HELP Transfer box nightmare!!!

Ive got a M reg 300tdi Disco with the ZF 4 Speed automatic.

My transfer box turned itself into soup....which is fine as been a mechanic I pulled the landy onto the workshop ramp and started taking the transfer box out.

I located a second hand transfer box for £100 along with an unworn out put shaft for the gearbox.

Slapped it all back together and it is now apparent that the ratios of the replacement transfer box are wrong.....from what I can make of the ratio sticker it say's. 1.222

The problem is that at 60-70mph the engine is at 3500 revs, if not more.

An educated guess that the manual and auto Disco's use different transfer boxes due to one been a 5 speed and one been a 4 speed...

My question is this.....What ratio transfer box do I need and has anybody got one that they want to sell???

I dont still have my old transfer box...there were no stickers on it anyway.
Any help at all would be great.

Hello mate, I can't answer your question, but if you take some time with this ratio calculator in the link below, you should be able to work it out. If not, I'm sure someone will be along to advise you later.

http://www.ashcroft-transmissions.co.uk/calc/ratio_calc.html

It will be alright off road though with that in, mine never sees 70mph anyway so it wouldnt bother me, you sure its not a defender tranny box? quite a common mod to swap deepender boxes for disco boxes so they can actually travel on the motorway without causing too much bleeding in the eardrums of the occupants.

have you done a search on here as it is mentioned quite a lot but as i say usually from disco to def not the other way round.

I am familiar with the disco TF box into the defenders.

The standard manual disco is 1:1.2

It just worries me that its working soooo hard at 60-70mph cant help but think somethings going to go bang!!

If anybody wants the 1.222 box that I have got at the moment slipping into a defender I am able to take on such a job....for a small fee obviously!!

I think the ZF is normally coupled with LT230 1:1.193 does this sound about rite?

Huddy44 said:

I am familiar with the disco TF box into the defenders.

The standard manual disco is 1:1.2

It just worries me that its working soooo hard at 60-70mph cant help but think somethings going to go bang!!

If anybody wants the 1.222 box that I have got at the moment slipping into a defender I am able to take on such a job....for a small fee obviously!!

I think the ZF is normally coupled with LT230 1:1.193 does this sound about rite?

Click to expand...

zf auto is normally couple with a 1.222 as manual in discoor borgwarner in rrc my favourite t/box

£100 was a good price !

Right then.... Just tested it on way home from work, at 60mph on a flat road the engine is sitting at 2000rpm.
Is this about rite?
It seems alot more "revvy" since the new TF box was fitted. Maybe I am been paranoid.
I have also aquired a 1:1.193 TF box from an old RR, would this reduce revs at cruising speeds?

Huddy44 said:

Right then.... Just tested it on way home from work, at 60mph on a flat road the engine is sitting at 2000rpm.
Is this about rite?
It seems alot more "revvy" since the new TF box was fitted. Maybe I am been paranoid.
I have also aquired a 1:1.193 TF box from an old RR, would this reduce revs at cruising speeds?

Click to expand...

Sounds about right to me. I think i am at about 2500rpm at 70mph so there or thereabouts.

Tyre size? it will make a big difference, as i said mine never sees anything like 120kph so can tell you about revs but again I am running 235/85 tyres so 32" tall and it has affected the gearing a fair bit, when i dropped to some 29" tall jobbies a couple of weeks agao it changed the whole landy's feel.

My tyre size - 245/75/16's which have been fitted for months & months.

Thanks for all the responses though guys!!

2500 is good for 70mph , I generally reckon about 2700 on the flat at that speed . And the 2 at 60 , again good and low . I would leave it at that myself and be glad of getting it !

I might take your advice, and work on the basis that if its not broken....dont fix it!!

Suppose it will just take some getting used to.

Thanks pal

You're welcome mate . Put your location up on your sig when you get time ....never know , someone might drop round .

Not a transmission expert by any means so sneer at me by all means.
Are you sure that the Auto box has changed up into its highest gear?
When I was looking for my Disco a guy told me that the Auto box goes into top and then at a certain speed it "locks" and the revs drop a tad more.
Might you have knocked something when you were fetching the TB out/in?
Apologies if this is bollox.

2000 @60 is good i would say i do about2200 at 60 with 235/85/16

It still locks up at 50mph. Which I am happy with. Thanks for all the replies though.
I am located in sherburn in elmet (Leeds) full garage services available for all!!!

A happy ending for once ! All cool then

hi huddy where abouts are you and is the 1.222 transfer box still available cheers

QUOTE - [U]"I am located in sherburn in elmet (Leeds) full garage services available for all!!!"[/U]

I have decided to keep the 1.2 TF box in the car after the replies on this forum. I have a 1.193 TF box out of a RR? I may be able to locate a 1.2 TF for sensible money if your interested?