Questions about drivetrain movement coming to a stop...

[Seafury]

So I need some opinions please.

When I come to a stop sometimes I can feel the whole drivetrain move, or bump, sometimes this even makes the autoshifter move right before my eyes it sorta jerks in place.

I thought this was the driveshaft bump issue but now i'm not so sure, should I see the shifter physically jerk? it doesn't come out of gear or anything it just sorta moves a bit one time then stops.


Seems to do it mostly when cold....
I do need I think all new suspension (200k miles, bottoms out on the rear on any bumps, brake dives hard, shutters/shakes over bumps)

Could these issues be from the worn suspension alowing alot of movement? bushings all look decent but probly will replace also, but no major play in anything including lbj's

Any ideas apreciated.

:thanks: T4R.org

 

[habanero]

Where my non-mechanic thoughts would go.....
The shifter is connected to the transmission which is not connected to the suspension. Assuming the transmission is securely bolted to the engine that would be transmission and motor mounts, wouldn't it? Assuming tranny tunnel and all that is connected to that isn't the thing that is moving. That's prolly where I would start looking, at any rate.

 

[Seafury]

Where my non-mechanic thoughts would go.....
The shifter is connected to the transmission which is not connected to the suspension. Assuming the transmission is securely bolted to the engine that would be transmission and motor mounts, wouldn't it? Assuming tranny tunnel and all that is connected to that isn't the thing that is moving. That's prolly where I would start looking, at any rate.

Good call I totally forgot about tranny mounts...that might be it. Not sure how to check this other then paying someone to tell me, I really prefer to do my own diag and work whenever possible.

Then again it might be visible damage I'll have to get under it with a light and snoop around harder then I have before :thumb3:

 

[Blanco]

The 'jerking' maybe an issue but here's an older posting I found regarding 'shifter movement'. My shifter moves naturally with the movement of the vehicle but I also have the infamous 'bump' as well, goes away after lubing the drivetrain but always seems to return.

<<Originally posted by Makakio

My understanding
of this issue (it's normal, BTW to see the auto-trans gear selector moving forward and back not only under acceleration but also braking and bumpy roads) is due to the design of the shift linkage and hte concept that the 4Runner is a body-on-frame (read: truck-based) design, versus a unitbody design. With a body-on-frame, the drivetrain is all suspended - meaning it flexes - under the frame and the frame/body union is inflexible (relaitvely - there are super-hard rubber mount bushings between frame and body). With unit-body construction, the powertrain is mounted directly to the body, which in it's entirety acts like a frame. Body-on-frame is a more rugged suited to offroad, towing, long suspension travel, etc and unitbody drives and handles better (it's dynamically "tighter"). So the movement of the shifters, which are in a 4Runner are directly linked to the tranny, is simply a view into the forces that your drivetrain and suspension are incurring as you motor along.

Again, that's as understand it. Do correct me if I'm off.>>

 

[Baja Runner]

Have you lubed your u-joints and slip yolk? Most likely the problem.

The shifter on all my 3rd gens have moved around when stopping/accelerating from a stop.

 

[kball]

The bump you feel could be just the trans downshifting to first as you come to a stop. Mine does this and sometimes it's a noticable bump.

How long since your trans fluid was serviced?

 

[Seafury]

I did have my shaft lubed (no homo) and my yokes recently, in hopes of curring the bump issue but no change after 1 treatment.

Thanks for that info on the body on frame stuff I didn't think of that, if the general consensus is that this movement is normal I will look over the mounts/linkage for any obvious issues and based on that outcome I will carry on. :cheers:

 

[Seafury]

The bump you feel could be just the trans downshifting to first as you come to a stop. Mine does this and sometimes it's a noticable bump.

How long since your trans fluid was serviced?

It's not the trans, its smooth as butter, service unknown bought from used stealership, will be doing fluids soon though.