The 110 has blown its gearbox again as er my other thread asking what the noise was (link). Happily stripped it out in a few hours (the advantage of a recent rebuild) and have now dropped it to ashcroft for what will be its third rebuild from them. while there the discussion of what box would be best for my needs came up, I currently run a 50A as that is what was behind my TD engine originally. The TDI engines had an uprated box, however the layshaft in these uprated lt77's is no longer available so if that is not good the box cannot be rebuilt, it is available for the 50A that I have. Ashcroft were trying to sell me, at great cost, a stumpy r380 as that would be better for my needs, is a better match for tdi, and they can rebuild it with an uprated bearing set on 5th. This all sounded very good until the question of life span came up:

From our great gearbox oracle James martin the lifesplan of an lt77 was somewhere between 60-100k miles.
Ashcroft also said lifespan 60-80 so agrees with James.
Based on when I last had mine rebuilt and the mot mileages the one that has just blown has done between 80-110k (cannot be bothered to dig out the paperwork invoice that i wrote the actual mileage on)
All of the above points to the lifespaln of an lt77 being correct at somewhere between 60-100k miles

When I then asked this question about the r380, which is a newer designed box, would have the HD bearing set on 5th, and cost nearly 3 times as much as getting my lt77 rebuilt because i would need to pay them for the core unit as well, i got the same answer and that the lifespan was about the same.

Both gearboxes having the same lifespan does not sound right, although they are the experts, and based on that I said to rebuild mine again and I would do my research in the mean time. No point paying a lot more money if there is no advantage in terms of how long it lasts (i know the gearing is slightly different and would be a slightly lower first and higher 5th which would be good). Does that sound right to the people on here, are both boxes really equal in terms of lifesplan?

Also if it is a route I want to go down I can then find my own r380 box so I do not have to pay for the core unit and just for the addition parts (stumpy bell housing, etc) and rebuild. Having said that are all r380's equal, and therefore any box form any vehicle will do, or do I need a specific box? I know it will need a stumpy bell housing and a different diff lock leaver to my lt77 etc but the lt77 had lots of different variants, is this the same for the r380?

Not sure how you are going through gearboxes? Ok there is an industry (Ashcroft mostly) rebuilding them. But plenty last just fine. We have several LT-77s well over 120 or 140 thousand miles. And R380’s with even more miles on them.

Tdi’s don’t make that much power and the 200 was supplied with the LT-77.

300bhp/ton said:

Not sure how you are going through gearboxes? Ok there is an industry (Ashcroft mostly) rebuilding them. But plenty last just fine. We have several LT-77s well over 120 or 140 thousand miles. And R380’s with even more miles on them.

Tdi’s don’t make that much power and the 200 was supplied with the LT-77.

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My 110 has 408k miles on the clock currently. On the gearbox first life they get much larger milage than the rebuild units in my experience and that seemed to tally with what James said form memory in an old thread. I did 160k before needing a rebuild on it first time around. This will be its third rebuild so I have got through three boxes, original and two rebuilds, in 408k miles meaning I am averaging 136k out of a box which is far more than any of the experts have given as a lifespan.
The 200tdi was supplied with a lt77 but, as I learned yesterday at Ashcroft, it was a different variant that had wider bearings in it to cope with the larger power from the tdi, either a 56G or 56H. These later variant had a different shaft which is no longer manufactured so can only be rebuilt as long as that shaft is in reusable condition.

I change the oil every 20k and for the last 5 years with my job average about 30k per year. So I am doing high milage on the motorways that these boxes were not originally designed for, remember they may have been fitted up to the mid 90's but they were designed in the 70's.

There is a jaguar box that will fit. Has a slightly higher 5th gear
Short bell housing etc

Now I don’t know the part number but was fitted to a previous 110 TDI.

Hicap phill said:

There is a jaguar box that will fit. Has a slightly higher 5th gear
Short bell housing etc

Now I don’t know the part number but was fitted to a previous 110 TDI.

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Don’t think Jag make any manual boxes. Certainly not of this period and not fitted to Land Rovers that I’m aware of.

12j, 19j & 200Tdi all use the LT-77. Across Defender, Disco1 and RRC including the VM diesels in the Range Rover. I think the Disco and RR might use the LT-77S for the V8’s.

Pre Defender V8’s use the Santana LT-85. I think they might have gone LT-77S too later on, but not 100% sure.

300Tdi onwards was R380. With the R380 stumpy produced for warranty replacement LT-77’s.

RRC also used the LT-95 but that is a 4 speeder. Think these were in the Stage 1 as well. Can’t recall if they found their way into early One Tens but might have.

