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Poor fuel consumption - answer found (I think)
Posted: Wed Aug 10, 2011 11:12 am
by Alacrity
I have very poor fuel mileage on my diesel 4x4, 20 - 22 mpg at best even pussyfooting around & I have finally - I believe - found the cause, or rather the MOT man did. When I picked it up he said that all four wheels were difficult to turn & sure enough he was right. It turns out the viscous coupling in the transfer box is seized, I am amazed I didnt feel it when driving. It has a LSD in the rear so that made things worse. So currently it is a 4x2 until I get hold of either another transfer box or a good vicious coupling to replace mine with.
Anyone??
Re: Poor fuel consumption - answer found (I think)
Posted: Wed Aug 10, 2011 11:43 am
by mikeonb4c
Alacrity wrote:I have very poor fuel mileage on my diesel 4x4, 20 - 22 mpg at best even pussyfooting around & I have finally - I believe - found the cause, or rather the MOT man did. When I picked it up he said that all four wheels were difficult to turn & sure enough he was right. It turns out the viscous coupling in the transfer box is seized, I am amazed I didnt feel it when driving. It has a LSD in the rear so that made things worse. So currently it is a 4x2 until I get hold of either another transfer box or a good vicious coupling to replace mine with.
Anyone??
What and interesting discovery. Makes you wonder what influence deterioration in viscous coupling performance might be having on the mpg of Bongos as they age etc. I'll be very interested to hear if you see a jump in fuel economy from the moment the front wheel drive was disconnected.
It is not clear to me how easy it is to obtain new replacement viscous couplings and, if it is, what the cost would be.

Re: Poor fuel consumption - answer found (I think)
Posted: Wed Aug 10, 2011 11:53 am
by scanner
Alacrity wrote: good vicious coupling
Oohh nasty - nothing like a good vicious coupling to make things all sticky.

Re: Poor fuel consumption - answer found (I think)
Posted: Wed Aug 10, 2011 12:10 pm
by Velocette
scanner wrote:Alacrity wrote: good vicious coupling
Oohh nasty - nothing like a good vicious coupling to make things all sticky.

I'm searching for a line about Everard's but not many would get it!
Re: Poor fuel consumption - answer found (I think)
Posted: Wed Aug 10, 2011 12:26 pm
by scanner
Velocette wrote:scanner wrote:Alacrity wrote: good vicious coupling
Oohh nasty - nothing like a good vicious coupling to make things all sticky.

I'm searching for a line about Everard's but not many would get it!
Well it is a grey day.

Re: Poor fuel consumption - answer found (I think)
Posted: Wed Aug 10, 2011 12:32 pm
by jaylee
Velocette wrote:scanner wrote:Alacrity wrote: good vicious coupling
Oohh nasty - nothing like a good vicious coupling to make things all sticky.

I'm searching for a line about Everard's but not many would get it!
Alacrity, were the front tires not showing any signs of "castling" due to the VC seizure??
Re: Poor fuel consumption - answer found (I think)
Posted: Wed Aug 10, 2011 2:37 pm
by Northern Bongolow
hi can you share the details of how he/you came to this failure, i know your well up on these things ---but---, has it failed, or was the fluid just warm, causing semi lockup, as it should.
when they fail dont they fail (not locked up).
he isnt just giving you the shockers need doing mate speech with a twist is he.
there are youtube video's that explain how to test,and how much slip should be expected,and what speed free rotation is allowed without it starting to lock.
i had (i thought) a problem with mine a while ago,it turned out to be fine.
jack all wheels up free,then put a long bar on one rear wheel nut, and fasten a 5ltr container of water to the end, there is a certain time allowed for the container to fall to the ground,if it falls slowly without driving the other wheels it will probably be fine, if it falls quickly, its knacked,if it stays its also knacked.
the limited rear diff may alter the results a little though so bare this in mind.
Re: Poor fuel consumption - answer found (I think)
Posted: Wed Aug 10, 2011 3:21 pm
by Alacrity
Well it appears I am barking up the wrong tree. I was just speaking to Allan's Vehicle Services on another matter & mentioned it to Allan & he said that the fact that I can't turn the propshaft's independent of each other by hand is normal, you need a screwdriver in each propshaft UJ to be able to turn them. I must admit I was never aware that if you have a rear LSD all four wheels will be difficult to turn (on a wheel free ramp). It doesn't seem right to me. Anyway I shall see what mpg I get on a run to Cardiff & back (towing) with the front propshaft off.
Sorry for the bum steer folks, I really thought I had found some reason for the high consumption.
Re: Poor fuel consumption - answer found (I think)
Posted: Thu Aug 11, 2011 9:15 pm
by Velocette
jaylee wrote:Velocette wrote:scanner wrote:
Oohh nasty - nothing like a good vicious coupling to make things all sticky.

