Rough vibration during lift off

[Stallion]

Good Morning to all from East Africa, Tanzania,

Mud Dog, hope all well at your end by the grace of the Almighty.

Ok team, yesterday was the time to check all my drive train fluids and greasing, hence all my oils checked out to be perfect, and I greased the prop cross joints and York. After that, I feel my Stallion lifts off from a stop quite roughly, she vibrates, whereas she wasn't at all vibrating during lift offs from stop till yesterday.

What can cause this? So far I've checked the engine, transmission and transfer mountings, they all check to be perfect.

Once she's lifted off, she gallops like a wild untamed Stallion, just the liftoff I feel is out of place.

Waiting for your responses by return.

Regards
Shermohamed

[Haboob]

Could be oil on the clutch plate, but have no idea why it should start now...

[Stallion]

Afternoon Haboob,

Thanks for your response on this. If there was Oil sipping into the Clutch plate, there would be oil leak from the bell housing, where there's no oil leak signs as yet.

Also noticed that the idling itself is rough, not smooth as it's supposed to be, but during idling, the Rev meter doesn't jerk, and the engine doesn't vibrate. As I was doubting the idle jet or air fuel mixture jet, but since the idling needle doesn't play up or down, and the mixture of air to fuel is okay, can't find anything as yet.

I've set the idle to 800 rpm, and it stays there on idling.

Regards
Shermohamed

[Stallion]

Also note, I've been using 15W40 engine oil in her, it's a Total Product. Just to add to the information.

Regards
Shermohamed

[Mud Dog]

From your description it sounds like you have developed a clutch shudder. The onset of this straight after your lube service could be purely co-incidental.

[Haboob]

That's why I said oil on the clutch plate, which is normally the result of a clutch shudder...

[Stallion]

Does that mean that the rear Crankshaft Oil Seal is going? Or the Pilot Bearing, or hotpots on the Pressure Plate fingers, or the Clutch Plate itself? These are faults that lead to Clutch Shudder, correct?

Regards
Shermohamed

[Mud Dog]

First thing would be to verify that it is indeed a clutch shudder. What mileage has the clutch done? If you increase the revs and ride the clutch a bit while pulling off, does it still have a jerky pull-off?

[Stallion]

Good Evening Mud Dog,

When giving it a little bit higher rev, like to 1,200 rpm during lift off, she doesn't vibrate, but i have now noticed another thing today while driving, at speeds of 80km/h on 4th or 5th gear, there's a vibration, i can feel it to the steering wheel and my left foot on the foot rest, this vibration can only be felt by the driver who knows, otherwise a passenger or a new driver with less mechanical knowledge, wouldn't notice.

The Stallion has now 252,037 kms on her clock, i bought her when she was reading at 223,229 kms on the 04th Oct 2017. Meaning i've clocked her with 28,808 kms in a period of 1 year, 3 months and a couple of days till to-date. Since i'd bought her, she's never been replaced with any clutch components, apart from the Clutch Slave Cylinder.

She was actually driven from Botswana to Tanzania with the previous owner, and was left in a car showroom for 1 year until i found her and purchased her. The mileage on her is original, i can tell from the analog digits on the clock, they're all in line horizontally, and the digits change smooth without any jolts or anything. With a figited counter, the digits wouldn't align in a straight horizontal line, and while changing, the digits would jolt. This is from my experience (correct me if i'm incorrect).

Regards
Shermohamed

[Haboob]

The other thing to look at with this vibration and that type of mileage, is the center Drive-shaft bearing and the actual drive shaft.
See if it is properly greased and then try and move it around. If you have unreasonable movement then start replacing, where there is the most movement...

[Mud Dog]

It's possible that you're picking up a small drive-shaft vibration at that specific speed range and it's irrespective of what gear you're in or even coasting down a long hill in neutral.

Such vibrations can be attributed to the centre carrier bearing (arguably the most common cause), a worn slip-joint, the pinion shaft bearing at the diff, worn universals and lastly the output shaft bearing at the X-fer case.

It could also in rarer cases be gearbox or engine mountings since these will usually manifest throughout the rev range while under power.

To do a quick check there should be no sideways play at all on the pinion and X-fer case ends, there should be no rotational play at all on the universals, the slip-joint and carrier bearing can each have a small amount of sideways deflection but not more than about 3mm on the joint and about 5mm on the carrier.

[Stallion]

Good Evening Haboob & Mud Dog,

Thank you for your responses.

While checking the under fluids, i also greased all the Cross Joints with the Yorks, plus checked for dug at all the Cross Joints and Center Bearing, found non, just the normal dug that has to be there, around a millimeter, as on the Pinion & Transfer Case ends, there are no sideways movements at all.

I remember while greasing the rear Prop Shaft York end, i may have over greased, as the York moved back while greasing, to the extent that i heard a click sound, when i stopped. Normally you would know that it has been greased when the grease pops out of the circumference of the York.

Nevertheless, i went to the Farm, and on my way to the farm, the vibration happened twice at the speed of 80 kms/h, and after that, there was no vibration at all, all the way to the farm and back, and till now, no vibrations at all, at all speeds and all gears.

I guess she was eager for a Farm trip after the underneath fluid checks and Greasing.

Anyways, with that sorted itself, i have run into another problem, of which am going to put it down on another topic, will appreciate any points and advises.

Regards
Shermohamed

[Mud Dog]

Sounds like you over-greased the slip-joint.

[Stallion]

Yup, that's what i thought