Occasional drivetrain noise I can't figure out

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Occasional drivetrain noise I can't figure out

Post by GadgetPhreak » Sun Mar 18, 2018 8:33 pm

We've been busy with a lot of Search & Rescue missions and training lately and yesterday at the end of a very long day some noises developed that I've been unable to root cause as of yet...

I'll start by stating that a lot of our missions have been in the snow and the Pinzgauer has been up to it's bumper several times this winter. Yesterday was dry and sunny (but still cold).

I've noticed two sounds that are abnormal. First there is a clunk that happens when slowing, accelerating, or hard turning at moderate speed. It is a heavy sound as if something shifted a short distance and bumped into something else. The sound is solid, like drivetrain components. It originates from behind the drivers seat and sounds like it's coming roughly from the midpoint of the vehicle.

The second sound happens just as I engage the clutch in 2nd or 3rd and sounds a bit like a fan belt squeal but more at the pitch of an old rusty door hinge opening or closing. Sometimes it's short (but it's a fast rotation speed sound) and occassionally it will squeal for 4-5 seconds, perhaps a little longer.

I put the Pinz up on the lift, greased the drive shaft and checked all nuts and bolts and anything that could move. Everything was solid with no excessive leaking and nothing was loose that I could find. The only thing that moved (aside from a little bit of play in the driveline) enough to make the clunk was the shifter linkage.. everything else (externally visible) was solid and well secured.

Recommendations on where I should look next? Throw out bearing for the squealing? We just put a remanufactured gearbox from EI and a new HD clutch in it last year..
King County Search & Rescue | Regional Special Vehicles Unit
1972 710M - Building up for SAR use
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Re: Occasional drivetrain noise I can't figure out

Post by Haf-e » Mon Mar 19, 2018 5:08 pm

The clunk noise might be coming from the motormount - there is a steel pin inside of it which limits movement - there was a thread about modifying by adding a piece of rubber hose to it or something...

Do you know if the throw out bearing was changed?

1971 Pinzgauer 710M

Disc Brake Conversion Kits for 710 and 712 Pinzgauers

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