We now own a 2018 MUX, on our first trip towing the van (Olympic 1800kgs) from Orange to the Southern Highlands (Feb 2018) had the transmission temp light come on twice when climbing hilly terrain. Some research indicated this is a common problem. So, purchased a cooler kit from Wholesale Automatics and commenced installation. The instructions are clear but getting the chrome grille off is not as easy. Undo 4 top clips and center screw, then gently pull grille out, really, it doesn't move and the fear of breakage plays on your mind. So here is my solution, you need to make a small lever so you can lift the plastic clips at the 4 attachment points while keeping forward pressure on grille. There is not much room and many items to scratch your arms, but it does come out. Cooler is easily installed then. Tip, fill cooler and hoses with trans fluid before connection to avoid fluid top up. Replacing the grill is a snap of course, check for leaks, job done. If you don't have the skills then go to a mechanic but they are not cheap. Cheers
rockylizard said
07:31 PM Sep 29, 2018
Gday...
I guess your experience as stated towing has determined the need for the transmission oil cooler.
However, you say the van is 1,800Kg which is very much under the 'rated towing capacity' of the M-UX. I would praps be looking for a cause of the problem before going direct to a non-OEM transmission oil cooler. It seems very strange that the M-UX was 'under stress' towing such a light van.
Also, is there any impact on the vehicle warranty (transmission particularly) adding a non-standard transmission oil cooler?
I will assume you are a qualified mechanic - if not, what would be the impact on warranty with the cooler being fitted by a DIY at home?
Cheers - John
Macca70 said
10:42 AM Nov 22, 2022
Wow what a spoilt sport downer reply, the aim was to inform other owners and save them money not be howled down by a naysayer. No not a mechanic but a fully qualified tafe trained 50 year experienced toolmaker and tooling engineer who has serviced and repaired vehicles for 60 years. Dealer quite happy with my fitment of trans cooler, no their is not a tranmission problem, but a clearly defined and documented heat problem with towing, 3.5 tons is a joke, in real life the towing cap is around 2.5tons if youcomply with rules for GCM, etc. So lets be a bit more positive and stop all this negative comment..cheers
yobarr said
12:30 PM Nov 22, 2022
Macca70 wrote:
Wow what a spoilt sport downer reply, the aim was to inform other owners and save them money not be howled down by a naysayer. No not a mechanic but a fully qualified tafe trained 50 year experienced toolmaker and tooling engineer who has serviced and repaired vehicles for 60 years. Dealer quite happy with my fitment of trans cooler, no their is not a tranmission problem, but a clearly defined and documented heat problem with towing, 3.5 tons is a joke, in real life the towing cap is around 2.5tons if youcomply with rules for GCM, etc. So lets be a bit more positive and stop all this negative comment..cheers
Hi Geoff. You may not have noticed that the thread is over 4 years old. Sadly, esteemed member Rockylizard "rode on ahead" more than 3 years ago so will not be able to respond to your assertions. Cheers
Warren-Pat_01 said
04:11 PM Nov 22, 2022
I have no idea as to how old posts pop up from time to time.
However Geoff, I was not going to take a chance warranty wise with our 2019 model, particularly when I was threatened by the dealer if I put a cooler on the car. Yes, I bought the same cooler kit last year as you did but I had it installed by one of Wholesale Automatic's preferred mechanics here in Townsville.
They also serviced the transmission & fitted a new filter for me - at 43.000kms. I'll have it serviced again next year after another 40,000kms. I'm not willing to take the dealer's advice that the transmission can take working at 115 degrees!
Since fitting it, the transmission temperature has not exceeded 95 degrees.
RockyL, I was surprised on one trip home from "the south" when just put of Proserpine we hit a storm with heavy rain & we were towing our 2000kg van & the auto transm temperature rose to 110 degrees! That convinced me to get a cooler.
On our last trip home (without the van), I did notice a temperature dropped when we drove through lots of water south of Walgett (the road was open for high clearance vehicles).
Tones said
11:54 AM Dec 31, 2022
Hi Warren. I am always interested to hear about the experiences of other Isuzu owners. We have done the same as you. Our Dmax had a cooler fitted by Automatic Transmissions and the difference is quite remarkable. Prior to fitment on our 2017 Dmax, the only way I could keep the auto temp from going through the roof was to lock into 4th and sit on about 92Km/hr on Cruise. Engine coolant temp was and still is around 87 degrees. Whenever I tried to tow in D the Auto trans temp would climb quickly past 100 and keep going until I stopped it by locking up again. Since the external cooler was fitted, we are now able to tow in D and the Engine coolant temp sits on 87 degrees. The auto trans temp sits about 10 degrees below the coolant temp with a bit of rise and fall from time to time. It certainly never climbs past the engine coolant temp since the cooler was fitted. Apparently the auto trans alarm temp is set at something like 139 degrees???? We intend keeping our vehicle for a few more years so I do not feel bad about the investment in a cooler. Now that it is out of Warranty, the dealership will not get their hands on it again anyway!!!!!!! Our van has an ATM of 2400Kg. I have three mates who have all done the same thing with all of them having identical results.
