LT95 Ratios

Technical questions and answers
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Raggylad
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LT95 Ratios

Post by Raggylad »

I have recently had to replace the LT95 on my 1983 110 V8 (transfer box decided to eat itself after shedding most of its oil on a long run). Finding a reconditioned box in UK - or a firm prepared to recondition my old box) - took a while, as the LT95 is increasingly rare but eventually I sourced a reconditioned box.
This was sold as a 110 box and has the correct 13C prefix serial number (thanks Dutch website ID'd elsewhere on the forum !). The driving experience is now much smoother and quieter ..... but the final drive gearing seems far taller than the old box. I'm having to change down earlier on familiar hills, acceleration in 3rd and 4th gears is noticeably slower and top end speed seems to have reduced (though I have yet to check this accurately with GPS). Basically, I now have to spend far more time in 3rd than before even on relatively shallow slopes and don't put it into overdrive until over 60mph on the flat (previously 50mph). I haven't tried towing yet, but am concerned that the vehicle is going to struggle more.
Luckily, I fitted a recon engine (with a 3.9 cam and SU HIF44s) last year, so I have a good power unit which partly counteracts the tall gear effect - the 'on cam/off cam' effect is particularly noticeable now.
Short of taking everything apart again (and those who have wrestled with their LT95s will recognise why I am reluctant to do this !) to count teeth on gearwheels, is there any way of identifying what final drive ratio I have ?
Do I have a justifiable beef with the supplier ? It seems to be a good box, but the innards don't seem to match the serial number on the casing and I've lost flexibility in my vehicle's capability. Or do I just suck it up and get used to driving differently ?
1983 110 V8 Station Waggon - LPG converted

There is nothing, absolutely nothing, quite so much fun as messing about in boats
5988
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Re: LT95 Ratios

Post by 5988 »

Have you got a tacho you can fit even temporarily,

If you know the engine speed you know the main box is direct drive and diffs are 3.54, tyres you'll know so you can work it out from knowing the rpm at a given speed.

Without that your a bit stuck

Suppose you could mark some points on the floor, and push it between then in top gear and count the number of times the engine turns ... Then calculate it - nor as accurate though

Is uite possible the supplier doesn't know someone changed the ratios is quite commonly done
5988
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Re: LT95 Ratios

Post by 5988 »

Infact can't you count the teeth just by dropping the bottom cover off the transfer box?
disco2hse
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Re: LT95 Ratios

Post by disco2hse »

1. Replaced the original top gears with LT95 from Rangie?
2. It is an LT95 from a Rangie?
Alan

1983 ex-army FFR 109 Stage 1
2005 Disco 2 HSE TD5
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Geoff
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Re: LT95 Ratios

Post by Geoff »

Yes, you have a justifiable beef with the supplier - it's not as described and, imo, not fit for purpose. You don't have to prove it unless the supplier disputes it. I would be so pissed off in your situation :x
2 1981 Stage One 109 V8 SWs
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Raggylad
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Re: LT95 Ratios

Post by Raggylad »

I've raised this over on the LR4x4 Forum as well. The consensus over there is that (given that the serial number on the casing - 13C - is correct for a 110) the transfer box ratios may have been swapped out for Range Rover ones at some stage in its life and that the reconditioner would just have replaced like with like.
I'm going to take a look at the ratios in the old box before I send it back as an exchange unit to see if they are salvageable and, if they are fit them to the new box. I'm not hopeful, as the old transfer box was pretty well trashed.
If that isn't possible, does anyone know where I can get hold of the correct ratios (1.3362:1, I think, for a 1983 110 V8 ?) new in UK ?
Thanks for all the input.
1983 110 V8 Station Waggon - LPG converted

There is nothing, absolutely nothing, quite so much fun as messing about in boats
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Geoff
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Re: LT95 Ratios

Post by Geoff »

Kind of defeats the purpose of buying a reconditioned unit, if you start putting your old bits in it, doesn't it? Assuming you got some sort of warranty, I imagine it would invalidate that too. I would be wanting to return it for a full refund at the very least, if not compensated for all the time & trouble (& expense?) of fitting it. From what you say about driving it, I'm sure everyone's right about the transfer box ratios having been swapped for Range Rover ones, and I don't see it makes any difference to your rights as a purchaser what the reconditioner thought (although I don't see how he could have replaced parts with new without knowing what they were) As far as I know the ratios in the early 110 LT95s are the same as for the Stage 1 - I actually have an early 110 LT95 in one of my Stage 1s and I've never noticed any difference in the gearing from my other Stage 1. I would have thought it was a matter of finding the part numbers from the relevant parts books and then start searching online, but if it was me I'd be wanting my money back and then back to the drawing board looking for another box, rather than doing the work I'd already paid someone else for - perhaps at the very least you can negotiate something to compensate for the trouble (yours) of putting it right.
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Raggylad
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Re: LT95 Ratios

Post by Raggylad »

While I pretty much agree with you, this is a daily driver and I need a working vehicle on the road with minimal interruption. It was off the road for 2 weeks getting this far.
I'll be speaking to the supplier tomorrow, in any case.
1983 110 V8 Station Waggon - LPG converted

There is nothing, absolutely nothing, quite so much fun as messing about in boats
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Geoff
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Re: LT95 Ratios

Post by Geoff »

That's how I ended up with two! :) (beware ebay!)
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Raggylad
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Re: LT95 Ratios

Post by Raggylad »

Long silence while I got this one sorted ...... and a cautionary tale.

As it turns out, there's nothing wrong with the transfer box ratios. As fitting the recon LT95 box was the only thing (as I thought) that had changed, I jumped to the conclusion that the symptoms described earlier were the result of that change. Wrong !

The 110 was off the road for about 10 days while the new box was sourced and fitted, so when I drove it again afterwards I noticed what was in fact a loss of power. I had forgotten that:

a. Engines running on LPG are very sensitive to the quality of the spark and

b. An 8 cylinder engine pulls best when more than 7 cylinders are firing reliably

A long run along the M4 motorway in wet conditions highlighted an intermittent misfire. Stopping at a service station, I found 2 plug leads slightly loose and one with a corroded terminal. Nipping the loose ones up and a bit of work with emery paper made an immediate difference. I've since fitted new leads, plugs distributor cap and rotor arm and the 110 is once again pulling as she should.

It just goes to prove that assumption is often the mother of f***up ..... and this one was nearly very expensive !
1983 110 V8 Station Waggon - LPG converted

There is nothing, absolutely nothing, quite so much fun as messing about in boats
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Geoff
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Re: LT95 Ratios

Post by Geoff »

I love it when a problem turns out to have a simple solution - glad you found it before you took the gearbox out!
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