Hi Guys. Just bought a Magna as a local run around, although I will be giving it a good run to the Sunshine Coast this week. Noticed today that when I put it into Park (4 speed auto) it creeps as though it is not locking. I have the pull the hand brake on to the last click to stop it running away. Any ideas what could be causing this ? No other problems with the auto as far as I can tell.

How far does it creep?

It will creep for as long as I leave the handbrake off, so it is not just rolling a few centimeters until it finds the lock position.

At a guess I'd say the selector cable needs adjusting or someone has put it in P whilst the car is still moving and stripped a few teeth from the shaft the "P" pawl meshes with....hopefully it's the former because if the P does not work the car will be unroadworthy.

Park will ratchet if selected while moving. Tested it before doing a manual conversion trying to break the park pin :)

Park will ratchet if selected while moving. Tested it before doing a manual conversion trying to break the park pin :)

This, I can vouch for in a TH Exec. I had to leave the car in a hurry in the dark, didn't realise I was still crawling at about Drive rolling speed. It began ratcheting, I slowed the vehicle with the brake, and it clunked in violently, first thought was "oh, f**k, I've just destroyed something expensive". Then I convinced myself it was a failsafe.

Can you push it when it's in park? Are you sure it's infinitely rolling, and not just rolling 50cm or so before you panic and stop the vehicle?

Might be the parking prawl that has failed?

This, I can vouch for in a TH Exec. I had to leave the car in a hurry in the dark, didn't realise I was still crawling at about Drive rolling speed. It began ratcheting, I slowed the vehicle with the brake, and it clunked in violently, first thought was "oh, f**k, I've just destroyed something expensive". Then I convinced myself it was a failsafe.

Can you push it when it's in park? Are you sure it's infinitely rolling, and not just rolling 50cm or so before you panic and stop the vehicle?

Might be the parking prawl that has failed?

We slammed it into park at about 20-40km/h 3 times, uphill. Wouldn't break.

Tried it several times today. It will roll down the complete drive if I allowed it. Spoke to the previous owner and he said it was reasonably common on Magna's. Don't know if that is just a line though. I am driving it to Queensland tomorrow and I know a transmission guy there, so if he is open, will get him to check it out. I have tried putting it into Park as it is rolling - no effect. Other than that, it works fine. Only starts in Park and Neutral, changes gear as it should. Obviously it is not safe the way it is as it started to roll away last night as I was getting out the door.

I must be seeing things - I thought I read that people were putting the gear selector into "P" whilst the car was moving........must be imagining it.
As I said in post #4, I hope it's just the selector needing adjustment. If it is the park pawl damaged, the bits from it are possible circulating in the transmission oil - I know in the Commodore 4L60E transmission that pawl failure by PARK abuse can cause shards of metal to enter the oil and circulate thru the transmission with dire results. Maybe the Magna is designed differently.
The workshop manual shows how to adjust/check the selector shaft and it seems pretty easy.

At this stage, I don't have a manual and can't say that I have seen one for sale, but will look online.

I have found a copy of a manual. It is for1998 onwards models but seems to be the same engine/gearbox, so I think it should be OK. However, there is no mention of such a fault in the Transmission section, so back to square 1.

At this stage, I don't have a manual and can't say that I have seen one for sale, but will look online.

PM me your email address and I'll attach the pdf file from the factory manual which up till recently was available for free download.

Edit....just re read your post - whilst the workshop manual does not have your specific fault, it does show how to adjust the selector cable which may be the problem.

"At a guess I'd say the selector cable needs adjusting or someone has put it in P whilst the car is still moving and stripped a few teeth from the shaft the "P" pawl meshes with....hopefully it's the former because if the P does not work the car will be unroadworthy. "

If it was only adjustment of the cable, I would expect it to be creeping in reverse rather than forward. It sounds more like the park teeth are stripped.

If it was only adjustment of the cable, I would expect it to be creeping in reverse rather than forward. It sounds more like the park teeth are stripped.

The selector cable could be stopping just short of the pawl engaging in that "nowhere land" after reverse but I know that's a long shot. OP was looking for possible causes so one has to mention them all.

I do appreciate all the suggestions. Hopefully I can resolve this next week.

However, I did encounter another problem on the trip to Brisbane, which may or may not be related. When decelerating from Highway speed, there is a severe vibration, which shakes the body, but does not really seem to be felt so much through the steering wheel. My guesses are CV joints and/or shafts, or lower/rear engine mounts. The top one appears to be new and the rear one also seems reasonably new. The right front seems old but could still be OK. Alternately, with the problem with the Park lock, could there be something in the gearbox causing this ?

For starters is not a common fault, this is just a line used when someone either cannot fix or can not afford to fix

Can be shifter cable, if is not adjusted proeprly as it can adjust 2 ways

The vibration could be so many things, I would get the car to a trans place as you advised and get it checked