300bhp/ton said:

Don’t think Jag make any manual boxes. Certainly not of this period and not fitted to Land Rovers that I’m aware of.

12j, 19j & 200Tdi all use the LT-77. Across Defender, Disco1 and RRC including the VM diesels in the Range Rover. I think the Disco and RR might use the LT-77S for the V8’s.

Pre Defender V8’s use the Santana LT-85. I think they might have gone LT-77S too later on, but not 100% sure.

300Tdi onwards was R380. With the R380 stumpy produced for warranty replacement LT-77’s.

RRC also used the LT-95 but that is a 4 speeder. Think these were in the Stage 1 as well. Can’t recall if they found their way into early One Tens but might have.

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Think jag nicked the model from triumph.
Also fitted to the tr7/8

Hicap phill said:

Think jag nicked the model from triumph.
Also fitted to the tr7/8

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5 speed TR7/8 uses LT-77. Jag XJ40 and X300 used a 5 speed Getrag.

300bhp/ton said:

12j, 19j & 200Tdi all use the LT-77. Across Defender, Disco1 and RRC including the VM diesels in the Range Rover. I think the Disco and RR might use the LT-77S for the V8’s.

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Yes but as mentioned above there were different versions and developments over that time

300bhp/ton said:

300Tdi onwards was R380. With the R380 stumpy produced for warranty replacement LT-77’s.

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Was there the same developments with the r380 or were they all the same fitted to defender and disco and therefore if I am looking for one I can look for the cheapest rather than a specific model?

@jamesmartin told me to buy K or L suffix because they had a stronger input and rear layshaft bearings. I did!

Just an idea, given your milage driven with much motorway 5th gear work when box would have time to get pretty warm would a gearbox oil cooler help.
I know Ashcroft do a kit for the R380. Oils do not like it if they are over their best operating temperature and start to brake down. Even if not the case the extra volume would likely help.

Changed the oil in my gear box's yesterday. Lt 77 has done 75k. I change at about 30k [sooner for the first]
Oil was pretty good looking and only a bit of filing fluff on the magnet. With fresh oil Fuchs Titan 3000 [ same in my tractors] I feel gear changed has smoothed up some.
The sort of driving I do is just about the opposite of @dag019, about 5k a year [ semi retired now] some off road most days, mostly single track lanes/roads and B roads, up hill and down winding stuff so plenty of changes and limited amount of 5th.
The 230 transfer is original and has 185k. Lots of wear but still works. It's oil was ok too

tottot said:

Changed the oil in my gear box's yesterday. Lt 77 has done 75k. I change at about 30k [sooner for the first]
Oil was pretty good looking and only a bit of filing fluff on the magnet. With fresh oil Fuchs Titan 3000 [ same in my tractors] I feel gear changed has smoothed up some.
The sort of driving I do is just about the opposite of @dag019, about 5k a year [ semi retired now] some off road most days, mostly single track lanes/roads and B roads, up hill and down winding stuff so plenty of changes and limited amount of 5th.
The 230 transfer is original and has 185k. Lots of wear but still works. It's oil was ok too

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The gearbox on my CSW was running fine (when it was on the road) until I changed the oil. Now 3rd pinches. Once I get back on the road I’ll send it away to be rebuilt. Maybe the old oil was masking something.

tottot said:

Changed the oil in my gear box's yesterday. Lt 77 has done 75k. I change at about 30k [sooner for the first]

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Is the change interval not 24k for the boxes? I do mine every 20k as it lines up nicely with resetting everything every 100k, same as I do the timing belt at 50k for the same reason. with the mileage I do 100k is relatively regular so having everything reset and line up makes a big difference. i am still running standard atf in my gearbox but it gets changed at least once a year base don 20k interval.

By "pinch" @doriz you mean it is a bit reluctant at times to go into that gear and if you pull back on stick a bit and try again it goes in fine? If so mine does that in 5th now and then.

dag019 said:

i am still running standard atf in my gearbox but it gets changed at least once a year base don 20k interval.

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On your recommendation I will switch to 20k, or every four years in my case. Titan 3000 is an ATF commonly used in commercial machinery.

tottot said:

On your recommendation I will switch to 20k, or every four years in my case. Titan 3000 is an ATF commonly used in commercial machinery.

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LINK I know it is haynes not actual land rover but it is listed here as renewal at 24k for both boxes and diffs. Also based on the other intervals listed they work on 12k per year so although it is not what it says I would be suggesting every 24k or two years whichever comes first, but I would much rather over service than under. Oil is a lot cheaper than a rebuild!

So rebuild the lt77 or sell a kidney for a stumpy?