smaller diameter Tire

[Sixpac2]

Hi,

I have a 04. 5 Dually 3. 73 gears, NV5600 with 235/80/17 tire.

We are full time RV'ers tow a heavy fifth wheel.



At the speed I LIKE to tow I NEED WANT 150 more rpm's to be in the sweet spot with out going to fast.



Is there a 17 inch tire that can help with that. The stock tire above is about 31. 5 in diameter.



Looking for any ideas or sugestions.



Thanks

 

[HBarlow]

That's one of the problems caused by the standard 3. 73 gear sets. That and some loss of starting torque.

I don't know if a smaller sized tire is available for use on 17" wheels. I doubt it but don't know. Use the Tire Rack - Your performance experts for tires and wheels website to find out. Using a smaller tire gives up load carrying capacity. You could get away with it on a dually but I wouldn't like the idea of doing it.

If I were you, I would bite the bullet and have a trusted shop replace the ring and pinion with a 4. 10 gear set. Should cost around $1000 to $1200 parts and labor. If your truck is 4 x 4 the price doubles.

 

[Motorhead]

I agree with Harvey on the 4:10's especially because you are full time rver's. I have a client with a '05 dually that tows a 14,000 5'er. He has 3:73's and burned up a trans already. I have talked to him about the 4:10's. You are alwaws better with a few extra RPM's than not enough RPM's.

 

[S.Morris]

The 4. 10 ratio will raise your rpm for any given gear by approx. 10%

 

[Sixpac2]

Update,

I found a Bridgestone commercial tire E rated with a steel sidewall

that is 225/75/17 it measures 1. 2 smaller in Diameter.



Using a gear calculator this would raise my RPM at 66 by 150 this would put me at 2000.



with the stock 235/80/17 at 2000 im at 69 MPH.



Ideas or comments appreiated.



Any reason this would not work.

 

[MisterBean]

SixPac,
Technically, your math and theory are on track. But, although I do NOT own or operate a dually or pull a 5er, our Father did with his 03. 5 3500 QC dually and he blew up the trans TWICE, before he finally upgraded to the 4. 10s... It's just my $0. 02, but your choice... Good luck!!!

Mark

 

[LBARTLETT]

if you need tires try the tires, if your tires are new change the gears, either way you're looking at about the same $'s

 

[AMink]

Will a 225 be too narrow for your existing rims?

 

[jhenderson]

Front and rear ring and pinion change would be at least twice the price of 6 new tires.

 

[AH64ID]

Some numbers to think about, since 2000 rpms is what you have mentioned.

Stock Tires 649 rev/mile, 3095 lbs/tire
50 in 5th, 68 in 6th

225/75/17, 687 rev/mile, 2755 lbs/tire
47 in 5th, 64 in 6th

245/70/17, 681 rev/mile, 3000 lbs/tire
47 in 5th, 65 in 6th

Stock tires, with 4. 10's
45 in 5th, 62 in 6th

What is the width of the DRW wheels? I think the steels are 17x6, but don't know on the aluminum, or what you have.

The 245/70 is a much better tire for weight handling.

 

[Sixpac2]

Some numbers to think about, since 2000 rpms is what you have mentioned.



Stock Tires 649 rev/mile, 3095 lbs/tire

50 in 5th, 68 in 6th



225/75/17, 687 rev/mile, 2755 lbs/tire

47 in 5th, 64 in 6th



245/70/17, 681 rev/mile, 3000 lbs/tire

47 in 5th, 65 in 6th



Stock tires, with 4. 10's

45 in 5th, 62 in 6th



What is the width of the DRW wheels? I think the steels are 17x6, but don't know on the aluminum, or what you have.



The 245/70 is a much better tire for weight handling.

I dont know what the rims are yet.

I think the 245 for the duals will be too wide.

I will have to check the width measurement.

All the wheels are steel no aluminum.



I have noticed the weight rating.

Not an issue for the rears but maybe for the front axle.

 

[AH64ID]

Empty the front axle on my truck has about 4800-4900 lbs on it.

I doubt 245's are too wide, it's only 5mm per tire wider in the middle, but one could look and tell. People fit 255/80/17's without issue.

 

[Deleted member 995608]

I vote 4:10 R&P's. Gear swap can easily be done in a days time and depending on the mileage on your truck, rebuilt front and rear axles is some good insurnace if your full time RV goers.



Besides, an odd ball sized tire could be difficult finding a replacement/s on the road.