LJ78 1992 Prado Auto Box Problem

[stokedcat]

Previous post was Autobox not engaging after engine start up.

Symptoms are Gears not engaging properly i.e. no drive or very little until engine warm.

On closer inspection and after checking oil and water levels which are ok there seems to be some sort of sucking noise going on and I cannot pin point it......the noise goes away after a few minutes and gears work....it suggests pressure to me or blockage somewhere?

Any help or suggestions of what it might be?

Cheers

Gary

 

[wobbly]

Have you checked the atf fluid in the gearbox?

The atf is heated up to operating temp in the bottom of the radiator, you have a pipe in and a pipe out. If you can hear a sucking noise, check the joint of each of the two pipes at the rad, think they are a push in fit with a rubber seal, any signs of atf on the bottom of the rad means its likely the seal is disturbed.

With the engine cold, get someone to start the car whilst you have a listen from the side underneath, see if you can pinpoint the source of the noise.

Pete

 

[stokedcat]

Hi Pete,

Having a look at it this morning and I am going to crawl under the front to see what's happening .....sounds logical and thanks for the suggestion..fingers crossed that's all it is.

I will post my findings later today

Cheers

Gary

 

[stokedcat]

Hi,

Checked out noise seems to be coming from the AT area.
Question is there an AT fluid filter behind the AT Sump? could it be blocked?

I am going to disconnect the AT Cooler hose and start vehicle up for a few seconds to see if the AT pump is sending a good flow of fluid.

I think it's then worth draining the system anyway now as I have to get the sump off to have a look as I don't have details on the AT system.

Perhaps the problem will present itself on closer inspection.

In the meantime if anybody has details on the AT system it would be much appreciated.

Cheers

Gary "going back under the vehicle"

 

[OG.]

Under the pan is a strainer as opposed to a proper filter. Remove the 4 bolts retaining the strainer and flush it out. Thouroughly clean the pan as well. When refitting the strainer make sure the gaskets are good and if not replace them. Any leaks here will compromise the oil pickup and lead to problems.

Obviously replace all the fluid with fresh at the same time. Check the level by starting the engine and cycling the box from P to L and back several times pausing in each position for 5 to 10 seconds. Finish in N and leave the engine running. Check the levels jusing the lower level marks and adjust as necessary. Once correct go for a drive to warm the oil and repeat the level check procedure, this time using the upper two level marks.

Check the old fluid - it should be translucent red and not brown. It also should be grit free and not smell burnt.

Some excellent info here:
http://www.autoshop101.com/autoshop15.html#AT

 

[stokedcat]

Thanks for the info an link much appreciated.

I will follow your procedure for refilling once I have hopefully determined the exact fault.

I will post my findings later.

Thanks

Gary

 

[wobbly]

Gary,

Word of warning.....cant remember if the 78 is the same as my 95, but the oil pipe in/out of the bottom of the rad on the 95 *look* like they are a screw in fitting, but they arent, they are push in, putting a spanner on what looks like the nut destroys the connection!

Maybe someone here knows if they screw or push in.

I think there is a breather on top of the auto box.

Pete