Slight vibration on accel felt in gas pedal?? Any Ideas??

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Lawrence
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Joined: April 11th, 2006, 4:50 am

Slight vibration on accel felt in gas pedal?? Any Ideas??

Unread post by Lawrence » November 23rd, 2016, 7:29 am

Hi guys. I'm getting a slight vibration from the Patrol when accelerating, mostly at lower revs. I suspect it's the u-joints, but weirdly enough I feel it in the gas pedal. Going to check the joints later when I get home. I am also suspicious about the transmission brake as some weeks ago, I pulled it up in the traffic and got nothing. Seems the cable broke. Maybe it's rubbing on the driveshaft. Any ideas?

Shann Low
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Joined: April 2nd, 2014, 3:14 am

Re: Slight vibration

Unread post by Shann Low » November 24th, 2016, 4:44 am

Yeah strap a go pro under there and get a look at whats vibrating while your moving.

Have you locked up the brakes in an emergency situation recently - have you created a flat spot on one or more tyres?

Tread separation starting on a tyre can cause what you describe as well!.

Buckeled rim, worn uni joints. Bad wheel alignment scrubbing one tyre.

Possibilities are endless but without getting a look at it what can you do?

You COULD put it up on jack stands... and run it with all wheels off the ground and physically LOOK for whats vibrating!.

Had issue like this for a long time with a vehicle we bought that I just couldn't find/fix! The rear of the car shimmied sideways at low speeds. You could feel it thru the seats, so much that everyone inside the vehicle commented on it!.

Driving behind the vehicle there was no obvious shimmy visible...

Tried jacking it up, running it with all wheel sup and nothing obvious.

Couldn't see any obvious tread separation happening, tested the rims for any signs of a buckle without result.

Swapped wheels with the spare thru all 4 corners and nothing changed.

In the end I went out and bought 4 mag rims off a similar model car and put 4 new tyres on and had a wheel alignment and balance & mysteriously it went away all together... but nothing else I tried worked.

And when i say I tried - the Bro In Law is a Tyre Industry insider, and we did actually try EVERYTHING to try and solve the mystery...

We put in new CV Joints and drive shafts, brakes, you name it...

There was nothing you could put your finger on - we tried to see if any of the wheels on the car were badly out of balance on his tyre balancer machine...

In the end in frustration the Bro In Law said - lets just change all 4 rims and put 4 new tyres on and balance them all up and see if that fixes it, and it did.

Still don't know what the issue was - I drove it with the rear end shimmy for over a year trying various 'fixes' & nothing except throwing the 4 rims and old tyres away (they weren't bald - they still had maybe 20,000kms tread left) worked to find the problem and fix it!.

Sometimes you just have to go back to basics and swap someone else's wheels and tyres that are known to be working well onto your vehicle to see if the problem goes away... i.e trial and error - and a process of elimination.

Good luck with it.

Lawrence
Been here a while
Posts: 278
Joined: April 11th, 2006, 4:50 am

Re: Slight vibration on accel felt in gas pedal?? Any Ideas?

Unread post by Lawrence » November 24th, 2016, 9:19 am

Thanks Shann. Checked the driveshaft again. it had all 4 bolts loose enough that I could turn them with my hand. Going tighten them now. That should sort it now.

Shann Low
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Joined: April 2nd, 2014, 3:14 am

Re: Slight vibration on accel felt in gas pedal?? Any Ideas?

Unread post by Shann Low » November 25th, 2016, 12:56 am

Good stuff, hopefully that sorts it out!

mydmax
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Joined: August 4th, 2011, 10:43 pm

Re: Slight vibration on accel felt in gas pedal?? Any Ideas?

Unread post by mydmax » November 25th, 2016, 7:23 am

What is a gas pedal? Is that an accelerator pedal by any chance? Must be a dual fuel petrol Patrol then.

If the bolts were that loose there would have been very obvious signs of clear definition, indicating no clamping force, between nuts and bolts head in relation to the flange faces. Close inspection is often required.
Use of a LED torch which has a defined light beam will often highlight items/problems not obvious by normal lamps or daylight. :thumb:

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