds, like a motor home, the strain on the parking pall is ... Great indeed.

So they came up with "Auto-Park"

In the Auto-park system they do away with the parking pall on the Transmission. Instead when you select PARK with the gear shift.. The parking brake is engaged instead.

Alas, the problem is sometimes it auto-engages when it should not.

[DriVer]

Quote:

Originally Posted by wa8yxm Well, on our car (or pick up) and on your "W" series the transmission has a "PARK" "gear" in which a pin (Called a pall) is inserted into a gear to keep the drive shaft from turning.... This is a good system, normally, however for a vehicle that weighs thousands of pounds, like a motor home, the strain on the parking pall is ... Great indeed. So they came up with "Auto-Park" In the Auto-park system they do away with the parking pall on the Transmission. Instead when you select PARK with the gear shift.. The parking brake is engaged instead.

.... and now the rest of the story. Let's start with the P Series.

The 4L80E and the 4L85E have both been equipped with auto park. The reason for the AutoPark is simple. In a transmission equipped with a parking pawl the transmission structure itself is rated to hold the fully loaded weight of the vehicle. When GM released the 80e and 85e to WCC for use in motorhomes it did so without a pawl because they said that the transmission case itself would not hold the fully loaded weight of a motorhome. Going back before WCC, Chevy came up with a auto apply parking brake to get around the weight limitations of the transmission case. That's it in a nutshell. The AAPB met Federal DOT standards in that it can hold the vehicle on just about any grade where a parking pawl would be used and it met the requirements to get certified.

The W24 had an auto apply parking brake on an Allison transmission, surely that's not the case with the Allison is it? Well I have ta tell ya pilgrim, it sure was. Allison didn't want to give WCC a parking pawl in a tranny that had to hold 24,000 GVW until year 2006 when they went to a 6 speed. That's just about the time when the J71 on the W24 was retired.

The R26 has an auto apply parking brake on the WABCO HPB system and this is the last vehicle that had an AAPB on a Workhorse Chassis. The reason for this is that a cable from the driver's position to a drum brake would be way too far for it to reach in the back of the vehicle, so we see an AAPB and an Allison transmission w/o a parking pawl just like the 3000 series trannies on RDPs.

That's it!

[codgerbill]

Hmmmm....
That brings another question.

If I park the W22 on an incline will the tranny in park hold it or would it be prudent to apple the emergency brake pedal?

[DriVer]

Quote:

Originally Posted by codgerbill If I park the W22 on an incline will the tranny in park hold it or would it be prudent to apple the emergency brake pedal?

Codgerbill, Although the parking pawl is rated for the load on the W22 here is the SOP that I use.

When you set the parking brake on any hill or small grade here's a tip.

1. Apply your service brake (foot applied brake) using your right foot.
2. Shift the transmission to Neutral.
3. Press as hard as you can on the parking brake with your left foot. Once the brake is set, let up on the service brake. The vehicle should bind up against the parking brake.
4. If the vehicles does not move, shift the transmission gearshift lever to PARK.

This procedure will prevent you from placing the entire weight of your motorhome on the parking pawl in the transmission. When you get ready to leave, it is expected that the transmission will shift easily out of PARK.

1. To get going again, step firmly on the service brake with your right foot.
2. Shift the transmission to NEUTRAL.
3. Hover your right foot over the top of the parking brake pedal, about 2 inches away and pull the release lever. The pedal should come back and strike the bottom of your foot and not slam into the stop. Pull you foot away and allow the pedal to come all the way back.
4. Shift to the most appropriate gear, D or R.
5. Release the service brake and transition your right foot to the accelerator pedal.

Remember only one foot at a time on either the gas or throttle.

[wa8yxm]

Quote:

Originally Posted by DriVer ...... The W24 had an auto apply parking brake on an Allison transmission, surely that's not the case is it with the Allison is it? Well I have ta tell ya pilgrim, it sure was. Allison didn't want to give WCC a parking pawl in a tranny that had to hold 24,000 GVW until year 2006 when they went to a 6 speed. That's just about the time when the J71 on the W24 was retired. ........ That's it!

I was not aware the W series ever had auto park.. however You, however, are a lot more informed on that.

'As for the quoted text though.. I have a 2005 with a genuine foot operated parking brake that I would truly like to know how to adjust.

It seems to be needing a bit of .. er.. tightening

Can you tell me if there is an adjustment, and how to do it, Thanks.

[4Knights]

Great info for future purchase, I currently have the P30 GM chassis and yes have the dreaded autoparkbrake feature or should I say creature! It can, will and does activate when it wants or at least when a myriad of things go wrong at the same time. Usually it's the rotten green switch other wise called a pressure sensor, amazon.com has them for $36.00 so anyone reading this needs to buy a few to keep on hand. Luckily for me when my RGS Failed I was parked and had Roger Haag aka oldusedbear online to help me diagnose, provide part number and guide me through the fix. All on speakerphone. Got to love technology now that you provided the "Paul Harvey" I know what model to avoid for future purchase as I never plan to purchase new, lotto win not withstanding
Ron

[DAN L]

Quote:

Originally Posted by wa8yxm 'As for the quoted text though.. I have a 2005 with a genuine foot operated parking brake that I would truly like to know how to adjust. It seems to be needing a bit of .. er.. tightening Can you tell me if there is an adjustment, and how to do it, Thanks.

if your driveshaft drum parking brake is similar to mine, there is a clevis at the top of the fwd side of the brake drum at the end of the cable.
i removed the cotter pin and then removed the clevis pin. the end of the cable is threaded though it did not look like it. i adjusted the cable shorter about 3 turns, reinstalled the clevis pin with a new cotter pin and all is well.
check the lining thickness on the brake with a mirror and make sure that you do not over tighten the pb adjustment. if 1 rear wheel is off of the ground and the transmission is in neutral, the driveshaft will turn by hand.
make sure the other wheels on the ground are securely chocked and the moho has safety jackstands under it before going underneath.

[DriVer]

Quote:

Originally Posted by DAN L .... .....

DAN L, Thanks for walking wa8yxm through the process. I knew when I read the post that one of the members would respond to the question pretty quickly. We all contribute toward making this forum a place where people can come for the best information in regard to their Workhorse.