LT77 gearbox oil cooling

[FridgeFreezer]

Indeed, RS part #555-409 written on the one in the photo, although numerous other ranges are available. Seen them a lot round the pits at Silverstone on brake calipers, gearboxes, radiators, coolers, you name it...

[Boydie]

On 6/23/2015 at 7:51 PM, pat_pending said:

Curious, as I'm sure I've seen coolers on 77s in military defenders.

I checked my parts catalogue and it shows an oil cooler take off for a Defender 77 box.

This adaptor looks identical to the one I fitted to my R380.

Over here in Oz the R380 gearbox when coupled with the V8 engine had them fitted to an oil cooler -- the same air cooled unit as fitted to the ZF4HP22 and 24 autos.  

Due to the outback heat I experience when I'm touring and the stress on the gearbox I filled one, it's "controlled" by a wax pellet the same as the engine oil cooler and flow only goes to the oil cooler if the gearbox oil gets well above hot, just how hot I'm not too sure but you certainly aren't able to hold the oil flow pipe.  I also carry as a spare part the original fitting should the cooler hoses burst or, as happened once before the corrugations and vibrations cause the oil cooler radiator to crack.

I used a set of autobox cooler hoses and extended them both with with thick wall type "B" 12.5mm (1/2") copper pipe. Expanding the ends of the copper pipe to extend the original steel portion of the auto hose and silver soldering them. The screw in fittings into the gearbox adaptor were the same thread as used for the auto box and I therefore retained the original swaged pipe ends and "O" rings. 

 

 

[L19MUD]

Did anyone ever progress with this? I have just completed a 330 mile run back from Devon to Suffolk in my 200tdi 90 and the gearbox got really hot. The long climbs out of Devon towing the camping trailer and 30 degree heat resulted in the temperature on the floor of the cab coming from the gearbox getting close to unbearable before there was a downpoor in Essex which cooled things down nicely. I have a wright off road floor mat with sound deadening underneath that which I think has helped.

 

Note I am not talking about what the Lt77 can cope with, but rather what is comfortable for the driver and passenger! I am running ATF and have a nice smooth gearchange both cold and hot

 

Adding a finned transfer case seems like a good idea to take the heat out of the combined T box and gearbox unit so I will do that when I rebuild the T Box but are there any other ideas to cut in cab temperatures?

[Bowie69]

Anything that can stop heat radiation from the gearbox will help.

So, if you are inclined, build something that wraps round the top and side of the boxes with an air gap between the box and the tunnel/seat box, and I guarantee it will be a lot cooler.

Also check exhaust, and shield that.

This is good stuff, easily workable and with a folded edge and a number of fasteners it won't rattle:

https://www.carbuilder.com/uk/embossed-aluminium-heat-shield-1000mm-x-1000mm

I get the same problem towing a folding camper in my audi, tunnel is too warm to comfortably lean your leg against after a couple of hours of motorway.

[FridgeFreezer]

6 hours ago, L19MUD said:

Adding a finned transfer case seems like a good idea to take the heat out of the combined T box and gearbox unit so I will do that when I rebuild the T Box but are there any other ideas to cut in cab temperatures?

We used foil-backed closed-cell foam (from ebay.co.uk/usr/car-insulation-uk) under the trans tunnel & seatbox and it massively cut noise & heat coming up - sealing any little holes or gaps makes a big difference too.

[L19MUD]

9 hours ago, FridgeFreezer said:

We used foil-backed closed-cell foam (from ebay.co.uk/usr/car-insulation-uk) under the trans tunnel & seatbox and it massively cut noise & heat coming up - sealing any little holes or gaps makes a big difference too.

I have some of that kicking about left over from my rebuild. I will give that a go when I pull the T box later in the year. Thanks

 

It is only a problem once or twice a year when doing a really long trip and then only if it is hot but it did really get unbearable in there

[Bigj66]

Now I’m really worried about my V8 and auto in the series 🥵🥵

A winter car only methinks..😊

[Gazzar]

Pop an extra oil cooler on the auto box. 

[Snagger]

I plant to fit the cooler to the R380 in my RRC.  I’d prefer to use a D2/P38 cooler and the Gen Parts oil stat unit, but if necessary, I’ll use the Syncro Gearboxes adaptor that has no thermostat - those genuine ones are rare and command silly prices.

[reb78]

Why don't Ashcroft or Syncro use thermostats in their coolers? Can you overcool the box? I have had thermostats fail on the coolant side of a BMW box - that used a small coolant:Oil cooler so is stat failure on the oil side a problem for the land rover ones?
 

The Syncro one looks identical to the Ashcroft one but is more expensive. 

[oneandtwo]

On 7/21/2021 at 5:07 PM, L19MUD said:

Did anyone ever progress with this? I have just completed a 330 mile run back from Devon to Suffolk in my 200tdi 90 and the gearbox got really hot. The long climbs out of Devon towing the camping trailer and 30 degree heat resulted in the temperature on the floor of the cab coming from the gearbox getting close to unbearable before there was a downpoor in Essex which cooled things down nicely. I have a wright off road floor mat with sound deadening underneath that which I think has helped.

 

Note I am not talking about what the Lt77 can cope with, but rather what is comfortable for the driver and passenger! I am running ATF and have a nice smooth gearchange both cold and hot

 

Adding a finned transfer case seems like a good idea to take the heat out of the combined T box and gearbox unit so I will do that when I rebuild the T Box but are there any other ideas to cut in cab temperatures?

I doing 160 miles from lands end to Taunton most weeks a few years ago in my old 300tdi 90, the floor and tunnel were incredibly hot during the summer - just fitting the Rocky Mountain finned lt230 sump made a massive improvement to the seatbox / tunnel far more than I expected it to.

I may take the TIG welder to a new one to make it fit my Puma.

[vulcan bomber]

13 hours ago, reb78 said:

Why don't Ashcroft or Syncro use thermostats in their coolers? Can you overcool the box? I have had thermostats fail on the coolant side of a BMW box - that used a small coolant:Oil cooler so is stat failure on the oil side a problem for the land rover ones?
 

The Syncro one looks identical to the Ashcroft one but is more expensive. 

I've got a plan for one to fit the Stumpy 380 with a stat in it at some point and you wont need to cut the floor.

[reb78]

On 7/24/2021 at 10:21 AM, vulcan bomber said:

I've got a plan for one to fit the Stumpy 380 with a stat in it at some point and you wont need to cut the floor.

This is one I would definitely like to add to the 110 as I rebuild it.

[vulcan bomber]

16 hours ago, reb78 said:

This is one I would definitely like to add to the 110 as I rebuild it.

Yours might be the one to provide the measurements to make a prototype. 

[ashtrans]

On 7/23/2021 at 9:08 PM, reb78 said:

Why don't Ashcroft or Syncro use thermostats in their coolers? Can you overcool the box? I have had thermostats fail on the coolant side of a BMW box - that used a small coolant:Oil cooler so is stat failure on the oil side a problem for the land rover ones?
 

The Syncro one looks identical to the Ashcroft one but is more expensive. 

Why don't Ashcroft or Syncro use thermostats in their coolers?

cost / more complex to make

Can you overcool the box?

I dont think so

The Syncro one looks identical to the Ashcroft one but is more expensive. 

we were making them first,

if you want one with thermostat we have used genuine @ £ 60 + V ea