Normal Jerk? (1 Viewer)

[cool dad]

My 80 jerks or should I say kicks when I shift it from "P"ark to "D"rive as well as from "P"ark to "R"everse. It has been like this from day one but I am not sure if this is normal or not. My worry is if this will ruin the transmission or do I just have to change some things like the ATF or something.

 

[Kalawang]

Mine does the same thing. It's been doing that for almost 4 years now. Used to worry me. It softens a bit when you grease the drive shafts, but comes back soon after.

I haven't found a way to gentle the shift yet.


Kalawang

 

[cool dad]

Kalawang, Thanks for the reassurance but is there a connection between the intensity of the jerk/kick and the idling speed? I was toying with the idea of reducing the idling speed to lessen the jerk or simply turning on the aircon before shifting. I know it is a remedial measure but have you tried this?

 

[CJF]

What is your idle speed?

Curtis

 

[Jason Andrews]

there is play in the t-case with the viscous coupling. It not gonna get much better or worse. I usually just go from reverse to drive while it is still rolling back just a little, without coming to a complete stop, and it seems to shift much smoother without the glunk!

 

[tech_dog]

I've had near collisions when shifting into P while the tcase was in low range. The combination of high idle, low gearing, and weak brakes can combine for a surprise lunge forward.

 

[Doc]

A worn or sloppy driveshaft yoke can also contribute to both a felt and audiable thump.l

 

[cool dad]

What is your idle speed?

Curtis

My idle speed is normally 750 to 800 and has been that way ever since. I noticed though that if I let the shifter pass through "N"eutral for a while before shifting to either "D" rive or "R"everse the jerking is somewhat lessened. Do your 80's exhibit the same habit?

 

[CJF]

On a petrol 91, at least, correct idle is 650rpm. Is 750-800 normal for your type rig?

Curtis

 

[KliersLC]

No viscous coupler on a 91, just a full time case...


Dan

 

[cool dad]

I guess its the normal idling speed for my rig as it was taken with the A/C on.Dunno though if thats what the specs say.

My 80 used to be a full time but I had it converted to a part time 4x4 with aisin locking hubs . Even before the conversion, it was already jerky when shifting to drive and reverse.

Not that I can't stand the jerk but Iam just worried it might lead to more serious problems later.

 

[Kalawang]

Kalawang, Thanks for the reassurance but is there a connection between the intensity of the jerk/kick and the idling speed? I was toying with the idea of reducing the idling speed to lessen the jerk or simply turning on the aircon before shifting. I know it is a remedial measure but have you tried this?

Back when my 80 was still new to me I had a mechanic crank down the idle. That lasted for only a few seconds as the machine cranked the idle back up and we stopped there. We didn't know what was bringing the idle up and at the time suspected a computer somewhere in the works. There's none in my engine, and these days I suspect some kind of vacuum control like in the BMW but have been too lazy to look for it because the engine works very well. My attention went off to the tie rod ends, steering dampers and the stabilizer bushings. After that there were a host of other things to grab my attention, not necessarily because they needed attention, but more because I wanted to give attention to my new aquisition.

The difficulty with a new experienced car is that even as you like what you have, you want to try to make it like new factory fresh. Move forward with caution and try out other 80's within your area. It's too easy to fix something until it breaks if you don't know what you're after. This forum is good for learning from the experiences of others, and costs a lot less than going your own way.


Kalawang

 

[cool dad]

Kalawang,
I guess your right. I realized that what we have is realy a truck disguised as an SUV. Its good to know though that we have friends here we can rely on for advise.

Thanks man

 

[CJF]

I guess its the normal idling speed for my rig as it was taken with the A/C on.

Should be lower with the A/C off though, right??

Curtis