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Range Rover L322 2005 4.4i HSE V8 (M62) Engine.

I had a new gearbox installed in January 2019. Only started using it in urban traffic since June this year, and when I'm getting stuck in traffic for a while, I'm losing my 4th/5th gear. If this happens I switch of the engine for about 30 minutes, and can then drive any distance on the open road without any problems, up to the point where I get stuck again in traffic.

Already replaced all pipes from gearbox to oil cooler, except the oil cooler
Repalced the gearbox thermostat and housing as well - thermostat was faulty when I took it out

My common sense says to me that it is heat related. I can drive more than 300Km on the open road - no problem, but as soon as I'm stuck in traffic, the problem occurs.
No warning lights or indications on my dashboard

Could it be related to the wrong gearbox oil, or could the oil have gotten damaged due to the faulty thermostat, and and possibly overheating off the oil it self on the few occurrences before I replaced the thermostat ?

Not sure if anybody else also maybe experienced this problem

Any feedback much appreciated.
 

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Range Rover L322 2005 4.4i HSE V8 (M62) Engine.

I had a new gearbox installed in January 2019. Only started using it in urban traffic since June this year, and when I'm getting stuck in traffic for a while, I'm losing my 4th/5th gear. If this happens I switch of the engine for about 30 minutes, and can then drive any distance on the open road without any problems, up to the point where I get stuck again in traffic.

Already replaced all pipes from gearbox to oil cooler, except the oil cooler
Repalced the gearbox thermostat and housing as well - thermostat was faulty when I took it out

My common sense says to me that it is heat related. I can drive more than 300Km on the open road - no problem, but as soon as I'm stuck in traffic, the problem occurs.
No warning lights or indications on my dashboard

Could it be related to the wrong gearbox oil, or could the oil have gotten damaged due to the faulty thermostat, and and possibly overheating off the oil it self on the few occurrences before I replaced the thermostat ?

Not sure if anybody else also maybe experienced this problem

Any feedback much appreciated.
This is a Hail Mary guess but is there a chance the donor could have had a different controller / TCM?

There’s a known difference in Mopar vehicles with the 545-RFE transmission in the Dodge Durango vs Dodge Ram. The Durango is programmed to use an undeclared gear between 2-3 for downshift, and is advertised as a 5 speed. The Ram contains the same unit, billed as the 645-RFE. The transmission uses this gear in the upshift sequence as well as when downshifting.


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A very common problem. The controller for your 5HP24 transmission is selecting its ‘cooling strategy’ mode because the fluid temperature sensor is telling it that the fluid is getting too hot.





This mode inhibits upshifts to ensure that the engine speed remains high, and therefore the oil pump in the transmission operates at high speed/maximum flow. Although it’s possible that the sensor is at fault, it’s more likely that either the bottom eight rows in the main radiator are blocked/restricted by sediment or that flow through the water side of the oil cooler itself is restricted. Replacement is the only solution in both cases.





If the fluid is overheating it will quickly deteriorate through oxidation (fluid life is halved for every 10°C increase in temperature) so you should consider replacing the fluid too. Only use one of the approved fluids in your 5HP24 to ensure that the torque converter lock-up clutch operates with the correct friction modification pack.





Phil
 

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@RRPhil, thank you for the detailed explanation. Will dismantle the oil cooler and test, and then do the oil replacement, before opening the gearbox to debug the sensor. Really appreciate your feedback.
 

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Just bear in mind that the most likely cause is the bottom of the main radiator becoming blocked/restricted by internal corrosion (unless, of course, the radiator has been replaced recently).



The bottom eight rows feed coolant to the oil cooler. The radiator blockage has no effect whatsoever on the engine temperature as the bottom hose is located above these lower eight rows.

Land Rover issued a Service Procedure to say that the restriction can be checked by measuring the flow rate of coolant when the drain tap is opened at the bottom of the radiator, but the tap is made of plastic and is likely to break off in your hand.



Phil
 

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Not sure about the later models, but the earlier 5-speeds just had a simple oil-to-water cooler which means the transmission fluid runs at about the same temperature as the coolant i.e. between 90°C and 110°C. At low loads the electrically-heated engine coolant thermostat operates the engine at even higher temperatures (for emission/fuel economy reasons) so the transmission fluid runs even hotter in these conditions. 110°-115°C is not uncommon.

The advantage of this type of transmission fluid cooling system over, say, an oil-to-air one is that automatic transmissions with torque converters fitted with lock-up clutches produce the majority of their heat load at low vehicle speeds, where air flow is at its minimum. Water has both a higher thermal conductivity and a higher specific heat capacity than air and therefore requires a lower volumetric flow to shift a given heat load. An oil-to-water cooler also acts as a transmission fluid heater at low ambient temperatures as the engine coolant gets up to temperature much more quickly. Note, however, that the thermostatic valve for the oil cooler prevents the engine coolant from entering the cooler until the transmission fluid is up to 80°C.

Phil
 

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Discussion Starter #8
Thank you Phil for all the input. I've tested 4 weeks ago when I replaced my Anti-Freeze, and when opening the little red plastic rain screw, the water come streaming out like when opening a tap (sorry for my bad English), so I do not think the radiator have a blockage.

Strange enough today, when driving a different route with a lot of uphill spots, the "TRans Fail Safe" warning came on as soon as I pulled away on a steep incline, just as discussed in this post:


I immediately pulled of the road, switched the engine of, and on again after 2 minutes, and all was good again, and it never happenned for the last 2/3rds of my journey. I will level the vehicle this weekend, and drain the gearboxfluid, and replace it with new ones (I did replace the filter inside the gearbox 6 weeks ago).

