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Help - Thud Sound on Bumps

Posted: Fri Jul 18, 2008 8:10 am
by JaffaPinz
Hey guys I bought Rodger Kitts 710K on Friday the 11th and have an unusual sound coming from what appears to be the engine area when I drive on a bumpy street or road. I would like you alls take on the cause.

What I hear is a knock or thud coming from under the engine cowl as I drive down the road after hitting a bump or rut with a tire

At first I thought it might be the limiting straps on the axle engaging but now realize that I am not moving the axle enough to do that.

Should I be looking at the engine mounts? or for something else that is loose? and if so what have you all seen?

Thanks,

Ciao,

Mike
Las Vegas NM

Posted: Fri Jul 18, 2008 8:27 am
by pcolette
I would check for a broken engine mount or sheared/loose studs on the mount.
Do a search on this forum for the topic "broken engine mount studs...". It gives a clear idea of one possible problem.
Paul

Posted: Fri Jul 18, 2008 11:08 am
by sdibaja
while you are under there checking out the motor mounts have a look at all of the rubber bushings in the suspension including the shock absorber rubbers... this is very common with all older rigs
rubber ages just sitting on the shelf, you have an old truck, a maintenance thing, not a big issue.

(oh, the shocks could be worn out allowing the suspension to bottom out and smack the rubber bumper)

Posted: Fri Jul 18, 2008 7:36 pm
by Profpinz
rubber bushings in the suspension including the shock absorber rubbers
There aren't many rubber bushings in the Pinzgauer suspension apart from the shock absorber rubbers! :wink:

Posted: Fri Jul 18, 2008 7:47 pm
by ka
well that sure explains all the racket, then, doesn't it?

Posted: Fri Jul 18, 2008 9:51 pm
by Profpinz
The Pinzgauer suspension is unique, as unlike most vehicles with live-axle, wishbone, etc, etc suspension, all the "pivot points" are internal (inside the diff housing ....even the Haflinger which has similar drivetrain design has the "pivots" externally)
Going by the brief description, I'd be thinking it's more like a worn suspension bearing cup/shell, axle casing flange or bearing flange.
Not an easy thing to fix unfortunately!

Posted: Sat Jul 19, 2008 9:46 am
by undysworld
A while back I had a "knock" from my front end when I hit a bump. (I know, it's not a "thud", but that's kind of subjective)

What I found was that there was excessive play at the "relay lever" which mounts onto the front diff. I'd call it an idler arm, but hey, I'm not Swiss. It is on page 37 of the parts manual, part #s 16 & 28. It ties the steering rod to the two track rods.

The lever would move up and down when I hit bumps, causing the noise.

It required removal of the "center support, front" (pg. 28 part # 1) to get at it. We reshimmed the lever, and it solved the problem.

IF this is your problem, let me know as I have extra shims of the correct size. Finding them was a bitch. I finally ordered them from Chicago - about $30 for a dozen or some such screwing. I only needed one or two.

(Apparently, few applications nowdays require shims. I was given about 5 lbs. of shims, from the old mechanics in Madison, but NONE of them fit.)

Good luck.
Paul

Posted: Tue Jul 22, 2008 12:15 pm
by Protoman333
ive had a thud or two in my time of ownership. ill discuss the two noises i can recall from the front that made a noise i can probably classify as "thuds".

1. the fan shroud mounting plate thingy. thats probably not what the manual refers to it as. the metal part of mine (its a thick plate with an equally thick piece of rubber backing glued to it to reduce vibration) broke ~ 5 years ago, leaving it to thud a bit until i could figure out what the he!l was thudding a bit. there was also a rattle thrown in every once and a while. grab hold of the shroud (i dont have to tell you to do this when the engine is shut off, do i? sorry...kidding) and if it wiggles its probably the thingy. very easy fix. order, receive, replace.

2. broken engine mount(s) or stud(s). a dead give away on mine was that the throttle was b*tch to use properly. it was literally like someone was using the hand throttle or the throttle lever underneath the dog house. basically, i let out on the clutch and it would go...and go faster...but id never give it more throttle. what was happening was the engine was actually moving off its mounts and producing tension on the throttle cable so even though i wouldnt move the gas pedal it was, in effect, getting more fuel and taking off. a b*tch to drive off road. just vroom, vroom, vroom, vroom up hills and over bumps. kinda like a kid just learning to drive might drive it. what im getting at is that this one would be very obvious if you had the same studs brake that i did. i never fixed this one, i just make sure that the remaining bolts holding it on are tight. from what i can tell, the entire engine would need to be removed and i simply cant do that (or cant find a shop to work on it that doesnt hand you @stroglide when they hand you the bill).

just throwing those 2 things out there. if not you, maybe someone else has one of these problems.