r380 gearbox rebuild

[milan]

Hi

My -97 Defender 130 finally needs some care Just came back from a one year trip from Sweden to the Middle east and then through Africa to SA together with my family. The car has performed superb, no breakdowns at all until we reached Capetown when all of a sudden I could hear a grinding noise from the gearbox when in first gear and "engine breaking". I changed the oil mainly to see what will come out and there was not to much metal stucked to the plug and the level was ok. The car was shiped back to Europe as this first overland trip has come to its end. Then, driving from Rotterdam back to Stockholm the grinding noise became more apparent in all the other gears as well except the fourth.

However, the shift is smooth and no troubles with syncros.

Since I'm planing to continue the journey and do all America, starting next summer, I'm obviously saving money at the moment. Even if we have a whole bunch of sponsors I still have to save up for the fuel and food and therefore all the maintenance of the car is done by myself. Unfortunately I have never rebuild a LR gearbox before and could need some advise.As I used to work as a engine mechanic and have access to a workshop I will give it a go myself. I understand that the best option for someone living in the UK would be to by an exchangeunit from ashcroft transmissions but for me the shiping costs will be to high.

I will start next week and hopefully I will get some tips and hints in this thread. I will also document the progress of my work here.

Ofcourse without stripping it I wont know whats wrong, but my guess is that the bearings on the layshaft have gone and that the play is to large, hopefully the gears are ok.

Any suggestions?

Regards

Milan

www.adventurefamily.se

[antony110]

Hi

My -97 Defender 130 finally needs some care Just came back from a one year trip from Sweden to the Middle east and then through Africa to SA together with my family. The car has performed superb, no breakdowns at all until we reached Capetown when all of a sudden I could hear a grinding noise from the gearbox when in first gear and "engine breaking". I changed the oil mainly to see what will come out and there was not to much metal stucked to the plug and the level was ok. The car was shiped back to Europe as this first overland trip has come to its end. Then, driving from Rotterdam back to Stockholm the grinding noise became more apparent in all the other gears as well except the fourth.

However, the shift is smooth and no troubles with syncros.

Since I'm planing to continue the journey and do all America, starting next summer, I'm obviously saving money at the moment. Even if we have a whole bunch of sponsors I still have to save up for the fuel and food and therefore all the maintenance of the car is done by myself. Unfortunately I have never rebuild a LR gearbox before and could need some advise.As I used to work as a engine mechanic and have access to a workshop I will give it a go myself. I understand that the best option for someone living in the UK would be to by an exchangeunit from ashcroft transmissions but for me the shiping costs will be to high.

I will start next week and hopefully I will get some tips and hints in this thread. I will also document the progress of my work here.

Ofcourse without stripping it I wont know whats wrong, but my guess is that the bearings on the layshaft have gone and that the play is to large, hopefully the gears are ok.

Any suggestions?

Regards

Milan

www.adventurefamily.se

iam afraid i do not know to much about the mechanics of the r380 but with your mechanical experience maybe the following might help.Hi im not sure if your used to ebay over there in Sweden or not (i lived in Denmark for 18 months and they did not have it.) but try this www.ebay.co.uk and put this item number in the search box 280349028112 this is a r380 gearbox overhaul manual if they will not post it to you i will, hope this regards Antony110

[Gromit]

It does sound like something on the layshaft alright.

I've just rebuilt my LT77 and found it pretty straightforward actually. I'm no mechanic, had no idea what was involoved but was willing to give it a go and learn how a gearbox works.

I did it with basic tools and a 10 ton hydraulic puller. I also bought a dremil to remove a large collar on the output shaft and a few bearing tracks. I had to make a press out of pipe to refit the collar. I also had the workshop manual. (Sorry, I don't have one for the R380)

When I pulled the box apart, I placed each set of components in a ziplock bag, labeled and placed on the floor in order of assembly.

It took me about 4 full days of work.

My box was making a clicking noise in all gears except 4th. I found the layshaft bearings a bit gritty, but they didn't look completely destroyed. The bearing behind the input shaft felt fine in my hand, but made a bit of noise when run underpressure on the shaft. I found the bearings deceptive that way in that it was difficult to determine their condition, so I replaced all of them.

Everything else was lightly covered with a grey sludge, which I assume was from the synchros. LOTS of carb cleaner used to cleaning everything that was being re-used.

I don't know the R380, but it can't be that different. Ashcroft supply a master rebuild kit for 160STG quid, which is what I used.

If you've somewhere to work, I say go for it.

vinny on here is in the middle of rebuilding his R380. Maybe send him a PM for any things to watch out for.

[milan]

Thanks for the replies. I do have a manual and I'm planing to get the kit from ashcroft but will wait to order until I strip it so I Know what more has to be replaced. There was no transmission backlash so I hope the shaft itself is ok.

Is there anything worth replacing, except the various components in the kit, to improve the strength of the box?

Another reason for doing it myself is to get the knowledge on how to do it, hope I wont need it again but in some parts of the world it's a good skill to know your vehicle.

I will contact Vinny

Milan

www.adventurefamily.se

[Gromit]

Apart from what's in the rebuild kit, there's not much else in the box, selector forks and the main and lay shafts, which are expensive. If one of the shafts is damaged, then it might be more cost effective getting a new box.

I've just noticed in the pictures, that the R380 rebuild kit doesn't have any oil pump gears, gaskets or slippers (maybe it doesn't use them, there are other rings pictured). The LT77 kit had all these.

