LT77 V8 Gearbox to 200 tdi Engine - Help !

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J

JonH

New Member
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15
Hi,

I have just taken the engine and gearbox out of my 1994 200Tdi Disco, I have an LT77 out of a V8 disco to replace the old worn box with. (The box came complete with Bell housing and Transfer box).

I have attached the Tdi bellhousing to the V8 gear box. That was the easy bit! I have now run into a big problem and am struggling to find a solution.

The diameter of the Spigot /input shaft on the V8 gearbox is less than the one that is fitted to the Tdi gearbox. So the hole in the centre of the spigot shaft bush is too big for the V8 shaft. I have just got a V8 spigot bush which fits the shaft ok, however the outer diameter is smaller than the diameter of the Tdi Bush! :confused:

Looks to me like I need a bush that has the overall diameter of the Tdi spigot bush but the internal diameter of the V8 shaft? I would love to hear from anyone who has encountered this issue or knows where I might get a suitable spigot. The other alternative is to swap the shafts over but I've never tried dismantling a gearbox before and the idea worries me! Any help or comments would be greatfully received.

Thanks

JonH
 
Further to what you have already stated I do beleive that the internals of the gearbox will need beafing up .A V8 LT 77 Gearbox in standard form on the back of a 200 tdi is really not up to it .
If you want it straight from the horses mouth have a word with the gearbox specialists.
 
Its that one again is it mad :D, yes the V8 has more torque than a tdi BUT the TDi is harsher, 'torque curve like the eiger' is how I heard it described before :)
 
Taking on board these useful comments it has sent me thinking seriously about my options. Having heard the pro's and cons of LT77 vs R380 I would love to know if it is possible to fit an R380 gearbox to a 200 tdi engine? Or would I run into more spigot shaft or bellhousing problems ? If I bought an R380 box would my 200 tdi transfer box and Bell Housing bolt straight on ?

Any thoughts/advice would be very much appreciated.

Thanks JonH
 
R380s were fitted to later Discoverys. The gearbox is shorter - so you will need to get a longer rear prop. Dunno about Tbox, spigot & bearing.
 
Thanks for the extra info on this. Very interesting!

It all looks very complicated the best way forward seems to be - either sell the V8 gearbox and source a Tdi version or strengthen the LT77s box for Tdi use. Does anyone know which parts need to be changed to make the V8 box suitable for use with the tdi?

Any help would be very much appreciated

Thanks JonH
 
Just searched the Ashcroft site and found this interesting synopsis of the LT77 gearbox :

The LT 77 was introduced to the Landrover range in approx 1983 with the suffix D box and was developed over the years to the suffix H which was last used in 1994.

The D and E are very similar the only difference being the reverse gear was a little fatter in the E,

When they went from E to F larger layshaft bearings were used.

The G was further improved by all the gear teeth including the pinion getting approx 20% thicker. Also a much wider pump was used to increase the lubrication and cope with the fact that some of the LT 77's were now being supplied oil cooled, ie V8 NAS 90, 3.9 RR Classic and the 3.5 EFI Discos.

The H (termed the LT 77S) was the same as the G in terms of strength but used a different syncro set up called the 'Double Syncro', In reality it didn't work much better and introduced some weak points into the design.

The really interesting thing is that there is no mention of any material difference between LT77 for Diesel or V8. All the revisions seem to apply to both. I think that If I was replacing the 1994 LT77S with an early LT77 there might well be some issues. I am very tempted to go down the line of having a sintered bronze spigot bush fabricated and giving it a whirl. Just wondering if anyone has actually had a go at this particular job before?

Cheers JonH
 
Had a thought on this :)

when you say the spigot shaft is smaller, are the splines and the diameter of the rest of the shaft the same?

The toruque goes threw the splines not the spigot on the end this is just to align the bow, so all you need if the bush.

May be worth drawing it up and taking it to a small engineering company or ask around to get one made out of phozy bronze or oilite :)
 
Yeah, The actual Shaft Diameter and Spline spec is the same on both input shafts. The weird thing is that on the V8 the last inch of the shaft appears to have been turned down to a smaller diameter than the one on the Tdi. And that is the only thing that is stopping the box mating perfectly with the engine.

I am really hoping to find somewhere open tomorrow that will be able to get one made for me as I have a few days off over Christmas and need to get the box and engine back in the car before I go back to work on 2nd Jan! so no pressure there then! :eek:

JonH
 
hi jon
may have a solution to help us both i have a 200tdi gearbox which i got when i bought my disco with a knackered v8 gearbox. I was told that it would go straight on but have found it wont with out all the trouble you are having. So my solution is are you interested in a swop. so both of us get what we want. If so please email me on [email protected]. and i will get your number or give you mine so to discuss what we can do. Depending on where you live.

Thanks

Cogajorh ( gary )
JonH said:
Hi,

I have just taken the engine and gearbox out of my 1994 200Tdi Disco, I have an LT77 out of a V8 disco to replace the old worn box with. (The box came complete with Bell housing and Transfer box).

I have attached the Tdi bellhousing to the V8 gear box. That was the easy bit! I have now run into a big problem and am struggling to find a solution.

The diameter of the Spigot /input shaft on the V8 gearbox is less than the one that is fitted to the Tdi gearbox. So the hole in the centre of the spigot shaft bush is too big for the V8 shaft. I have just got a V8 spigot bush which fits the shaft ok, however the outer diameter is smaller than the diameter of the Tdi Bush! :confused:

Looks to me like I need a bush that has the overall diameter of the Tdi spigot bush but the internal diameter of the V8 shaft? I would love to hear from anyone who has encountered this issue or knows where I might get a suitable spigot. The other alternative is to swap the shafts over but I've never tried dismantling a gearbox before and the idea worries me! Any help or comments would be greatfully received.

Thanks

JonH
Click to expand...
 
The Mad Hat Man said:
R380s were fitted to later Discoverys. The gearbox is shorter - so you will need to get a longer rear prop. Dunno about Tbox, spigot & bearing.
Click to expand...
r380(300 box) is a difrent lenth but so is the bellhousing
therfor is acualy the same lenth
and goes straight in to a 200
there is lots of threads on here about the same thing
but bearin mind that the 300 altho is a smother box is also a weeker box than a 200
 
rock-sliders said:
r380(300 box) is a difrent lenth but so is the bellhousing
therfor is acualy the same lenth
and goes straight in to a 200
there is lots of threads on here about the same thing
but bearin mind that the 300 altho is a smother box is also a weeker box than a 200
Click to expand...


3yr old thread revival





you must be bored :p
 
but not as board as u must be
stalkin me on here all the time you wierdo
ive not only got muky kev to worie about by the looks of it
 
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