hi all.. In my investigating a decent tow vehicle for a proposed fifth wheeler I chatted to a guy who seriously advised going to a higher than standard diff ratio if consistently wanting to pull a decent load .....better take off power, better hill climbing ability, lower transmission temperatures all point to a better fit for purpose tow vehicle , at the expense of slightly higher fuel bills and a lower top speed .... But I recon those would be worth it..
i also found this on the Webb that also has interest to all who wish to tow decent loads,
This also is a note re diff ratios and Iveco
Daily Dual Cab models (50C17D and 70C17D) are very popular in towed motorhome, horsefloat or similar applications In order to support the required maneuvering and gradient capabilities of the vehicle, three different rear axle ratios have been made available for each of the two models. The standard ratio is designed to support an application with a standard semitrailer in terms of weight and dimensions (4.44 for 50C and 4.556 for 70C). A lower ratio is made available as a selectable option for applications where the vehicle is not towing, or is towing very limited trailers in terms of weight and dimensions (example: a small Bobcat), such ratios are 4.18 for 50C and 4.30 for 70C. A higher ratio is also made available where the application requires the towing of a larger trailer, and where the full GCM of the vehicle is reached (5.11 for 50C and 5.13 for 70C)
Thought this might benefit some in the same boat as I,
any thoughts regarding diff ratios from those more knowledgable than I would be appreciated, cheers
-- Edited by Avago on Thursday 10th of August 2017 10:21:35 PM
A diff cluster can be changed anytime, why not use it prior and decide if you need it down the track a little. Its not like we should be doing this gig in a big hurry, so what if your take-offs are a bit slow. A nice cruising speed is relavant too
A diff cluster can be changed anytime, why not use it prior and decide if you need it down the track a little. Its not like we should be doing this gig in a big hurry, so what if your take-offs are a bit slow. A nice cruising speed is relavant too
I'm led to believe that a diff ratio alteration can cost around $2000 which is to be avoided if possible.
i think the hill climbing ability is probably the highest consideration for me as I've heard of quite a number of Iveco owners needing to get a real run up to a reasonable gradient and then theres a lot of transmission movement up and down that some find annoying apparently.
thats one thing I really like about our current 2014 Ranger .. When towing our 25 footer up a reasonable gradient im often wondering when is this thing going to drop down ? The torque is just terrific and the diff and engine ratios just seem to work really well together creating a good strong tow experience.
i wouldn't then like to hop in an Iveco to find that I need to charge at hills etc and a tow speed of 95klm/hr suits us well.
How big a 5th wheeler are you planning on towing? What ATM will 5th wheeler have? Consider what Wheelbase you need as well, especially if you want full height toolbox behind the cab.
How big a 5th wheeler are you planning on towing? What ATM will 5th wheeler have? Consider what Wheelbase you need as well, especially if you want full height toolbox behind the cab.
Thanks for your response Chris, we are looking around the 30 -35 ft range preferably of light composite build if I can find one secondhand ... And I am informed that by going to the longest wheelbase it will give about a 1200mm storage area behind the dual cab and full width of the tray wide and still leave allowance for the overhang etc. This storage I will have built to full roof height overlaid by a rack to go out vertical with a bull bar on which to put a decent sized boat. That's the plan anyway.
As regards weight of the fiver, non lightweights seem to be average around 4ton or thereabouts . Cheers
Sort the ratio now ! I would deff say higher ratio numerically (lower geared ) is best . To cruise 80 to 100 kph ., Ok pulling power on hills ..
I agree ... Do you have personal experience with Ivecos ? If so how do you rate them and what are you pulling with what engine and diff ratio etc as I'm curious to hear how others find them or what they would have ordered if they had their time over again
hi all.. In my investigating a decent tow vehicle for a proposed fifth wheeler I chatted to a guy who seriously advised going to a higher than standard diff ratio if consistently wanting to pull a decent load .....better take off power, better hill climbing ability, lower transmission temperatures all point to a better fit for purpose tow vehicle , at the expense of slightly higher fuel bills and a lower top speed .... But I recon those would be worth it..
i also found this on the Webb that also has interest to all who wish to tow decent loads,
This also is a note re diff ratios and Iveco
Daily Dual Cab models (50C17D and 70C17D) are very popular in towed motorhome, horsefloat or similar applications In order to support the required maneuvering and gradient capabilities of the vehicle, three different rear axle ratios have been made available for each of the two models. The standard ratio is designed to support an application with a standard semitrailer in terms of weight and dimensions (4.44 for 50C and 4.556 for 70C). A lower ratio is made available as a selectable option for applications where the vehicle is not towing, or is towing very limited trailers in terms of weight and dimensions (example: a small Bobcat), such ratios are 4.18 for 50C and 4.30 for 70C. A higher ratio is also made available where the application requires the towing of a larger trailer, and where the full GCM of the vehicle is reached (5.11 for 50C and 5.13 for 70C)
Thought this might benefit some in the same boat as I,
any thoughts regarding diff ratios from those more knowledgable than I would be appreciated, cheers
Hi Avago
My take on diff ratios. Firstly be careful when specifing high or low as there is some confusion what it means. The ratio is bigger(higher) as the gearing gets lower for more pulling power. So be specific about the number and what you want.
50 c ``````70c % different approx
4.18 4.30 6% , 6% faster ratio
4.44` 4.556 standard
5.11 5.13 13%, 11 % slower ratio
From the table you can see the steps are not very large but more significant for the slower move. Perhaps I would say that you should consider what proportion of driving will be done with the van towing compared to with it off. If you mostly drive with it on then go for the slower ratio. The step down from the highest gear in the gearbox looks to be about 14% or 20% depending on the box/engine fitted.
Cheers Jaahn
PS I have no experience with IVECO.
-- Edited by Jaahn on Sunday 13th of August 2017 06:38:39 PM
The ratio is bigger(higher) as the gearing gets lower for more pulling power. So be specific about the number and what you want.