Tones
-- Edited by Tones on Saturday 31st of December 2022 11:54:57 AM
-- Edited by Tones on Saturday 31st of December 2022 11:56:36 AM
So much for car dealerships saying "110-115 degrees is well within the transmission's operating range." What they are really saying is "Come back soon & we'll sell you another car!"
We now own a 2018 MUX, on our first trip towing the van (Olympic 1800kgs) from Orange to the Southern Highlands (Feb 2018) had the transmission temp light come on twice when climbing hilly terrain. Some research indicated this is a common problem. So, purchased a cooler kit from Wholesale Automatics and commenced installation. The instructions are clear but getting the chrome grille off is not as easy. Undo 4 top clips and center screw, then gently pull grille out, really, it doesn't move and the fear of breakage plays on your mind. So here is my solution, you need to make a small lever so you can lift the plastic clips at the 4 attachment points while keeping forward pressure on grille. There is not much room and many items to scratch your arms, but it does come out. Cooler is easily installed then. Tip, fill cooler and hoses with trans fluid before connection to avoid fluid top up. Replacing the grill is a snap of course, check for leaks, job done. If you don't have the skills then go to a mechanic but they are not cheap. Cheers
Gday...
I guess your experience as stated towing has determined the need for the transmission oil cooler.
However, you say the van is 1,800Kg which is very much under the 'rated towing capacity' of the M-UX. I would praps be looking for a cause of the problem before going direct to a non-OEM transmission oil cooler. It seems very strange that the M-UX was 'under stress' towing such a light van.
Also, is there any impact on the vehicle warranty (transmission particularly) adding a non-standard transmission oil cooler?
I will assume you are a qualified mechanic - if not, what would be the impact on warranty with the cooler being fitted by a DIY at home?
Cheers - John
Hi Geoff. You may not have noticed that the thread is over 4 years old. Sadly, esteemed member Rockylizard "rode on ahead" more than 3 years ago so will not be able to respond to your assertions. Cheers
However Geoff, I was not going to take a chance warranty wise with our 2019 model, particularly when I was threatened by the dealer if I put a cooler on the car. Yes, I bought the same cooler kit last year as you did but I had it installed by one of Wholesale Automatic's preferred mechanics here in Townsville.
They also serviced the transmission & fitted a new filter for me - at 43.000kms. I'll have it serviced again next year after another 40,000kms. I'm not willing to take the dealer's advice that the transmission can take working at 115 degrees!
Since fitting it, the transmission temperature has not exceeded 95 degrees.
RockyL, I was surprised on one trip home from "the south" when just put of Proserpine we hit a storm with heavy rain & we were towing our 2000kg van & the auto transm temperature rose to 110 degrees! That convinced me to get a cooler.
On our last trip home (without the van), I did notice a temperature dropped when we drove through lots of water south of Walgett (the road was open for high clearance vehicles).
Hi Warren. I am always interested to hear about the experiences of other Isuzu owners. We have done the same as you. Our Dmax had a cooler fitted by Automatic Transmissions and the difference is quite remarkable. Prior to fitment on our 2017 Dmax, the only way I could keep the auto temp from going through the roof was to lock into 4th and sit on about 92Km/hr on Cruise. Engine coolant temp was and still is around 87 degrees. Whenever I tried to tow in D the Auto trans temp would climb quickly past 100 and keep going until I stopped it by locking up again. Since the external cooler was fitted, we are now able to tow in D and the Engine coolant temp sits on 87 degrees. The auto trans temp sits about 10 degrees below the coolant temp with a bit of rise and fall from time to time. It certainly never climbs past the engine coolant temp since the cooler was fitted. Apparently the auto trans alarm temp is set at something like 139 degrees???? We intend keeping our vehicle for a few more years so I do not feel bad about the investment in a cooler. Now that it is out of Warranty, the dealership will not get their hands on it again anyway!!!!!!! Our van has an ATM of 2400Kg. I have three mates who have all done the same thing with all of them having identical results.
Tones
-- Edited by Tones on Saturday 31st of December 2022 11:54:57 AM
-- Edited by Tones on Saturday 31st of December 2022 11:56:36 AM
This is the final justification I used to fit the cooler - www.colvoss.com.au/blog/2019/12/7/automatic-transmission-operating-fluid-temperatures
So much for car dealerships saying "110-115 degrees is well within the transmission's operating range." What they are really saying is "Come back soon & we'll sell you another car!"