1.2 to 1.4 Transfer Box Costs

[Def88]

Hi All,

I have my Land Rover 90 1988 with a 200tdi disco automatic on a 1.2 transfer box at the moment. It’s great on motorways but any kind of incline it really starts to struggle, say A roads etc. After speaking with Glencoyne Engineering they’ve recommended to go to the 1.4 transfer box to have that extra power and stop the lock up at 48mph and constant changing of up and down the gears. It’s fitted with a 4 speed auto.
 

Would anyone recommend any garages and what kind of cost this may involve as it’s something I’m looking at doing maybe in a few months, 

Thanks All

[Def88]

Tyre size is also 265/75/R16’s

[FridgeFreezer]

I thought a healthy 200TDi should pull that gearing but I'm no TDI expert.

It's not a very hard job to DIY, given your location I'd say it's worth joining Shire Land Rover Club and see who's got a transfer box for sale and if anyone is willing to give a hand with fitting.

We're at Broxhead this Sunday / pub social on the 7th you'd be welcome at either or both.

[vulcan bomber]

I had a 1.2 transfer box on my 200TDi for 5 days, it was bloody awful. With the 1.4 box on it will tow 3.5 ton trailers over the speed limit relativly easily but the power delivery isnt there for a 1.2... 5th became almost obsolite when unladen.

 

The transferbox is a fairly simple thing to change, if you and a mate can hold a spanner between you then you'll be able to change it yourself.

[Bowie69]

I have the LT230 innards available for not much cash which would allow you to convert your 1.2 to a 1.4, if you are handy with a spanner this could saves you hundreds....

Let me know if interested.

[bishbosh]

My 200TDi auto 90 with a 1.2 also struggled on hills so can understand the OP's problem. As others have said, changing a transfer case is not hard if you have a helper.

[Def88]

Thank you all for your replies! Really helpful,

I’ll try and do some more digging and figure how is best to change it. 

[Anderzander]

I have a 1.2 in a Td5 with a map - in all normal circumstances it’s perfect, but I had a 500kg trailer on it with a 1600kg tractor on it recently - and that needed the clutch working on some hill starts. 

I’m started to think the ideal would be a Roverdrive with a 1.4 - if I could leave it in high for normal driving, and drop it down for towing .. seems like I’d get the best of both worlds. 

Though that said I don’t tow very often. 

[muddy]

I would advise the same, we used to have a 300 auto disco on 235/85 tyres and until you got it up to 70-80mph it would always drop speed on hills, once at cruising speed it was in a sweet spot and would happily sit there but the defender aerodynamics won't allow that.

What tools and facilities do you have available?

[ThreePointFive]

I have a 1.2 and it takes a pretty steep hill to slow it down. If anything I wish I had a 6th gear on the motorway. 

Do you 1.4s not find it difficult for cruising?

[FridgeFreezer]

3 hours ago, Anderzander said:

I’m started to think the ideal would be a Roverdrive with a 1.4

That's what we've got in the ambulance and I can confirm it's luvverly, V8 does help cruising though.

[Paul C]

I have a 1.2 behind the R380 in my 300tdi but managed to get the 1.4 box with it when I purchased it, so will be refitting that but changing the R380 5th gear to the V8 discovery gears for higher overdrive 5th.

Edited February 22 by Paul C

[Def88]

I think I’ve heard different things with the 1.2, some people like it with the manual defender, but with this auto box and 4 gears it just hits 48mph and goes into 4th and feels like I haven’t got enough to push on up a hill. Normal driving on the motorway is great, but A roads if you hit a steepish hill it always drop a gear at 48mph and changes between the two which is a bit annoying 

[FridgeFreezer]

You might want to look at the ratio calculator on Ashcroft Transmissions website, you probably want to compare your overall ratios to a Disco or Range Rover on stock tyres as that's what the auto box is geared for - assuming it's not from a V8 which I've heard has less well suited ratios for diesel conversions.

[Bowie69]

48mph is not 4th, that is lockup engaging and about right speedwise.

I think default is 52mph on 205s, that yours is lower suggests something is not quite right. Normally a higher gear will give a higher lockup. 

How is your kickdown cable adjusted? Too slack and it won't kick down and make it feel really sluggish being off boost. 

The auto is a higher 4th gear ratio that the manual boxes, around 0.7:1, so that combined with the tyres and you are really stretching the poor oil burner, and they aren't exactly fast as standard.... 

That brings me to final point, are you sure the TDi is running properly? 

[Maverik]

You've also got the option of 1.3... ashcroft do the this as a gearing option, I had half intended to do it on my manual 200tdi, as I think it would compliment it more than a 1.4 for all around "use".

But Auto's are a little different but worth considering.

[Chicken Drumstick]

I'd guess the only risk with a 1.3:1, you could go to the cost and expense of buying and fitting, only to find it is a halfway house and doesn't solve the problem. A 1.4 would normally be a lot cheaper to try out.