Might be worth asking about that.

As for improving the box, I'm sure the oracle that is ashcrofts could advise. Don't some of them have oil coolers?

[milan]

Well, the shafts are not that expensive, at least not compared to a new box. I will check about the pump, thanks.

Oil coolers are a good option and they should have been mounted from factory. However aftermarket kits are expensive unless I find the time to build it myself.

But there must be a bunch of springs rings and other small things, not included in the kit, worth changing.

[western]

Oil coolers are a good option and they should have been mounted from factory

gearbox oil coolers are not fitted as standard, only to vehicles that are built for certain duties.

[Gromit]

But there must be a bunch of springs rings and other small things, not included in the kit, worth changing.

I included the roller bearings, which were not in the kit. In the end, Ashcrofts send me 2nd hand ones, so I just picked the best from mine and theirs.

The slipper springs are the only thing I can think of that was missing from the kit, that could have been replaced.

They move a small amount and don't really seem to be affected by wear, well mine were fine.

[milan]

I included the roller bearings, which were not in the kit. In the end, Ashcrofts send me 2nd hand ones, so I just picked the best from mine and theirs.

The slipper springs are the only thing I can think of that was missing from the kit, that could have been replaced.

They move a small amount and don't really seem to be affected by wear, well mine were fine.

Ok, I will order new bearings separately. Did you mean needle bearings as it seems to me that the rollerbearings are included?

[milan]

Hmmm. looking at the kit the needle bearings are included as well.....

[Gromit]

Yes, sorry meant needle bearings.

[rick]

gearbox oil coolers are not fitted as standard, only to vehicles that are built for certain duties.

But they should've been....

BTW, all TD5's sold here had g/box oil coolers, or what passes for a cooler on the TD5......

[Retroanaconda]

In the UK it's not really warm enough to warrant it I would have thought.

[Ibex94]

The worst bit about trying to rebuild an R380 is trying to undo the 5th laygear fixing which is tightened to 220Nm and requires a long reach socket.

The other thing is don't try and copy the restraint bracket shown in the manual - been there got that t-shirt prety un rewarding. Would suggest instead you build a f***off big peg spanner to fit the holes in the fifth gear, this will then allow you to yark on the socket wrench while steadying the laygear with peg spanner and grunting ohh yer bas**** .

Pulling seal collar off main shaft was also found to be v tight and I bruised mine where the puller bit in. Might be worth having spare to hand it can't be expensive. There is a bearing track to pull of lay gear but being harder is much easier. Instead of trying to horse these components on when rebuilding suggest you warm them up to about 150 C mine just slipped straight on no bother.

I gave up and got Ashcroft to do it (had to rebuild what had been taken apart for failed attempt first) on reflection I recon plan B would have worked well.

Hope you succeed.

Rob

[Gromit]

Pulling seal collar off main shaft was also found to be v tight and I bruised mine where the puller bit in. Might be worth having spare to hand it can't be expensive. There is a bearing track to pull of lay gear but being harder is much easier. Instead of trying to horse these components on when rebuilding suggest you warm them up to about 150 C mine just slipped straight on no bother.

I had the same problem; I think there's a reason one is included in the rebuild kit!

The puller wouldn't shift mine so I ended up carefully cutting a slot in it with a dremil and then tapping it round to break the seal, then the puller was able to manage it.

Pitty I didn't think to heat the new one. Mind you, I was faffing about so much with lengths of pipe for so long, it would have been stone cold.

[Ibex94]

I had the same problem; I think there's a reason one is included in the rebuild kit!

The puller wouldn't shift mine so I ended up carefully cutting a slot in it with a dremil and then tapping it round to break the seal, then the puller was able to manage it.

Pitty I didn't think to heat the new one. Mind you, I was faffing about so much with lengths of pipe for so long, it would have been stone cold.

You shouldn't need lengths of scaffold tube etc mine just slipped over by hand once warm.

Rob

[milan]

I got around doing it now. Taking the box apart was actually very easy with a good set of standard tools. Taking out the gearbox was however a bi...ch. My dads lift couldn't cope with the weight of my (fully laden) car so had to do it the bush way, that is, roll up the front of the car on a set of spare wheels and crawl around as a greasemonkey.

Now to the conclusion this far.

As suspected, the rear roller bearing on the layshaft is busted. Looks as the damage was caused by debris from the two teeths missing on the fifth laygear . The other bearings appear to be in a fairly good stand and so do all the other components. Eg. Mainshaft splines are as new, syncros look as new and so on. Weird, I have covered more than 200 000 km with the vehicle. Anyway I will get the maste rebuild kit from Ashcroft as the bits are apart.

The bad thing is as follows. When I took the oil pump to out I discovered that the hosing is pretty worned out, in particular where the impeller tap/shat is supported and also the surface at wich the pump ring rotates against. I'm not quite sure how critical this is in a gearbox, in a engine it would be consideed scrap. This means that either I have to do a lot of machining and insert at bush both at the tap and the outer surface or buy a "new" housing. Although I find it od that there isn't any wear in any components so there must be a good pressure. I have not seen any data on the tolerance to measure the pump housing wear.

Any advice ?

Will post photos tomorrow.

[Gromit]

good pressure. I have not seen any data on the tolerance to measure the pump housing wear.

I noticed wear marks on the casing where the oil gears run, nothing too bad though. There was no mention in the workshop manual for the LT77 as to what is acceptable or not, so I can't advise.