LT77 Gearbox Problems

[JonB]

Hello.

My 110 county, Originally 2.5td, Currently 200tdi has gearbox problems.

It started with a whine about 1 week ago.

Next it started making Banging noises & jumping out of high ratio.

Then the speedo stopped working

Now it sounds just like a very old London tube train complete with the vibration!

I guess the transfer box is foobar

It was involved in an accident a couple of years ago where the front axle moved back, jammed the slide on the front prop & eventually sheared the bolt off the front diff so i suspect the front output from the transfer box might not have enjoyed that much.

I have access to a low mileage disco 1 complete gearbox & transfer box.

I know the final ratio is higher than the landy box but, will the 1st gear ratio be much higher?

Its a heavy vehicle (winch etc fitted) & it will struggle pulling away on a slope with trailer with a 1st gear higher than the current.

Any help re the above gratefully received, also do i need any special parts to make it fit.

Thanks (The hint of snow in the air and it always appears to break down!)

Jon.

[Ex Member]

Changing to a higher transfer ratio will impact all gears. IMO, in a heavy 110 the disco box will be too high for first gear unless you are happy with starting in low range....

[ejparrott]

For a 110 the general consensus does seem to be to stick with 1.4 at the most, 90's being lighter tend to get away with the 1.2.

[JonB]

Damn, i was hoping that the 1st gear on the disco box would be lower ratio than the 110 1st gear.

Is there a way to reduce the 1st gear ratio in the main box to compensate the higher overall from the transfer box?

Jon.

[Simon Smith]

I had a disco T box in my old 200Tdi 110, and while it made top gear much higher, it still pulled well to 85 mph. Towing a trailer seemed largely unafected, and I didn't really notice the difference in first gear. I was on 235/85-16 Tyres.

[miketomcat]

You could fit a 1.6 t-box from an early 110 that will make all high range gears lower but if you use motorways I would recommend it 70 becomes unpleasant. Also 90's have a slightly lower t-box 1.44 as aposed to the 1.41 in a 110. Personal I'd stick with a 110 t-box.

Mike

[DaveSIIA]

My 300Tdi 110 is happy enough with a 1.2 transfer box. Much better on motorways and not noticed any problems towing heavy (2.5 ton +) trailers in the Peak District. Low box not needed, except for restarts on steep roads with maximum weight in tow.

I'd fit the Disco transfer box to keep you mobile for now and see how you get on. The swap isn't a major job.

[LiamC]

I have a disco transfer box in my 110. Yes 1st is now a bit too high but the benefit for motorway cruising more than makes up for it. I have had to use low box on a couple of occasions for a very steep hill start but overall I'm very pleased with the 1.2 box.

[JonB]

Thanks for all the information.

The Garage have had a look and report the diff has cracked

For now the garage have suggested fitting the complete Discovery gearbox / transfer box. (Once i have got the gearbox to them that is)

I will keep the old one & perhaps rebuild or replace the transfer box during the summer.

While its out a new clutch is probably worth doing & they can replace the slightly dodgy starter motor as well.

Are many parts going to have to be swapped from the 110 box to the Disco box?

Will it be simpler just to swap out the transfer box rather then the entire gearbox?

There a good little local Garage (I have no facility's usable during the winter) but not land rover specialists.

Thanks

Jon

[Mo Murphy]

Jon,

You only need to change the transfer box which is bolted to the back of the gearbox, not the gearbox itself. The diff is a part of the transfer box. If you use the discovery gearbox you will find the gearstick sticking up between the seats and not through the tunnel as it does now, as it is not a straight swap nor can it be simply converted ?

HTH

Mo

[JonB]

Thanks, i thought as much but wanted to confirm it, i will call the garage tomorrow & let them know what's required.

[ejparrott]

To use the disco gearbox you'd have to take it apart to change the bellhousing, input shaft and the selectors...plus a few other bits I think - nearly did it once a few years ago. By the time you'd done that you might as well rebuild yours anyway. Just change the T'box for now, and let us know how you get on with the taller gearing.