runaway trans!!!

[92Ty#1524]

My truck creeps backwards on inclines when in park. I've taken the shift linkage off and verified that the trans IS in park. Still does it. Not a fast roll but a barely noticeable to the naked eye creep. Anyone seen this?

 

[gmcturbo]

Re: runaway trans!!!

well, i would say that your park pawl isnt fully engaging. happened to me before, ended up being the bracket for the cable at the trans pan was loose at both bolts.

 

[92Ty#1524]

Re: runaway trans!!!

That was my first thought, too. Is why I've got the shift cable disconnected. Still does it.

 

[Wikid 1]

Re: runaway trans!!!

do you have the front driveshaft out?

 

[92Ty#1524]

Re: runaway trans!!!

Yes. Just put the motor back in after some mods. Wanted to some tuning before I wasted my time puting all the pieces back on.

 

[dgoodhue]

Re: runaway trans!!!

You need the front driveshaft in for park to work...

 

[GM TURBO]

Re: runaway trans!!!

I didn't think ya'all had hills in Texas.



Front propshaft will do it every time.

 

[92Ty#1524]

Re: runaway trans!!!

No hills at my end of the state. Sloped driveway. Is why it took so long to notice the prob. Then again, it spends more time on jack stands than on the ground.

Thanx for the help, guys.

 

[James Thomas]

Re: runaway trans!!!

So the front shaft out will keep the mechanical parking pawl from engaging and allow the shaft to turn? I must be missing somthing (seriously, no joke intended).

__________
James

 

[dgoodhue]

Re: runaway trans!!!

So the front shaft out will keep the mechanical parking pawl from engaging and allow the shaft to turn? I must be missing somthing (seriously, no joke intended).

__________
James

The transmission outshaft still locks, its the tranfer case that spin.

 

[George Blake]

Re: runaway trans!!!

Viscous clutch in the transfer case is AFTER the parking pawl if you follow the flow of force.
With the front prop out, there is no "counterforce" on the viscous and the viscous releases(it operates on fluid shear), away rolls the truck. The viscous doesn't care what's going on in the trans and it's not computer controlled so just because the truck is off and the trans is in park doesn't mean anything to the transfercase. If you have the front prop out, use your parking brake and/or block the wheels and don't park on hills. Even on a slight incline the truck will slowly roll maybe 5 to 8 feet over a 6 hour period. May not be enough to do damage to someone's car but wouldn't stop them from filing a claim on you.

 

[James Thomas]

Re: runaway trans!!!

Thanks for the info.

__________
James