Discos would have had something like a 235/70 tyre or equiv, all about 29" tall. A 265/75R16 is 31.7" tall with the same gearing would be over geared. I'd guess the 1.4 would bring them pretty close mph per 1000rpm. I'll have a look on the Ashcroft gearing calculator now.

....

The Ashcroft calculator only shows one gear set for the ZF 4-speed auto, so I'll assume they are all the same.

235/70R16 - 1.2:1 - 60mph = 2172rpm

265/75R16 - 1.2:1 - 60mph = 1987rpm

235/70R16 - 1.4:1 - 60mph = 2528rpm

265/75R16 - 1.4:1 - 60mph = 2313rpm

 

I'd image a 1.4 would drive a heck of a lot better than the 1.2 with the only trade off being slightly more noise at motorway speeds. 50mph is only just over 1600rpm with the 1.2 and big tyres, so right on the boost threshold or just off boost, so no wonder it struggles to maintain speed at this rpm.

[Def88]

I think the consensus is to change to the 1.4, next job is finding one and fitting. Realistically I don’t do a huge amount of motorway miles and even if I do use the motorway my 1988 won’t be sitting at 70mph.. more like a casual 55-60. I’d rather have an overall better driving experience for those A Roads and the 200tdi will never be a quiet car, if anything.. it’s a bit strange being in a defender that prefers the motorway?! 
 

I’ve never had a problem with the engine at all either, it’s had a new turbo and hoses too and serviced every 6000 miles just to stay on top of it. I’m unsure of the mileage on the actual engine but the car shows 156000 but the conversion was done around 8 years ago.

 

thank you everyone for the help! And anymore advice on sourcing and fitting the 1.4 would be great!  

[Chicken Drumstick]

1 minute ago, Def88 said:

I think the consensus is to change to the 1.4, next job is finding one and fitting. Realistically I don’t do a huge amount of motorway miles and even if I do use the motorway my 1988 won’t be sitting at 70mph.. more like a casual 55-60. I’d rather have an overall better driving experience for those A Roads and the 200tdi will never be a quiet car, if anything.. it’s a bit strange being in a defender that prefers the motorway?! 
 

I’ve never had a problem with the engine at all either, it’s had a new turbo and hoses too and serviced every 6000 miles just to stay on top of it. I’m unsure of the mileage on the actual engine but the car shows 156000 but the conversion was done around 8 years ago.

 

thank you everyone for the help! And anymore advice on sourcing and fitting the 1.4 would be great!  

Swapping over should be quite easy and perfectly DIY'able if you have tools, space and a mate to help. Or look at swapping the internals over. If you get somewhere to do either job it is at max 1 days effort, but really more like 1/2 day. So don't let them overcharge you on labour. Any half decent mechanic should be able to do, nothing specialist about the job. Although if it is an LR place doing it. Then transfer box and new one in should be more like 1.5 -2 hrs.

[FridgeFreezer]

3 hours ago, Def88 said:

And anymore advice on sourcing and fitting the 1.4 would be great!  

Only what I said above - get on the ShireLRC facebook and ask around if someone's got a 1.4 transfer box locally, you never know who's got one sat at the back of the shed.

[Bowie69]

Yup, or is you fancy dismantling, and remantling your current known good box, I have the 1.4 gearset. 

[Paul C]

On 2/23/2024 at 8:34 PM, Maverik said:

You've also got the option of 1.3... ashcroft do the this as a gearing option, I had half intended to do it on my manual 200tdi, as I think it would compliment it more than a 1.4 for all around "use".

But Auto's are a little different but worth considering.

I have fitted the 1.3 to mine with the 4.6 auto, as I found the 1.2 too high and the 1.4 a little low. I haven't had it on the road yet but had done plenty of kms with the other ratios before I made the decision.  I am running 285/65/18 which are around 32"

[uninformed]

If anyone is going to do or supply the gear sets to convert their LT230 ratios, make sure you have the correct input gear rear bearing support plate. These changed in ~1998. 
 

And note, there are different input gear tooth count and even width depending on which ratio and year you have. So don’t mix and match. 
 

Less likely but possible, if you get an old gear set from suffix C/D cases, the dog teeth on the low and high range output gears (and corresponding high/low selector hub & ring) will be thicker than later cases. Again you can’t mix and match these. 

Suffix A/B cases have a larger intermediate shaft and use roller bearings so won’t swap anyway. 

[Bowie69]

Yup, this is the whole matched set, as mine was an earlier box and was fitting a 1.0:1.

So should fit anything, by my reckoning. 

[Eightpot]

Another interesting gearing option from Ashcrofts on thier recon boxes is the modified 5th gear ratio which gives 1.2ish cruising on a 1.4 box - would work out well if you don't do much towing.