Knock/Shudder/Bumpy feeling when stopping and accelerating

[greg.kruger]

Good day all, I need your help.

I bought myself a Toyota D4D Hilux 4X4 Autobox (2011 Model). The vehicle is in peak condition. After a while I noticed a knocking sound coming from the body. At first I did not think much of it since it was my first time driving a Bakkie and a Autobox vehicle. After a while I realized that it was not normal. It gives me a Knock/Shutter/Bumpy feeling ONLY when I bring the vehicle to a FULL STOP and then again when I ACCELLERATE. The car being in drive it automatically moves forward without a knock up until I apply power to the drivetrain. The whole issue is that the car does not always do this. It comes and goes; the Knock/Shutter/Bumpy feeling varies in intensity and sometime it is gone all together. The sensation is definitely there and I do not notice the issue with other Bakkies I have driven. Two important facts I picked up is that.

1. The Knock/Shutter/Bumpy feeling is absent or very light in 4x4.
2. The Knock/Shutter/Bumpy feeling is absent on high speed/any other action apart from stopping and going.

This is the history of trying to solve the issue. Toyota did the following:

1. Engine Mountings Checked
2. Gearbox Mountings Checked
3. I had the Diff checked: Twice
4. Drive Shaft Checked
5. I had the Gearbox Check:
• Solenoids Replaced.
• Valve Chamber Replaced.
• Torque Converter Replaced.
• Pressure Pump Replaced.
• All Clutch Packs replaced.

The issue does not go away. After each consultation, the knock goes away for a while, and comes back again in say two days or so.
Please help me. I have no Idea what to do anymore. I am actually considering to sell the car.

[Mud Dog]

Welcome Greg!

Your problem is one that I have never encountered before but on initial thought it points to the box. However, you've covered all the things that I would have ordinarily suggested, so it's quite a perplexing problem to pin point.

I also have to wonder if it's not something to do with the rear axle since the problem is less when front wheel drive comes into play. The rear axle drive force is transferred into the vehicle through the leaf packs and I would check the U-bolts and the hanger pins / hanger pin bushes just to eliminate them from being a possibility. Could the axle be wrapping? Are the rear leaf packs still OEM?

Where does it feel / sound like it's coming from? Front / middle / rear?

[greg.kruger]

Hi,

I am not sure about the leave packs....??? Toyota had a look a look and did not see anything out place. I am not a technician myself, but everything seems fine at first glance.
The feeling comes from the back somewhere for sure. You sometimes feel it under your feet.

I read the comments of another person on the group, and he stated that it might be the "Spline Slide Coupling behind the Centre Bearing" that needs oil?
I don't know. I have been struggling with this issue for too long to be sure.

[Mud Dog]

The splined slip-joint must be greased, never oiled. There is a grease nipple on the shaft at the joint for this purpose, but if you had the drive-shaft checked out, they would have picked up any problems with the slip-joint or universal joints. Additionally, you would experience a vibration at speed rather than just acceleration or stopping.

I'm still thinking that the box is the most likely culprit. Maybe it's time to take it to someone other than an agent, like a gearbox specialist and ask their opinion.