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Strange sound when in 1st gear.
Posted: Mon Aug 30, 2010 2:17 pm
by SimonB
I have had a condition (if it is one) on my Paj for a while now, but the Marcuskraal trip just highlighted the issue a bit further to me.
When in first gear I have what I can only describe as a gentle, "thrum, thrum, thrum", slightly high pitched, which seems to come from the front. It happens in 2H all the way through 4Hlc, although possibly louder in 4WD.
It doesn't seem to happen in the other gears.
Any ideas?
Re: Strange sound when in 1st gear.
Posted: Mon Aug 30, 2010 2:52 pm
by 4ePikanini
only thing I can think of is the first gear syncro ring might be worn.
Re: Strange sound when in 1st gear.
Posted: Mon Aug 30, 2010 3:12 pm
by 4ePajero
I hope I understand the noise.
If it sounds like a tin can rattling, check the dust flange over the tail shaft at the end of the transfer case.
They often come loose (it's just a press fit).
Check it in any case.
Re: Strange sound when in 1st gear.
Posted: Mon Aug 30, 2010 3:20 pm
by SimonB
No definitely not like a tin can... but will take a look anyway.
It's more like a cyclical hum, the frequency of which increases as the revs increase, although the pitch doesn't change
Re: Strange sound when in 1st gear.
Posted: Tue Aug 31, 2010 4:58 pm
by Scubadude
SimonB wrote:No definitely not like a tin can... but will take a look anyway.
It's more like a cyclical hum, the frequency of which increases as the revs increase, although the pitch doesn't change
Worn propshaft universals?
Re: Strange sound when in 1st gear.
Posted: Tue Aug 31, 2010 5:10 pm
by SimonB
Scubadude wrote:SimonB wrote:No definitely not like a tin can... but will take a look anyway.
It's more like a cyclical hum, the frequency of which increases as the revs increase, although the pitch doesn't change
Worn propshaft universals?
Then I would imagine that it would happen in all gears? Not just first?
Re: Strange sound when in 1st gear.
Posted: Wed Sep 01, 2010 9:35 pm
by Scubadude
SimonB wrote:Scubadude wrote:SimonB wrote:No definitely not like a tin can... but will take a look anyway.
It's more like a cyclical hum, the frequency of which increases as the revs increase, although the pitch doesn't change
Worn propshaft universals?
Then I would imagine that it would happen in all gears? Not just first?
Not quite ... worn UJ's typically make that low speed drive train rumble, more noticable in first gear at first. I once rebuilt the propshaft on my Colt due to low speed drive train drone and "quick judder" on rapid take-offs. Could not believe how a R 1500 job transformed my driving experience ... not only at low speeds but also while cruising. Could also be the propshaft itself that is running out of true (they balance the shaft when rebuilding in any case). Either way, take it to a prop shaft shop, they'll check it out in no time. If they find a problem be glad its a quick and relatively inexpensive fix.