1.667:1 transfer box in a disco?

Russell 1 said:

I'm trying to get my head around how the egt would rise due to different gearing. I had a quick read and it looks like more fuel means higher egt and incorrect timing, leaky valves and restrictive exhaust will do the same. I'm not arguing but I can't see why the egt would rise.
Edit:

Unless I suppose it is counting on the cooling effect of the intercooler, are these things tuned that close to their limit ,134hp from a 2.5l?

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Basically when you plant the pedal the engine tries to repsond by giving you what you want and loads it up massively, the tall tyres means the time under large loads in each gear is increased quite a bit, large loads = high egts, conversely high rpms and decent boost will be lower egts.
Its a game like all engine tuning, sometimes you wint other times you lose big time.

I took out the 1.19 tfer box in my 90 and stuck in a 1.4, lovely and now revs easier/pulls better and now I can actually use top gear, with the 1.19 it would literally spend an age trying to get enough revs to grab the next gear.
Dont get me wrong, like all defenders its still a bag of wnak but its now a usable bag of wnak!

Ok thanks all I will bear that in mind

beginning to wonder what weights you are trying to pull.
The TD5 is set up tp tow up to 3.5 tonne and it will do it, as I have done it loads of times, but the closer you get to the max, the harder it is obviously.
I have known someone overload a trailer with stone slabs and use low ratio to take off and/or go up hils and then change to high range on the move, but that may be a step too high for you.
With existing ratios, bigger tyres would make the whole situation worse, unless you fancy driving around in low box all the time. Even then....
Best of luck!

2.7 tonne is the max I pull at the moment but it really takes a lot of clutch slipping to pull away in 1st high so I have been using 1st low and then 1high. Even once I've pulled away the gears seam far to high. Empty with no trailer it is fine but I feel it's working to hard with a trailer and won't last. I did a job last year than involved shifting 40 tone of gear ( obviously not in one go) and I'm sure that's what killed my shogun and that had led miles on it.

Russell 1 said:

2.7 tonne is the max I pull at the moment but it really takes a lot of clutch slipping to pull away in 1st high so I have been using 1st low and then 1high. Even once I've pulled away the gears seam far to high. Empty with no trailer it is fine but I feel it's working to hard with a trailer and won't last. I did a job last year than involved shifting 40 tone of gear ( obviously not in one go) and I'm sure that's what killed my shogun and that had led miles on it.

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That really doesn't sound right. Wondering if there is another fault there. i.e. wondering if you have everything standard on the LR or not, cos as standard it really shouldn't be like that.
Wot does everyone else think?

Might be as simple as slipping clutch ?

sierrafery said:

Might be as simple as slipping clutch

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Possibly, but I'd a thort he'd have found that going up any sort of a hill with all that on board. But agree, it could be something else simple. i suppose there are peeps who have never experienced a slipping clutch and therefore don't recognise it as such.

It's definitely not a slipping clutch. Everything is standard and I very much suspect the engine is putting out the power it is supposed to. There are a few hills around here but nothing mental. I'll keep an eye out for a cheap 1.4 and see if that helps

Russell 1 said:

I'll keep an eye out for a cheap 1.4 and see if that helps

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My bad that i wasted my time to explain you things... i'm wondering why did you ask in the first place if you were determined to bastardise the D2 anyway

Calm yourself, I will also look in to fitting an exhaust gas temperature gauge to keep an eye on things. If it dies soon after I will have to move to a different car because as it is, its not really up to the job of heavy, regular towing. I do like the car though so if I can make it more suitable for not a lot I will have a go.

If you think it's better to do experiments rather than remap it then that's it... meanwhile count the threads on the wastegate rod between the locknut and the valve, standard setup is at 13, turn back the nut and adjuster as to let 10 and you'll gain some guts right away... if you'll not feel improvement then maybe the turbo is ''tired" or some other issue so better read some live data with tester cos if the boost is low no ratio will help
1. did you ever clean the MAP sensor?
2. did you try wih MAF unplugged?

btw what year is the D2 and do you still have EGR?

I say again, having done what you are doing over a period of 6 years at relatively high speeds, doing distances of 500 miles at a time and in an auto, in a totally unmodified TD5, I had no problems.
Your car is not behaving normally and you need to get it all checked out.
Get to the bottom of the problem that your vehicle has. Do not assume it is as it should be and then go trying to "improve" it.
And are you sure you are not trying to tow actually more than 3.5 tonnes? Have you put the loaded trailer on a weighbridge?
Are you counting the weight of the trailer as well as the load?
Seriously mate, a TD5 in good nick should do the job.

Russell 1 said:

Has anyone put a 1.667:1 or a 1.4:1 transfer box in a discovery? If so what does it drive like? I do a fair bit of towing and I find pulling away difficult with any sort of weight in the trailer. As it will need a new gearbox soon I'm thinking I could be wise to change the t box.
Motorways and driving over 50 are not needed where I live.

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i fitted a 1.4 for a customer who was towing a very heavy trailer(6 wheel cattle trailer 50 miles to newark cattle market once a week)it worked well towing with the load,but we later fitted an overdrive to make his return empty trailer trip better, he ran it for years with no problems, i still service the truck 10 years later,but it hasnt the overdrive now as it failed

Always wished it was easier to fit an overdrive on a Disco like you can on a Defender. Although 5th gear is pretty OK on a TD5.
Wonder how many beasts he loaded in it!

Stanleysteamer said:

Always wished it was easier to fit an overdrive on a Disco like you can on a Defender. Although 5th gear is pretty OK on a TD5.
Wonder how many beasts he loaded in it!

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had to cut the floor and extend the tunnel a few inches under the cubby box,but 1.4 and overdrive gave him the best of both worlds for a good few years,

jamesmartin said:

i fitted a 1.4 for a customer who was towing a very heavy trailer(6 wheel cattle trailer 50miles tonewark cvattle market once a week)it worked well towing with the load,but we later fitted an overdrive to make his return empty trailer trip better

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Did he have EGT gauge and if yes what was the EGT then? IMO playing with ratios on a Td5 without watching the EGT is risky.

sierrafery said:

Did he have EGT gauge and if yes what was the EGT then? IMO playing with ratios on a Td5 without watching the EGT is risky.

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no, and never had egt issues or any other apart from a sprung tow hitch frame he has fitted at the dealers as the 6 wheel trailer held the rear of the truck up or lifted it on uneven roads ,the truck would let air out of the suspension and it would lower the rear too much and compressor to level it up was too slow,

it's hard to know if there were EGT issues or not while no EGT gauge was fitted ... i also thought i had no EGT issues when i made some remap experiments and bigger tyres on mine cos there was no visible sign and it ran like a dream but my joy faded away when i fitted the gauge and saw 850-900 under heavy load .... not long after that i had to replace the head due to a crack... can be coincidental or not.

sierrafery said:

it's hard to know if there were EGT issues or not while no EGT gauge was fitted ... i also thought i had no EGT issues when i made some remap experiments and bigger tyres on mine cos there was no visible sign and it ran like a dream but my joy faded away when i fitted the gauge and saw 850-900 under heavy load .... not long after that i had to replace the head due to a crack... can be coincidental or not.

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youd expect a lot of warped manifold issues at least,which occur with standard discos especially after the loads he pulled the regularity and years concerned,never had head problems or gasket changed unlike mine which is bog standard

jamesmartin said:

had to cut the floor and extend the tunnel a few inches under the cubby box,but 1.4 and overdrive gave him the best of both worlds for a good few years,

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Must have misunderstood, did you fit the overdrive on a Disco? If so, you have cheered me up as I always though it ought ot have been possible with a bit of bodywork modification.