Tire And Wheel Switch On R Model Advice

[WOLFWALKER]

Hi, was wondering if any one had any advice on switching out Rear tires from a 66 U model mack with 6 lugs to a 75 R model that has 5 lug axle. The tires are 10.00 x20's and I did have to switch out the seprator rings also to get the wheel clamps and nuts to tighten up.

But the problem is on one side the clearence between the tire and leaf spring is only about 3/4 of an inch where as the other side is more like 1 1/2 of an inch clearance from the leaf springs .Also with the truck loaded the tires seem to rub each other when the truck hits a dip or hole in the road, and the truck vibrates and is hard to hold in the road since the wheels where switched out.

I want to switch them out because the tires are mud grip and I need the extra traction here in the mountains of Virginia and was hoping I wouldn't need to change out the tires and have to remove the tires from the rims and switch out the rims in order to change out these tires and rims.

So any one who has some advice please email me at, Wolfwalker2223@aol.com ,or respond to this page.

Thank you

[Rob]

Hi, was wondering if any one had any advice on switching out Rear tires from a 66 U model mack with 6 lugs to a 75 R model that has 5 lug axle. The tires are 10.00 x20's and I did have to switch out the seprator rings also to get the wheel clamps and nuts to tighten up.

But the problem is on one side the clearence between the tire and leaf spring is only about 3/4 of an inch where as the other side is more like 1 1/2 of an inch clearance from the leaf springs .Also with the truck loaded the tires seem to rub each other when the truck hits a dip or hole in the road, and the truck vibrates and is hard to hold in the road since the wheels where switched out.

I want to switch them out because the tires are mud grip and I need the extra traction here in the mountains of Virginia and was hoping I wouldn't need to change out the tires and have to remove the tires from the rims and switch out the rims in order to change out these tires and rims.

So any one who has some advice please email me at, Wolfwalker2223@aol.com ,or respond to this page.

Thank you

Are your spacer rings the same size keeping the tires apart? If the tires are rubbing, the spacer needs to be wider. I've never seen different rim offsets in Dayton style wheels but that doesn't mean they don't exist. I've never had problems switching sets of tires from one truck with Daytons, to another. It could be that someone mounted larger tires on a narrower rim also. Might be a good idea to check rim widths of both sets.

Rob

[WOLFWALKER]

Are your spacer rings the same size keeping the tires apart? If the tires are rubbing, the spacer needs to be wider. I've never seen different rim offsets in Dayton style wheels but that doesn't mean they don't exist. I've never had problems switching sets of tires from one truck with Daytons, to another. It could be that someone mounted larger tires on a narrower rim also. Might be a good idea to check rim widths of both sets.

Rob

Rob, if i put the wider spacer on then my wedges that hold the wheel on wont bottom out on the stops, will this hurt the mounting or as long as they are tight they nessesarly dont need to bottom out when you tighten them up?

I will have to measure the rims, if they seem different than I will have to switch out the tires to the original rims that came off the truck and try that ,but what a hassle that will be changing out 8 tires and wheels which I was trying to avoid.

Thanks for your help and advice

[Rob]

Rob, if i put the wider spacer on then my wedges that hold the wheel on wont bottom out on the stops, will this hurt the mounting or as long as they are tight they nessesarly dont need to bottom out when you tighten them up?

I will have to measure the rims, if they seem different than I will have to switch out the tires to the original rims that came off the truck and try that ,but what a hassle that will be changing out 8 tires and wheels which I was trying to avoid.

Thanks for your help and advice

If I am following correctly: You do not want the wedges to "bottom out" onto the webs. It they do, there is not sufficient clamping force against the seat of the rim to avoid spinning of the rim on the hub. This could lead to the rim and tires departing the vehicle at an inopportune time and really hurt somebody.

There should be a slight space inbetween the wedge clamp, and the seat on the spider when the lug nuts are sufficiently tightened. There are different stud lengths, different spacer widths etc. to accomplish what you need done.

My best advice would be to take the truck and tires to a reputable tire dealer/installer and let them do the job for you. They have the experience, and the hundred dollars or so spent to ensure a safe install is money well spent.

I don't handle tires much anymore as I've found that finding the right combination is best left to someone knowing more than I.

Good luck,

Rob

[MACKS]

Wolf-I don't know if this will help or not but on my 83 RD I can only use rims that are 8.5 inches wide 8 inch rims just wont fit right they seam to be to loose,they wont fit right on the front or the back,I asked some tire guys about it and they couldent give me a reason why.Measure the width of the rims from boath trucks and see if there the same,I bet one is wider that the other,If the rims are clean the numbers are stamped also check the pitch,it will be stamped right next to the width.