drive train hum

[prelude]

Hi there,

Since a few weeks the train noise of my P38 has become a bit too much. I have been wrecking my head trying to figure out where this comes from. General consensus is that it comes from the u-joints of the front shaft. I read about the out of phase design and the tilted diff and I have checked that straight away. I have also checked for play on the u joints and since they are fairly cheap I rebuilt a spare shaft and put that in yesterday. Almost no difference.

My range has a 2" lift. There is a difference between highway and normal mode. I did recalibrate the EAS after the lift so I am probably riding a bit higher on highway mode but not by much I think. Last year I replaced just about everything drive train related; half shafts, rebuilt diff with lockers and pegging, rebuilt transfer case etc. etc. so I must assume that everything related to those parts is most likely in order but I can not be certain.

At one point I suspected the front left CV since my boot had been punctered a while back and although I could not find any evidence, some dirt my have gottin in when the stick (I asume) punctured it. Since the drone whilst driving is of a fairly high pitch I can only conclude that it must be anywhere before the diff input since that turns at a higher speed then the axles/wheels.

Before I buy myself some double cardan beauties though, I would like to check what the actual problem is in stead of just trial and error buying :) Anyone any thoughts?

Thanks!
-P

[Pedro_The_Swift]

In the D2 we'd remove the front shaft and drive with the cdl locked,, that would eliminate the carden as the problem,,
Can you RR guys do that?

[prelude]

I guess we could, though I am not sure what the VCU would think about that :) I guess for a short test drive it would never be a problem...

I'll see if I can manage to do that

-P

[Pedro_The_Swift]

Anyone else have a thought on running a RR on just one shaft???
(before something else goes bang....)

[Pedro_The_Swift]

Just had the word from GOD down in Tassie,, and it will be fine for a test [smilebigeye]

[rangieman]

Just had the word from GOD down in Tassie,, and it will be fine for a test [smilebigeye]

https://youtu.be/plZRe1kPWZw

[Roverlord off road spares]

https://youtu.be/plZRe1kPWZw
Pedro was referring to the God in Tassie not the son called the messiah.[biggrin] I know it gets confusing, Justin and Jesus both start with the letter J.[biggrin]

[AK83]

Pedro was referring to the God in Tassie not the son called the messiah.[biggrin] I know it gets confusing, Justin and Jesus both start with the letter J.[biggrin]

Justin, Jesus! .. Jehova .. they all start with a J. [tonguewink]

Between the three of them, they have The Holy Trinity of J's covered! [thumbsupbig]

[prelude]

Please thank "god" down in tassie for me when you see him :)

In the mean time, 140693 from technical to monty python. I love python!

-P

[zzsteve]

My D2 driveline drone - particularly at one speed, or a narrow range of speeds was a deteriorating rubber donut on the rear propshaft to diff coupling. They look fine until you remove it and flex it a bit. Don't even know if I have one on my P38. I'll check when the rain stops.
Cheers,
Steve

[prelude]

My two P38's certainly do not have them, but I have noticed them for sale, specifically for the P38. I guess it is optional to use them?

In any case, I crawled underneath the car yesterday when changing my road wheels for my MTR's and I took a crowbar to the different parts. There is some play on the front U-joint but not on the diff so far as I can tell. Interestingly there is only some play on 1 axis of the cross part. At the transfercase side there seems to be very little play on the U-joint but there seems to be some play between the transfercase housing and the output shaft. Since no oil is leaking from the seal I take it that this is within tolerances though I do seem to recall there is a bearing in which the VCU rests so I would not really expect there to be ANY play.

What surprises me the most is that the u-joint's are brand new and installed recently. I guess they are cheap replacements...

In the rear there is also some play on the diff side U-joint but no where else it seems.

Unfortunatly I have committed to driving to the abenteuer und allrad messe so I hope they hang in there for another 1000K's

Cheers!
-P

[Scouse]

Have you checked all of the wheel bearings? I had a drone for ages before finally finding a bearing was on the way out.

[prelude]

Since my trip to wales where one failed catastrophically in 2016 I have replaced them all. Have done at most 30K so I should think they are ok. I have tested them ofcourse but I can't find anything wrong with the bearings.

Thanks though!

-P