HDJ81 shaking badly when stopped in Drive, and reverse. (2 Viewers)

[Bonznfc]

1992 HDJ81 RHD auto trans. I have had it for about 7 months. Basically, whenever I come to a stop it starts shaking and pulling. The Hi/Lo transmission lever shakes badly as well. As soon as I let off the brakes and get going it stops. If I put in Neutral it stops as well. The transmission also shifts hard both up and down gears (maybe unrelated). Any ideas? I have looked through the FSM and can’t find a direction to go.

 

[roscoFJ73]

Is it from the engine running rough, or idling too slow? Have you looked at your engine/gearbox mounts? What do you mean by "pulling" ?

 

[MonsterCruiser]

What RPM do you see in each case?

 

[Bonznfc]

The RPM while stopped in D/Rev is a needle width below the 600 mark. When I put it in park it ticks ups to slightly above 600 and smooths out. By pulling I mean that I have to maintain firm to hard brake pressure to keep it stopped. Much more than my other cruiser. The engine runs smooth in Nuetral or with the RPM above 600. Thanks for the replies.

 

[Dork]

Mine shakes pretty good at that low of rpm too. Smooths right out over 750. Not sure if the hdt is different, but the fsm spec for the hdft is 800rpm +/-50.

I'd try just giving it some skinny pedal when in park, and if that helps adjust the idle to suit. Might be a free fix.

 

[roscoFJ73]

The RPM while stopped in D/Rev is a needle width below the 600 mark

There's your problem, the transmission, engine and its accessories are not designed for that low rpm. I keep my idle around 900. Its much easier on the power steering and alternator.

 

[Bonznfc]

I’ll adjust the idle up a good bit and see how it goes. Appreciate the replies.

 

[MonsterCruiser]

Check the FSM, but I think the 1HDT is either 650 or 700 +/- 50. I had a similar issue to what you're seeing when I was on a road trip. Any time I was stopped at a light I was shifting into neutral until I got somewhere I could get my hands on some wrenches to make the adjustment.

 

[Bonznfc]

Check the FSM, but I think the 1HDT is either 650 or 700 +/- 50. I had a similar issue to what you're seeing when I was on a road trip. Any time I was stopped at a light I was shifting into neutral until I got somewhere I could get my hands on some wrenches to make the adjustment.

Just got back home and into the FSM, it’s higher than I expected, 1HDT A/T 750-850 rpm, M/T 600-700rpm.
I shoulda figured this one out before I posted.

 

[Bonznfc]

Well, I adjusted the RPM up, and in the process realized 2 things.
1. In park or nuetral, the RPM is at 800 after adjusting, but still drops lower when I put it in Drive/Rev
2. When I turn the A/C on, the RPM drops instead of increasing. So I'm guessing the A/C idle up is either not getting vacuum or the actuator is bad.
On to more trouble shooting.

 

[beaas]

2. When I turn the A/C on, the RPM drops instead of increasing. So I'm guessing the A/C idle up is either not getting vacuum or the actuator is bad.
On to more trouble shooting.

You can adjust your AC idle too. 17 mm if I remember correct, at the bottom right of the picture.

 

[Bonznfc]

I finally got to working on the 80 and the idle adjustment screw is gone!. Not sure when or how but I need a new one. I have looked in my parts guide, FSMs ect and cannot find the part number for the screw or its size/thread. Anyone know the part number or size. Thanks

 

[roscoFJ73]

Any fuel injection shop would have nut and bolt bucket with them in it. Or do you have nut and bolt specialist in town? I sometimes look around the engine bay and see if another screw will fit.

 

[Coyomog]

I assume that the issue is corrected by now, but the torque converter could be bad and causing the problems.

 

[bonzaiamo21]

I recently learned that the excessive vibration is due to the over supply of fuel into the pump.... the idle must be set to 7500rpm when ac is off and the idle up must be set to 8000rpm or slightly higher than 7500rpm when ac is on.

I thought I had a bad vacuum pump, brake booster or injection pump...

 

[Eurasiaoverland]

I recently learned that the excessive vibration is due to the over supply of fuel into the pump.... the idle must be set to 7500rpm when ac is off and the idle up must be set to 8000rpm or slightly higher than 7500rpm when ac is on.

I thought I had a bad vacuum pump, brake booster or injection pump...

Unless you are running a jet engine, your numbers are out by a factor of ten.

 

[Squash]

If all shaking stops when in N then I would assume a transmission issue. My 1991 with the A442F fully hydraulic transmission would also do this sort of thing, and actually stall the engine as if it were a manual transmission.
You get used to dropping in N when stopping.
Had the torque converter and transmission rebuild.