Towing

[rev pete]

Its me again lol Does anybody know what weight the 2.5 diesel can legally tow.??? And what weight it is happy towing??

[mikexgough]

2WD: 1504.5kg - 4WD: 1632kg - Nose weight: 85kg - figures for the Bongo being unconverted ....

[Alacrity]

If you are towing anything heavy or big, & the Bongo is auto, be sure to fit an additional transmission oil cooler. Takes about an hour to fit & costs less than £100.00. A LOT cheaper than a tranny rebuild. See HERE for picture of one fitted to my Bongo.

[mikeonb4c]

2WD: 1504.5kg - 4WD: 1632kg - Nose weight: 85kg - figures for the Bongo being unconverted ....

I don't know, but that sounds like the weight of the Bongo itself from the figures on Allans site that Kirsty flagged up yesterday

Did I read on here long ago some peeps saying the Bongo can tow about 2 tons (sorry - not good on metric )?

[missfixit70]

Those towing figures look about right to me, @85% of the vehicle weight, there's a factsheet in the members area that explains the why's & wherefores of towing.

[mikeonb4c]

Those towing figures look about right to me, @85% of the vehicle weight, there's a factsheet in the members area that explains the why's & wherefores of towing.

Of course - must learn to read more carefully. Either that or I'm suffering from the lack of oxygen at 13,000 ft

[rev pete]

Thanks again folks the numbers look right to me. I must investigate the oil cooler but I will not be towing a caravan. Maybe a canal cruiser but not very far possible 40 miles twice a year I think but not sure yet. many thanks chaps

[wise-child]

I'm looking to tow a trailer tent that weighs about 750kg unladen with a 2L petrol 2001 AFT 2WD Auto Bongo. Will this be problematic? What's this about adding extra coolant?

With any answers please bear in mind as far as mechanical knowledge goes I'm a veritable void....

[mikeonb4c]

I'm looking to tow a trailer tent that weighs about 750kg unladen with a 2L petrol 2001 AFT 2WD Auto Bongo. Will this be problematic? What's this about adding extra coolant?

With any answers please bear in mind as far as mechanical knowledge goes I'm a veritable void....

You should be OK, but the 2l has a lot less engine torque and doesn't tow as well as the diesel or the V6 so you must expect it to labour a certain amount up hills etc.

You wouldn't add extra coolant but people have discussed increasing the capacity of the radiator for cooling the auto gearbox and that may be worht considering if not too complex. Bf member Alacrity is one who comes to mind and who seems to work a lot with autoboxes - you could try PMing him if he doesn't come on here with thoughts.

[Alacrity]

Bf member Alacrity is one who comes to mind and who seems to work a lot with autoboxes - you could try PMing him if he doesn't come on here with thoughts.

I have been working with nothing but a lot of autoboxes for 30 years now

As Mike says, it not more coolant you add its more cooling you add to the auto box in the shape of an additional oil cooler that fits to the front of the aircon condensor rad & connects into one of the existing oil cooler lines so you are effectively running two oil coolers.

The main source of heat in any automatic gearbox with a torque converter is the converter itself. So the more load you put on the vehicle the more heat is generated. Towing something either heavy or (to a lesser degree) big with a lot of wind resistance will add to the heat being generated by the converter. Excessive heat degrades the oil faster & turns the dozens of O rings in the gearbox hard, so they loose their ability to seal correctly & the clutches within the transmission will start to suffer due to low oil pressure. A very expensive bill from someone like me will follow!

Don't forget if towing a caravan they get heavier after you buy them & fill then with stuff!!

[mikeonb4c]

I have been working with nothing but a lot of autoboxes for 30 years now

Thought as much but didn't like to assume just in case. Point noted for future reference

[missfixit70]

Bf member Alacrity is one who comes to mind and who seems to work a lot with autoboxes - you could try PMing him if he doesn't come on here with thoughts.

I have been working with nothing but a lot of autoboxes for 30 years now

As Mike says, it not more coolant you add its more cooling you add to the auto box in the shape of an additional oil cooler that fits to the front of the aircon condensor rad & connects into one of the existing oil cooler lines so you are effectively running two oil coolers.

The main source of heat in any automatic gearbox with a torque converter is the converter itself. So the more load you put on the vehicle the more heat is generated. Towing something either heavy or (to a lesser degree) big with a lot of wind resistance will add to the heat being generated by the converter. Excessive heat degrades the oil faster & turns the dozens of O rings in the gearbox hard, so they loose their ability to seal correctly & the clutches within the transmission will start to suffer due to low oil pressure. A very expensive bill from someone like me will follow!

Don't forget if towing a caravan they get heavier after you buy them & fill then with stuff!!

I don't know much about autoboxes at all, but just wondered about how the "lock up" function affects the heat generated by the TQ?

[Alacrity]

Lock up was introduced in the early 80's & was accelerated by the change from 3 to 4 speed autos (there were the odd 3 speed lock up's but it was rare). On most automatics 4th gear is an overdrive & what started happening when 4 speed non lockup boxes came in was that the TC started 'converting' or working again when in 4th slogging up freeways at speed (it started out in the US) & trans temps were going through the roof. At the same time manufacturers were starting to look seriously about improving fuel consumption/emissions. The lock up torque converter solved the overheating on long fast journeys & improved fuel economy at the same time (no slip/wasted energy). All non lock up converters slip, being a fluid connection. Slip = heat. Cutting tolerances right down helps but the moment you introduce a lock up clutch then you have no slip at all just 100% drive from the crankshaft to the transmission input shaft the moment it engages = negligible heat generation. The Bongo's lock up operation is crude (but very effective) to say the least with it feeling like a 5th gear, but at least you know it's working.

Most modern transmissions have controlled lock up operation where it isn't a simple on/off system but is controlled by the trans ECU from off through a slipping or 'controlled phase' to fully engaged. They often don't fully engage until 70mph +. This enables the manufacturer to bring lock up in very early without causing the low speed engine overgearing judder we (I) can get on our vehicle's.

So the lock up will help prevent overheating but only once it engages. The heat is generated when pulling away or long hard climbs when it isn't engaged. If you think about towing with a manual car - what part suffers most? The clutch. What takes the place of the clutch on an auto - you've guessed it, the torque converter.

Here endeth the lesson

[Bob]

Great input, thanks.

[missfixit70]

As Bob said, nicely explained Something for the shed draggers to think about & take note of.