P38 front prob probs

i know the plot thickens with my RR but here goes,

a few weeks back the front prop fell out when i was driving along, in the process of finding a new one to put in. at one garage one guy said without even looking at it that he reckons that the viscus in the A/T box has seized and if i stick a new one it it will happen all over again.

so how can i chaeck if the worst has happened?

can i jack the jeep up and drive the wheels and see if the front of the center box is spinng with the back?

should show with props on and slow tight turn, will crab on full lock

fanatic said:

should show with props on and slow tight turn, will crab on full lock

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can you explain a little bit more please?

P38_Ireland said:

i know the plot thickens with my RR but here goes,

a few weeks back the front prop fell out when i was driving along, in the process of finding a new one to put in. at one garage one guy said without even looking at it that he reckons that the viscus in the A/T box has seized and if i stick a new one it it will happen all over again.

so how can i chaeck if the worst has happened?

can i jack the jeep up and drive the wheels and see if the front of the center box is spinng with the back?

Click to expand...

If the problem is on a Range Rover, how are you going to fix it by jacking up a Jeep?

P38_Ireland said:

i know the plot thickens with my RR but here goes,

a few weeks back the front prop fell out when i was driving along, in the process of finding a new one to put in. at one garage one guy said without even looking at it that he reckons that the viscus in the A/T box has seized and if i stick a new one it it will happen all over again.

so how can i chaeck if the worst has happened?

can i jack the jeep up and drive the wheels and see if the front of the center box is spinng with the back?

Click to expand...

Put transfer box in nuetral, jack up one front wheel, try to turn it. You should be able to turn it with difficulty. But you have no front prop on, so pop a couple of bolts through drive flange at transfer box and put a bar through them, you should be able to turn the drive flange with reasonable ease, if you cannot turn it at all your viscous coupling is siezed.

cheers mate will give that a try this evening?

both ways will work, crabbing will feel like the car does not want to turn, it will feel like it wants to slip wheels on the road-not a smooth turn.(transmission wind up)

This would indicate viscous/ centre diff issue

thanks gents for the knowledge.

i got under the RR and marked the front diff mount drove foreward 4 feet and got under for another look and the mark i made had rotated 180 degrees.

god i hate that mechanic who put the fear of god in to me! one less problem to deal with now. so just need to fit a new prop.

thanks again for all the advice lads.

ok so if it were to turn out that my viscous has seized what can i do? can i replace the transfer box? is it simple to plug and play or is it a case of opening the existing part and working on it?

P38_Ireland said:

ok so if it were to turn out that my viscous has seized what can i do? can i replace the transfer box? is it simple to plug and play or is it a case of opening the existing part and working on it?

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The VCU is a sealed unit filled with a silicone based gel, so can't be fixed as such and it will need to be replaced, but it can be done without replacing the whole transfer box, as it sits between the transferbox output and the front prop. If you've got RAVE it's worth taking a look at the transfer box section. If not, shame on you, go download it! Seriously it's well worth it, almost everything you could want to know about your RR in one handy navigatable pdf, direct from LR. You'll find it at The Green Oval - Downloads | Land Rover Data

yeah im actually in the middle or reading about it, i got the RAVE cd when i bought the rr.

how much does one of these viscous couplers go for from the scrappie? cant seem to find one on fleebay......

There's one seller on fleabay with 2 for sale. Here's one RANGE ROVER P38,CLASSIC,VISCOUS COUPLING,TRIED @ TESTED on eBay (end time 01-Feb-10 08:37:00 GMT) and the other will be under his other items, but they ain't cheap. Mind you I've seen them for more on there too.

feckin hell! well its better than what the mechanic told me it would cost. in excess of €700 and thats not a main stealer!

as for fitting. i see on the rave software it has some gismo for removing it. is that just a fancy part or can anyone handy do it?

did some more digging, i see its possible to buy a transfer box with viscous coupling cheaper than the viscous coupling on its own!

RANGE ROVER P38 TRANSFER BOX FROM A 4.6 AUTOMATIC on eBay (end time 13-Jan-10 12:19:00 GMT)

will any viscous coupling do? as in i have a 2.5 can i use one from a V8?

P38_Ireland said:

feckin hell! well its better than what the mechanic told me it would cost. in excess of €700 and thats not a main stealer!

as for fitting. i see on the rave software it has some gismo for removing it. is that just a fancy part or can anyone handy do it?

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Looking at the procedure, it's removal of the front output flange that presents the difficulty, once that's off it's fairly straight forward. As long as you can immobilise the flange, (which it should be if the VCU's seized), you can remove the retaining nut, and then just use a standard hub puller to remove the flange.

Refitting could be tricker cause you won't have a seized VCU to hold the flange steady while you tighten the nut, so you'll need to find another way. The pic shows a viscous coupling tool to steady the flange, also available on fleabay for about £10. The procedure also says to ensure you use a new seal, washer and nut, when you refit the flange.

P38_Ireland said:

did some more digging, i see its possible to buy a transfer box with viscous coupling cheaper than the viscous coupling on its own!

RANGE ROVER P38 TRANSFER BOX FROM A 4.6 AUTOMATIC on eBay (end time 13-Jan-10 12:19:00 GMT)

will any viscous coupling do? as in i have a 2.5 can i use one from a V8?

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You'll need to check the final drive ratios in RAVE, I think they differ between diesel and V8, also between auto and manual, but there's no reason you couldn't get the complete transfer box, remove the VCU to replace yours as that will be the same, and then flog the rest of the box to help cover your costs.

kernowdragon said:

You'll need to check the final drive ratios in RAVE, I think they differ between diesel and V8, also between auto and manual, but there's no reason you couldn't get the complete transfer box, remove the VCU to replace yours as that will be the same, and then flog the rest of the box to help cover your costs.

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well if i get the complete box for around £150 inc the VCU i would happily hang on to it to save it for a rainy day!

many thanks for the advice again guys, and Kernowdragon congrats on your 1000th post!

P38_Ireland said:

well if i get the complete box for around £150 inc the VCU i would happily hang on to it to save it for a rainy day!

many thanks for the advice again guys, and Kernowdragon congrats on your 1000th post!

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You're welcome! Blimey I've been busy

Dont bother replacing the VCU , just leave the front prop off , problem solved , been running a 2.5 dse around Donegal for over a year now like that , drives better , tows better , and cheaper to run , getting a extra 6 mpg without the front prop fitted