My L322 have the gearboxcooler which is mounted on the lower side of the Radiator - I already replaced this as well as the thermostat and the housing on which the Thermostat/OilCooler is mounted.

Wicus
 

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Not sure about the later models, but the earlier 5-speeds just had a simple oil-to-water cooler which means the transmission fluid runs at about the same temperature as the coolant i.e. between 90°C and 110°C. At low loads the electrically-heated engine coolant thermostat operates the engine at even higher temperatures (for emission/fuel economy reasons) so the transmission fluid runs even hotter in these conditions. 110°-115°C is not uncommon.

The advantage of this type of transmission fluid cooling system over, say, an oil-to-air one is that automatic transmissions with torque converters fitted with lock-up clutches produce the majority of their heat load at low vehicle speeds, where air flow is at its minimum. Water has both a higher thermal conductivity and a higher specific heat capacity than air and therefore requires a lower volumetric flow to shift a given heat load. An oil-to-water cooler also acts as a transmission fluid heater at low ambient temperatures as the engine coolant gets up to temperature much more quickly. Note, however, that the thermostatic valve for the oil cooler prevents the engine coolant from entering the cooler until the transmission fluid is up to 80°C.

Phil
So, given that, city driving would be really bad in a setup like this?

What worries me is these high temps and the “lifetime” transmission fluid fill that is only to be changed at 150k.

I have a 2012 L322 S/C with 146k and the 6 speed ZF.


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I will drain out the old gearbox oil, and replace with new ones, and fill it up while the vehicle is in Park, and the engine running.

Does anybody know with the vehicle switched off, how much oil the sump itself will hold ? I want to meassure how much comes out when I unscrew the drain plug, which I think would be a good indication if the gearbox had to less oil in. (The same "transfail safe error" occured again today, only once, and it was on an uphill pull away - no problems for the rest of the day driving)
 

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I will drain out the old gearbox oil, and replace with new ones, and fill it up while the vehicle is in Park, and the engine running.

Does anybody know with the vehicle switched off, how much oil the sump itself will hold ? I want to meassure how much comes out when I unscrew the drain plug, which I think would be a good indication if the gearbox had to less oil in. (The same "transfail safe error" occured again today, only once, and it was on an uphill pull away - no problems for the rest of the day driving)
Sorry to answer your question with a question, but does anyone know if it is recommended to replace the entire pan when doing one of these supposed “lifetime” trans fluid changes?


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An experienced Rover mechanic can flow test your trans cooler with compressed air if desired, rather than just replacing it with new. In addition to the Euro fluids, Valvoline MaxLife Multi-Vehicle trans fluid meets the LT71141 spec for the BMW mill rides, as does BG Premium Synthetic. Drain and refill is said to require 6.3 qts / 6.0 L, with a full system capacity of 10.5 qts / 9.9 L (including torque converter and cooling circuit), although I believe some folks have found otherwise.

My 116K mile 2004 (with new cooling system) routinely hits Trans Overheat while ascending certain long, steep Sierra mountain grades while pulling a 5,000 lb camping trailer. I've found that pulling over and fast-idling in neutral for 3 or 4 minutes brings the temp back down to normal, with dash warning extinguished. Not an optimal situation, but I've decided to live with it. Tranny still fine after 10K miles of desert/mountain towing on new BG trans fluid, about to be changed out again as a precaution.
 

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FYI, based on the capacities listed above, a single tranny drain and refill should result in about 60% new fluid, while a subsequent, second drain (if desired) should result in about 84%. A pressurized flush could potentially result in something closer to 100%, but I'll defer to others on that procedure, as I've never done it with an L322.

Crazy as it sounds, I've hit Trans Overheat probably 30 times over the last year while towing up mountains, but was able to pull over and cool down within 1 minute each time, so these were all short duration (3-4 minute) events. I have no idea what my 10K mile fluid looks like right now, nor what may be happening internally with the trans. That said, my 116K mile tranny still works like new. At this point I'm not convinced that Overheat episodes are quite the "sky is falling" events as often depicted on this board, so long as those events are brief, they happen with newer fluid, and you change that fluid frequently in severe service cases like mine. Obviously Overheat = BAD, but that's a relative term. I'll know more once I change out my current, 10K mile fluid soon, including whether it's burnt or not. (Trivia: Black color is not a reliable indicator of "burnt" fluid. It could simply be very spent and dirty. And red dye in trans fluid, helpful in identifying leaks, will somewhat mask any blackening due to oxidation or dirt. Smell is more reliable for burnt -- compare it to a virgin sample of fluid, or normal used fluid.)
 

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Discussion Starter #14
I've opened the sump plug below and drained the oil out, which had a brown looking colour. Only 2.8 Liter of Gearbox oil came out. I then follow the whole procedure for refilling

1) Fill up until it runs out at the filler plug
2) Close the filler plug, start the vehicle and let it reach 45 Degrees Celcuis, while mowing between P/R/N/D and Sport mode M1/2/3/4/5/4/3/2/1.
3) While vehicle is idling in Park , open fill plug and fill up again until it comes out of. the filler plug ==> At this point I could only add another one liter

In total I drained 2.8L, and added 4 Liter back - I'm not getting close to many posts which said it would take between 5-6 Liter of Oil

Am I missing something here, or is this correct for the zf5speed M62 gearbox ?

The last thing I want to do is tilting. the vehicle side ways with jacks to "force" in the additional 1-2 liters, and maybe damaging the gearbox operation by overfilling.
 
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