5 speed manual or LT77S ?

[Tank]

My Land Rover Discovery (up to 1994MY) Workshop Manual shows and describes a 5 speed manual gearbox and also an LT77S 5 speed manual gearbox, they look identical, are there 2x 5 speed gearboxes? How do you tell which is which, what is the "Ferrobestos" bush for? What does it do? Anyone got a special tool to remove the Seal Collar on the rear of the output shaft, Anyone know whether the oil pump gears in the box are made of steel or plastic? Any help would be appreciated, Regards Frank.

[Tank]

C'mon boys and girls there must be somebody out there that knows the ins and outs of this gearbox, the w/shop manual shows a "5 Speed" and an "LT77S", I've never seen a gearbox that needs so many "Specialist Tools and pullers" to dismantle, any tips or help will be appreciated, Regards Frank.

[Lotz-A-Landies]

My Land Rover Discovery (up to 1994MY) Workshop Manual shows and describes a 5 speed manual gearbox and also an LT77S 5 speed manual gearbox, they look identical, are there 2x 5 speed gearboxes? ...

...Regards Frank.
Frank You are correct about the specialist tools.

In fact there are variants of 2 main types of 5 speed in the Disco 1 and 2

The Range Rover had the first version of the LT77 starting in 1982 this was modified as below and later Discos received the R380 5 speed. The LT77S is actually the H suffix (version) of the LT77 gearbox.

"The gearbox number will be stamped or dot punched on the oval machined flat directly below the filler level plug, on the right hand side of the gearbox main casing. The relevant numbers we require are the first two and the last letter, i.e. the number may be 56A1234567G, we would call this a 56G."

From the Ashcroft Transmissions UK site (http://www.ashcroft-transmissions.co.uk/part_1.html#pa1)

LT 77 Development

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.

[cmurray]

Anyone got a special tool to remove the Seal Collar on the rear of the output shaft
Frank,
When I rebuilt my LT77, I used a 2 arm puller to pull the 5th gear housing off, as doing this pulled the seal collar off at the same time.

[Tank]

Thanks for that info, I'm still stumped by this "Ferrobestos" bush which is behind the rear seal collar, which I have spent the last 2 days unsucessfully trying to remove, I've busted 2 pullers, one a hydraulic, have frozen it, have heated it and it wont budge.
Reason I was asking about the oil pump gears is because of the heat applied to the seal collar would have damagged them if they were plastic, I have no reason to believe they are plastic, but I read somewhere that oil viscosity (too heavy) could break the plastic shaft, but I dont think that's the case here, any tips on how to get this seal collar off, Regards Frank.

[Tank]

Frank,
When I rebuilt my LT77, I used a 2 arm puller to pull the 5th gear housing off, as doing this pulled the seal collar off at the same time.
As you can see from my latest (posted after yours) this collar is well and truly stuck, I believe if I did it your way, with this collar as tight as it is I would probably damage the fith gear housing, as you can see in my post above it may come to having to cut the bugger off, any idea what this "Ferrobestos" bush behind the collar does??, Regards Frank.

[cmurray]

As you can see from my latest (posted after yours) this collar is well and truly stuck, I believe if I did it your way, with this collar as tight as it is I would probably damage the fith gear housing, as you can see in my post above it may come to having to cut the bugger off, any idea what this "Ferrobestos" bush behind the collar does??, Regards Frank.

Frank,
This bush is used as a seal between the oil pump and the main shaft, as the oil pump pumps oil through the mainshaft and into the bearings that support the gears on it.

[MacMan]

rear seal collar, which I have spent the last 2 days unsucessfully trying to remove, I've busted 2 pullers, one a hydraulic, have frozen it, have heated it and it wont budge.

I'm mid way through dismantling a D suffix LT77, and that collar was a b@stard of a thing. I had to weaken it and cut slots in it with a grinder in order to get it to budge.

You wait until you get to pull the 5th gear. That's a real bugger because you can't afford to damage it.

[Tank]

MacMan, I'm really looking forward to getting to 5th gear, I can't understand why L/R make it sooo hard, can pull most gearboxes down and rebuild in hours, no special tools, except a dummy cluster gear shaft, can you tell me if the oil pump gears are steel or plastic, Thanks, Regards Frank.

[MacMan]

I'll be able to when I get that far. Been too busy with other things at the moment but I want to get cracking again in about 10 days.

I've been using an hydraulic puller and I've had to make a heap of adapters and tools. I've been taking pics as I go, but so far only have the LT230 pics online.

http://members.optusnet.com.au/~macmanmike/LT230Rebuild/ (http://members.optusnet.com.au/%7Emacmanmike/LT230Rebuild/)

[Blknight.aus]

if its the same as the bit I think your thinking of in the LT77 that I had to last do a recuild on I used a 2 leg puller and then with a pin torch (very small oxy torch essentially) heated the bits of the ring that werent held by the puller to red heat while someone else gingerly applied torque to the puller arm (bout 1/6th of a turn at a time) and then smaked the lifting screw with a brass head hammer.

you can also slice it with a dremel if youve the patients and the old smack it with a chisel trick that you can use on ford wheel bearings works a treat as well (I special ground a chisel for this job)

[Tank]

Thanks all for your help, I bought a 10 ton Hyd. puller and bearing splitter set(old one was a 5 tonner) off ebay this arvo for $187.00 (delivered), local tool places wanted $350, repco $600, same kit same brand, christ some of these mobs have some mark/up, will have puller by mid next week so should be able to get box apart then, if not I will paint it green and throw it into the long grass down the back paddock.
Any sugestions on where I can buy Gaskets, seals, bearings and "That" rear seal collar, Regards Frank.

[Blknight.aus]

Im pretty sure that the last lot I got came thanks to Tim at landrovers only and he sourced some out of fourwheel drives in melbourne.

[MacMan]

if its the same as the bit I think your thinking of in the LT77 that I had to last do a recuild on I used a 2 leg puller and then with a pin torch (very small oxy torch essentially) heated the bits of the ring that werent held by the puller to red heat while someone else gingerly applied torque to the puller arm (bout 1/6th of a turn at a time) and then smaked the lifting screw with a brass head hammer.

I did exactly that for 5th gear - neighbour with his torch, but as I applied pressure with the puller and home made adapter I was using high velocity blows with a very light hammer and punch on the rebated face of the gear. The vibration was what got the movement.

It's going to be fun getting it back on!

I found the guys at Karcraft EXTREMELY helpful. The big box of parts (including gaskets) shown in my pics came from them. They had all parts in hand and the freight was next day.

[Tank]

My new 10 tonne puller should be here mid week, I was going to pull this box right down as I was told it was seized, it had been out in the open for a couple of years. The oil had plenty of water in the 5th gear section but next to none in the main. Turns out the box was jammed in 2 gears at once, once I rectified this the box turns over nicely, can't see any rusty gears in the main box, so I will give it a good flush out and just pull the back cover off to replace the buggered (now) seal collar and check out the oil pump gears and flush the oil ways.
Thanks again for all your help, hope I can reciprocate someday, Regards Frank.