Alright,
Another day another problem when owning a P38, this time, in my drive-train.
Following a replacement*4-pin diff install 2 weeks ago (due to horrendous noise being a fooked pinion bearing) I continued to get a 'rumbling' on over-run from the rear at speeds over 50MPH then vanishes below this speed, however, I started to get a 'wind-down' noise (the old hairdryer noise) from 30-0 which I initially thought was the rear diff starting to strain, gradually getting louder.
Anyways, due to loosing a rear diff on my old P38 due to a seized VCU, I asked the garage fitting the diff to check the VCU (I was there at the time) and they jacked up both N/S wheels and with hand break off, they rotated the rear prop back and forth, showing a fair bit of slack and clunking also the guy tried to turn the rear wheel by hand (one in the air) with no look and he stated that the VCU was on it's way out, but should be ok until end of month, when I said I would replace it (I wasn't too sure about this test mind as I had checked the VCU by the turn-circle test and no skipping/scrubbing etc).
Anyways, like I said, the noise from 30-0 was getting louder so had it back to the garage and they stated that the VCU was causing wind-up and if I am lucky, the rear diff may not be shagged (noting the noise I was hearing was from the rear), so I panic bought another VCU on next day delivery to fit, hoping to save any further damage.
So, VCU arrived, went to fit it but thought I'd test it first as still was not totally convinced. Jacked front N/S wheel up, transfer in Neutral, Handbreak on and applied a normal sized wrench and the wheel turned nicely with my weight on it at a stable speed, so VCU was fine (the prop was moving so diff wasn't taking the turn).
Removed front prop and tried the RR, rumbling still there, but winding noise from 30-0 gone, however, now on lift-off the RR lightly jerks twice and you can hear the rear diff engaging at these times (imaging strong engine breaking/a sticking break etc). Now I'm thinking this is excentuated due to the removal of load as only 2WD but with the slack/clunk when tested with both N/S wheels off the ground, could this be the Transfer box chain?
Both the original garage and a second opinion guy have looked at the RR with front prop removed and believe the front diff is on it's way out (input bearing) due to extremely hot flange but cold diff housing (after a drive) I have checked/changed the diff oil and it was full/pretty clean. The 'rumble' from the rear is pretty likely to be a bearing and the second opinion man confirmed this.
Now question is, should I be worried about the jerkiness on lift-off and would this cause two diff failures?*
For reference, the RR has done 150,000, gearbox seems ok apart from a clunk from 'P' to 'R' or 'D' to 'R' which I hear is 'normal' but changes up and down no issues.
Any help/ideas would be great, Im currently running on the rear prop only and not sure whether to reconnect or leave as is until such time that I get the diff changed.
Regards,
Diehard
Another day another problem when owning a P38, this time, in my drive-train.
Following a replacement*4-pin diff install 2 weeks ago (due to horrendous noise being a fooked pinion bearing) I continued to get a 'rumbling' on over-run from the rear at speeds over 50MPH then vanishes below this speed, however, I started to get a 'wind-down' noise (the old hairdryer noise) from 30-0 which I initially thought was the rear diff starting to strain, gradually getting louder.
Anyways, due to loosing a rear diff on my old P38 due to a seized VCU, I asked the garage fitting the diff to check the VCU (I was there at the time) and they jacked up both N/S wheels and with hand break off, they rotated the rear prop back and forth, showing a fair bit of slack and clunking also the guy tried to turn the rear wheel by hand (one in the air) with no look and he stated that the VCU was on it's way out, but should be ok until end of month, when I said I would replace it (I wasn't too sure about this test mind as I had checked the VCU by the turn-circle test and no skipping/scrubbing etc).
Anyways, like I said, the noise from 30-0 was getting louder so had it back to the garage and they stated that the VCU was causing wind-up and if I am lucky, the rear diff may not be shagged (noting the noise I was hearing was from the rear), so I panic bought another VCU on next day delivery to fit, hoping to save any further damage.
So, VCU arrived, went to fit it but thought I'd test it first as still was not totally convinced. Jacked front N/S wheel up, transfer in Neutral, Handbreak on and applied a normal sized wrench and the wheel turned nicely with my weight on it at a stable speed, so VCU was fine (the prop was moving so diff wasn't taking the turn).
Removed front prop and tried the RR, rumbling still there, but winding noise from 30-0 gone, however, now on lift-off the RR lightly jerks twice and you can hear the rear diff engaging at these times (imaging strong engine breaking/a sticking break etc). Now I'm thinking this is excentuated due to the removal of load as only 2WD but with the slack/clunk when tested with both N/S wheels off the ground, could this be the Transfer box chain?
Both the original garage and a second opinion guy have looked at the RR with front prop removed and believe the front diff is on it's way out (input bearing) due to extremely hot flange but cold diff housing (after a drive) I have checked/changed the diff oil and it was full/pretty clean. The 'rumble' from the rear is pretty likely to be a bearing and the second opinion man confirmed this.
Now question is, should I be worried about the jerkiness on lift-off and would this cause two diff failures?*
For reference, the RR has done 150,000, gearbox seems ok apart from a clunk from 'P' to 'R' or 'D' to 'R' which I hear is 'normal' but changes up and down no issues.
Any help/ideas would be great, Im currently running on the rear prop only and not sure whether to reconnect or leave as is until such time that I get the diff changed.
Regards,
Diehard