Jump to content

P38 in ICU


pep73
 Share

Recommended Posts

Evening all as the title says my '00 P38 is in the ICU, driving down the road the other day and this almighty racket from underneath starts and stops as quick, looked in the rear view expecting a shopping trolley in the road but nothing! pulled over checked it through all the gears- moving ok, got out quick look under- no fluids visible, as i was only a half mile from the house i drove her home and could not believe my eyes.... my front prop shaft GONE! as im not near as clued in as i should be ive loads of questions starting with why was the front prop turning in 2wheel drive or does it always turn and the front drives get their power from the front diff? I can see all you guys PYSL at these questions but im on this for your answers as soon as you can compose yourselves :D the biggest question is how and why this would happen??????? i'll make tea and await your helpful synopsis! as always ladies and gents thanks in advance!

Link to comment
Share on other sites

I'm not 100% familiar with P38's transfer box but if the front prop fell off you'd lose drive unless it was in difflock... and if it was in difflock on the road you'd get transmission wind up and something would explode, like the transfer box or possibly a pair of propshaft UJ's (although it's a rare failure to have both fil at once & the prop fall completely of).

If you are looking to educate yourself, have a read of the RAVE manuals (see part numbers forum or technical archive for links) which explain how everything works (or doesn't).

Link to comment
Share on other sites

P38 has a viscous coupling in the transfer case so you wouldn't lose drive. It's permanent 4x4 like all Range Rovers.

VC won't like that much slip and will overheat and give up eventually. If it hasn't already locked solid.

Usually when props give up you get some warning in the form of squealing and vibration beforehand.

Link to comment
Share on other sites

P38 has a viscous coupling in the transfer case so you wouldn't lose drive. It's permanent 4x4 like all Range Rovers.

VC won't like that much slip and will overheat and give up eventually. If it hasn't already locked solid.

Usually when props give up you get some warning in the form of squealing and vibration beforehand.

Yes there is a viscous coupling in the transfer case, this VC ensures the front and rear propshafts spin at much the same speed, allowing just enough difference to allow for normal turns in car parks etc that use full steering lock.

With such lack of knowledge and awareness as detailed in the first post, I have to say IF the front propshaft is totally missing, and the VC is still in place, it will cope with the situation quite happily as it is mechanically connected to the rear output shaft, it is the front shaft that is viscous coupled, so that output shaft will turn without imposing any load on the VC.

Yes, I'm aware my assessment disagrees with that provided by Highway_Star.

As a matter of interest, the handbrake will still be effective, braking the rear wheels via the propshaft and rear axle.

Again "With such lack of knowledge and awareness as detailed in the first post", I am not going to make further conjecture about what has actually happened, what the primary failure was, etc.

I suggest two actions:

Take photos of the underneath, showing in as much detail as possible, both where the propshaft normally attaches to the front axle, and where the propshaft normally attaches to the transfer box.

Secondly, I suggest you walk back the half mile and look for the propshaft, which should be in the gutter or roadside verge.

These suggested actions take your initial diagnosis at face value.

Regards.

Link to comment
Share on other sites

I had a similar failure on the outside lane of the M6 passing under the M56. Because I was traveling at speed my prop took out the side of the gearbox and the floor of the car so you were very lucky.

I have several front props if you need one. :i-m_so_happy:

Link to comment
Share on other sites

Yes there is a viscous coupling in the transfer case, this VC ensures the front and rear propshafts spin at much the same speed, allowing just enough difference to allow for normal turns in car parks etc that use full steering lock.

With such lack of knowledge and awareness as detailed in the first post, I have to say IF the front propshaft is totally missing, and the VC is still in place, it will cope with the situation quite happily as it is mechanically connected to the rear output shaft, it is the front shaft that is viscous coupled, so that output shaft will turn without imposing any load on the VC.

Yes, I'm aware my assessment disagrees with that provided by Highway_Star.

The rear output is not fixed to the input, so the VC will have to work hard to transmit power to one prop if the other is missing.

From Rave:

"The differential unit is driven from the intermediate shaft through a Morse chain. The outer casing of the differential unit is the input, while the sun gear provides the front output and the planet carrier the rear output."

So despite the unusual layout of the epicyclic differential in the Borg Warner, it operates exactly the same as an axle diff, with the VC providing a coupling between front and rear that allows some slip. Unless the VC is already locked completely solid, you will notice a difference when accelerating, much like the delay from the torqueconverter of an autobox (which operates on the same principle).

I do agree with the rest of your post, we need more info to make any useful comments.

I find it hard to believe the prop would work loose at the transferbox and diff at exactly the same time. One end will go first, causing the prop to flay out and hit everything in reach on the underside, likely causing major damage if it were to happen at speed.

@pep73, are you sure the front prop was fitted when you bought the Range Rover? Sometimes an unscrupulous seller will remove the front prop to hide problems with the VC.

Filip

Link to comment
Share on other sites

Evening all Thanks so much for the replies firstly and secondly apologies on delay in replying, and also on lack of info, the prop was defo there to start with and it caused a bit of damage on its final spin- battered the pan of the transfer box, ive got some investigative work to do before i go ripping out the VC, so lets say the VC locked up solid? was it the motion of the front axle turning that broke the spicer at the trans box followed by the prop battering my trans box pan and eventually jamming causing it to brake off and land god knows where? (i checked the road that night and further searching next day-nothing). I started her during the week and she'd barely move so knocked it off until i have the time to give her some tlc.

Link to comment
Share on other sites

  • 3 weeks later...

hey all just a quick update- i removed the VC during the week and sure enough its locked up solid. I've repaired the damage to the pan but the pick up pipe to the filter didnt survive, i'll be replacing the filter anyway and at €15 its all good, not so on the prop and the new VC-€400. I have the feelers gone out for used so if anyone on here from ireland can help??? BTW i only loosened the cross member on the side and knocked it down enough to wiggle out the housing and the VC in one.

Link to comment
Share on other sites

Thanks for the update, they are always useful.

When I was active with the 38A, some years ago, I reluctantly came to the conclusion that the VC was a consumable item, requiring 'regular' replacement, it's just that it didn't appear in the maintenance schedule.

Other items requiring a similar maintenance regime were the radiator fan VC, the air springs (don't just check them, as advised, replace them), and possibly the vent flap motors in the HEVAC.

Regards.

Link to comment
Share on other sites

I have the feelers gone out for used so if anyone on here from ireland can help???

I have about 4 or 5 transfer boxes kicking around there must be a good one there. One of my gearboxes only had 85K on it.

Link to comment
Share on other sites

I have about 4 or 5 transfer boxes kicking around there must be a good one there. One of my gearboxes only had 85K on it.

hi simon what kind of shillings are you talking if you are willing to part that is.... if you would prefer to pm me for that kind of chat ?

Link to comment
Share on other sites

Thanks for the update, they are always useful.

When I was active with the 38A, some years ago, I reluctantly came to the conclusion that the VC was a consumable item, requiring 'regular' replacement, it's just that it didn't appear in the maintenance schedule.

Other items requiring a similar maintenance regime were the radiator fan VC, the air springs (don't just check them, as advised, replace them), and possibly the vent flap motors in the HEVAC.

Regards.

Cheers for that David,

I now have the parts and of course the weather has turned to pooh! being diy mechanic without a garage is a nightmare in this country!!!!!!

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...

Important Information

We use cookies to ensure you get the best experience. By using our website you agree to our Cookie Policy