I'm searching for a line about Everard's but not many would get it!
Alacrity, were the front tires not showing any signs of "castling" due to the VC seizure??

I meant this Everard ....
http://www.shipphotos.co.uk/pages/alacrity.htm most of their ships had ity endings to their names
Re: Poor fuel consumption - answer found (I think)
Posted: Thu Aug 11, 2011 10:48 pm
by missfixit70
Velocette wrote: I'm searching for a line about Everard's but not many would get it!
You're right, I'm pretty sure I just saw some tumbleweed rolling past

I was in the merch & I was nowhere near getting that one

Re: Poor fuel consumption - answer found (I think)
Posted: Fri Aug 12, 2011 1:12 pm
by Velocette
missfixit70 wrote:Velocette wrote: I'm searching for a line about Everard's but not many would get it!
You're right, I'm pretty sure I just saw some tumbleweed rolling past

I was in the merch & I was nowhere near getting that one

You probably have to have been in the Merch and be over 60!
They used to say if a ship was duff to sell it to Everard's and call it "The Calamity".

Re: Poor fuel consumption - answer found (I think)
Posted: Fri Aug 12, 2011 9:55 pm
by Rhinoman
Back on topic...
I've always had a bit of wheelspin when pulling away with a bit of lock from cold. I've no idea whether thats normal or not, it doesn't seem so bad once its warmed up.
Re: Poor fuel consumption - answer found (I think)
Posted: Fri Aug 12, 2011 10:34 pm
by Diplomat
Getting back off topic...
The Everard comment wouldn't have been lost on me if Velocette might have been less subtle and prefaced Everard with 'F.T.'
Every schoolboy of a certain age, particularly ones who listened to Niton, North Foreland and Land's End on the trawler band, knew that ships ending with ..ity were Everards and those ending with ..ence were London and Rochester.
later in life, when I came to live near Greenhithe, I was able to view some of the Everard fleet and see for myself their uniquely unattractive colour scheme.
I'm sure that when I first noted Alacrity's presence on the forum I was minded of Everards but I would have been distracted from that thought by the fact that our Alacrity's speedboat is considerably smarter than the rusty khaki of the Greenhithe ships.
Frank
Re: Poor fuel consumption - answer found (I think)
Posted: Fri Aug 12, 2011 11:41 pm
by Velocette
Diplomat wrote:Getting back off topic...
The Everard comment wouldn't have been lost on me if Velocette might have been less subtle and prefaced Everard with 'F.T.'
Every schoolboy of a certain age, particularly ones who listened to Niton, North Foreland and Land's End on the trawler band, knew that ships ending with ..ity were Everards and those ending with ..ence were London and Rochester.
later in life, when I came to live near Greenhithe, I was able to view some of the Everard fleet and see for myself their uniquely unattractive colour scheme.
I'm sure that when I first noted Alacrity's presence on the forum I was minded of Everards but I would have been distracted from that thought by the fact that our Alacrity's speedboat is considerably smarter than the rusty khaki of the Greenhithe ships.
Frank
I remembered one being moored at Avonmouth when I was working there and I often wondered if that was why Viv Stanishall renamed the Thekla the Old Profanity although it was nothing to do with Everards AFAIK. Oops sorry, there I go again,
Re: Poor fuel consumption - answer found (I think)
Posted: Wed Aug 17, 2011 11:29 am
by Alacrity

Yes I guess mine is a little faster, but it won't carry as much or go as far - possibly more fun though!
Well I have just done 510 mile round trip to Cardiff & back, towing (a light boat), without the front propshaft on & I got a fabulous 21.7mpg.

So Allan was right & there appears there is nothing wrong with the transfer box. The only thing I can think of now is to send it to get the pump & injectors looked at.
Still don't get why it is difficult to turn
all four wheels though, I would have thought the fronts should be easy to turn. I have an LSD in the back so that will mean turning a rear will be trying to turn all four of them.