Which Transfer box with LT85 - which Overdrive?

[Oakmaster]

Apologies if this is a daft question

I have a 1989 110 Pickup, originally fitted with the Turbo D, but at some point replaced by a 3.5 Carb V8 (LPG) There is a an LT85 gearbox (which howls) and I need to replace the clutch, so was wondering what to do? I found the GKN Overdrive really useful (esp when towing) on my 300Tdi 110 CSW (when it was working) and had a Rangerover Type Fariey on my Stage 1 V8 Its all going to have to come to bits to sort the Gearbox and clutch, so I was wondering if my GKN overdrive would fit?

Which Transfer box was fitted to the LT85? and would this transfer box take an overdrive?

thanks

[PieEater3142]

Not entirely sure if this is right but:

http://www.ashcroft-...od&productId=81

It says LT85's were fitted to V8 defenders and as far as I'm aware these were all LT230's, Borg and Warner were only on the Rangies but I could be wrong (and depends where the engine came from)? Guru's am I right here?

What box do you have on there at the moment?

As far as Overdrives go, GKN no longer make theirs but parts can be bought from Devon4x4 and you can pick on up for £400-600. However you will need to be careful about the number of teeth on the input gear. pioneer (another member here) went to fit a GKN overdrive only to find that his LT230 was from a V8 and so was not a 1.41 ratio meaning that the number of input gears was wrong and he couldn't fix a different input gear for the overdrive. If you have an LT230 at present on the back of a V8 you might want to check what ratio it is. This is written (but often: falls off, gets covered in mud, burnt off when getting filler cap off etc.) under the filler bung. If it's not there note the suffix of your transfer box and check on ashcrofts:

http://www.ashcroft-...od&productId=45

Although this cant guarantee anything as pioneer will attest, his innards were not what the box said on the outside.

If you have a V8 on an LT230 it could be the 1.41 or 1.2 ratio (1.2 was on 90's 1.41 on 110), if it's 1.2 you probably don't need an overdrive as 80mph is attainable at about 2700rpm, with 60mph in 4th, at which point most people here will agree, it's better to stick with the transfer box you have.

Also just a thought as you say it howls, ashcroft say people replace the LT85 with R380 suffix L as it lasts longer. Is the howling due to worn bearings? Are you looking to replace/refurbish the gearbox or just the cluch?

If you're thinking of changing your running gear, best to have a play with this:

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

and see what best meets your purpose. Get your suffix numbers first (only the transfer box if you have an lt85) and the size of your tyres and diff ratio - standard is 3.54

[Bingy]

I thinkk before you go any further, you need to know what the serial number and suffix the transfer box is. Yes internals can be swapped, but you will then have more of an idea whats down there.

Have a look at the full page below for Ashcrofts. ~There are a couple of vids on here that will help you find your serial and suffix numbers

As your gearbox is an LT85 mated to a 3.5 V8, you could possibly have a 1.667 ratio box down there. If motorway cruising is what you are after, then simply swap for a 1.2 ratio and forget the overdrive. Low ratio is uninfected.

http://www.ashcroft-...od&productId=45

HTH

[Oakmaster]

I thinkk before you go any further, you need to know what the serial number and suffix the transfer box is. Yes internals can be swapped, but you will then have more of an idea whats down there. Have a look at the full page below for Ashcrofts. ~There are a couple of vids on here that will help you find your serial and suffix numbers As your gearbox is an LT85 mated to a 3.5 V8, you could possibly have a 1.667 ratio box down there. If motorway cruising is what you are after, then simply swap for a 1.2 ratio and forget the overdrive. Low ratio is uninfected. http://www.ashcroft-...od&productId=45 HTH

Thank you for the advice and help, I suppose one factor is that I already have the overdrive.