We still have our noisy beast! It's been across to Perth a couple of times ... and a long stay in Tassie one year!.
One thing we've never mastered is tyre pressures. When Winnebago de-rated the truck to make it suitable for car drivers!! , they never changed the tyre placard. So, we tried what the placard said (80psi) and got a harsh bone-shaker ride. Have had at least two or three blowouts over the years too!!
Then I started to 'think' abut it. With a GVM of 6 tonnes plus, having 80 psi in the dual wheels might be appropriate. With a GVM of 4.5 tonnes (plus food and clothes), it should be 15 or 20 psi lower! Dual wheels on the rear axle mean I should NOT lower it too much in case the tyres rub? I'm thinking I need to get down to my nearest garage and deflate the tyres to 70 psi all round.
Are there any other T4000 owners out there with experience ... or must I re-invent the wheel? I'm thinking the front axle carries rather less than 2 tonnes ... with the balance being carried by the dual wheels. Do I need to verify this with a weighbridge?
riccardo
PS My wheels and tyres are standard ... although the recently fitted wheels had a LR of 120 on them. I used to run truck tyres with a 10 or 12 PR rating.
Peter_n_Margaret said
08:25 PM May 5, 2020
You need 2 pieces of information to calculate an approximate appropriate tyre pressure which has NOTHING to do with the vehicle make or model.
1. You need a weigh bridge load reading for each axle separately for the fully loaded vehicle, ready for travel.
2. On the side of the tyre there is a maximum pressure at a maximum load moulded into the tyre. There are 2 different numbers - one for "single" and one for "dual". They are both required.
When you have all of those numbers, post them here.
No numbers, no correct pressure can be established, by ANYONE.
Cheers,
Peter
riccardo said
09:13 PM May 5, 2020
Thanks for your quick reply. The beast is in storage at the south coast for the moment. As soon as we can we shall go down there and recover it. The local "tip" has said they will do the weighing for us, and then I will publish the numbers.
riccardo
Tony Bev said
04:10 PM May 6, 2020
Hi Riccardo
I do not have your type of vehicle, or your number of wheels, or the same weight on my axels, so I can only generalise
As you have rightly pointed out, the tyre pressure placard means nothing, as that vehicle manufacture specified loads (truck/bus), and possibly tyres, are not the same as specified
Also bear in mind, that different tyre manufactures, can have a different LR (Load Rating), of the same size tyres, due to their different constructions
This is another reason, to look at the tyre, and not the tyre placard, Max pressure, and LR numbers
You asked, do you have to re-invent the wheel, my answer is certainly not, as there are plenty of friendly and helpful people on this forum, who will gladly do their best to help
As Peter, (Peter n Margaret), above has already said, no one can give you a correct tyre pressure to use, without the weights of each axle, the two LR, and MAX Pressure numbers, stamped on your tyres
I am sure that when you come back with your numbers, (no urgency as no one is going anywhere, due to the Coronavirus), that Peter, and/or other technical minded people will gladly explain, how they deciphered the numbers
PS, I am not a techie, I was just one of those schoolboys, who never got clipped behind the ear, as I was always eager to learn, and still learning
riccardo said
04:20 PM May 6, 2020
Thanks for the comment. It may be another month before we can get down ... and there will be mucho battery charging before we set of for a weighbridge. Have you noted they are few and far between nowadays? Riccardo
Tony Bev said
05:02 PM May 6, 2020
riccardo wrote:
Thanks for the comment. It may be another month before we can get down ... and there will be mucho battery charging before we set of for a weighbridge. Have you noted they are few and far between nowadays? Riccardo
Hi Riccardo
It may be another month before we can get down ... and there will be mucho battery charging before we set of for a weighbridge
That is why I mentioned that there is no urgency, to come back with your numbers Not sure what is happening in the Canberra area, but in my part of the world, (SW of WA), I am only allowed to travel within my regional area Also as it is now starting to get cold, wet, and windy, I shall probably not travel until I can go and catch the sun, in the north
We still have our noisy beast! It's been across to Perth a couple of times ... and a long stay in Tassie one year!.
One thing we've never mastered is tyre pressures. When Winnebago de-rated the truck to make it suitable for car drivers!! , they never changed the tyre placard. So, we tried what the placard said (80psi) and got a harsh bone-shaker ride. Have had at least two or three blowouts over the years too!!
Then I started to 'think' abut it. With a GVM of 6 tonnes plus, having 80 psi in the dual wheels might be appropriate. With a GVM of 4.5 tonnes (plus food and clothes), it should be 15 or 20 psi lower! Dual wheels on the rear axle mean I should NOT lower it too much in case the tyres rub? I'm thinking I need to get down to my nearest garage and deflate the tyres to 70 psi all round.
Are there any other T4000 owners out there with experience ... or must I re-invent the wheel? I'm thinking the front axle carries rather less than 2 tonnes ... with the balance being carried by the dual wheels. Do I need to verify this with a weighbridge?
riccardo
PS My wheels and tyres are standard ... although the recently fitted wheels had a LR of 120 on them. I used to run truck tyres with a 10 or 12 PR rating.
1. You need a weigh bridge load reading for each axle separately for the fully loaded vehicle, ready for travel.
2. On the side of the tyre there is a maximum pressure at a maximum load moulded into the tyre. There are 2 different numbers - one for "single" and one for "dual". They are both required.
When you have all of those numbers, post them here.
No numbers, no correct pressure can be established, by ANYONE.
Cheers,
Peter
riccardo
I do not have your type of vehicle, or your number of wheels, or the same weight on my axels, so I can only generalise
As you have rightly pointed out, the tyre pressure placard means nothing, as that vehicle manufacture specified loads (truck/bus), and possibly tyres, are not the same as specified
Also bear in mind, that different tyre manufactures, can have a different LR (Load Rating), of the same size tyres, due to their different constructions
This is another reason, to look at the tyre, and not the tyre placard, Max pressure, and LR numbers
You asked, do you have to re-invent the wheel, my answer is certainly not, as there are plenty of friendly and helpful people on this forum, who will gladly do their best to help
As Peter, (Peter n Margaret), above has already said, no one can give you a correct tyre pressure to use, without the weights of each axle, the two LR, and MAX Pressure numbers, stamped on your tyres
I am sure that when you come back with your numbers, (no urgency as no one is going anywhere, due to the Coronavirus), that Peter, and/or other technical minded people will gladly explain, how they deciphered the numbers
PS, I am not a techie, I was just one of those schoolboys, who never got clipped behind the ear, as I was always eager to learn, and still learning
Hi Riccardo
That is why I mentioned that there is no urgency, to come back with your numbers
Not sure what is happening in the Canberra area, but in my part of the world, (SW of WA), I am only allowed to travel within my regional area
Also as it is now starting to get cold, wet, and windy, I shall probably not travel until I can go and catch the sun, in the north